Human physiology worksheet with answers

Which hormone, released by the pineal gland in darkness, helps regulate the sleep–wake cycle?

1. AAdrenaline
2. BOxytocin
3. CCortisol
4. DMelatonin

What is the typical resting membrane potential of a neuron?

1. AAbout −70 mV
2. BAbout +70 mV
3. CAbout 0 mV
4. DAbout −10 mV

Which neurotransmitter is released at the neuromuscular junction of skeletal muscle?

1. ANoradrenaline
2. BDopamine
3. CAcetylcholine
4. DSerotonin

Why is the oxygen–haemoglobin dissociation curve S-shaped?

1. AHaemoglobin can bind only one oxygen molecule
2. BRed cells change size as they take up oxygen
3. CBinding of one oxygen makes the next bind more easily
4. DOxygen dissolves better in plasma at high partial pressure

Which ABO blood group has both anti-A and anti-B antibodies in the plasma?

1. AGroup A
2. BGroup AB
3. CGroup B
4. DGroup O

Besides lowering glucose, insulin moves which ion into cells, an effect used to treat hyperkalaemia?

1. ASodium
2. BChloride
3. CCalcium
4. DPotassium

Which transporter in the thick ascending limb of the loop of Henle is key to building the medullary concentration gradient?

1. AAquaporin-2 water channels
2. BThe Na⁺–K⁺–2Cl⁻ cotransporter (NKCC2)
3. CThe epithelial sodium channel (ENaC)
4. DThe sodium–glucose cotransporter (SGLT2)

A healthy person stands up quickly after lying down. Which reflex response prevents fainting?

1. AThe baroreceptor reflex raises heart rate and vasoconstriction
2. BADH release immediately doubles blood volume
3. CThe Bainbridge reflex lowers heart rate
4. DThe chemoreceptor reflex raises breathing rate and arterial oxygen levels