Chapter 13: Spinal Cord and Spinal Nerves Review

What does the reflex arc consists of?

a receptor, a sensory neuron, a center in the CNS which may or may not contain an interneuron, motor neuron, effector

a deeper groove on the anterior surface of the spinal cord

anterior median sulcus

What is an example of an ascending tract?

anterior spinothalamic tract

The upper portion is composed of simple squamous epithelial cells, and the lower portion contains a delicate network of collagen and elastic fibers.

arachnoid mater

spider mother is what layer

arachnoid mater

a narrow canal which runs the length of the spinal cord; it is located in the center of the gray commisure and contains cerebrospinal fluid from the ventricles of the brain

central canal

The _____ _______ is due to the large amount of nerves supplying the upper torso

cervical enlargement

How many spinal nerves are coccygeal?

1

How many spinal nerves are thoracic?

12

How many spinal nerves are lumbar?

5

How many spinal nerves are sacral?

5

How many spinal nerves are cervical?

8

A pin prick is picked up by the receptor and the sensory neuron sends the impulse to the spinal cord via the dorsal root. A synapse occurs with an interneuron in the gray matter of the spinal cord. The interneuorn synapses with the motor neuron and the impulse is sent out the ventral root to the effector. What is this an example of?

Flexor Reflex

Which reflex involves the use of more than two neurons?

Flexor Reflex

Where is the lumbar plexus located

anterior and lateral abdominal wall, genitals, lower extremities

sensory AXONS which conduct sensory impulses toward the brain

ascending tract

Where is the sacral plexus located?

buttock and perineum

"horse tail" spinal segments fan out from the conus medullaris and resemble the hairs of a horse

cauda equina

below the lumbar enlargement at the end of the spinal cord is an area that forms a cone shaped extremity in the area of the first and second lumbar vertebra

conus medullaris

What reflex occurs where a stimulus causes a flexion of the muscle of one limb and an extension of the muscle on the other limb.

crossed extension reflex

This extends from the pia mater through the arachnoid mater to the dura mater. These structures prevent lateral movement of the spinal cord.

denticulate ligaments

The area of the body surface which is monitored by the ventral rami and the dorsal roots. By knowing the areas the nerves go into, the most lesion can be located by testing the areas with a hair or pin

dermatome

what is an example of a descending tract?

lateral corticospinal tract

motor AXONS which conduct motor impulses from the brain to the effectors

descending tract

The cell bodies of the sensory neurons are located in swollen structures called _____ _____ ____

dorsal root ganglion

What is the tough mother that is composed of dense connective tissue more specifically collagen

dura mater

What are the three parts of meninges called?

dura mater, arachnoid mater, pia mater

fibers of the perinerium which invaginate to cover each of the fibers (axon and dendrites) of the fascicles

endoneurium

dense fibrous C.T. covering the whole nerve

epineurium

a non-nervous fibrous C.T. sheet that anchors the spinal cord to the coccyx . It is a continuation of the inner-most protective covering of the brain called pia mater.

filum terminale

a collection of cell bodies of neurons located out of the CNS

ganglion

a bridge of axons crossing from one side of the spinal cord to the other side

gray commisure

Where is the cervical plexus located?

head, neck, upper shoulders

it relays impulses up and down the spinal cord

interneuron

transfers an impulse from a sensory neuron to the motor neuron

interneuron

The spinal nerves exit the _____ _____ which are formed by the stacking of the vertebrae

intervertebral foramen

The _____ ______ is due to the large amounts of nerves supplying the lower torso

lumbar enlargement

protective membranous covering of the brain and spinal cord

meninges

Axons of ____ ___ exit the spinal cord as a ______ ___.

motor neurons, ventral root

Where is the brachial plexus located?

neck, shoulder

the invagination of the epineurium which covers bundles of axons

perineurium

A thin mesh of elastic and collagen fibers which is in close association to the brain and spinal cord.

pia mater

this is the layer that means delicate mother

pia mater

braid, a network of interwoven nerves of adjacent ventral rami

plexus

a shallow long groove on the posterior surface of the spinal cord

posterior median sulcus

Reflexes are possible due to the components of the ____ ___

reflex arc

The second function of the spinal cord is to serve as a _____ ____

reflex center

these are rapid automatic responses to a stimuli

reflexes

These neurons carry sensory information to the spinal cord via the dorsal root.

sensory neurons

this reflex involves the contraction of skeletal muscles

somatic reflex

This delivers impulses to and from the brain and peripheral nervous system

spinal cord

One of 31 pairs of nerves that originate at each of the 31 segments of the spinal cord. The spinal nerves are formed as a result of the union of the dorsal and ventral roots. Because they carry both sensory and motor fibers they are called mixed nerves.

spinal nerve

The dorsal and ventral roots join to form a ______ ____ carrying both sensory and motor fibers

spinal nerve

this reflex is carried out by the spine alone

spinal reflex

The spinal cord is divided into 31 segments. They are named by a letter designated by the area of the vertebral column as well as by chronological number

spinal segment

This reflex involves receptors in the muscles which are called muscle spindles or spindle fibers. They are a type of stretch receptor.

stretch reflex

When stimulated, a sensory neuron sends an impulse into the dorsal root. The impulse synapses with a motor neuron in gray matter of the spinal cord. The axon of the motor neuron exits the ventral root and goes to the effector causing a knee to jerk. What example is this of?

stretch reflex

This reflex monitors the tension produced during muscular contractions and prevents tearing and breaking of tendons. The receptors are called golgi tendon organs

tendon reflex

a bundle of fibers (myelinated axons and dendrites) with the central nervous system

tract

this reflex involves the contraction of smooth or cardiac muscles or secretion by glands

visceral reflex

myelinated axons of neurons

white matter