ATI TEAS 6 - Science (Human Anatomy and Physiology) BIOL MISC CLASS NOTES

The Nucleus.Pulmonary: Flow of blood between the heart and the lungs. Deoxygenated blood flows from the right ventricle to the lungs through pulmonary arteries. Oxygenated blood flows back to the left atrium through the pulmonary veins. Systemic: Flow of blood to the entire body with the exception of coronary and pulmonary. Blood exits the left ventricle through the aorta, which branches into the carotid arteries, subclavian arteries, common iliac arteries, and the renal artery. Blood returns to the heart through the jugular veins, subclavian veins, common iliac veins, and renal veins, which empty into the superior and inferior vena cavae. -Portal circulation: Included in Systemic. Flow of blood from the digestive system to the liver and then to the heart and renal circulation, which is the flow of blood between the heart and kidneys. Blood Pressure Fluid pressure generated by the cardiac cycle. Arterial: Functions by transporting oxygen-poor blood into the lungs and oxygen-rich blood to the body tissues. -Arteries branch into smaller arterioles which contract and expand based on signals from the body. -Arterioles are where adjustments are made in blood delivery to specific areas based on complex communication from body systems. Capillary Beds: Diffusion sites for exchanges between blood and interstitial fluid. Capillary: Has thinnest wall of any vein, consisting of single cell endothelial cells. Merge into venues which in turn merge with larger diameter tubules called veins. -Veins transport blood from body tissues back to the hearts. Thin and contain smooth muscle and function as blood volume reserves. -Valves inside the veins facilitate this transport. Lymphatic System -Function: To return excess tissue fluid to the bloodstream. -Consists of transport vessels and lymphoid organs. Lymph Vascular System: Consists of lymph capillaries, lymph vessels, and lymph ducts. -Function: Return excess fluid to blood, Return of protein from capillaries, Transport of fats from the digestive tract, Disposal of debris and cellular waste. Lymphoid Organs -Consist of lymph nodes, spleen, appendix, adenoids, thymus, tonsils, and small patches of tissue in the small intestines. Lymph Nodes: Located at intervals through the lymph vessel system. Contains lymphocytes and plasma cells. Spleen: Filters blood, stores of RBC and macrophages. Thymus: Secrets hormones. Major site of lymphocyte maturation. Spleen -Upper left of the abdomen, behind the stomach and below diaphragm. -Lymphoid tissue -Blood vessels are connected to the spleen by splenic sinuses. -Function: Filter unwanted materials from the blood (including old RBC) and to help fight infections. -Up to 10% of the population has one or more accessory spleens that tend to form at the hilum of the original spleen. Peritoneal Ligaments that Support the Spleen -Gastrolienal: Connects the stomach to the spleen -Lienorenal: Connects the kidney to the spleen -Middle Section of the Phenicol ligament: Connects the left colic flex use to the thoracic diaphragm Heart Functions -Atrial Contraction: Fills ventricles and then ventricular contractions empty them, forcing circulation "cardiac cycle" -Cardiac Muscles attach to each other and signals for contraction spreading rapidly. -Complex Electrical System: Controls the heartbeat -Cardiac Muscle Cells: Produce and conduct electrical signals. Capillaries Drain interstitial fluid that fills the spaces between cells -Filters it through a system of lymph nodes that are enriched in lymphocytes and provide surveillance by immune system. Lymph -Essentially plasma with RBCs removed -Large numbers of leukocytes and lymphocytes are enriched in lymph nodes -Where they monitor and respond to foreign molecules washed into the system. -Nodes are enriched in oral, nasal, and genital regions where foreign entities enter the body. Pathologies (Health Issues) Heart attack, stroke, aneurysms, atherosclerosis, arrhythmia and hypertension. Cardiovascular System Functions Transporting nutrients, waste, chemical messengers, and immune molecules. 2 Integrated Circulatory System -Closed Circulatory System -Open Lymphatic System Closed Circulatory System Double-loop system consisting of thick-walled arteries that transport blood away from the hear, thinner-walled veins that transport blood to the heart, and capillaries made of a single layer of endothelium that form a network that connects arteries to veins in tissues. Transports blood Double Loops -Pulmonary: Carries deoxygenated blood from the right ventricle to the lungs and returns oxygenated blood to the left atrium. -Systemic: Carries oxygenated blood from left ventricle to the body, returning deoxygenated blood to the right Open Lymphatic System Circulates and filters interstitial fluid between cells and eventually drains into the circulatory system. -Cleans up excess fluid and proteins and returns them to the blood. Systole and Diastole (Contraction Cycles) Systole: Contraction of heart muscles Diastole: Relaxation of heart muscles Controlled: by a "pacemaker" called the Sinoatrial Node, which sends out electrical signal. Arteries vs. Veins -Arteries have thick walls to withstand the pressure of blood pumped by the hearts. -Veins have walls with a thinner muscle layer and larger lumen. Simplified Overview of the Heart Cycle The ventricles contract (ventricular systole), causing the Atrioventricular Valves (including mitral and tricuspid valves) to close, making a "lub" sounds. Subsequently, the empty ventricles are filled with blood pushed out during Atrial Systole. Same time, the Semilunar Valves in the aorta and pulmonary arteries close, preventing blood from falling back into the ventricles, making a "dub" sound, and completing the "lub-dub" sound of the heart. Where does Gastrointestinal start and end? Starts at mouth Ends at Anus What does saliva provide? What initiates it? Amylase and Lipase Initiates chemical digestion for starch and lipids. Bolus Food packaged into small parcels Then swallowed Peristalsis Moves bolus down to stomach through gastric sphincter (prevents back flow into esophagus) Pepsin -Initiates chemical digestion of proteins by this enzyme -Activated by acid and autocatalyst