WGU D203 ANATOMY & PHYSIOLOGY STUDY GUIDE ANSWERS 2025.

Anatomy - ANS The study of the body's structure Physiology - ANS The Study of the body's functioning Levels of human body (smallest to largest) - ANS Chemical, cellular, tissue, organ, organ system, organismal 11 Basic systems that make up human body - ANS Skeletal, Muscular, Nervous, Respiratory, Cardiovascular, Digestive, Urinary, Immune(lymphatic), Integumentary, Endocrine, Reproductive (male and female) Anterior (Ventral) - ANS Front/ Direction toward front of body Posterior (Dorsal) - ANS Back/ Direction toward back of body Superior (Cranial) - ANS Position above/ higher than another part of the body Inferior (Caudal) - ANS Position below or lower then another part of the body proper; near or toward the tail Lateral - ANS Side or direction toward the side of the body Medial - ANS Middle or direction toward middle of the body Proximal - ANS Position in a limb that is nearer to the point of attachment or trunk of the body. Distal - ANS Position in a limb that is farther from the point of attachment or the trunk of the body Superficial - ANS Position closer to the surface of the body Deep - ANS Position farther from the surface of the body What percent of body weight does skeletal system account for? - ANS 20% Humans have a vertebral column (backbone) so they are classified as what? - ANS vertebrates The bones of the skeleton are divided into two divisions: - ANS axial and appendicular Axial skeleton is comprised of - ANS Head and trunk of the body. It includes the skull, vertebral column (spine), and rib cage. Bones along the center, or axis, of the body. Bones of the extremities. It is appended to the axial skeleton. Appendicular skeleton is comprised of - ANS remaining bones that are not axial so the bones of the limbs (arms, legs, hands, feet) and girdles(shoulder and pelvic) How many bones in adult human skeleton - ANS 206 Compact bone tissue - ANS forms the extremely hard outside layer of bones. Gives bones their smooth, dense, solid appearance. Accounts for 80% of total bone mass of adult skeleton Spongy bone tissue - ANS Fills part or all of interior of bones. It is porous like a sponge, with irregular networks of spaces. Much less dense than compact bones. Greater surface area than compact bones but only 20% of bone mass. Five classifications of bones based on size and structure - ANS Long bones, short bones, flat bones, irregular bones, sesamoid bones Long Bones - ANS consist of long shaft, are cylindrical in cross-section, and usually expanded at either end. Mostly comprised of compact bone but have spongy bone within ends. ACT AS LEVERS FOR THE SKELETAL MUSCLES TO ACT UPON. Short Bones - ANS Generally equal in width and length. Mainly composed of spongy bone surrounded by thin layer of compact bone. ALLOW SMALL AMOUNTS OF VARIED MOVEMENT WHEN ARTICULATED TOGETHER Flat Bones - ANS Smooth, thin bones comprising of 2 thin and flat plates of compact bone, between which lies a layer of spongy bone. THEY PROTECT SOFT INTERNAL STRUCTURES AND PROVIDE ATTACHMENT FOR MUSCLES Irregular Bones - ANS Elaborate in shape - not classified into any other category Sesamoid Bones - ANS Small or bony nodules embedded in a tendon where it passes over an angular structure like a knee, hand, wrist, or foot What type of bone are these? Humerus (upper arm), femur (thigh), clavicle (collarbone), radius(forearm), ulna(forearm), phalanges(fingers and toes), tibia (lower leg), fibula (lower leg) - ANS Long Bones What type of bones are these? Carpal (wrist) and tarsal (ankle) bones - ANS Short Bones What type of bones are these? Skull (Cranial), rib cage, scapula (shoulder blade) - ANS Flat Bones What type of bones are these? Vertebrae (spine), hip bones, mandible (jaw) - ANS Irregular Bones What type of bones are these? Patella (kneecap) - ANS Sesamoid Bones Joint (articulation) - ANS where two bones come together 3 categories of joints (articulations) based on range of movement - ANS immoveable, partly moveable, and movable 3 main types of joints (articulations) based on structure - ANS Cartilaginous, Fibrous, Synovial Cartilaginous Joints - ANS Connected by hyaline cartilage, have no joint cavity (Joint b/w adjacent vertebrae in spine) Fibrous Joint - ANS Connected by dense connective tissue and have no joint cavity (skull, ribcage) Synovial Joines - ANS Fluid filled cavity called a bursa that surrounds and provides cushion for articulating bones (hip, knee joints) bursa - ANS a closed, fluid-filled sac that works as a cushion and gliding surface to reduce friction between tissues of the body 3 types of connective tissue - ANS Cartilage, Ligament, Tendon Cartilage - ANS Tough but flexible tissue that covers ends of bones of moveable joints and protects bones by preventing them from rubbing against each other. Gives shape and support to other parts of body like ears, nose, and windpipe Ligament - ANS Bines one bone to another. Helps to hold structures together and allows for side to side stability. The ACL (anterior cruciate ligament) attaches the thigh bone to the shin bone and stabilizes the knee joint What does ACL stand for? - ANS anterior cruciate ligament Tendon - ANS Attaches muscle to bone. Aids in movement of bone or structure. EX: Achilles tendon connects calf muscle to heel bone. What is the human fetus mostly made up of during early development? - ANS Cartilage Ossification - ANS Bone tissue is created from cartilage Major functions of the skeletal system? - ANS 1. Support, Shape, and Protection 2. Movement 3.Storage and Release of Minerals 4.Formation of Blood Cells Immovable joints - ANS allow little or no movement at the joint. Most immovable joints are fibrous joints. Besides the bones of the cranium, immovable joints include joints between the tibia and fibula in the lower leg, and between the radius and ulna in the lower arm. Partly movable joints - ANS permit slight movement. Most partly movable joints are cartilaginous joints. Besides the joints between vertebrae, they include the joints between the ribs and sternum (breastbone). Movable joints - ANS allow bones to move freely. ALL MOEVABLE JOINTS ARE SYNOVIAL JOINTS. Besides the knee, they include the shoulder, hip, and elbow. Movable joints are the most common type of joints in your body. Skeletal system releases what 2 very important minerals? - ANS Calcium and phosphorus Homeostasis - ANS State of balance among the different body systems that is necessary for survival Hematopoiesis - ANS formation of blood cells. This process includes the production of red blood cells, white blood cells, and platelets by the red bone marrow, a fibrous tissue found in the center of most bones. red bone marrow - ANS a fibrous tissue found in the center of most bones What do red blood cells do? - ANS transport oxygen What do white blood cells do? - ANS participate in the immune response of the body What do platelets do? - ANS platelets play a role in blood clotting Around how many muscles is the muscular system made up of? - ANS more than 600 muscles throughout the human body 3 Types of Muscle Tissue - ANS skeletal, cardiac, and smooth Skeletal muscles - ANS comprise the majority of the muscles in the body. They are made up of three layers of tissue. There are more than 600 skeletal muscles in the human body. ALL OF THE SKELETAL MUSCLES ARE VOLUNTARY. Cardiac muscle - ANS is only found in the heart. Cardiac muscle is INVOLUNTARY. An involuntary muscle is one that operates independently of your intent or control. When cardiac muscle contracts, the heart beats and pumps blood. Smooth muscle - ANS found in the internal organs such as the stomach, intestine, and bladder. These muscles are also INVOLUNTARY. For example, the smooth