Nervous System

Question 1

Central Nervous System (CNS)

Answer 1

brain and spinal cord

Question 2

Peripheral Nervous System (PNS)

Answer 2

Everything that isn’t brain and spinal cord

Question 3

Describe function of Spinal Cord

Answer 3

• Localized control - reflex activity (does not get back to brain)
• conduction of impulses to & from higher levels

Question 4

Neuron

Answer 4

basic functional unit of the nervous system

Question 5

Nerve

Answer 5

collection of axons located in PNS; will also contain supporting cells (Schwan cells) and CT (endoneurium, perineurium, and epineurium)

Question 6

Tract

Answer 6

collection of neuronal cell processes traveling within the CNS

Question 7

Ganglion

Answer 7

collection of neuron cell bodies outside of the CNS

Question 8

Nucleus

Answer 8

collection of neuron cell bodies within the CNS

Question 9

“Afferent”

Answer 9

• toward CNS

- sensory

Question 10

“Efferent’

Answer 10

• away from CNS

- motor

Question 11

Primary Afferent Neurons

Answer 11

• conduct sensory impulses from periphery into CNS
• pseudounipolar neurons
• come into the dorsal root and then the dorsal gray horn

Question 12

Final Efferent Neurons

Answer 12

• conduct motor impulses from CNS to effector organ
• aka Lower Motor Neuron (LMN)
• take signal from ventral gray horn out the ventral root

Question 13

Monosynaptic Patellar Reflex

Answer 13

• simplest kind of reflex

- involves a primary afferent neuron and a lower motor neuron

Question 14

Interneurons

Answer 14

• relatively short neurons interposed between afferent and efferent neurons
• located entirely within CNS
• May be excitatory or inhibitory

Question 15

Withdrawal Reflex

Answer 15

• local action

- nothing to do with pain (pain comes later)

Question 16

Projection Neurons

Answer 16

• Located in CNS
• send axons longer distances than interneurons
• can be an ascending tract to the brain
• can come from the brain down as an Upper Motor Neuron (UMN)

Question 17

ipsilateral

Answer 17

occurring on the same side of the body

Question 18

contralateral

Answer 18

occurring on the opposite side of the body

Question 19

somatic

Answer 19

main body mass

Question 20

visceral

Answer 20

organs and blood vessels

Question 21

General Somatic Efferent (GSE)

Answer 21

• multipolar neurons that supply most of the skeletal muscles of the body
• single neuron extends all the way from CNS to muscle fibers involved

Question 22

General Visceral Efferent (GVE)

Answer 22

• multipolar neurons that supply smooth muscle, cardiac muscle, and glands
• form autonomic nervous system (ANS)
• consist of a 2-neuron chain between CNS and effector organ

Question 23

General Somatic Afferent (GSA)

Answer 23

• pseudounipolar neurons that carry sensory info from somatic body systems (skin, musculoskeletal system, etc)
• cell bodies are located in sensory ganglia

Question 24

General Visceral Afferent (GVA)

Answer 24

• pseudounipolar neurons carry sensory info from visceral body systems
• cell bodies located in sensory ganglia

Question 25

Special Somatic Afferent (SSA)

Answer 25

Bipolar neurons that carry visual and auditory info

Question 26

Special Visceral Afferent (SVA)

Answer 26

Bipolar and pseudounipolar neurons that carry taste and smell sensations

Question 27

The epaxial region (area above transverse processes) has what type of spinal nerve branches?

Answer 27

dorsal branches

Question 28

The hypaxial region (area below transverse processes) has what type of spinal nerve branches?

Answer 28

ventral branches

Question 29

How many pairs of cervical spinal nerves are there?

Answer 29

8 pairs

Question 30

How many pairs of thoracic spinal nerves are there?

Answer 30

13 pairs

Question 31

How many pairs of lumbar spinal nerves are there?

Answer 31

7 pairs

Question 32

How many pairs of sacral spinal nerves are there?

Answer 32

3 pairs

Question 33

Describe a withdrawl reflex

Answer 33

1. receptor gets signal 2. primary afferent neuron picks up signal and takes to dorsal horn 3. from dorsal horn, excitatory and inhibitory interneurons send signal to flexor and extensor muscles, respectively 4. Flexors flex and Extensors extend and the paw is withdrawn

Question 34

Basic make up of ALL spinal nerves

Answer 34

Dorsal root (sensory, afferent) and ventral root (motor, efferent) join to form spinal nerve which divides into dorsal branch (motor and sensory), ventral branch (motor and sensory), and communcating branch (ramus communicans)