UNC BIOL 252 Lab Exam 1

vertebral foramen

canal through which spinal cord passes

vertebral canal

formed by vertebral column and contains spinal cord and the beginnings of spinal nerves

cervical enlargement

supplies nerves to the shoulder and upper limbs

lumbar enlargement

nerves to pelvic region and lower limbs

spinal nerves

31 pairs of nerves arising from the spinal cord

conus medularis

The cone-shaped termination of the spinal cord

cauda equina

collection of lumbar sacral, and coccygeal spinal nerves below the end of the spinal cord

filum terminale

extension of pia mater that anchors the spinal cord to the coccyx

C1-C8 nerves are named according to vertebrae (inferior or superior) to the nerve

inferior

For all spinal nerves outside of C1-C8, they are named according to the the (superior or inferior) vertebrae

superior

The end of the spinal cord only extends to which vertebra?

L1

dermatome

Area of skin supplied by a single pair of spinal nerves

Meninges

cover and protect the brain and spinal cord

dura mater

thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord

epidural space

fat-filled space surrounding the dura mater that is the common site of injection for anesthetic

arachnoid mater

middle layer of the meninges

subarachnoid space

a space in the meninges beneath the arachnoid membrane and above the pia mater that contains the cerebrospinal fluid

pia mater

Innermost layer of the meninges

denticulate ligaments

20 pairs of lateral projections that anchor the spinal cord to the dura mater and limit the movement of the spinal cord

filum terminale

the continuation of the pia mater past the conus medularis that anchors the end of the spinal cord to the sacrum

central canal

the canal of the spinal cord that runs through the center and connects the ventricles of the brain; filled with cerebrospinal fluid

white matter

outer region of the spinal cord that contains myelinated axons

gray matter

the cell bodies of neurons and their synapses with other neurons

somatic neurons have terminals in the:

skin, skeletal muscles, or bones

visceral neurons have terminals in:

smooth muscles, cardiac muscles, glands, or other viscera within body cavities

the two categories of peripheral nervous system neurons

motor or sensory

motor neurons bring signals from ________ to the __________

spinal cord; muscles and glands of the body

sensory neurons bring information into the ___________ from the ________

spinal cord; skin and other organs

dorsal horn

the cell bodies here are interneurons that receive connections from sensory neurons

the dorsal-most region of the dorsal horn receives ____________________ neurons from the _________________

somatic sensory; skin, skeletal muscles, and bones

the region of the dorsal horn closest to the center of the spinal cord contains interneurons that receive connections from _______________________ neurons from __________________

visceral sensory; organs within body cavities

lateral horn

contains cell bodies for visceral motor neurons

the visceral motor neurons within the lateral horn send signals to ___________________

smooth muscle, cardiac muscle, and glands

ventral horn

contains cell bodies for somatic motor neurons

somatic motor neurons send signals to:

skeletal muscle

descending pathways

the systems of neurons that bring information from the brain down to the appropriate muscle or gland of the body

corticospinal tract

information travels from the cortex to the spinal cord via two neurons

the upper motor neuron of the corticospinal tract travels within the __________ and is an _________________ of the CNS

corticospinal tract; interneuron

the lower motor neuron of the corticospinal tract travels with the ____________ and eventually reaches its _________________

spinal nerve; skeletal muscle target

ascending pathways

The systems of neurons that bring information up to the brain. Signals travel along three neurons. An example is the spinothalamic tract.

1st order neuron

the sensory neuron extends from the source of the stimulus to the dorsal horn where it synapses with a 2nd order neuron

2nd order neuron

this interneuron crosses to the other side of the spinal cord and then its axon enters the white matter. from the white matter, the axon occupies the spinothalamic tract until reaching its snaps (sensory nerve action potential) in the thalamus

3rd order neuron

this next interneuron relays the signal from the 2nd order neuron up to the cerebral cortex, allowing conscious awareness of sensation

spinal nerve

a peripheral nerve attached to the spinal cord

dorsal root

contains only sensory neurons that are entering the dorsal horn of the spinal cord

dorsal root ganglion

contains cell bodies of sensory neurons

sensory neurons are called ____________ because of the single process that stems from the cell body

unipolar

ventral root

contains only axons of motor neurons

spinal reflexes

involuntary and stereotyped reactions

polysynaptic reflex

the stimulus travels along a sensory neuron that synapses with one of several interneurons in the dorsal horn then several sets of motor neurons are stimulated to exact a motor response

monosynaptic reflex

sensory neuron synapses directly onto motor neuron in the ventral horn

the withdrawal reflex is an example of a _______________

polysynaptic reflex

the patellar reflex is an example of a _________________

monosynaptic reflex

rami

branches of spinal nerves

dorsal and ventral ramus

carry somatic motor and somatic sensory neurons to the skin, muscle, and bones

communicating rami

carry visceral motor and visceral sensory neurons to the smooth muscle, cardiac muscle, and glands of the body

sympathetic ganglia

contain a second cell body for the sympathetic nervous system (the first is in the lateral horn spinal segments T1-L2)

sympathetic train/trunk

runs parallel to the spinal cord and distributes innervation to the viscera

visceral sensory neurons travel from ___________ through the ___________ and into the ____________ before reaching the ____________

their visceral targets; communicating rami; dorsal root; dorsal horn

referred pain

pain that is felt in a location other than where the pain originates

The pain of a heart attack may be felt in the left shoulder; this is an example of

referred pain

intercostal nerves

supply muscles of the ribs, anterolateral thorax, and abdominal wall

plexus

combine somatic motor and sensory neurons from as many as 6 ventral rami

brachial plexus

C5-T1 spinal nerve rami supplies the upper limb

lumbosacral plexus

Formed of L2-S2 rami. Supplies the lower limb.

central pattern generators

neural mechanisms in the spinal cord that generate rhythmic patterns of motor output for locomotion

What explains why the cervical and lumbar enlargements are larger than the spinal cord between them?