muscles around your lungs open and close your airways; the smooth muscle in your stomach helps you digest food. What are the six ways muscles are classified? - ANS size, shape, fiber direction, location, action, and origin. Muscle named based on Location - ANS Muscle names may identify a specific region of the body. Ex the frontalis muscle is located on the frontal bone of the skull Muscle named based on Size - ANS Many muscles are identified by their size from large to small. Ex glutes refers to 3 distinct muscles: Gluteus maximus (largest), gluteus medius (medium), and gluteus minimus (small). Muscles can also be described as longus (long) and brevis(short) Muscles named based on shape - ANS Muscle shapes can be important indicators of the name of a muscle. Ex. Trapezius muscle is shaped like a trapezoid. Orbicularis is circular shaped. Muscles named based on Fiber Direction - ANS Muscles named by the direction the muscle fiber runs in relation to the midline of the body, which runs down the center of the body from head to toe. Can be rectus(straight) or transverse (perpendicular to midline). If muscle fibers run at an angle, those muscles are called oblique. Rectus fiber direction of muscles - ANS When muscle fiber runs straight. The muscle responsible for "six pack abs" after hundreds of sit ups is called rectus abdominis. Transverse fiber direction of muscles - ANS If muscle fibers run perpendicular to the midline, those muscles are called transverse. The transversus abdominis stabilizes the trunk. Oblique Muscle - ANS If muscle fibers run at an angle, those muscles are called oblique. The internal obliques are activated by bending or rotating your trunk. Muscles named based on Action - ANS Many muscles are named by their function. Two of the most common actions are flexor (flexion) and extensor (extension). You use flexor and extensor muscles when you bend and straighten your arm or leg. Two most common muscle actions - ANS flexor(flexion) and extensor(extension) Muscles named based on Origin/Insertion - ANS Muscles can also be identified by their attachment points. The first part of the muscle name is the origin, and the second part of the name is the insertion. Let's look, for example, at the sternocleidomastoid muscle. Sterno (sternum) and cleido (clavicle) are the origin points; mastoid is the insertion. As seen with the sternocleidomastoid, there can be more than one origin point. Where are axial muscles located? - ANS The axial muscles are located in the head, neck, and trunk of the body. Found in the same location as axial bones. Where are the appendicular muscles located? - ANS The appendicular muscles are located in the arms and legs. Found in the same area as appendicular bones. A good way to determine if something is axial vs appendicular? - ANS To keep the terms straight, when thinking about the axial muscles, think of areas of the body where there's only one, such as one head (skull), neck, spine, rib cage, or sternum. The appendicular muscles always have two of each such as two arms, legs, feet, and hands. What is the main function of skeletal muscles? - ANS Skeletal muscle allows for movement by pulling on our bones. Without these muscles, we would not be able to perform many of our daily activities. What is the main function of Cardiac muscle? - ANS Cardiac muscle is involuntary and allows blood to pump through the circulatory system. Without this muscle, blood would not be able to carry oxygen and nutrients to all systems in the body. What is the main function of smooth muscle? - ANS Smooth muscle involuntarily contracts to help move food through the digestive system and urine through the urinary system. Smooth muscle also assists the reproductive system, arteries, and airways. Muscle contraction - ANS Tightening or shortening of your muscle. Muscle contraction assists with stability and temperature regulation Muscle relaxation - ANS occurs when the muscle returns to its normal state after muscle contraction. Sliding filament theory - ANS describes the process of muscle contraction and relaxation. When signaled by the brain, a skeletal muscle contracts as the thin filaments, or fibers, are pulled and then slide past the thick filaments within the fiber's sarcomeres. The sarcomeres relax by returning to normal. Sarcomeres - ANS Small units of muscle tissue that shorten (contract). Groups of muscles work together to help us function in which ways? - ANS Movement, posture, stabilization, balance, breathing, protection, and temperature regulation. Name the 2 nervous system parts - ANS Central Nervous System (CNS) and the Peripheral Nervous System(PNS) Nervous Tissue - ANS The nervous system is made up of a type of specialized tissue known as nervous tissue, which consists of the brain, the spinal cord, and the nerves, neurons, and neuroglia, which are all responsible for the control of the body and the communication among its parts. What is included in the Central Nervous System (CNS) - ANS brain and spinal cord What is included in the Peripheral Nervous System (PNS) - ANS all nervous tissue in the body outside of the CNS Main function of the PNS - ANS to connect the CNS to the rest of the body. The PNS serves as a communication relay, going back and forth between the CNS and muscles, organs, and glands throughout the body Neuron - ANS individual cell. Neurons assist in sending messages throughout the nervous system. nerve - ANS Group of neuron cells 3 basic parts of a neuron - ANS Cell body and 2 types of extensions (1 axon and multiple dendrites) What does the cell body do? - ANS Contains genetic information of the neuron, maintains its structure, and provides it with energy. What does an axon do? - ANS It's like a mouth that allows a neuron to talk with other neurons. myelin sheath - ANS a fatty substance on the axon which speeds up rate at which they can send information to other neurons. Only some neurons have these What are dendrites? - ANS they are the ears of neurons and allow them to hear messages from other neurons Neuroglia (glial cells) - ANS comprises nervous tissue. Thought to once hold neurons together, now known to play vital toles in nervous system 6 types of neuroglia - ANS ependymal cells, oligodendrocytes, astrocytes, microglia in the CNS, satellite and Schwann cells in the PNS 3 major regions of the brain - ANS forebrain, midbrain, hindbrain Forebrain - ANS anterior (forwardmost) region of the brain and includes cerebrum, thalamus, hypothalamus, hippocampus, amygdala cerebrum - ANS Largest part of the brain. Divided from front to back into 2 halves called left and right hemishpheres.2 halves further divided into 4 lobes (frontal, parietal, temporal, and occipital) What 4 structures make up the limbic system - ANS thalamus, hypothalamus, hippocampus, and amygdala 4 lobes of the cerebrum - ANS frontal lobe, parietal lobe, temporal lobe, occipital lobe midbrain - ANS smallest region of the brain. Topmost part of the brainstem, connecting hindbrain and forebrain Hindbrain - ANS lowest regios of the brain and consists of cerebellum, medulla oblongata, and the pons. These components connect the rest of the brain with the spinal cord and pass nerve impulses(signals) between the brain and the spinal cord. Spinal cord - ANS long, thin, tubular bundle of nervous tissue extending from brain stem down the center of the back to the pelvis, connecting the brain with the PNS. Spinal cord is enclosed within vertebral column. Center is made up on mainly cell bodies of neurons surrounded by myelinated axons Spinal nerves - ANS connect the spinal cord to the PNS, exit from the spinal cord between vertebrae Meninges - ANS three layer protective sheath that also contains cushioning cerebrospinal fluid Blood-brain