B1W1: Intro to Nervous System

Question 1

Basic Organization of Nervous System

Answer 1

CNS: brain, spinal cord (nerve cell bodies)

PNS: nerves, ganglia, nerve endings

• -afferent=somatic and visceral
• -efferent=somatic and visceral (sympathetic/parasympathetic, both autonomic)

Question 2

Ganglia

Answer 2

nerve cell bodies outside PNS

Question 3

Neurons

Answer 3

consist of cell body, dendrites, axon

Question 4

Glila

Answer 4

“glue”, non-neuronal structures for support

Question 5

Unipolar neuron

Answer 5

Cell body –> axon –> dendrite, no branching (invertebrates)

Question 6

Bipolar neuron

Answer 6

Axon –> cell body –> dendrite (retina, olfactory)

Question 7

Pseudounipolar

Answer 7

Dendrites to CNS (dorsal root ganglia), cell body branching out, dendrites to skin/muscle

Single branch goes out from cell body

Question 8

Multipolar

Answer 8

several dendrites pop directly off of cell body

normal

Question 9

Spinal cord and nerves

Answer 9

Spinal cord enlarged at cervical/lumbar for lypmhs

Cervical nerves are above their corresponding vertebrae; C8 above T1; spinal nerves then below vertebrae

C1 above atlas, before base of skull

Question 10

White matter

Answer 10

neuron processes (dendrites and axons)

found in inner brain, outer spinal cord

Question 11

Grey matter

Answer 11

neuron cell bodies

cortex, nuclei, ganglia, inner spinal cord

Question 12

Typical spinal unit

Answer 12

1. gray matter
2. white matter
3. motor anterior ventral root and sensory posterior dorsal root
4. spinal nerve (where ventral and dorsal root combine)
5. dorsal ramus and ventral ramus
6. plexuses (lumbosacral, cervical, brachial)

Question 13

White communicating rami

Answer 13

Spinal cord to sympathetic chain at T1-L2; myelinated; “exit ramp”

Sympathetic efference enters to get to sympathetic trunk

Question 14

Gray communicating rami

Answer 14

Connects sympathetic chain to spinal nerves at all levels, “entry ramp”

Question 15

Sympathetic trunk–coming and going

Answer 15

Spinal nerves enter spinal cord by exiting sympathetic trunk via dorsal and ventral rami

To get back to sympathetic trunk, use rami communicants

Question 16

Genearl model of visceral motor pathway

Answer 16

Preganglionic neuron –> ganglia –> post ganglionic neuron

cell body of postganglionic neuron is in ganglion
parasympathetic=cranial sacral outflow
sympathetic=thoracolumbar outflow

Question 17

Clinical concerns: somatic sensory

Answer 17

If spinal nerves damaged, will lose feeling in very specific places (dermatome map)

Question 18

Clinical concerns: Somatic motor

Answer 18

If damaged, paralysis

Check reflexes to know certain nerves working

Question 19

Clinical concerns: Visceral sensory

Answer 19

Referred pain; since visceral and somatic sensory info synapses in same place, body believes pain is coming from somatic sensory (i.e. heart attack, arm hurts)

Question 20

Clinical concerns: Visceral motor

Answer 20

Could lose homeostatic fn

Question 21

C6

Answer 21

controls thumb

Question 22

C8

Answer 22

controls little finger

Question 23

L1-L4

Answer 23

anterior/inner surface of lower limb

Question 24

S2, S3, S4

Answer 24

perineum

Question 25

T4

Answer 25

nipple

Question 26

T10

Answer 26

umbilicus

Question 27

Where is the spinal cord enlarged at?

Answer 27

Cervical and lumbar regions for innervating the lymphs

Question 28

For a given spinal nerve, how does it exit the vertebral canal?

Answer 28

Passing through an intervertebral foramen

Question 29

Conus medullaris

Answer 29

Caudal end of the spinal cord that ends at L1/L2 vertebral level; creates pool of CSF in lumbar region that lets us do lumbar puncture and spinal tap

Question 30

Cauda equina

Answer 30

What spinal roots of lower spinal cord form

Question 31

Three plexuses

Answer 31

networks of peripheral nerves formed by ventral primary rami cervical, brachial, lumbrosacral

Question 32

Dorsal/posterior ramus

Answer 32

innervates skin/muscles of back

Question 33

Ventral/anterior ramus

Answer 33

innervates body in wall of stomach

Question 34

Sympathetic NS organization

Answer 34

Thoracolumbar outflow | Preganglionic neuron cell bodies are located within T1-L2 levels of the spinal cord in interomediolateral cell column

Question 35

Parasympathetic NS organization

Answer 35

Craniosacral outflow | Preganglionic neuron cell bodies within the brainstem or S2-S4 levels of spinal cord in interomediolateral cell column