A.There are more neurons in these regions that receive information from the limbs

B.The neurons between the enlargements are smaller, but approximately equal in number to those in the enlargements

C.There are more neurons in these regions that send information to the limbs

D.The spinal nerves have to narrow to pass through the intervertebral foramen

A and D

Why are the lumbar, sacral, and coccygeal spinal nerves present within the lumbar vertebral canal?

A. The spinal cord grows more slowly, but will reach the lower parts of the vertebral canal in adulthood.

B. Spinal nerves pass through the thoracic vertebral canal on their way to the appropriate intervertebral foramen in the sacrum and coccyx.

C. The spinal cord becomes the filum terminale, so there's nothing left but spinal nerves in this region.

D. The spinal cord no longer resides in the these regions but the spinal nerves still pass through on their way to the approbpriate intervertebral foramen.

D

Which of the following is NOT found anywhere within the dorsal root, ventral root, or spinal nerve?

A. Motor axons

B. Interneuron axons

C. Sensory axons

D. Sensory neuron cell bodies

B

Match the functional grouping of the peripheral nervous system with the central nervous system structure with which it begins or ends.

A. Dorsal horn

B. Lateral horn

C. Ventral horn

1. Somatic motor

2. Somatic sensory

3. Visceral motor

4. Visceral sensory

1. C

2. A

3. B

4. A

A monosynaptic reflex involves a total of _____ neurons.

2

For most of the spinal cord, a given spinal segment is located more _________ than the corresponding spinal nerve's exit from the vertebral canal.

A. posteriorly

B. superiorly

C. laterally

D. medially

E. anteriorly

F. inferiorly

B

If it is part of an ascending pathway, a neuron that has its cell body in the dorsal horn will...

A. have its axon traveling with a spinal nerve

B. synapse in the cerebral cortex

C. be a sensory neuron

D. have its axon in a white matter column

E. synapse in the thalamus

D and E

An upper motor neuron...

A. synapses in the dorsal horn

B. is an interneuron

C. is a motor neuron

D. may have its cell body in the primary motor cortex

E. may have its cell body in the thalamus

F. synapses in the ventral horn

B,D, and F

The sympathetic chain contains a group of cell bodies called the sympathetic chain ___________ . This structure contains a second cell body for the sympathetic nervous system, the first in the series being found in the _______ horn of spinal segments T1-L2. The purpose of the ___________ rami is to carry visceral motor and visceral sensory neurons to and from this sympathetic chain.

ganglia, lateral, communicating

Check all that apply: Which structures contain motor neurons?

A. Ventral root

B. Dorsal ramus

C. Ventral ramus

D. Dorsal root ganglion

E. Dorsal root

A, B, and C

The region of the spinal cord that gives off the L1 spinal nerves is located ___.

A. At the first lumbar vertebra

B. Superior to the first lumbar vertebra

C. Inferior to the first lumbar vertebra

B

Match the functional grouping with the appropriate part of the spinal cord.

A. Lateral horn

B. Dorsal horn

C. Ventral horn

1. Somatic motor neurons originate here

2. Visceral motor neurons originate here

3. Sensory neurons terminate here

1. C

2. A

3. B

A fractured vertebra damages the left ventral root of a single spinal nerve. What is the impact to the patient's left side?

A. No motor control in the region supplied by that spinal nerve.

B. No sensation in the region supplied by that spinal nerve.

C. Neither motor control nor sensation to the region supplied by that spinal nerve.

A

Match the cell bodies of neurons with their location.

A. Dorsal root ganglia

B. Ventral horn of the spinal cord

C. Sympathetic chain ganglia

D. Dorsal horn of the spinal cord

1. Sensory neuron cell bodies

2. Motor neuron cell bodies

3. Interneuron cell bodies

4. Sympathetic neuron cell bodies

1. D

2. B

3. A

4. C

The grouping of ventral rami that travel to innervate the upper limb is called the " _________________ plexus."

brachial

Four weeks following fertilization the forerunner to the brain and spinal cord is formed, the _________________

neural tube

6 major divisions of the brain

cerebrum, diencephalon, midbrain, pons, medulla oblongata, cerebellum

nuclei

the central gray matter of the brain

ventricles

fluid filled cavity of the brain

cortex

superficial region of gray matter

white matter of the brain

contains myelinated axons traveling to and from the brain's nuclio and cortex

cerebrospinal fluid

a fluid that nourishes and protects the brain; produced from blood at the choroid plexuses in the walls of the ventricles

lateral ventricles

A set of paired ventricles lying within the cerebral hemispheres.

septum pellucidum

thin membrane that separates lateral ventricles

3rd ventricle of brain

connected to the lateral ventricles by the interventricular foramen

interventricular foramen

connects lateral ventricles to third ventricle

cerebral aqueduct

a narrow tube interconnecting the third and fourth ventricles of the brain, located in the center of the mesencephalon

4th ventricle

ventricle between pons and cerebellum

central canal of spinal cord

4th ventricle narrows to become this

dural venous sinuses

large veins in the dura mater that drain blood away from the brain and scalp

arachnoid granulations

Extensions of the arachnoid mater that allow excess CSF to be absorbed by the dural sinuses

falx cerebri

located within the longitudinal hemisphere and separates the two cerebral hemispheres

superior sagittal sinus

A venous sinus located in the midline just dorsal to the corpus callosum, between the two cerebral hemispheres.

tentorium cerebelli

located within the transverse fissure that separates cerebrum from cerebellum