exam 3: chapter 13 spinal cord and nerves

__ is a collection of somas together in one place

ganglia

__ are bundles of axons

nerves

ganglia and nerves are only in the __

PNS

a __ is a collection on somas with a common function

center

a ___ is a center with a visible boundary

nucleus

the __ __ is grey matter that covers the brain

neural cortex

__ are bundles of axons with common origins, destinations and functions

tracts

__ are large tracts in the spinal cord

columns

__ are centers and tracts that link the brain with the body

pathways

the spinal cord is inside the __ __

vertebral canal

the spinal cord is surrounded by CT called spinal ___

meninges

spinal roots exit the vertebral canal through the ___ ___

intervertebral foramen

dorsal and central roots combine to form the __ __

spinal nerve

there are __ pairs of spinal nerves

31

how many cervical nerves?

8

how many thoracic nerves ?

12

how many lumbar nerves?

5

how many sacral nerves?

5

how many coccyx nerves?

1

the stretched spina roofed after L2 are called __ __

spina equina

a lumbar puncture at L3 and 4 is called a __ __

spinal tap

the intervertebral foramen is maintained by ___ __ between vertebrae

intervertebral discs

a __ __ occurs when the nucleus pulposus ruptures through the anulus fibrosis and compresses nerves

herniated disc

a __ __ occurs when the intervertebral disc is distorted or displaced causing pressure

slipped disc

cervical and lumbar enlargements of cord house cell bodies of __ __ for muscles of appendages

motor neurons

a __ is a region of skin surface that is innervated by one pair of spinal nerves

dermatome

axons from multiple nerves intermingle in a __ __

nerve plexus

__ is a loss of motor function

paralysis

__ is sensory dysfunction (loss of both motor and sensory below injury)

paresthesia

__ is a sever between T1 and L4 that causes loss of lower limb function

paraplegia

__ is when a sever in the cervical region results in loss of all limb function

quadriplegia

there are 10 million __ neurons

sensory

there are 500 thousand __ neurons

motor

there are 20 billion __

interneurons

interneurons are organized into __ __

neuronal pools

sensory groups have limited __ sources

input

motor groups have limited __ locations

output

spread of info is organized into __ __

neural circuits

__ = one neuron that pools to many

divergence

__ __ = divergence and serial processing (multiple at once)

parallel processing

__ __ = one neuron to next (linear transmission)

serial processing

__ = many neurons that pool to one

convergence

__ = positive feedback loop (continues signal until inhibited by another neuron)

reverberation

__ reflex = sensory perception in, motor response out

simple

__ __ = single reflex, negative feedback ( opposes stimulus as form of defense, fast)

reflex arc

a __ reflex is a monosynaptic stretch carried on A fibers. (sudden stretch of ligament activates muscle spindles and signals quadriceps group to contract)

patellar

a __ __ is a specialized muscle fiber

muscle spindle

__ __ prevent overstretching of muscles and tendons and maintain upright position

muscle spindles

a __ reflex is a flex to withdraw

flexor

__ __ inhibits extensors

reciprocal inhibition

__ __ reflex maintains balance

crossed extensor