Nervous System Organization and Spinal Cord

Question 1

What is a dendrite?

Answer 1

Highly branched processes that typically function as the “receiving end” for information coming to the neuronal cell body

Question 2

What is an axon hillock?

Answer 2

point of axon origin from the cell body

Question 3

What is an axon terminal?

Answer 3

where the neuron communicates with other cells

Question 4

What is an axon?

Answer 4

A single process arising from the

neuronal cell body that carries information away from the cell body toward other cells

Question 5

What is a neuronal cell body? (soma)

Answer 5

Neuronal cytoplasm contains organelle
that provide energy and synthesize chemical signaling molecules (neurotransmitters) that are critical in cell-to-cell communication.

Question 6

Define synapse

Answer 6

the specialized site of the axon where the neuron communicates with another cell

Question 7

What do synaptic vesicles do?

Answer 7

filled with chemical neurotransmitters that are released upon stimulation

Question 8

What is a synaptic cleft?

Answer 8

narrow gap between pre- and post- synaptic cells into which neurotransmitters are released

Question 9

What are bipolar neurons?

Answer 9

have two distinct processes – one dendrite and one axon. They are found in special sense organs where they relay information about sight, smell or hearing.

Question 10

What are unipolar neurons?

Answer 10

have a dendrite and axon that are basically continuous. This is the typical shape of sensory neurons of the peripheral nervous system.

Question 11

What are multipolar neurons?

Answer 11

have two or more dendrites and an axon. They are the most common type of neuron. This is the typical shape of a motor neuron controlling skeletal muscles.

Question 12

What are the 5 functions of astrocytes?

Answer 12

• help to create and maintain the blood-brain barrier that isolates the CNS from substances circulating in blood
• Provide structural support
• Regulate ion, nutrient and
dissolved gas concentrations in
fluid surrounding neurons
• Take up and recycle
neurotransmitters
• Form scar tissue after neural
injury

Question 13

What are the 6 functions of microglia?

Answer 13

• Migratory cells that continuously move through neural tissue
• Scavenge and remove cellular debris, wastes and pathogens by phagocytosis
• Help to remodel synapses
• Fight microbes and cancer
• Repair trauma
• Respond to autoimmune
diseases

Question 14

What are the 2 functions of oligodendrocytes?

Answer 14

• Provide a structural framework in the CNS by stabilizing the positions of axons
• Produce myelin, a membranous wrapping around CNS axons that functions like insulation on a wire, increasing the speed of nerve impulse transmission

Question 15

What is the function of a Schwann cell?

Answer 15

Produce myelin, a membranous wrapping around PNS axons that functions like insulation on a wire, increasing the speed of nerve impulse transmission
Participate in repair of damaged nerves in the peripheral nervous system

Question 16

Where does the spinal cord end?

Answer 16

Between the L1 and L2 vertebrae

Question 17

What is the cauda equina?

Answer 17

the spinal nerve roots that extend inferiorly beyond the tapered end of the spinal cord resemble a horse’s tail and are called the cauda equina.

Question 18

How many vertebrae are there?

Answer 18

33

Question 19

How many pairs of spinal nerves are there?

Answer 19

31

Question 20

The C1 spinal nerve exits ________ the C1 vertebra pedicle and is somatic motor only.

Answer 20

ABOVE

Question 21

The C8 spinal nerve exits _________ the C7 vertebra pedicle

Answer 21

BELOW

Question 22

At all levels below, spinal nerves exit _______ the corresponding vertebral pedicle.

Answer 22

Below

Question 23

What does the cervical enlargement innervate?

Answer 23

shoulder and upper extremity

Question 24

What does the lumbar enlargement innervate?

Answer 24

pelvis and lower extremity

Question 25

What is the conus medullaris

Answer 25

tapered end of spinal cord

Question 26

What is cauda equina

Answer 26

Nerve roots extending beyond the tapered end of the spinal cord; bundle of nerve roots looks like a “horse’s tail”

Question 27

What is filum terminale

Answer 27

Slender fibrous strand that extends to the coccyx providing longitudinal support to the spinal cord

Question 28

What are the spinal meninges?

Answer 28

3 layers of membranes that surround the spinal cord and provide physical stability and shock absorption. They are continuous with the cranial meninges that surround the brain.

Question 29

What are the functions of cerebrospinal fluid?

Answer 29

this fluid functions as a shock absorber and a diffusion medium for dissolved gases, nutrients, chemical messengers and wastes

Question 30

In a lumbar puncture where is the needle inserted?

Answer 30

Between the 3rd and 4th lumbar vertebrae

Question 31

What is gray matter

Answer 31

Contains the cell bodies of neurons and neuroglial cells

Question 32

What is white matter

Answer 32

contains myelinated axons that are running in bundles carrying either information that is ascending toward the brain or descending from the brain.

Question 33

What do dorsal roots do

Answer 33

carry sensory information into the CNS.

Question 34

What do ventral roots do

Answer 34

carry motor information out of the CNS.

Question 35

What do spinal nerves do

Answer 35

carry both sensory and motor information.

Question 36

What is the directions of sensory information

Answer 36

IN over dorsal root; coming from sensory receptors

Question 37

What is the directions of motor information

Answer 37

OUT over ventral root; going to skeletal muscles

Question 38

Where are sensory neuron cell bodies located?

Answer 38

Dorsal root ganglion