barrier - ANS protects the brain and spinal cord from circulation and from most toxins or pathogens in the blood. It is a highly selective membrane that separates the circulating blood from fluid in the CNS. It allows water, certain gases, glucose, and some other molecules needed by brain and spinal cord to cross from blood to CNS while keeping out harmful substances. Amygdala - ANS One of two structures located in the temporal lobe of the cerebrum that performs a role in the processing of memory, decision making, and emotional responses Astrocytes - ANS star-shaped neuroglia found in the CNS that have several functions, including support of the blood-brain barrier, provision of nutrients to neurons, repair to nervous tissue following injury, and facilitation of neurotransmission cerebrospinal fluid - ANS clear fluid produced by the brain that forms a thin layer within the meninges and provides protection and cushioning for the brain and spinal cord cerebrum - ANS the largest part of the brain that controls conscious functions such as reasoning and sight cerebellum - ANS the part of the brain below the cerebrum and behind the brain stem that coordinates balance ependymal cells - ANS type of neuroglia found in the CNS that play a critical role in making and secreting cerebrospinal fluid forebrain - ANS a region located at the front of the brain that is responsible for processing learning and memory frontal lobe - ANS a part of each hemisphere of the cerebrum that controls memory and emotions hindbrain - ANS a region located at the lower back part of the brain that connects the brain to the spinal cord and coordinates many vital functions, such as breathing and heartbeat hippocampus - ANS a part of the forebrain that has a major role in learning and motivation hypothalamus - ANS a part of the brain that secretes hormones and connects the brain with the endocrine system limbic system - ANS a set of brain structures located primarily in the forebrain that supports a variety of functions, including emotion, behavior, motivation, long-term memory, and olfaction (smell) medulla oblongata - ANS a long stem-like structure which makes up part of the brainstem that controls the heart rate, respiration rate, and blood pressure meninges - ANS a three-layer protective sheath that surrounds the brain and spinal cord microglia - ANS specialized type of neuroglia found in the CNS that remove damaged neurons myelin sheath - ANS the lipid layer around the axon of a neuron that allows nerve impulses to travel more rapidly down the axon nerve - ANS a structure in the nervous system that consists of cable-like bundles of axons and makes up most of the PNS nerve impulse - ANS a signal transmitted along a nerve fiber nervous tissue - ANS a specialized tissue found in the nervous system consisting of the brain, the spinal cord, and the nerves, neurons, and neuroglia that is responsible for the control of the body and the communication among its parts neuroglia - ANS cells that function primarily to provide support to the neurons and the rest of the nervous system neuron - ANS a functional unit of the nervous system that transmits nerve impulses; also called a nerve cell occipital lobe - ANS a part of each hemisphere of the cerebrum that is dedicated almost solely to vision oligodendrocytes - ANS a type of neuroglia found in the CNS that makes myelin, an insulating substance for axons parietal lobe - ANS the part of each hemisphere of the cerebrum that is involved in the sense of touch peripheral nervous system (PNS) - ANS one of two major divisions of the nervous system that consists of all nervous tissue that lies outside the central nervous system pons - ANS a structure that makes up part of the brainstem and is responsible for receiving sensory information from the face and regulating sleep cycles satellite cells - ANS a type of neuroglia found in the PNS that is responsible for muscle regeneration Schwann cells - ANS a variety of neuroglia in the PNS that keep peripheral nerve fibers alive and in myelinated axons form the myelin sheath. Make myelin to insulate axons in the PNS spinal cord - ANS a thin tubular bundle of CNS tissue that extends from the brainstem down the back to the pelvis and connects the brain with the peripheral nervous system temporal lobe - ANS a part of each hemisphere of the cerebrum that is involved in hearing thalamus - ANS the inner part of the brain that is a major hub for nerve impulses traveling back and forth between the cerebrum and spinal cord The brain controls mental processes like: - ANS reasoning, imagination, memory, language The brain controls what basic involuntary physical processes? - ANS breathing and heartbeat The brain controls what voluntary activities? - ANS Walking, writing, etc... Function of the cerebellum (hindbrain) - ANS balance, posture function of the medulla oblagata (hindbrain) - ANS heartbeat, blood pressure function of the pons (Hindbrain) - ANS facial senses, sleep cycles function of the hypothalamus (forebrain) - ANS managing hormones function of the thalamus (forebrain) - ANS Consciousness, sleep, alertness function of the hippocampus (forebrain) - ANS learning, motivation function of the amygdala (forebrain) - ANS decision making, emotional responses Function of the Cerebrum (forebrain) - ANS Memory, reasoning, touch, vibration, vision, hearing Another term for frontal lobes - ANS cerebral cortex Another term for parietal lobes - ANS Somatosensory cortex Function of the midbrain - ANS Wakefulness, attention, ability to focus, arousal Reflexes - ANS rapid involuntary responses that do not require input from the brain that are controlled by the spinal cord Main function of the PNS - ANS carrying info from the body, delivering it to the brain, and sending commands from the brain to the rest of the body How are peripheral nerves classified? - ANS Based on the direction in which they carry nerve impulses Sensory Nerves - ANS Transmit information from sensory receptors in the body to the CNS. Like files uploaded to the internet using wifi/ethernet Motor Nerves - ANS transmit info from the CNS to muscles, organs, and glands. These nerves function like streaming service - they deliver content Mixed Nerved - ANS Contain sensory and motor neurons so they can transmit both to and from the CNS. These nerves are the ethernet cable or wifi - they upload files to a nervous system and download or stream show The PNS is divided into what 2 parts? - ANS Autonomic Nervous System and Somatic Nervous System Autonomic Nervous System - ANS Controls involuntary actions. Think 'automatic'. Controls involuntary functions like digestion, blood pressure, and heart rate. Responsible for all actions that happen inside body that occur without your control. Somatic Nervous System - ANS Controls voluntary actions like eating, walking, talking. System is responsible for all actions you take because you choose to do so. Receives signals or sensory info from external environment and control the commands that come from the brain. 3 divisions of the autonomic nervous system - ANS Sympathetic nervous system, parasympathetic nervous system, enteric nervous system Sympathetic nervous system - ANS controls flight or fight response. Activates in high stress environments. It prepares you to flee by speeding up heart rate, widening air passages in lungs, increasing blood flow to skeletal muscles. Parasympathetic nervous system - ANS Returns body to normal after flight or fight response. Division activates when relaxing. Heart decreases or returns to normal, air passages in lungs narrow, blood flow to skeletal muscles is reduced Enteric nervous system - ANS controls digestive system and functions. Shuts down when sympathetic nervous system is in control and turns back on when parasympathetic nervous system is reactivated. 