Mucus Lubricates the food in the saliva The 3 Main Secretions of the Stomach Pepsinogen (chief cells), Mucus(goblet cells), hydrochloric acid (parietal cells) Chyme All three secretions together Chyme neutralized by? Bicarbonate in pancreatic secretions Duodenum receives what from gall bladder? Alkaline bile juices. Duodenum produces what enzymes? -"Brush Border" enzymes -Proteases, Lactase and other disaccharides, and bicarbonate. Villi and Microvilli function? Absorb polar digested nutrients into blood, lipids into lacteals as chylomicrons, and B12 Blood carrying nutrients passes through? Allowing what to happen? -Through hepatic portal duct to the liver - Allowing liver enzymes to deaminate amino, convert ammonia to urea, metabolize consumed toxins, and to store glucose as glycogen. Small Intestines Absorb what? A lot of water and nutrients Small intestines include what structure in the order of digestion? Duodenum->jejunum->ileum Digestive System Functions -Movement: Mixes and passes nutrients through the system and eliminates waste. -Secretion: Enzymes, hormones, and other substances necessary for digestion are secreted into the digestive tract. -Digestion: Chemical breakdown of nutrients into smaller units that enter the internal environment -Absorption: Passage of nutrients through plasma membranes into the blood or lymph and then to the body. Structure of Digestive System Mouth, pharynx, esophagus, stomach, small and large intestines, rectum, and anus. Enzyme Function Infused into digestive systems to assist the absorption and processing of nutrients. What controls the Digestive System? Nervous and Endocrine Systems Beginning of Digestion -Mouth: By chewing and mixing of nutrients with saliva. -Salivary Glands: Stimulated and secrete saliva. ~Saliva: Contains enzymes that initiate the breakdown of starch in digestion. -Once swallowed, food moved down Pharynx into the Esophagus, headed towards the stomach. Stomach Functions -Mixing and storing foods -Dissolving and degrading good via secretions -Controlling passage of food into the small intestines. Protein digestion begins in stomach Absorption Process -Acidity helps break down the food and make nutrients available for absorption. Smooth muscle contractions move nutrients into the small intestines where absorption process begins. Small Intestines -Enzymes from pancreas, liver, and stomach are transported here to aid digestion. -Enzymes act on fats, carbohydrates, nucleic acids, and proteins. -Gall Bladder: stores bile (useful in fat break down) -Epithelial cells at the surface of villi (microvilli), to further increase the ability of the small intestine to serve as the main absorption organ. Large Intestines -Colon -Concentrates, mixes, and stores waste material -Rectal wall is distended by waste material, the nervous system triggers an impulse in the body to expel the waste from the rectum. -Muscle sphincter at the end of the anus is stimulating facilitates the expelling of waste matter. -Speed of waste movement through colon is influenced by volume of fiber and other undigested materials present. -Lack of Bulk in diet: Bowel obstructions, constipation. Liver -Largest solid organ in body, largest gland -4 Lobes: Right, left, quadrate, and caudate. -Secured to diaphragm and abdominal walls by 5 ligaments (falciform, coronary, right triangular, left triangular, and round ligaments). -Lobules: Blood enters here through branches of the hepatic portal vein and hepatic artery. Then flows through small channels called sinusoids. -Processes all the blood that passes through digestive system. -Nutrients are converted into forms appropriate for the body to use Liver Function -Production of bile, certain blood plasma proteins, cholesterol -Storage of excess glucose in the form of glycogen -Regulation of amino acids and blood clotting -Processing of hemoglobin’s -Conversion of ammonia -Purification of the blood -Controlling infections by boosting immune factors and removing bacteria. Pancreas -Head: wider side, Tail: Narrower side -Exocrine and endocrine tissue -Exocrine: Secretes digestive enzymes from a series of ducts that collectively form the main pancreatic duct. ~Main pancreatic duct *connects to common bile duct+ near duodenum -Endocrine: Secretes hormones (insulin) into the bloodstream. -Blood is supplied from the splenic artery, gastroduodenal artery, and the superior mesenteric artery. Digestive Role in Pancreas -Assists in the digestion of foods by secreting enzymes (to the SM.INT.) that help break down many foods, like fats and proteins. -Precursors to enzymes (zymogens) are produced by groups of exocrine cells (acini). -Converted through a chemical reaction in the gut, to an active enzyme (like pancreatic lipase and amylase) once entered into small intestines. -Secretes large amounts of sodium bicarbonate to neutralize the stomach avid that reaches the small intestines. -Exocrine Secretions: ~Controlled by hormones released by the stomach/duodenum when food is present. ~Flow into the main pancreatic duct and are delivered to the duodenum through duct. Nervous System Senses, Interprets, and Issues commands as a response to conditions in the body's environment. Made by a very complex communication system organized as a grid of neurons. Integrates muscles and nerves. How are messages sent across Plasma Membrane? By Action Potential When do messages occur? Occur when a neuron is Stimulated past a necessary threshold. Stimulations Occur in a sequence from the stimulation point of One neuron to its contact with another neuron. Chemical Synapse "Point of Contact" -A substance is released that stimulates or inhabits the action of the adjoining cell. Framework for Nervous System Network fans out across the body forming the framework. -The direction the information flows depends on the specific organizations of nerve circuits and pathways. 3 General Functional Types of Neurons *The Sensory Neurons, Motor Neurons, and Interneurons. Sensory Neurons Transmit Signals to the Central Nervous System (CNS) from the sensory receptors associated with touch, pain, temperature, hearing, sight, smell, and taste. Motor Neurons Transmits Signals from CNS to the rest of the body such as by signaling muscles or glands to respond. Interneurons