Chapter 13 A and P

The reflex that limits muscle tension is the __________ reflex.

Tendon reflex

A reflex arc always includes a(n) __________.

afferent axon efferent axon sensory receptor

Which processes are always part of a reflex arc? efferent action potential afferent action potential receptor activation

all of them

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

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 fibular nerve sciatic nerve tibial nerve

obturator nerve

Which of these cervical plexus nerves innervates the diaphragm? lesser occipital nerve great auricular nerve phrenic nerve transverse cervical nerve

phrenic nerve

The brachial plexus gives rise to all of the following nerves, except the ulnar. phrenic. median. radial. musculocutaneous.

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 subdural space lies between

the dura mater and the arachnoid mater.

What is the efferent motor root of a nerve?

the ventral root

In meningitis,

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

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

Which of the following is true regarding an epidural block?

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

In which of the following would the delay between stimulus and response be greater? a polysynaptic reflex a monosynaptic reflex

a polysynaptic reflex

All of the following are true of polysynaptic reflexes, except that they are arranged according to dermatomes. are intersegmental in distribution. have reverberating circuits that prolong the reflexive motor response. involve pools of interneurons. involve reciprocal innervation.

are arranged according to dermatomes.

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