Anatomy Unit 1: Introduction To The Nervous System

Front 1

Central Nervous System vs. Peripheral Nervous System

Back 1

-CNS=brain+spinal cord
-PNS: roots, spinal nerves, rami, peripheral nerves, ganglia

Front 2

Sensory vs. Motor information

Back 2

-sensory: afferent info, periphery receptors --> CNS
-motor: efferent info, CNS --> skeletal, cardiac, smooth muscle

Front 3

Somatic vs. Visceral

Back 3

-somatic=body surface or muscoloskeletal
-visceral=organs, glands, organs w/smooth or cardiac muscle

Front 4

Structure, Fxn, location of Lower Motor Neurons

Back 4

-final common pathway from CNS-->skeletal muscle
-cell bodies located in spinal cord (ventral horn)
-axons extend out to PNS and eventually signal muscles

Front 5

Structure, fxn, location of Primary Sensory Neurons

Back 5

-convey sensory info from periphery to CNS
-part of the axon is located at receptor on periphery
-cell body is in PNS
-axon continues into white matter of spinal cord (ends in dorsal horn of grey matter)

Front 6

Fxn/location of astrocytes

Back 6

-CNS
-helps maintain blood-brain barrier

Front 7

Fxn/location of oligodendrocyctes

Back 7

-CNS
-myelin forming cells

Front 8

Fxn/location of microglia

Back 8

-CNS
-scavenger cells

Front 9

Fxn/location of Schwann cells

Back 9

-PNS myelin-forming cells
-myelin surrounds membranes of most axons
-allows for increased speed in action potential propagation without increasing diameter of axon

Front 10

What layers surround the spinal cord and what are they collectively called?

Back 10

-meninges:
-pia mater
-arachnoid mater/subarachnoid space
-dura mater

Front 11

Fxns/location of the spinal cord?

Back 11

-vertebral canal
-motor innervation of neck, trunk, extremities
-process/relay sensory info from neck, trunk, extremities to brain
-integrate sensory and motor fxns of basic reflexes

Front 12

What are the two main regions of the cross section of the spinal cord?

Back 12

-grey matter (cell bodies)
-white matter (axons)

Front 13

What are the different regions of white/gray matter in a cross section of the spinal cord?

Back 13

-White matter: posterior column, anterior column, lateral column
-grey matter: dorsal horn, lateral horn, ventral horn, intermediate grey

Front 14

What does it mean that the spinal cord/spinal nerves are segmentally organized?

Back 14

-spinal cord can be divided into segments just like the vertebrae
-each segment is has its respective spinal nerves that innervate a specific section of the body
-C1-C8
-T1-T12
-L1-L5
-S1-S5
-Coccygeal nerve

Front 15

What is the relationship between spinal segments and vertebrae?

Back 15

-except in the cervical spine, the spinal segments are superior to the intevertebral foramen through which their spinal nerve passes
-b/c in early development, the spinal cord and vertebral grow at the same rate, but later the vertebral column grows faster, thus shifting the spinal cord in a relatively rostral direction
-most of the vertebral growth occurs in the thoracic/lumbar region, thus leaving the cervical spine relatively even

Front 16

What are the main components of spinal nerves and their functions?

Back 16

-dorsal root (axons of sensory neurons)
-dorsal root ganglion (cell body of sensory nerves; gathers ventral root within as well)
-ventral root (axons of lower motor neurons)
-spinal nerve (region where dorsal and ventral root neurons meet and cross)
-ventral ramus (sensory and motor neurons responsible for ventral side)
-dorsal ramus (sensory and motor neurons responsible for dorsal side)

Front 17

What is a dermatome? What dermatomes serve as reference locations?

Back 17

-an area of skin innervated by the branches of a single spinal nerve
-T4=nipple line
-T10=umbilicus

Front 18

What is a sensory cutaneous field?

Back 18

-area of skin supplied by a specific cutaneous nerve
-crosses dermatomes

Front 19

What is a myotome?

Back 19

-all the muscles innervated by a single spinal nerve

Front 20

Why does herpres zoster have a dermatomal distribution?

Back 20

-varicella virus (chicken pox) inserts DNA into neurons and remains dormant for a period of time
-later in life, often in times of stress, virus becomes reactivated and infects a spefic nerve and introducing lesions across the entire dermatome

Front 21

Somatic motor system vs. Visceral motor System

Back 21

-somatic motor=skeletal muscles
-autonomic (visceral) motor=smooth or cardiac muscle

Front 22

Somatic sensory system vs. Visceral sensory system

Back 22

-somatic sensations=well localized
-visceral sensations=poorly localized

Front 23

What/where is the pia mater?

Back 23

-meningeal layer
-thin layer stuck directly to spinal cord

Front 24

What/where is the arachnoid mater/subarachnoid space and what does it contain?

Back 24

-arachnoid mater=meningeal layer stuck to the dura mater
-subarachnoid space is maintained by tribechulae and is filled with cerebrospinal fluid

Front 25

What/where is the dura mater?

Back 25

-outermost layer of the meninges
-toughest layer; attached to arachnoid mater

Front 26

What/where is the epidural space?

Back 26

-between the dura mater and the vertebra
-contains fat & veins

Front 27

What are the main components of peripheral nerves and their functions?

Back 27

-epineurium: surrounds the fascicles of a nerve; continuous with the dura mater
-perineurium: surrounds the axons of a fascicle; continuous with the arachnoid mater
-fascicles: groups of budled myelinated and unmyelinated axons
-fxn of the connective tissues is to provide tinsel strength to axons that are thin and would otherwise tear easily

Front 28

Where does the spinal cord end on the vertebral column, what is this point and inferior section of nerves called?

Back 28

-L1/L2
-caudus midularis
-cauda equinus