Test 10 ( physiology)

1. The light reflex involves the following structures:

a. Edinger-Westphal nucleus

b. ciliary ganglion

c. lateral geniculate body

d. oculomotor nerve

e. occipital cortex

answera. T   b.T   c.F   d.T   e.F
When a light is shone in one eye, the afferent impulse travel through the optic nerve, optic chiasm and optic tract. Before reaching the lateral geniculate body, the impulse travels through small fibres which leave the tract and pass to the pretectal nucleus, which send fibres to synapse in the Edinger-Wetphal nuclei on the ipsilateral and contralateral sides. From here, impulse travel via parasympathetic fibres in the oculomotor nerve to the ciliary ganglion in the orbit. Postganglionic parasympathetic fibres then pass to the constrictor pupillae via the short ciliary nerves, causing pupillary constriction.

2. The following are true about the autonomic nervous system:

a. the postganglionic neurones are largely unmyelinated

b. all preganglionic neurones are cholinergic

c. the preganglionic neurones of the sympathetic nervous system are 
    shorter than the parasympathetic nervous system

d. the parasympathetic outflow is only found in the cranial nerves

e. the sympathetic preganglionic neurones leave the spinal cord via 
    the dorsal roots of spinal nerves T1-L3

answera.T   b.T   c.T   d.F   e.F
Parasympathetic outflow is also found in the sacral outflow (S2-4).
The sympathetic preganglionic neurones leave the spinal cord via the ventral roots of spinal nerves T1-L3.
 

3. The effects of glucocorticoid hormones include:

a. increase hepatic glycogen synthesis

b. decrease glucose uptake by the adipose tissue

c. decrease hepatic gluconeogesis

d. increase protein synthesis in the skeletal muscles

e. decrease glucose uptake by the skeletal muscles

answera.T   b.T   c.F   d.F   e.T
Effects of glucocorticoid hormones include:
Liver: increase gluconeogenesis and glycogen synthesis
Adipose tissue: decrease glucose uptake but increase fat mobilization
Skeletal muscle: decrease protein synthesis and glucose uptake; increase protein degradation.
 

4. The secretion of insulin is stimulated by:

a. adrenaline

b. somatostatin

c. fatty acids

d. acetylcholine

e. amino acids

answera.F   b.F   c.T   d.T   e.T
Insulin secretion is stimulated by: increase blood glucose, acetylcholine, amino acids, fatty acids, glucagon and sulphonylurea.
It is inhibited by somatostatin and adrenaline.

5. Insulin:

a. is secreted as a pro-insulin

b. increases protein synthesis

c. is required for glucose uptake in all tissues

d. is a steroid hormone

e. increases the uptake of lipoprotein

answera.T   b.T   c.F   d.F   e.T
Brain and liver does not require insulin for glucose uptake.
It is a peptide hormone.

6. The followings are steroid hormones:

a. corticotrophic hormone (ACTH)

b. aldosterone

c. thyroxine

d. growth hormone

e. thyroid-stimulating hormones (TSH)

answera.F   b.T   c.F   d.F   e.F
Steroid hormones include: oestrogen, progesterone, testosterone and aldosterone. 

7. The following have a lower concentration in the cerebrospinal fluid (CSF) than 
     plasma:

a. glucose

b. sodium

c. potassium

d. magnesium

e. bicarbonate

answera.F   b.F   c.F   d.T    e.T
The concentration of glucose, sodium, potassium and calcium are all lower in the CSF than in the plasma.
The concentration of bicarbonate, chloride, hydrogen ions (and therefore lower pH) and magnesium are all higher in the CSF than in the plasma

8. The cerebrospinal fluid:

a. has a normal volume of 150 ml

b. has a normal opening pressure of 7 - 18 cm H₂O

c. flows from the ventricles to the subarachnoid space via the 
    foramen of Monro

d. does not contain neutrophils in normal individuals

e. has a lower concentration of immunoglobulilns than the plasma

answera.T   b.T   c.F   d.T   e.T
The connection between the ventricles and the subarachnoid space is through the foramina Lushka and Magendie.

9. The following sensations are conveyed in the dorsal column of the spinal cord:

a. pain

b. temperature

c. vibration

d. proprioception

e. joint position
 

answera.F   b.F   c.T   d.T   e.T
Pain and temperature are conveyed in the lateral spinothalamic pathway.

10. In the neurones:

a. the axons convey impulse away from the cell body

b. neurotransmitters are synthesized in the cell bodies and then 
    transported to the axons

c. the condition velocity increases with fibre diameter

d. the excitability is increased if the extracellular calcium 
    concentration is decreased

e. there is an influx of Na+ and efflux of K+ during depolarization.

answera.T   b.F   c.T   d.T   e.T
Neurotransmitters are synthesized locally in the axon terminal.
 
 

More MCQs