3 types of neurons - ANS Sensory neurons, motor neurons, and interneurons Sensory neurons (afferent neurons) - ANS carry impulses from sensory receptors in tissues and organs to the CNS. Change physical stimuli into nerve impulses. Ex touch hot stove, physical stimuli felt by fingers transmitted to brain by nerve impulse motor neurons (efferent neurons) - ANS carry impulses from the CNS to muscles and glands. They change nerve signals to activate muscles. Ex touch hot stove, motor neurons bring message from brain to muscles that you should remove hand from hot stove interneurons - ANS middlemen, carrying nerve impulses back and forth between sensory and motor neurons. They process the info received and send out the command once it is made. Neuroglia function - ANS support neurons and help them carry out the basic function of nervous tissues, which is to transmit nerve impulses. Functions include holding neurons in place, supplying neurons with nutrients, regulating the repair of neurons, destroying pathogens, removing dead neurons, and directing axons to their targets What is associated with higher intelligence? - ANS Having more neuroglia Nerve impulse is what type of phenomenon - ANS electricsal phenomenon. Nerve impulses are caused by change in internal electrical charge of a nerve cell membrane, resulting in an electric current that helps neurons communicate with one another Resting potential - ANS neuron is not actively transmitting a nerve impulse and is in resting state. Has more negative internal charge Action potential - ANS initiated with neuron receives a stimulus from another neuron that is strong enough to make its internal charge significantly more positive. Change is also called DEPOLARIZATION. Reversal of electrical charge across the membrane of a resting neuron that travels down the axon of the neuron as a nerve impulse 3 parts that action potential is composed of - ANS Depolarization, Repolarization, Refractory or recovery period Depolarization - ANS Occurs when there is a strong positive change in charge across the membrane Repolarization - ANS occurs after the peak of depolarization and is defined as the membrane potential becoming more negative, moving towards a resting state. Refractory or recovery period - ANS occurs right before the membrane potential settles back to resting synapse - ANS the junction across which a nerve impulse passes from an axon terminal to a neuron, muscle cell, or gland cell. neuromuscular junction - ANS where the nervous system and muscular system join forces. At the neuromuscular junction, a motor neuron terminal connects to the muscle fiber, and the muscle fiber responds to the messages from the motor neuron to create a muscle contraction. musculoskeletal system - ANS The skeletal system provides a system of levers that allow body movement. The muscular system provides the force that moves the levers. These two systems together are referred to as the musculoskeletal system, a body system that provides form, support, stability, and movement to the body. You previously learned about all the parts that make up the musculoskeletal system: bones, muscles, cartilage, tendons, ligaments, joints, and other connective tissue that supports and binds tissues and organs together. he respiratory system is divided into what two parts - ANS the upper respiratory and lower respiratory tracts upper respiratory tract - ANS includes the nasal cavity, larynx, and pharynx. You can visualize the upper respiratory tract as a long straw that sticks out of your nose, extends down the back of your mouth, and ends inside your body above the lungs. nasal cavity - ANS large, air-filled space in the skull above and behind the nose in the middle of the face. It is a continuation of the two nostrils mucous membranes - ANS Tissue that lines inner body surfaces and body openings and produces mucus. Hair in the nose and mucus produced by mucous membranes help trap larger foreign particles in the air before they go deeper into the respiratory tract. Sneezing is an involuntary response that occurs when nerves lining the nasal passage are irritated by various particles. pharynx - ANS also known as the throat, connects the nasal cavity to the back of the mouth. The pharynx has dual functions—both air and food pass through it—so it is part of both the respiratory and the digestive systems. Air passes from the mouth or nasal cavity through the pharynx to the larynx in the respiratory system. larynx - ANS connects the pharynx to the trachea. It helps conduct air through the upper respiratory tract. The larynx is also called the voice box because it contains the vocal cords, which vibrate when air flows over them, thereby producing sound. lower respiratory tract - ANS comprised of the trachea, primary bronchi, and lungs. The lower respiratory tract continues from the pharynx (the bottom of the upper respiratory tract) down into the lungs. The lower respiratory tract does not open to the outside of your body. trachea - ANS also known as the windpipe, and it connects the larynx to the bronchi. primary bronchi - ANS The primary bronchi include the right and left branches, one per lung. They are a pathway to each lung and draw air from the upper respiratory tract deep into the lungs. lungs - ANS largest organ of the respiratory system, and they consist of two parts: the right lung and left lung. They are protected by the rib cage, which is part of the skeletal system. As you can see in the following image, the left lung is smaller than the right lung because it shares space with the heart. Air moves through the larynx when you breathe in. Which structure does the air enter next? - ANS Trachea What is the structural role of the pharynx? - ANS To transport air between the nasal cavity and larynx. The pharynx is part of the upper respiratory tract and is commonly known as the throat. It is above the larynx and below the nasal cavity. vocal cords - ANS two folded pairs of membranes in the larynx (voice box) that vibrate when air that is exhaled passes through them, producing sound How long can the brain go without oxygen before brain damage occurs? - ANS brain damage can occur after three or four minutes without oxygen epiglottis - ANS a flap of cartilage at the root of the tongue, which is depressed during swallowing to cover the opening of the airway Functions of the larynx - ANS First, the larynx helps conduct air through the respiratory tract. Second, the larynx houses the vocal cords, which enable you to speak and sing. Third, the larynx prevents food from traveling into the trachea and lower respiratory tract. If swallowed material does get past the epiglottis to enter the larynx, it irritates the larynx and stimulates a strong cough reflex. This generally expels the material out of the larynx and into the throat. Aspiration - ANS Liquids aspirate into the airway (go down the wrong pipe). Usually when taking a breath and swallowing at the same time main role of primary bronchi - ANS to provide a space for air to travel in and out of the lungs while preventing any foreign material from entering the lungs. The bronchi capture foreign material, such as dust, in small hair-like structures and expels the foreign material through coughing. As blood travels through the lungs, it absorbs the clean, oxygenated air and carries it to other parts of your body. function of the trachea - ANS to prevent larger foreign materials, including food, from traveling through the respiratory tract instead of the digestive tract. It is the connection between the larynx and the bronchi. The trachea also contains mucus that filters the air particles