Option H6: Gas exchange

H.6.1 Define partial pressure

H.6.2 Explain the oxygen dissociation curves of adult haemoglobin, fetal haemoglobin and myoglobin

H.6.3 Describe how carbon dioxide is carried by the blood, including the action of carbonic anhydrase, the chloride shift and buffering by plasma proteins

H.6.4 Explain the role of the Bohr shift in the supply of oxygen to respiring tissues

H.6.5 Explain how and why ventilation rate varies with exercise

H.6.6 Outline the possible causes of asthma and its effects on the gas exchange system

H.6.7 Explain the problem of gas exchange at high altitudes and the way the body acclimatizes

Option H5: The transport system

H.5.1 Explain the events of the cardiac cycle, including atrial and ventricular systole and diastole and heart sounds

H.5.2 Analyse data showing pressure and volume changes in the left atrium, left ventricle and the aorta, during cardiac cycle.

H.5.3 Outline the mechanisms that control the heartbeat, including the roles of the SA (sinoatrial) node, AV (atrioventricular) node and conducting fibres in the ventricular walls

H.5.4 Outline atherosclerosis and the causes of cononary thrombosis

H.5.5 Discuss factors that affect the incidence of cononary heart disease

Option H4: Functions of the liver

H.4.1 Outline the circulation of the blood through liver tissue, including the hepatic artery, hepatic portal vein, sinusoids and hepatic vein

H.4.2 Explain the role of the liver in regulating levels of nutrients in the blood

H.4.3 Outline the role of the liver in the storage of nutrients, including carbohydrates, iron, vitamin A and vitamin D

H.4.4 State that the liver synthesizes plasma protein and cholesterol

H.4.5 State that the liver has a role in detoxification

H.4.6 Describe the process of erythrocyte and haemoglobin breakdown in the liver, including phagocytosis, digestion of globin and bile pigment formation

H.4.7 Explain the liver damage caused by excessive alcohol consumption

Option H3: Absorption of digested foods

H.3.1 Draw and label a diagram showing a transverse section of the ileum as seen under a light microscope

H.3.2 Explain the structural features of a epithelial cell of a villus as seen in electron micrographs, including microvilli, mitochondria, pinocytotic vesicles and tight junction

H.3.3 Explain the mechanism used by the ileum to absorb and transport food, including facilitated diffusion, active transport and endocytosis

H.3.4 List the materials that are not absorbed and are egested

Option H2: Digestion

H.2.1 State that digestive juices are secreted into the alimentary canal by glands, including salivary glands, gastric glands in the stomach wall, the pancreas and the wall of the small intestine

H.2.2 Explain the structural features of exocrine gland cells

H.2.3 Compare the composition of saliva, gastric juice and pancreatic juice

H.2.4 Outline the control of digestive juice secretion by nerves and 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

H.2.6 Outline the reason for cellulose not being digested in the alimentary canal

H.2.7 Explain why pepsin and trypsin are initially synthesized as inactive precursors and how they are subsequently activated

H.2.8 Discuss the roles of gastric acid and Helicobacter pylori in the development of stomach uclers and stomach cancers

H.2.9 Explain the problem of lipid digestion in a hydrophilic medium and the role of bile in overcoming this

Option H1: Hormonal control

H.1.1 State that hormones are chemical messengers secreted endocrine glands into the blood and transported to specific target cells

H.1.2 State that hormones can be steroids, proteins and tyrosine derivatives, with one example of each

H.1.3 Distinguish between the mode of action of steroid hormones and protein hormones

H.1.4 Outline the relationship between the hypothalamus and the pituitary gland

H.1.5 Explain the control of ADH (vasopressin) secretion by negative feedback