Lecture Notes Exam 3 Tissues Hierarchy of body plans o Cell smallest unit of life o Tissue collection of similarly strucutred functioning cells o Organ group of tissues that work together for 1 function o Organ system group of cooperating organs Some can belong to more than 1 system 4 types of tissue o Epithelium covers surfaces of tissues and organs Bound by tight junctions 5 types of epithelia cells Simple squamous Stratified squamous Columnar Pseudostratified columnar Cuboidal Has a basal apical orientation deep superficial Basal surface attached to base special collagem Apical surface in contact with air lumen Basal lamina dense mat of ECM o Connective tissue cells scattered in ECM that holds organs in place Volume of cells ECM Matrix is hard liquid or jelly like 3 fiber types Elastic makes tissues elastic Reticular join connective tissue to tissues Collagenous strength and flexibility 5 types of connective tissue Loose binds epithelia to tissue o Most common o Has all 3 fiber types Fibrous dense with collagenous fibers o Tendons muslce to bone o Ligaments bones to bones Bone mineralized connective tissue of blood vessels Blood carries nutrients and wastes o Plasma is the ECM o Erythrocytes red blood cells o Leukocytes white blood cells o Osteoblasts make bone o Osteons functional units of mineralized matrixes around a central canal Cartilage collagenous fibers in a rubbery matrix chondroitin sufate o Chondrocytes secrete collagen and chondroitin sulfate o Fetal skeleton Adipose specialized for fat storage o Muscle tissue used for movement Skeletal voluntary Striated Sarcomere contractile unit Smooth muscles of organs Cardiac heart muscles auto rhythmic Spindle shaped Not striated Striated Intercalated discs o Nervous tissue transmit impulses Dendrites axons Glial cells support cells and nourish protect Digestive System 5x height in humans 4 major fucntions o Food processing o Absorption of nutrients from food 0rganic o Absorption of electrolytes from food inorganic Ca2 Na K Cl o Absorption of water Digestion breaking food into absorbable monomers Enzymatic hydrolysis using enzymes to hydrolyze food Evolution o Primitive intracellular digestion in vacuoles o Advanced extracellular digestion in lumens of digestive organs cells absorb monomers Food processing which enzymes will act Saliva o Mouth basic breakdown formation of bolus Chewing teeth makes food easier to swallow and increases surface area on Mucous to protect teeth and mouth Ptyalin salivary amylase to break down starches into disaccharides o Swallowing Pharynx epiglottis covers trachea esophagus Carried by peristaltic contractions o Stomach bag sealed by 2 sphincters gastroesophageal pyloric Bolus becomes chyme Gastric pit glands produce gastric juice H and Cl made by parietal cells to make HCl pH of around 2 Pepsinogen made by chief cells and converted to pepsin by HCl and pepsin itself positive feedback Peristalitc movement churns chyme o Small intestine 3x height In the duodenum Alkaline mucus pH 7 5 7 8 Cholecystokinin and secretin stimulate the pancrease to make digestiv enzymes and the liver to release bile Enterogastrone shuts down the stomach activities Jejum and ileum Crypts of liberkuhn secrete more enzymes Pancreas secretes enzymes for all 4 macromolecules Liver makes bile and stores it in the gallbladder o Bile detergents to break up fat molecules to increase surface area for lipase o Also helpes get rid of bilirubin Absorption of nutrients o Small intestine Very foled and many villi and microvilli to increase surface area Process determined by polarity Hydrophillic sugars amino acids and nucleotides absorbed by cells and taken by capillaries in villi Hydrophobic fats and lipids first cleaved by lipase and fatty acids and glycerol absorbed by cell and made back into fats o Chylomicron mixed with cholesterol and proteins Carried out by lacteal in villus Collected and processed by liver o Liver 1st major organ for blood and lymph from intestine Hepatic portal shunt blood from intestines goes to the liver Control nutrient content and detoxify blood o 98 of organic material completely hydrolyzed and absorbed Absorption of water and electrolytes o Large intestin colon Connected to ileum small intestine by ileocaecal sphincter Water and salt absorption Caecum Humans have an apppendix that might have some immune function Blind pouch for cellulose digestion especially herbivores Feces chyme with water and salt removed and compacted Symbiotic bacteria eat remaining nutrients o Rectume anus Primitive no circulation each cell is in contact with the outside Circulation and Gas Exchange Chapter 42 o Simple pseudocoelom Advanced full organ system o Open circulation arthropods molluscs blood not completely enclosed in tubes Hemolymph empties into sinuses that surround major organs o Closed circulation annelides chordates blood contained in velssels to from heart More efficient because high blood pressure possible keeps blood flowing and maintains heat Evolution of closed circulation Single circulation fish heart with 2 chambers 1 atrium 1 ventricle Double circulation o Amphibians 3 chambers 2A 1V Blood mixes in ventricle Limits metabolic activity o Reptiles 3 5 chambers 2A 1 5V Transition to separaation of pulmonary and systemic circuits o Birds mammals 4 chambers 2A 2V Complete separation of pulmonary and systemic circuits o Right atrium Mitrial valve right ventricle semilunar valve pulmonary artery lungs pulmonary vein left atrium tricuspid valve left ventricle semilunar aorta body superior and inferior vena cava right atrium Heart o Sound Thub AV mitral and tricuspid valves Lub semilunar valves o Systole contraction o Diastole relaxation o Electrical activity Don t need nervous impulses intrinsic contraction Electrically connected by intercalated discs pacemakers Sinoatrial node SA atria contract Atrioventricular node AV passes impulse to the bundle of His to the purkinje fibers ventricles contract Controlling heartbeat Most nervous control is on the SA node Vagus nerve deccrease in heartbeat Also sensitive to hormones Blood vessels o Endothelium smooth muscle connective tissue epithelium o Artery thicker more muscle away from heart o Veins valves thinner come to heart o Capillaries very thin 10 m endothelium only for exchange in Microcirculation controlling blood flow by sphincters in arterioles o Blushing o Thermoregulation control heat flow and keep in core o Second wind shift in metabolic processes in muslces
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