Human physiology worksheet with answers

Which part of the brain regulates body temperature, hunger and thirst?

1. ACerebellum
2. BMedulla oblongata
3. COccipital lobe
4. DHypothalamus

Exchange of gases and nutrients between blood and tissues happens mainly across the walls of:

1. AArterioles
2. BArteries
3. CVeins
4. DCapillaries

Most homeostatic control systems in the body work by:

1. APositive feedback
2. BNegative feedback
3. CRandom variation
4. DFeed-forward only

How does glucagon raise blood glucose?

1. AIt stimulates glycogen breakdown and gluconeogenesis in the liver
2. BIt blocks insulin receptors on fat cells
3. CIt slows glucose absorption from the gut
4. DIt stimulates glucose uptake by muscle

What causes the first heart sound (S1)?

1. AClosure of the aortic and pulmonary valves
2. BClosure of the mitral and tricuspid valves
3. CBlood filling the atria
4. DOpening of the aortic valve

Which ion enters the cell to cause the depolarisation phase of a typical neuronal action potential?

1. APotassium (K⁺)
2. BChloride (Cl⁻)
3. CCalcium (Ca²⁺)
4. DSodium (Na⁺)

According to the length–tension relationship, why does a skeletal muscle fibre produce less force when overstretched?

1. AThe neuromuscular junction stops working
2. BCalcium is no longer released from the sarcoplasmic reticulum when stretched
3. CThe muscle runs out of ATP when stretched
4. DActin and myosin overlap less, so fewer cross-bridges form

Which mechanism mainly creates the concentration gradient in the medulla of the kidney?

1. AThe countercurrent multiplier of the loop of Henle
2. BSecretion of urea into the proximal tubule
3. CADH acting on the descending limb
4. DGlomerular filtration