Question

multiple choice. choose the one alternative that best completes the statement or answers the question.

1. the area of skin that sensory nerve fibers of a particular spinal nerve innervate is called a

a) funiculus.
b) dermatome.
c) commissure.
d) homunculus.

1. the cell bodies of primary sensory neurons are located within the

a) postcentral gyrus of cerebral cortex.
b) lateral horns of gray matter.
c) thalamus.
d) posterior root ganglia of spinal nerves.

1. cn innervates the superior and medial rectus muscles of the eye and also contributes to the parasympathetic response of the body.

a) ii
b) vi
c) iv
d) iii

1. the primary motor area of the brain is in the

a) lateral part of the occipital lobe.
b) postcentral gyrus of the parietal lobe.
c) precentral gyrus of the frontal lobe.
d) posterior sulcus of the temporal lobe.
5)
referring to the pictured sensory pathway, what may be perceived?
a) stepping on a sharp piece of glass
b) the water temperature when washing dishes
c) a mosquito biting your calf
d) sitting on a tack

1. which of the following is not a function of the hypothalamus?

a) production of hormones
b) control of hunger and thirst
c) control of postural reflexes
d) regulation of body temperature

1. a fetus possesses a mutation that causes the diencephalon region of the developing brain to cease growing. which structures in the mature brain will be missing/abnormal if the fetus survives to birth and childhood?

a) the cerebrum
b) the cerebellum
c) the thalamus, pineal gland, and hypothalamus
d) the pons, midbrain, and medulla

1. the pattern of gray matter in the spinal cord is divided into

a) horns.
b) somatotopy.
c) meninges.
d) funiculi.

1. which of the following cranial nerves would not be considered mixed (i.e. containing both motor and sensory fibers)?

a) facial
b) trigeminal
c) olfactory
d) glossopharyngeal

1. a posterior root contains

a) motor axons only.
b) a mix of sensory and motor axons.
c) autonomic nervous system axons.
d) sensory axons only.

1. extra credit:

the contraction of the triceps brachii in the triceps reflex (a stretch reflex) is an example of a
a) polysynaptic reflex.
b) crossed extensor reflex.
c) reflex which requires interneurons.
d) monosynaptic reflex.

Explanation:

1. A dermatome is the area of skin innervated by a spinal nerve.
2. The cell bodies of primary sensory neurons are in the posterior root ganglia.
3. The oculomotor nerve (CN III) innervates the superior and medial rectus muscles and contributes to parasympathetic responses.
4. The primary motor area is in the precentral gyrus of the frontal lobe.
5. The pathway likely represents a sensory pathway for temperature (washing dishes).
6. The hypothalamus does not control postural reflexes.
7. The diencephalon includes the thalamus, pineal gland, and hypothalamus.
8. Gray matter in the spinal cord is divided into horns.
9. The olfactory nerve is sensory only (not mixed).
10. A posterior root contains sensory axons only.
11. The triceps reflex is a monosynaptic reflex.

Answer:

1. B. dermatome
2. D. posterior root ganglia of spinal nerves
3. D. III
4. C. precentral gyrus of the frontal lobe
5. B. The water temperature when washing dishes
6. C. Control of postural reflexes
7. C. The thalamus, pineal gland, and hypothalamus
8. A. horns
9. C. olfactory
10. D. sensory axons only
11. D. monosynaptic reflex