Anatomy and Physiology Ch 13

The tough, fibrous, outermost covering of the spinal cord is the

dura mater

The connective tissue layer that covers Schwann cells is the __________.

endoneurium

The ________ is a strand of fibrous tissue that provides longitudinal support as a component of the coccygeal ligament.

filum terminale

A distinction about the flexor reflex is that it __________.

moves a limb away from a painful stimulus

The white matter of the spinal cord is mainly

myelinated and unmyelinated axons.

Which nerve does NOT belong to the sacral plexus?

obturator nerve

Which of these cervical plexus nerves innervates the diaphragm?

phrenic nerve

The brachial plexus gives rise to all of the following nerves, except the

phrenic.

The layer of the meninges in direct contact with the spinal cord is the

pia mater

What area of the body does the obturator nerve serve?

skin over the medial surface of the leg

The __________ is part of the CNS and the __________ is part of the PNS.

spinal cord; spinal nerve

A dorsal and ventral root of each spinal segment unite to form a

spinal nerve.

The cerebrospinal fluid (CSF) circulates within the __________.

subarachnoid space

Cerebrospinal fluid flows within the

subarachnoid space.

Samples of CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the

subarachnoid space.

The reflex that limits muscle tension is the __________ reflex.

tendon

The subdural space lies between

the dura mater and the arachnoid mater.

Which of the following is true regarding an epidural block?

-It can provide mainly sensory anesthesia, depending on the anesthetic selected. -It can provide sensory and motor anesthesia, depending on the anesthetic selected. -It is commonly used as a method of pain control during labor and delivery. -It affects only the spinal nerves in the immediate area of the injection.

A reflex arc always includes a(n) __________.

-efferent axon -sensory receptor -afferent axon

In meningitis

-inflammation of the meninges occurs. -CSF flow can be disrupted. -viruses can be the cause. -bacteria can be the cause.

All of the following are true of polysynaptic reflexes, except that they

-involve reciprocal innervation. -involve pools of interneurons. -have reverberating circuits that prolong the reflexive motor response. -are intersegmental in distribution. -*are arranged according to dermatomes.*

Which processes are always part of a reflex arc?

-receptor activation -afferent action potential -efferent action potential

The spinal cord consists of __________ segments, each associated with two pairs of nerve roots.

31

The spinal cord stops elongating at about __________ years of age.

4

In which of the following would the delay between stimulus and response be greater?

a polysynaptic reflex

Spinal nerves are

both sensory and motor.

Which nerve plexus innervates the pectoral girdle and upper limbs?

brachial plexus

The dorsal root ganglia mainly contain

cell bodies of sensory neurons

The __________ reflex involves activating muscles contralateral to the receptor.

crossed extensor

The region of the body surface monitored by a pair of spinal nerves is known as a(n) __________.

dermatome