that you breathe in, keeping those particles out of your lungs and keeping you from getting sick. Additionally, the trachea regulates the temperature of the air you breathe. About how many breaths do most people take in one day? - ANS most people take around 17,000 breaths in one day (typically breathe 12-20 times per minute) ventilation - ANS The technical name for breathing which consists of inhalation and exhalation Inhalation - ANS occurs when you breathe in and air enters your lungs. The chest expands outward and the diaphragm contracts in a downward motion Exhalation - ANS occurs when you breathe out and air leaves your lungs and the diaphragm contracts in an upward motion. diaphragm - ANS a large, dome-shaped muscle below the lungs that allows breathing to occur when it alternately contracts and relaxes thorax - ANS the body cavity that fills the chest Respiration - ANS the process of breathing 2 types of Respiration - ANS external respiration and internal respiration external respiration - ANS oxygen is inhaled into the lungs, and carbon dioxide is exhaled out of the lungs in a process called gas exchange gas exchange - ANS the biological process through which gases are transferred across cell membranes to either enter or leave the blood alveoli - ANS the tiny sacs in the lungs where pulmonary gas exchange takes place. They transfer oxygen to the blood so that it can be used to give your body energy Internal respiration - ANS Occurs within your body's tissues. Blood transports oxygen from the lungs to the tissues in your body to be diffused as energy, and then the blood carries carbon dioxide (the waste of that process) away from the tissues back to the lungs. What are the events involved in internal respiration? (What does O2 do, what does CO2 do) - ANS Oxygen is used by the blood, Carbon dioxide moves from body cells into blood three components of the cardiovascular system - ANS the heart, blood vessels, and blood W woman's heart beats faster than a man's: T or F? - ANS True. a woman's heart beats faster than a man's? The difference in heartbeats per minute is due to the size of the heart. Because a woman's heart is slightly smaller, it must pump more often to move blood through the body. heart - ANS a muscular organ located behind the sternum (breastbone), slightly to the left of the center of the chest four chambers of the heart - ANS two upper chambers called atria and two lower chambers called ventricles. Each side of the heart contains an atrium on top and a ventricle on the bottom. atria - ANS the two upper chambers of the heart that pump blood to the ventricle below it; the singular form is atrium. The atria are also called receiving chambers because blood coming into the heart first enters these two chambers. The right atrium receives blood from the upper and lower body. The left atrium receives blood from the lungs. ventricle - ANS one of two lower chambers of the heart that pumps blood out of the heart. The ventricles are also called discharging chambers because blood leaving the heart passes out through these two chambers. The right ventricle sends blood to the lungs, and the left ventricle sends blood to the rest of your body. Where does the right atrium receive blood from? - ANS The right atrium receives blood from the upper and lower body Where does the left atrium receive blood from - ANS The left atrium receives blood from the lungs. Where does the right ventricle send blood to? - ANS The right ventricle sends blood to the lungs Where does the left ventricle send blood to? - ANS the left ventricle sends blood to the rest of your body other than the lungs What four valves does the heart contain? - ANS tricuspid, bicuspid, aortic, pulmonary tricuspid valve - ANS allows blood to flow from the right atrium into the right ventricle. bicuspid valve - ANS also called the mitral valve, allows blood to flow from the left atrium to the left ventricle. aortic valve - ANS is located between the left ventricle and aorta. It prevents blood in the aortic from flowing back into the heart. pulmonary valve - ANS located between the right ventricle and the pulmonary artery. It prevents blood from flowing back into the heart. Three Types of Blood Vessels - ANS artery, vein, capillary artery - ANS carries blood away from the heart to the rest of your body. vein - ANS carries blood to the heart. capillary - ANS the smallest type of blood vessel. They are so small that only one red blood cell at a time can squeeze through a capillary. Capillaries connect arterioles and venules (the smallest arteries and veins). Function of all arteries (there is one exception) - ANS arteries carry oxygenated blood (blood containing oxygen) away from your heart What is the one artery that does not carry oxygenated blood away from the heart? - ANS pulmonary artery pulmonary artery - ANS carries deoxygenated blood (blood from which oxygen has been removed and replaced with carbon dioxide) from your heart to your lungs. This is part of the gas exchange process in the respiratory system aorta - ANS The largest artery, extends from the heart down into the abdominal area. Oxygenated blood is pumped directly into the aorta from the left ventricle of the heart. Blood pumps from the aorta into smaller arteries called arterioles. arterioles - ANS a small branch of an artery leading into capillaries Function of Veins - ANS Veins carry deoxygenated blood to the heart. The two largest veins in your body are the superior vena cava, which carries blood from the upper body directly to the right atrium of the heart and the inferior vena cava, which carries blood from the lower body directly to the right atrium of the heart. superior vena cava - ANS a vein that carries blood from the upper body directly to the right atrium of the heart inferior vena cava - ANS a vein that carries blood from the lower body directly to the right atrium pulmonary veins - ANS a vein carrying oxygenated blood from the lungs to the left atrium of the heart venules - ANS the smallest veins, which receive blood from capillaries and transport it to larger veins Blood - ANS a fluid connective tissue that circulates throughout your body through blood vessels of the cardiovascular system. The main components of blood - ANS plasma and three types of cells: red blood cells, white blood cells, and platelets Red blood cells - ANS make up the largest quantity of cells in blood (about 45% of the blood by volume), and they make up about 25% of all the cells in the human body. White blood cells - ANS are part of your body's immune system. This type of cell is the least numerous in the blood. Platelets - ANS are cell fragments, but there are more of them than there are white blood cells. Plasma - ANS is the yellowish liquid component of human blood and makes up about 55% of the blood by volume. Where is blood flowing in a vein - ANS towards the heart Where is blood flowing in an artery - ANS away from the heart (a away) What does pulmonary mean? - ANS Related to the lungs 6 steps of blood flow - ANS 1. The right atrium collects blood from two large veins, the superior vena cava (from the upper body) and the inferior vena cava (from the lower body). 2. The blood that collects in the right atrium is pumped through the tricuspid valve into the right ventricle. 3. From the right ventricle, the blood is pumped through the pulmonary valve into the pulmonary artery. The pulmonary artery carries the blood to the lungs, where it enters the pulmonary circulation, gives up carbon dioxide, and picks up oxygen. 4. The oxygenated blood travels back from the lungs through the pulmonary veins (of which there are four) and enters the left atrium of the heart. 5. From the left atrium, the blood is pumped through the bicuspid valve into the left ventricle. 