Week 3: Central Nervous System

The dorsal root of spinal nerve contains:

Only sensory fibers

An image of the cross-section of a spinal cord would show anterior (or ventral) horns. What is in that region?

Cell bodies of motor neurons

Voluntary motor impulses leave the spinal cord via the ________ of gray matter.

Anterior horn

A disease that damages the cells of the anterior gray horn will...

Cause paralysis or weakness in the skeletal muscles.

What do neurons in the precentral gyrus do?

They allow conscious control of skilled voluntary muscle movements.

True or False: Spinal nerves are mixed nerves.

True

In relation to the spinal cord, where is the epidural space?

External to the dura mater.

While playing rugby, Sonny is tackled hard. As he tries to get up, he finds that he has difficulty flexing and adducting his left thigh and extending his left leg. Which nerve innervating the lower limb may be damaged?

Femoral Nerve

Which of the following is not a function associated with the spinal cord?

Integrate sensory information at the conscious level

What is true about the spinothalamic tract?

It is an ascending pathway that carries sensory information.

An unlearned and involuntary but predictable motor response to a stimulus that is rapid and does not involve any processing by the brain:

Learned reflex

Which of the following is not considered a region of the spinal cord?

Pelvic

Why type of nerves is found in the dorsal root?

Only afferent nerves

Which of the following is incorrect?

11 thoracic spinal nerves (There are 12 thoracic spinal nerves)

Select the true statement regarding nerve connective tissue layers: (a) Epineurium forms the outer covering of the nerve (b) Perineurium adheres directly to nerve axons (c) Endoneurium surrounds bundles of axons known as fascicles (d) All of the above are true

A

A reflex that causes reciprocal activation of the antagonist muscle is the:

Crossed-extensor

What are the ascending tracts and what do they do?

White matter that transmits sensory information to the brain.

Which spinal cord plexus supplies the abdominal wall? (a) More than one of the choices are correct (b) cervical plexus (c) lumbar plexus (d) brachial plexus (e) sacral plexus

(e) More than one of the choices are correct.

The specific patch of skin that is innervated by a specific spinal nerve is called a(n)_______.

Dermatome

True or False: Damage to the posterior root of the third thoracic spinal nerve would result in loss of motor function to the intercostal muscles controlled by that nerve.

False

Which of the groups of spinal nerves listed below do NOT form a plexus?

T2-T11

Which of the following conveys sensory information to the brain and spinal cord?

The afferent division of the PNS

What is linked to the posterior gray horn of the spinal cord?

The dorsal root of the spinal nerve that carries sensory fibers.