BIOL 112 1st EditionExam # 3 Study Guide Lectures: 15 - 21Lecture 15 (March 18)Introduction to the Digestive System (1 question)Cells —> Tissue —> Organ —> Organ SystemTissue: a group of cells with common structure/function, made up of the same differentiated typeOrgan: specific collection or grouping of different tissues, the whole having some specific function (ex. skin)Organ System: collection of different organs with specific overall function to bodyDifferent types of tissue:•Epithelial Tissue: make up digestive system, various types (stratified squamous, cuboidal, simple columnar, simple squamous, pseudo stratified columnar) apical surface is on the outside, basal faces another type of tissue on the inside.•Connective Tissue: Loose connective tissue, fibrous connective tissue, adipose tissue, cartilage; these tissues hold parts of the body together.•Muscle Tissue: Skeletal muscle (voluntary muscles), smooth muscle (organs), cardiac muscle (heart); how the animal moves aroundThe Digestive System (9 questions)Four Major Functions:•Processing food•Digestion: Breaking of each of the macromolecule types into monomers (we cannot absorb polymers — they are too big)•Hydrolysis (Catabolic Reaction) -Polysaccharides —> simple sugars -Proteins —> amino acids -Lipids —> fatty acids and glycerol -Nucleic acids —> nucleotides•Absorbs organic nutrients that are produced from processing the food•Absorption of electrolytes•Absorption of waterDigestion: went from intracellular (in primitive organisms) to extracellular (in advanced organisms)•Mouth —> Pharynx —> Esophagus —> Stomach —> Intestines —> Anus•If you were to take out your entire digestive system, it would be approximately 5 times your heightAbsorption•In advanced animals, there is no phagocytosis in digestion; all absorption then must be with monomers across the plasma membrane•passive diffusion, facilitated diffusion, active transport•Total absorptive area of small intestine is about the size of a tennis court! These things increase surface area for absorption:•Circular Folds: inner face of intestine•Villi: on folds, smaller finger-like projection of tissue•Microvilli: “brush border”Lecture 16 (March 20) Significance of Liver•1st major organ for blood and lymph coming from intestines•Hepatic-Portal Shunt: Blood from the intestines goes through the liver before it goes to the rest of the body, liver acts as a filter and a buffer•Liver controls nutrient concentrations in blood, also detoxifies blood from intestines, takesout things that are not healthy and destroys them to regulate blood streamCaecum -In humans, this includes the appendix -Blind pouch - in some animals, this is a fermentation site for symbiotic bacteria and protists digesting celluloseColon -Chyme coated with thick mucus -Salts removed by active transport through intestinal wall, sent to blood -Water is removed osmotically when salts are transported out -About 90% of water is removed•Removal of water coupled with peristaltic movements that pack chyme into a compactmass: feces -About 30% of feces is dead bacteria•Feces propelled to rectum•Anus is final sphincterThe Circulatory System (22 Questions!)Circulatory System functions:•Biggest function: transport of materials throughout body•Gas Exchange: Transports gasses exchanged for respiration•Nutrients: Materials picked up by digestive system are distributed throughout body•Wastes: Products to be removed by excretory system•Hormones: Communication and control throughout body•Body Defenses: Inflammatory/Immune SystemsTypes of Circulatory Systems:•Open Circulation: arthropods, molluscs. Blood is not completely enclosed in vessels throughout circuit to/from heart. Blood empties into sacs called sinuses which surround many major organs•Closed Circulation: annelids, chordates (us). Blood is contained entirely in vessels in circuit to/from heart. Regarded as more efficient because higher blood pressure is maintained in circuit.Components of Circulation System:•Human heart: right/left atrium; right/left ventricle•Between each atrium and ventricle: valves; permits one-way flow of blood from each atrium into each ventricle only Atrioventricular Valves -Left - Mitral Valve -Right - Tricuspid Valve•Between each ventricle and blood vessel: Semilunar Valves•Heartbeat: “thub-lub” -Thub: AV valves snap shut after atria contract -Lub: Semilunar valves snap shut after ventricles contractLecture 17 (March 25)Blood Vessels•Artery: Multilayered tube (lumen) - endothelium, smooth muscles, connective tissue, epithelium, thicker and much more muscle than a vein, carry blood away from heart•Vein: Multilayered tube (lumen) - endothelium, smooth muscles, connective tissue, epithelium•Distinguish arteries and veins•Structural Artery - thicker walls, more muscle than vein; veins have valves, arteries do not•Functional Artery - carries blood away from heart; vein always carries blood towards heart•Capillaries•Between arteries and veins in circulation cycle•Only one cell layer thick: endothelium cells•All exchanges occur through endothelial cells of capillaries•Exchanges involve diffusion, active transport and/or endo/exocytosis through endothelial cellsLymphatic System•collect excess fluids from intercellular spaces of tissues: lymph (normally no blood cells in this)•Also colonies of lymphatic (immune) cells in walls of intestines: Peyer’s Patches. Immune surveillance of digestive organs•Lymph Nodes: filter lymph as it professes through vessels towards upper torso of body, major immune surveillance posts, remove bacteria, fungi, debris•Lymph vessels collect and eventually return lymph to blood circulation at major connection site, thoracic duct•Failure of Lymphatic Return•Elephantiasis: caused by tiny parasitic roundworms lodging in lymph nodes and plugging up lymph system. no lymph flow leads to accumulation of lymph fluids in area normally drained by a part of lymph system. leads to gross swelling of leg, or arm,or scrotum.•Cancer Metastasis: spread of cancer cells throughout body. lymph nodes do not filter out cancer cells because they are not recognized as being “foreign”, even through theyare. cancer cells use lymph system as vehicle for spreading throughout the body.Human Circulation•Pulmonary Circuit: Right atrium —> Right Ventricle —> pulmonary artery —>