Anatomy and Physiology: Structure, Function, and Homeostasis
What this domain tests
This section checks whether you can link body structure to function and use correct anatomical terms. Expect questions on tissue types, organ systems, direction terms, and homeostasis.
Core rules and concepts
- Anatomy is structure; physiology is function. A question asking "where" is anatomy; "how" is physiology.
- Anatomical position: standing, face forward, arms at sides, palms forward. Use it for all direction terms.
- Direction pairs: superior/inferior, anterior/posterior, medial/lateral, proximal/distal, superficial/deep.
- The diaphragm separates thoracic and abdominal cavities. The mediastinum holds the heart, trachea, and oesophagus.
- Right lung has three lobes; left lung has two and a cardiac notch. The left ventricle has the thickest myocardium because it pumps to the systemic circulation.
- Homeostasis uses negative feedback: a change triggers a response that reverses it. Example: rising body temperature triggers sweating and vasodilation.
Worked example
A man has stroke volume 70 mL and heart rate 75 beats/min. Cardiac output = SV × HR = 70 × 75 = 5,250 mL/min = 5.25 L/min. Reasoning: cardiac output is volume per minute, so multiply rather than add; convert millilitres to litres by dividing by 1,000. A normal adult resting cardiac output is about 5 L/min.
Traps that cost marks
- Swapping afferent (towards) and efferent (away).
- Calling the left lung three-lobed.
- Mixing up the roles of the atria (receiving) and ventricles (pumping).
- Using "above/below" instead of superior/inferior in formal answers.