6. From the left ventricle, the blood is pumped through the aortic valve into the aorta, which subsequently branches into smaller arteries that carry the blood throughout the rest of your body Name the two types of circulation of blood flow from the heart - ANS pulmonary and systemic Systemic circulation - ANS supplies oxygenated blood from the heart to your body Pulmonary circulation - ANS carries deoxygenated blood from your body to the lungs for gas exchange. cardiac cycle - ANS the performance of the human heart from the ending of one heartbeat to the beginning of the next, consisting of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, following a period of robust contraction and pumping of blood, dubbed systole 2 parts of the cardiac cycle - ANS diastole (dub sound) and systole (lub sound) Blood pressure - ANS the measure of the force exerted by circulating blood on the walls of arteries Diastole - ANS a part of a heartbeat (cardiac cycle) in which the atria contract and pump blood into the ventricles, while the ventricles relax and fill with blood from the atria Systole - ANS the part of a heartbeat in which the atria relax and fill with blood from the lungs and body, while the ventricles contract and pump blood out of the heart What does the top number and bottom number represent in blood pressure reading? example 120/80 mmHg - ANS The top number (120) represents systole, and the bottom number (80) represents diastole. The primary role of blood is to - ANS supply nutrients and oxygen throughout your body and remove carbon dioxide, which is a waste product Role of Red blood cells - ANS deliver oxygenated blood throughout your body and collect carbon dioxide (deoxygenated blood) from around your body. The red blood cells transport both oxygen and carbon dioxide. Role of White blood cells - ANS help support the immune system by fighting off infections and foreign material. They destroy and remove old or abnormal cells and cellular debris, as well as attack pathogens and foreign substances. You will learn more about the role and types of white blood cells in the lesson on the immune system. Role of Platelets - ANS help to prevent and stop bleeding. They arrive at the scene when you have a cut or open wound. They help with clotting your blood to stop bleeding. Platelets are key players in the process of sealing a ruptured blood vessel and preventing further loss of blood. Role of Plasma - ANS assists in removing waste from your body digestive system - ANS a body system including a series of hollow organs joined in a long, twisting tube from the mouth to the anus 2 categories of the digestive system - ANS organs of the gastrointestinal tract (GI) and accessory organs Organs of the GI tract include which structures? - ANS include all the structures through which food passes. How long is the GI tract before and after death? - ANS 25 feet in length during life and closer to 35 feet in length when measured after death, once smooth muscle tone is lost organs of the digestive tract are divided into what two sections - ANS the upper and lower GI tracts upper gastrointestinal tract - ANS includes the mouth, pharynx, esophagus, salivary gland, and stomach lower gastrointestinal tract - ANS includes the small intestine, large intestine, and anus pharynx - ANS also known as the throat, a tubular organ that connects the mouth and nasal cavity with the larynx and through which air and food pass esophagus - ANS a long, narrow, tube-like digestive organ through which food passes from the pharynx to the stomach stomach - ANS an organ located on the left side of your body and marks the end of the upper GI tract. It is the connection between the esophagus and the small intestine. An empty stomach is only about the size of your fist but can stretch to hold as much as 4 liters of food and fluid, or more than 75 times its empty volume, and then return to its resting size when empty. small intestine - ANS The small intestine is about 10 feet long in a living person. It is the structure between the stomach and large intestine. The small intestine is divided into three parts - the duodenum, jejunum, and ileum The 3 divisions of the small intestine - ANS the duodenum, jejunum, and ileum how long is the small intestine? - ANS about 10 feet long in a living person duodenum - ANS he first part of the small intestine. It is the shortest section, averaging about 10 inches long. jejunum - ANS the middle section and measures about eight feet long. ileum - ANS the last part of the small intestine and measures about 10 feet long. large intestine - ANS The large intestine is also known as the large colon and is divided into four parts: cecum, colon, rectum, and anus: 4 divisions of the large intestine - ANS cecum, colon, rectum, and anus cecum - ANS a pouch connected to the junction of the small and large intestines colon - ANS the main part of the large intestine between the small intestine and rectum where water and salts are removed from liquid food waste to form feces rectum - ANS is the area between the colon and the anus. anus - ANS the final part of the large intestine with an opening to the outside for feces to pass through Name the the accessory organs - ANS The liver, gallbladder, and pancreas True or False: Food travels through accessory organs - ANS False, food does not travel directly through the accessory organs. liver - ANS is the largest gland in your body, weighing about three pounds in an adult. It is also one of the most important organs. It is located near the stomach. gallbladder - ANS a small, hollow, pouch-like organ that lies just under the right side of the liver. It is about three inches long and shaped like a tapered sac. pancreas - ANS a glandular organ that is part of both the digestive system and the endocrine system. It is located behind the stomach, with the head of the pancreas surrounded by the duodenum of the small intestine. The pancreas is about six inches long. Produces enzymes that process proteins. Function of all accessory organs in the digestive system - ANS All the accessory organs play a role in the digestive system by storing or secreting substances to assist with digestion. Ingestion (upper GI) - ANS taking food into the body. As you chew your food, the salivary glands produce saliva, which contains digestive enzymes that help moisten and break down food. Once you have chewed your food, you push it to the back of your mouth and swallow it down the pharynx. Swallowing is the last voluntary function you perform when eating. The remainder of the digestive process is controlled by your body. peristalsis (upper GI) - ANS a distinctive pattern of smooth muscle contractions that propels foodstuffs through the esophagus and intestines. Peristalsis is so powerful that foods and liquids you swallow enter your stomach even if you are standing on your head segmentation (upper GI) - ANS a process in which food is mixed with digestive enzymes to prepare nutrients for absorption elimination (lower GI) - ANS the removal of undigested food contents and waste products from the body Mechanical digestion - ANS a purely physical process that does not change the chemical nature of the food. Instead, it breaks the food into smaller pieces, which increases the surface area of the food and allows food particles to be acted upon more effectively by digestive enzymes. Mechanical digestion includes mastication, or chewing, as well as tongue movements that help break food into smaller bits and mix food with saliva. chemical digestion - ANS starting in the mouth, digestive secretions break down complex food molecules into their chemical building blocks (e.g., proteins break down into separate