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Option H: Further human physiology H1 Hormonal control State that hormones are chemical messengers secreted by H.1.1 endocrine glands into the blood and transported to speciic target cells. State that hormones can be steroids, proteins and tyrosine H.1.2 derivatives, with one example of each. Distinguish between the mode of action of steroid hormones and H.1.3 protein hormones. Obj Notes 1 1 2 H.1.4 Outline the relationship between the hypothalamus and the pituitary gland. 2 H.1.5 Explain the control of ADH (vasopresin) secretion by negative feedback. 3 H2 Digestion Obj Notes State that digestive juices are secreted into the alimentary canal by H.2.1 glands, including salivary glands, gastric glands in the stomach wall, the pancreas and the wall of the small intestine. 1 H.2.2 Explain the sructural features of exocrine gland cells. 3 H.2.3 Compare the composition of saliva, gastric juice and pancreatic juice. Outline the control of digestive juice, secretion by nerves and H.2.4 hormones, using the example of secretion of gastric juice. H.2.5 Outline the role of membrane-bound enzymes on the surface of epithelial cells in the small intestine in digestion. Steroid hormones enter cells and interact with genes directly. Protein hormones bind to receptors in the membrane, which causes the release of a secondary messenger inside the cell. Include the portal vein connecting the hypothalamus and the anterior pituitary gland, and the neurosecretory cells connecting the hypothalamus and the posterior pituitary gland. Include neurosecretory cells in the hypothalamus, transport of ADH to the posterior pituitary gland for storage, and release under stimulus by osmoreceptors in the hypothalamus. Include the secretory cells grouped into acini and ducts, and the ultrastructure of secretory cells as seen in the electron micrographs. 3 2 2 Limit this to the initial release of gastric juice under nerve stimulation after sight or smell of food, and sustained release under the influence of gastrin secreted when food is in the stomach. Some digestive enzymes (for example, maltase) are immovilized in the exposed plasma membranes of epithelial cells in intestinal villi. Option H: Further human physiology Outline the reasons for cellulose not being digested in the alimentary canal. Explain why pepsin and trypsin are initially synthesized as inactive H.2.7 precursors and how they are subsequently activated. Discuss the roles of gastric acid and Helicobacter pylori in the H.2.8 development of stomach ulcers and stomach cancers. H.2.6 H.2.9 Explain the problem of lipid digestion in a hydrophilic medium and the role of bile in overcoming this. H3 Absorption of digested foods Draw and label a diagram showing a transverse section of the ileum as seen under a light microscope. Explain the structural features of an epithelial cell of a villus as seen H.3.2 in electron micrographs, including microvilli, mitochondria, pinocytotic vesicles and tight junctions. Explain the mechanisms used by the ileum to absorb and transport H.3.3 food, including facilitated diffusion, active transport, and endocytosis. H.3.1 H.3.4 List the materials that are not absorbed and are egested. 2 3 3 3 Lipid molecules tend to coalexce and are only accessible to lipase at the lipid-water interface. Bile molecules have a hydrophilic end and a hydrophobic end, and thus prevent lipid droplets coalescing. The maximum surface is exposed to lipases. The need for lipase to be water-soluble and to have an active site to which a hydrophobic substrate binds should be mentioned. Obj Notes 1 Include mucosa and layers of longitudinal and circular muscle. 3 3 1 Limit this to cellulose, lignin, bile pigments, bacteria and intestinal cells. Option H: Further human physiology H4 Functions of the liver H.4.1 H.4.2 H.4.3 H.4.4 H.4.5 H.4.6 H.4.7 H5 Outline the circulation of blood through liver tissue, including the hepatic artery, hepatic portal vein, sinusoids and hepatic vein. Explain the role of the liver in regulating levels of nutrients in the blood. Outline the role of the liver in the storage of nutrients, including carbohydrate, iron, vitamin A and vitamin D. State that the liver synthesizes plasma proteins and cholesterol. State that the liver has a role in detoxification. Describe the process of erythrocyte and hemoglobin breakdown in the liver, including phagocytosis, digestion of globin and bile pigment formation. Explain the liver damage caused by excessive alcohol consumption. The transport system Explain the events of the cardiac cycle, including atrial and ventricular systole and diastole, and heart sounds. Analyze data showing pressure and volume changes in the left H.5.2 atrium, left ventricle and the aorta, during the cardiac cycle. Outline the mechanisms that control the heartbeat, including the H.5.3 roles of the SA (sinoatrial) node, AV (atrioventricular) node and conducting fibers in the ventricular walls. H.5.4 Outline atherosclerosis and the causes of coronary thrombosis. H.5.1 H.5.5 Discuss factors that affect the incidence of coronary heart disease. Obj Notes 2 The difference in structure between sinusoids and capillaries should also be mentioned. Reference to lobules or acini is not required. 3 2 1 1 2 3 Obj Notes 3 3 Recall of quantitative data is not expected. 2 2 3 Risk factors include having parents who have experienced heart attacks (genetics), age, being male, smoking, obesity, eating too much saturated fat and cholesterol, and lack of exercise. Option H: Further human physiology H6 Gas exchange H.6.1 Define partial pressure. Explain the oxygen dissociation curves of adult hemogblobin, fetal H.6.2 hemoglobin and myoglobin. Describe how carbon dioxide is carried by the blood, including the H.6.3 action of carbonic anhydrase, the chloride shift and buffering by plasma proteins. Explain the role of the Bohr shift in the supply of oxygen to respiring H.6.4 tissues. H.6.5 Explain how and why ventilation rate varies with exercise. Outline the possible causes of asthma and its effects on the gas exchange system. Explain the problem of gas exchange at high altitudes and the way H.6.7 the body acclimatizes. H.6.6 Obj Notes 1 3 2 3 3 2 3 Limit this to the effects of changes in carbon dioxide concentration leading to a lowering of blood pH. This is detected by chemosensors in the aorta and carotid arteries that send impulses to the breathing center of the brain. Nerve impulses are then sent to the diaphragm and the intercostal muscles to increase contraction or relaxation rates.