OSU Physiology 3200 Exam 1 Prep Questions And Answers Well Defined Graded A+

Physiology - correct answers Knowledge (study) of nature, study of function (how the body works) Characteristics of life: almost all cells can.. - correct answers 1. Exchange materials with environment 2. Obtain energy from organic nutrients 3. Synthesize complex molecules 4. Duplicate themselves 5. Detect and respond to signals in their environment 6. Cell differentiation (cells specialize to perform different functions) 4 broad types of cells - correct answers 1. Muscle cells (myocytes) 2. Nerve cells (neurons) 3. Epithelial cells 4. Connective tissue cells Muscle cells - correct answers Also called myocytes, generate mechanical force and movement. Includes skeletal, cardiac, and smooth muscle cells Nerve cells - correct answers Also called neurons, are specialized to initiate and conduct electrical signals, often control the activity of other cells Epithelial cells - correct answers Located on the surface of the body or a hollow organ, are specialized for secretion and protection Connective tissue cells - correct answers Connect, anchor, and support body structures. Includes loose connective tissue, dense connective tissue, blood, cartilage, bone, and adipose tissue Tissue - correct answers An aggregate of differentiated cells with similar properties Organ - correct answers a collection of tissues joined in a structural unit to serve a common function (ex: heart) Organ system - correct answers Organs that are linked together to serve an overall function (ex: the cardiovascular system or the gastrointestinal system) Organism - correct answers Coordinates the activities of these systems to maintain a stable internal environment. This means managing the content and distribution of body fluids in response to changes or external stimuli Body fluid compartments - correct answers Cells that make up complex organisms exist in an "internal sea" of ECF enclosed within the integument of the body. In animals with a closed vascular system, the ECFs are compartmentalized to enable exchange of nutrients and waste Percentage of the body that is water - correct answers 60% How much water is in a 70 kg man? - correct answers 70 kg x 0.6 = 42 kg (42 L) Intracellular fluid - correct answers Found inside cells, makes up 2/3 of the water in the body How much ICF is in a 70 kg man? - correct answers 42 L x 2/3 = 28 L How much ECF in a 70 kg man? - correct answers 42 L x 1/3 = 14 L Extracellular fluid - correct answers 20% plasma volume 80% interstitial fluid volume Composition is similar to seawater Plasma volume - correct answers Found in the cardiovascular system, constantly being pumped around to transport materials, contains plasma proteins (interstitial fluid contains very few of these) Interstitial fluid volume - correct answers Found in between the cells How much plasma volume in 70 kg man? - correct answers 14 L x 0.2 = 2.8 L How much interstitial fluid volume in 70 kg man? - correct answers 14 L x 0.8 = 11.2 L Total volume of blood in body - correct answers Around 6 L Cell membrane - correct answers Also known as the plasma membrane, separates the ICF from the ECF, separates inside and outside of cell Capillary wall - correct answers Separates the interstitial fluid from the blood plasma Plasma proteins - correct answers Very important in keeping the fluid inside the cardiovascular system Edema - correct answers Too much interstitial fluid What is inside the cell? - correct answers 1. Nucleus 2. Cytoplasm Cytoplasm - correct answers Region outside the nucleus, composed of cell organelles and the cytosol (fluid surrounding organelles) Ca2+ - correct answers An ion that can be stored in the sarcoplasmic reticulum, certain signals cause its release. The are free Ca2+ and bound Ca2+ Cells are ____________ to the composition of the fluid that surrounds them - correct answers Very sensitive Membrane potential battery - correct answers Each cell is like a battery At rest: inside of cell slightly negative Activated cell: battery reverses for short time, inside of cell becomes positive (action potential) Used to send info long-distance and to communicate, very sensitive to concentrations of Na+, K+, and other ions in interstitial fluid Claude Bernard - correct answers French physiologist who talked about a well-regulated internal environment Walter Cannon - correct answers American scientist, coined the term homeostasis Homeostasis - correct answers The relative constancy of the internal environment When the is a change in the ECF composition, the body - correct answers Initiates reactions to correct or minimize that change Much of physiology is a study of mechanisms that - correct answers Mediate response to change-using homeostatic systems In response to a fall in body temperature - correct answers -The core temperature of the body is continuously sensed by thermoreceptors located in the body -The temperature information is sent to the integrating center in the hypothalamus -In the integrating center, this body core temperature is continuously compared to the set point (37 degrees C, 98.6 degrees F) -If the body core temperature has fallen to 36 degrees C, the integrating center will produce changes in the effectors to bring the body temperature back up NEGATIVE FEEDBACK The effectors and their responses to falling body temperature stimulus - correct answers 1. Blood vessels in skin constrict 2. Voluntary muscles- curl un in ball, add clothes 3. General muscle activity- shivering Negative feedback - correct answers Used by homeostatic control systems to keep a variable within a certain range, response decreases the effect of the stimulus Reflex - correct answers A biological control system that directly links a stimulus (like change in temperature) with a response (like vessel constriction) Reflex arc - correct answers Pathway mediating a reflex Stimulus - correct answers A detectable change in the controlled variable Receptor - correct answers A sensor that the stimulus acts upon (there are many other types of receptors too) Afferent pathway - correct answers Relays signal from receptor to integrating center, can be neural or hormonal Efferent pathway - correct answers After the integrating center integrates the input from many receptors, it sends its response to the effectors via this pathway Feedforward mechanisms - correct answers Sometimes help negative feedback mechanisms, anticipate changes, minimize fluctuations in the variable that is being controlled and can speed up the body's response Examples of feedforward mechamisms - correct answers -Thermoreceptors making skin temperature drop when entering a cold room before the core temperature falls -Olfactory cues activate digestive system - Preparing for exercise: initiate sympathetic activation to reduce lag and buffer adrenaline rush Positive feedback - correct answers Magnifies a change, leads to an explosive system, less common than negative feedback but still important, typically end with a major event that stops the process Baby being delivered - correct answers POSITIVE FEEDBACK -Stimulus: increased pressure on the cervix -Effector: oxytocin acting on the uterus -Response: contraction and increased pressure Other examples of positive feedback - correct answers -Ovulation: estrogen leads to more estrogen release -Action potentials: Na+ entry leading to Na+ channel opening -Muscle contraction: Ca2+ entry leads to Ca2+ release in the channel Communication between cells - correct answers Homeostatic responses rely on this to cause a response Cell communication messengers - correct answers Hormones, neurotransmitters, paracrine or autocrine agents Determined by where it travels (same substance can be different things in different parts of the body) Hormone - correct answers A chemical messenger secreted by endocrine cells into the bloodstream Neurotransmitter - correct answers A chemical messenger released by a neuron to affect a muscle, gland, or nerve cell. It travels through the synaptic cleft (10-20 nm space) Paracrine agent - correct answers A chemical messenger released by a cell that acts on cells nearby within a tissue Autocrine agent - correct answers A chemical messenger released into the interstitial fluid that acts upon the very cell that secreted it Balance - correct answers When the healthy condition is present, the loss or gain of substances from individual response mechanisms is balanced Negative balance - correct answers When individual reflex responses result in an overall loss of a substance in the body Positive balance - correct answers When responses result in an overall gain of a substance Adaptation - correct answers Inherited biological control mechanism (ex- ethnicity) Acclimation - correct answers When control mechanisms change in response to prolonged exposure to a stimulus or stress (ex- athletes training in low O environments so their blood can carry more O) Nucleus - correct answers Stores DNA, produces RNA Ribosomes - correct answers Protein synthesis Endoplasmic reticulum - correct answers Rough and smooth Rough ER - correct answers Packaging proteins Smooth ER - correct answers Stores lipids and Ca2+ Golgi apparatus - correct answers Post-transitional modification Endosomes - correct answers Sorting, trafficking Mitochondria - correct answers Cell respiration Cytosome - correct answers transport and motility