amino acids).2 Carbohydrates - ANS ex bread, beans, and potatoes - are the main source of energy in your body Proteins - ANS ex meat, eggs, and tofu - help build and repair body tissues Fats - ANS ex avocados, nut butter, and coconut oil - produce energy and protect organs Name the 3 Macronutrients - ANS Carbohydrates, proteins, and fats absorption - ANS a process in which substances such as nutrients are absorbed into the blood. few substances, such as water and some minerals and vitamins, are absorbed in the stomach and large intestine, but about 95% of nutrient molecules are absorbed in the small intestine. Absorption of most molecules takes place in the what part of your small intestine - ANS jejunum (2nd part) What part of the small intestine is iron absorbed in? - ANS duodenum (1st part) What part of the small intestine is vitamin b12 absorbed in? - ANS last part of your small intestine, called the ileum excretion - ANS the process of removing wastes and excess water from the body. The large intestine performs excretion by eliminating the solid wastes that remain after the digestion of food. The large intestine also absorbs some water from the solid waste Kidneys and their role in excretion - ANS The kidneys, another organ of excretion, remove liquid waste from your body through urination. Elimination - ANS the removal of undigested food contents and waste products from the body. Most absorption occurs in the small intestine. Any food left over travels to the large intestine and will be eliminated from your body through the rectum and out of the anus. The large intestine will temporarily store feces before elimination. defecation - ANS the discharge of feces from the body, commonly called pooping Briefly describe process of eating cake through the digestive system - ANS 1. The cake entered her upper GI tract when she inserted it into her mouth, where it mixed with saliva. 2. Sandra chewed the cake with her teeth, then pushed it to the back of her mouth with her tongue to be swallowed down her pharynx. 3. The cake traveled down the esophagus to the stomach, where it mixed with additional digestive enzymes before traveling to the small intestine. 4. In the small intestine, what was formerly cake went through segmentation, and nutrients such as sugar (a carbohydrate) and fat (from the butter) were absorbed into the bloodstream from the small intestine. 5. In the large intestine, the solid matter that her body could not use formed into feces, which Sandra will eliminate during defecation. What do your kidneys do? - ANS The kidneys filter and remove waste and water from the blood to produce urine. They help to filter and eliminate toxins What is dialysis? - ANS the clinical purification of blood by dialysis, as a substitute for the normal function of the kidney. The four primary structure of the urinary system - ANS the kidneys, ureters, bladder, and urethra How much urine does the urinary system draw out of the body per day? - ANS draws 1-2 liters of urine out of your body each day. What is a kidney shaped like? - ANS bean-shaped, which is how kidney beans got their name Where are the kidneys located? - ANS located in the lower back on both sides of the spine. They are paired organs, like the lungs, but you can survive with only one. renal cortex - ANS the outer portion of the kidney. The kidney itself is wrapped in a fibrous capsule and consists of a thin outer layer called the renal cortex renal medulla - ANS thicker inner layer, the innermost part of the kidney urine - ANS a liquid waste product of the body that is formed by the kidneys and excreted by the other organs of the urinary system. The color and odor of urine can change based on factors such as how much water you drink, what foods you eat, and the effects of various illnesses. nephron - ANS one of the million tiny structural and functional units of the kidney that filters blood and forms urine. Each nephron spans the cortex and medulla layers of the kidney ureters - ANS a muscular, tube-like organ of the urinary system that moves urine by peristalsis from the kidney to the bladder bladder - ANS a muscular pouch attached to the ureters and urethra urethra - ANS a tube-like organ of the urinary system that carries urine out of the body from the bladder What is the function of peristalsis in the urinary system? - ANS To transport urine through the ureter What is the functional unit of the kidney? - ANS nephron What are the structures of the kidney, from the outermost to the innermost parts of the kidney? - ANS Renal cortex, renal medulla, renal pelvis What does taking a deep breath do? - ANS allows your body to efficiently exchange incoming oxygen with outgoing carbon dioxide to reestablish the balance of the two gases in your body. This efficient exchange of gases can slow your heart rate and stabilize your blood pressure. Which organs require energy to function - ANS All your organ systems require energy to function, and energy enters your body as a result of eating and drinking. How is carbon dioxide removed from your body? - ANS Gas exchange Which system eliminates solid waste? - ANS Digestive System Which system eliminates liquid waste? - ANS Urinary System What occurs in your body when you breath more slowly? Choose two answers. - ANS Blood pressure is stabilized, The oxygen and carbon dioxide in your cells are balanced Which system are macronutrients delivered to after being broken down in the digestive system? - ANS the cardiovascular system What does the pancreas do? - ANS It produces amylase, protease and lipase then releases them into the small intestine steps of urine formation - ANS 1. glomerular filtration 2. tubular reabsorption 3. tubular secretion 7 parts of the immune system - ANS white blood cells, the spleen, bone marrow, the thymus, the tonsils, lymph nodes, and antibodies main cell type in the immune system? - ANS White blood cells White blood cells - ANS also known as leukocytes, are cells in blood that defend the body against invading microorganisms and other threats. White blood cells make up a small percentage of the blood; they are mostly located in the immune system. 3 types of white blood cells - ANS lymphocytes, neutrophils, and monocytes two types of lymphocytes - ANS B cells and T cells Can you live without a spleen? - ANS Yes, but you are highly susceptible to infections Where is the spleen located? - ANS upper left quadrant of the abdomen, next to your stomach spleen - ANS an organ of the lymphatic system found on the left side of the body next to the stomach macrophages - ANS a type of monocyte (white blood cell) found in body tissue that destroys damaged red blood cells, bacteria, or viruses monocyte - ANS a type of white blood cell that becomes a macrophage when it leaves the bloodstream and enters the body's tissue Lymph - ANS a clear fluid containing a type of white blood cells known as lymphocytes and helps the body fight infections by transporting white blood cells to where they are needed. Filtered in the spleen. Extra function of the spleen in a fetus - ANS In a fetus, the spleen has the additional function of producing red blood cells. This function is taken over by bone marrow after birth. Bone marrow - ANS produces white blood cells, which are the main cells of defense. located inside bones and is composed of soft tissue. B cells and T cells are produced in the bone marrow, but they mature in different locations. 