Human Anatomy and Physiology
Core concepts
Know the levels of organization: cells, tissues, organs, systems. Master the major systems: skeletal, muscular, digestive, circulatory, respiratory, excretory, nervous, endocrine, immune, and reproductive. Know blood composition and functions, the heart's chambers and circulation (pulmonary vs systemic), gas exchange, nephron function, and nerve impulse transmission and synapses. Understand hormonal regulation and homeostasis (negative feedback). Know the roles of the digestive enzymes and the sites of absorption.
Traps
Arteries carry blood away from the heart, not always oxygenated blood (pulmonary artery is deoxygenated). The left ventricle has the thickest wall. Nephrons filter, reabsorb, and secrete; urine formation is not just filtration. Nerve impulses are electrical along the axon but chemical at synapses. Negative feedback restores the set point; positive feedback amplifies. Do not confuse the roles of insulin and glucagon.
Worked example / rule of thumb
Rule of thumb: "follow the blood, follow the feedback." Worked example: blood path is right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta. If blood glucose rises, insulin is released and lowers it; if it falls, glucagon raises it. For a question on gas exchange, answer alveoli with thin walls and rich capillary supply.