Blood & ANS

Question 1

With regard to the transmitters and receptors employed in the autonomic nervous system:

Answer 1

noradrenaline acts on α receptors.

α and β receptors are both adrenergic receptors.

Question 2

The autonomic nervous system has a hierarchy of levels of reflex control. Which answer CORRECTLY orders these reflex loops from low level to high level?

Answer 2

ganglion, spinal cord, brainstem, hypothalamus

Question 3

Which ONE of the following is likely to cause a significant transfusion reaction, assuming this is the first transfusion for all recipients?

Answer 3

A person who is blood group AB positive donates to a person who is blood group A positive.

A person who is A positive will have anti B antibodies in their plasma which will react with the incoming B antigens.

Question 4

Which ONE of the following statements about human lymphocytes is INCORRECT?

Answer 4

Lymphocytes are the largest of all the white blood cells in humans.

Lymphocytes are actually the smallest of all the white blood cells.

Question 5

Choose the list of terms from the autonomic nervous system that best matches the following descriptors:

has cell bodies located in a chain outside the spinal cord
has cell bodies in the central nervous system
has nicotinic acetylcholine receptors
is dominant during rest

Answer 5

sympathetic, pre-ganglionic, post-ganglionic, parasympathetic

The first refers to the sympathetic chain. The second could be sympathetic or parasympathetic so that doesn’t discriminate, but all pre-ganglionic neurons are in the CNS in the spinal cord grey matter or brain stem. Nicotinic acetylcholine receptors are used for the pre-ganglionic to post-ganglionic neurons. This means
that the receptors are on the post-synaptic side which is the post-ganglionic neuron.
The parasympathetic system is more active than the sympathetic system in times of rest or after meals.

Question 6

Which ONE of the following statements about haemostasis is CORRECT?

Answer 6

Calcium ions are required for several steps of the prothrombin activation cascade.

Calcium ions are required for several steps of the clotting pathways.

Question 7

In healthy endothelial cells, arachidonic acid is converted to ——— which ———-formation of blood clots.

Answer 7

Prostacyclin: inhibits

Question 8

Which ONE of the following triggers erythropoietin release?

Answer 8

Decreased blood oxygen levels

Question 9

Which ONE of the following statements about erythropoietin is CORRECT?

Answer 9

Erythropoietin stimulates the production of proerythroblasts from the bone marrow.

Question 10

The first step of haemostasis is:

Answer 10

Vascular spasm.

Question 11

Which ONE of the following statements about haemostasis is CORRECT?

Answer 11

The extrinsic pathway is initiated by the release of factor III from damaged tissue to complex with factor VII and V.

The extrinsic pathway is initiated by the release of factor III from damaged tissue.

Question 12

Which ONE of the following statements about the autonomic nervous system is CORRECT?

Answer 12

Areas related to autonomic function in the brainstem regulate cardiovascular and respiratory function.

Areas related to autonomic function in the brain stem integrate afferent input and send signals to control cardio-respiratory function.

Question 13

Which type of leukocyte defends against parasitic infections?

Answer 13

Eosinophils

Question 14

Which ONE of the following statements is INCORRECT? Neutrophils:

Answer 14

Generally have single large non-segmented nuclei.

Neutrophils have a multilobed nucleus.

Question 15

Which ONE of the following statements about iron metabolism in humans is INCORRECT?

Answer 15

Vitamin C can increase iron absorption by oxidising ferrous ions to ferric ions.

Vitamin C does increase iron absorption but it does
this by reducing ferric ions to ferrous ions which are more easily absorbed.

Question 16

Which ONE of the following organs does the autonomic nervous system NOT exert control over?

Answer 16

Skeletal muscle

The ANS can modify blood flow to some extent,
but it does not synapse with the skeletal muscle (like the muscles in biceps or hamstrings).

Question 17

Which ONE of the following statements about haemoglobin is INCORRECT?

Answer 17

Haemoglobin is an excellent acid-base buffer because the iron binds bicarbonate.

Haemoglobin is an excellent acid-base buffer but
the reason is because deoxygenated haemoglobin picks up excess hydrogen ions that have been generated by the reaction between carbon dioxide and water.

Question 18

The primary neurotransmitter used by both sympathetic and parasympathetic axons is:

Answer 18

acetylcholine at pre-ganglionic synapses.

The key here is that it is used by both sympathetic and parasympathetic axons. That means it has to be ACh as noradrenaline is only sympathetic. It has to be at the pre-ganglionic synapse, because the post-ganglionic synapse is with the target organ where sympathetics
need noradrenaline.

Question 19

The parasympathetic system has neurons that:

Answer 19

have short post-ganglionic axons.

The parasympathetic system tends to have its ganglia close to the end-organs.

Question 20

Pernicious anaemia is associated with which ONE of the following?

Answer 20

Insufficient Vitamin B12.

Pernicious anaemia is a result of inadequate absorption of vitamin B12 .

Question 21

The human erythrocyte:

Answer 21

develops from a committed myeloid stem cell.

The human erythrocyte does develop from a committed myeloid stem cell.

Question 22

The main site of haematopoiesis in the fetus from the second to the seventh month is the:

Answer 22

Liver