2 types of bone marrow - ANS red marrow and yellow marrow yellow bone marrow - ANS contains fat tissue, which is used to create energy for the body red bone marrow - ANS produces all the blood cells, such as red blood cells, white blood cells, and platelets. Where do B Cells mature? - ANS bone marrow Where do T cells mature? - ANS T cells travel to the thymus to mature thymus gland - ANS The organ of the lymphatic system in which T cells mature. An organ with two lobes found in the space between the sternum (breastbone) and the aorta of the heart. Connective tissue holds the lobes closely together but also separates them and forms a capsule. At its largest in newborns How much does the thymus shrink each year and what age does it lessen this rate? - ANS The shrinking of the thymus gland begins at birth at a rate of about three percent tissue loss per year. This shrinking continues until 35-45 years of age, and then the rate declines to about one percent loss per year for the rest of one's life. Tonsils - ANS Found at the back of your throat and often become infected as they fight off germs entering the mouth and throat from spreading to the rest of the body. Small organs of the lymphatic system in the back of the throat that help fight off germs in the mouth and throat Why are tonsils removed? - ANS Tonsils are often removed in people who have recurring throat infections since swollen tonsils can interfere with breathing or swallowing. lymphatic system - ANS a part of the immune system that uses a system of tissues, nodes, and vessels to channel lymph, a fluid containing infection-fighting white blood cells, throughout the body to fight infections Lymph nodes - ANS Small bean-shaped nodes that filter pathogens from lymph. Commonly found near the groin, armpits, neck, chest, and abdomen. If lymph is not properly filtered and drained, it can cause areas of the body to swell. Lymph nodes help clean and remove extra lymph from your body while getting rid of viruses and bacteria. pathogen - ANS disease-causing organisms antigen - ANS a type of protein molecule on the surface of a pathogen that the immune system recognizes as foreign (not produced by your own body). The immune system responds to an antigen by creating an antibody antibody - ANS a protein produced by plasma cells that defends the body against a specific pathogen by binding to an antigen. A large Y-shaped protein produced by the immune system that precisely matches and binds to that specific antigen to target it for destruction by other immune cells. This specificity is what allows the immune system to "remember" that pathogen in the future. What is adaptive immune response? - ANS When the same pathogen enters your body after the first exposure, your body sends the antibodies associated with that antigen to help fight off the infection. B cells - ANS major cells involved in the creation of antibodies that circulate in blood plasma (which you learned about previously in the lesson on the cardiovascular system) and lymph. B cells help keep track of all the pathogens from previous exposure T cells - ANS a type of lymphocyte that matures in the thymus and helps regulate the body's immune response and can also kill infected cells in the body 2 subsystems of immune system - ANS the innate immune system and the adaptive immune system. They both help protect and prevent foreign pathogens (disease-causing organisms) from entering the body, but in different ways. innate immune system - ANS a subset of the human immune system that produces rapid but nonspecific responses to pathogens. Innate immune responses are generic, rather than tailored to a particular pathogen. The innate system responds in the same general way to every pathogen it encounters. Although the innate immune system provides immediate and rapid defenses against pathogens, it does not provide long-lasting immunity to them. adaptive immune system - ANS is highly specific to a particular pathogen (or its antigen) and longer lasting. An adaptive immune response is set in motion by antigens that the immune system recognizes as foreign. An important function of the adaptive immune system that is not shared by the innate immune system is the creation of immunological memory—or immunity—which occurs after the initial response to a specific pathogen. Immunity allows for a faster, stronger response on subsequent encounters with the same pathogen, usually before the pathogen can even cause symptoms of illness. immunity - ANS the condition that permits either natural or acquired resistance to disease The most common types of pathogens that attack humans - ANS bacteria, viruses, fungi, and protozoa Bacteria - ANS Single-celled organisms without a nucleus. Example of sickness: Food poisoning (E. coli). Symptoms: Diarrhea, stomach cramps, nausea, vomiting Virus - ANS Nonliving particles that reproduce by taking over living cells. Example of sickness: Common cold (rhinovirus). Symptoms: Sneezing, runny nose, sore throat, coughing Fungi - ANS Single-celled organisms with a nucleus. Example of sickness: Athlete's foot (dermatophytes). Symptoms: Itchiness, burning, scaly rash Protozoa - ANS Single-celled organisms with a nucleus. Example of sickness: Malaria (plasmodium parasite spread by mosquitos). Symptoms: Fever, chills, achiness, fatigue lymphatic system - ANS part of the adaptive immune system that assists your body in fighting off infections. It is made up of organs, tissues, nodes, and vessels that carry lymph throughout your body and help to filter it. organs of the lymphatic system - ANS lymph nodes, lymphatic vessels, thymus gland, spleen, tonsils Lymphatic vessels - ANS a network of capillaries (thin tubes) that operate much like your blood vessels. They carry lymph from your body's tissues, transport it to the lymph nodes where it gets filtered, and then move it to larger ducts that return the lymph to your bloodstream. The two major lymphatic ducts that collect lymph from different parts of your body and ultimately return it to the blood circulation are: - ANS thoracic duct and the right lymphatic duct right lymphatic duct - ANS a vessel that receives lymph fluid drained from the right sides of the head, trunk, and right upper limb trunks thoracic duct - ANS a lymphatic vessel that is larger than the right lymphatic duct and that receives the remaining lymph fluid not drained to the right lymphatic duct Types of T cells - ANS The major types are cytotoxic T cells and helper T cells. Both types develop from T cells that become activated when you are exposed to antigens Neutrophils - ANS white blood cells that travel throughout the body in the blood. They are usually the first immune cells to arrive at the site of an infection. Macrophages - ANS a type of white blood cell found in body tissue that destroy damaged red blood cells, bacteria, or viruses. They are the most efficient at devouring substantial numbers of pathogens or other cells. dendritic cells - ANS specialized white blood cells that patrol the body searching for antigens that produce infections Eosinophils - ANS a white blood cell containing granules that are readily stained by eosin. mast cells - ANS Cells that release chemicals (such as histamine) that promote inflammation. Which body parts move lymph into the right lymphatic duct? Choose two answers. - ANS Right arm, Right side of the head What is the function of the spleen? - ANS filter blood and help fight infections. It breaks down old blood cells. What percent of body weight is your skin? - ANS fifteen percent of your body weight largest organ in the body - ANS skin Skin is divided into what 2 layers? - ANS epidermis and dermis epidermis - ANS the thin, outer layer of skin that lacks nerve endings and blood vessels. If you cut your skin at only the epidermis layer, you would not bleed and it would not hurt as much as a deeper cut. Without blood to bring epidermal cells oxygen and nutrients, the epidermal cells must absorb oxygen directly from the air. These cells also obtain nutrients via diffusion