Anatomy Exam 3 - Introduction To Nervous System

Front 1

Central Nervous System (CNS)

Back 1

-brain
-spinal cord
-retina

-damage to CNS cannot be repaired

Front 2

Peripheral Nervous System (PNS)

Back 2

-consists of peripheral ganglia & nerves
-carries efferent (motor) information to muscles & organs from the CNS
-carries afferent (sensory) information to CNS from sensory receptors

Front 3

Neurons

Back 3

-Post-mitotic cells (generally don't divide) --> loss of function = lost for lifetime
-Transmit information via nerve impulses
-Nucleus located in cell body
-Axon extends for long distances to targets
-Axon terminals release neurotransmitters
-Dendrites receive information from other neurons

Front 4

Perikaryon

Back 4

-Cell Body
-synthetic center of the neuron where most of protein synthesis occurs

Front 5

Dendrites

Back 5

-cellular processes radiating from cell body
-most (but not all) neurons hae dendrites
-specialized to receive synapses from other neurons

Front 6

Axon

Back 6

-typically the longest process of the neuron
-can be mm to over a meter in length

Front 7

Axon Terminals

Back 7

-specialized endings of the axon that contact target cell synapses (like muscles, glands, or other neurons)

Front 8

Types of Neuron Structures

Back 8

-Unipolar
-Bipolar
-Mulitpolar

-Bipolar & unipolar cells are typical of afferent or sensory neurons
-Efferent neurons as well as interneurons (the most numerous type of neurons) are typically multipolar in shape

Front 9

Sensory Neurons (Afferent)

Back 9

-conduct impulses to the brain/spinal cord from specialized receptors

Front 10

Motor Neurons (Efferent)

Back 10

-conduct impulses away from CNS towards target tissue

Front 11

Interneurons

Back 11

-over 99% of neurons are in this class
-conduct impulses/information between neurons

Front 12

Nucleus

Back 12

-cluster of neuron cell bodies in CNS

Front 13

Tract

Back 13

-group of axons in CNS

Front 14

Ganglion

Back 14

-cluster of neuron cell bodies in PNS

Front 15

Nerve

Back 15

-group of axons in PNS

Front 16

Grey Matter

Back 16

-cell bodies

Front 17

White Matter

Back 17

-axons
-white due to myelin sheath --> a fatty covering over axons

Front 18

Plexus

Back 18

-region where mixing of nerve fibers into new groups occur

Front 19

Main Components of Brain

Back 19

-Cerebral Cortex (4 lobes)
-Cerebellum
-Spinal Cord
-Corpus Callosum
-Brain Stem (midbrain, pons, medulla)

Front 20

Frontal Lobe

Back 20

-contains primary motor cortex, prefrontal working memory, & Broca's speech areas

Front 21

Parietal Lobes

Back 21

-contains primary somatosensory cortex

Front 22

Occipital Lobe

Back 22

-contains primary visual cortex

Front 23

Temporal Lobe

Back 23

-contains primary auditory cortex
-important for memory

Front 24

Cranial Nerves

Back 24

-12 pairs
-Originate from brain
-Lead to head, neck, & trunk
-Mostly mixed nerves
-Special senses represented
-Designated I-XII or by name

Front 25

Cranial Nerve I

Back 25

-Olfactory N.
-Sensory: Smell

Front 26

Cranial Nerve II

Back 26

-Optic N.
-Sensory: Vision

Front 27

Cranial Nerve III

Back 27

-Occulomotor N.
-Motor: Eye Movement
-Parasympathetic constriction of pupils

Front 28

Cranial Nerve IV

Back 28

-Trochlear
-Motor: Eye Muscle

Front 29

Cranial Nerve V

Back 29

-Trigemial N.
-Motor: Motor Muscles of Mastication
-Sensory: Head & Face

Front 30

Cranial Nerve VI

Back 30

-Abducens N.
-Motor: Eye Muscle

Front 31

Cranial Nerve VII

Back 31

-Facial N.
-Motor: Muscles of Face
-Parasympathetic lacrimal, salivary, & nasal glands

Front 32

Cranial Nerve VIII

Back 32

-Vestibulocochlear N.
-Balance (vestibular) head position & movement
-Hearing (cochlear)

Front 33

Cranial Nerve IX

Back 33

-Glossopharyngeal N.
-Some taste fibers & other sensory fibers lining throat
-Parasympathetic involved with blood pressure

Front 34

Cranial Nerve X

Back 34

-Vagus N.
-Motor to pharynx, larynx, & soft palate for swallowing
-Parasympathetic to gut for gastric secretion & movement (slows heart rate)
-Afferent from thoracic & abdominal viscera

Front 35

Cranial Nerve XI

Back 35

-Accessory N.
-Motor: Sternocleidomastoid & Trapezius

Front 36

Cranial Nerve XII

Back 36

-Hypoglossal N.
-Motor: Tongue Muscles

Front 37

Spinal Nerves

Back 37

-31 Pairs
-Originate from spinal cord
-Mixed Nerves / 2-way communication
-Names according to level from which they arrive
a) 8 pairs Cervical (C1-C8)
b) 12 pairs Thoracic (T1-T12)
c) 5 pairs Lumbar (L1-L5)
d) 5 pairs Sacral (S1-S5)
e) 1 pair coccygeal (Co)

Front 38

Spinal Nerves (innervation)

Back 38

-innervate somatic structures: skin & skeletal muscles of the body wall
-Spinal Nerves DO NOT ENTER BODY CAVITIES (therefore do not innervate visceral organs)

Front 39

Spinal Cord Divided into...

Back 39

-Segments

Front 40

Anterior (Ventral) Horn

Back 40

-contains cell bodies of motor neurons
-these are final output neurons & called "lower motor neurons"

Front 41

Ventral Roots

Back 41

-Course from ventral horns to spinal nerves

Front 42

Spinal Nerves (exit)

Back 42

-where ventral root & dorsal root spilt
-exit vertebral column at interverterbal foramina
-Splits into dorsal & ventral rami

Front 43

Dorsal Rami

Back 43

-splits of of spinal nerve
-innervates back (intrinsic musculature & skin)

Front 44

Ventral Rami

Back 44

-typically larger than dorsal rami
-innervate anterior side of body & extremities

Front 45

Upper Motor Neurons

Back 45

-located in CNS in motor centers such as the primary motor regions of the cerebral cortex of the Red Nucleus of the midbrain
-their axons cousr down & synapse on lower motor neurons in ventral (anterior) horn of the spinal cord or brain stem

Front 46

Lower Motor Neurons

Back 46

-Located in ventral (anterior) horn of spinal cord or brain stem
-upper motor neurons synapse on lower motor neurons

Front 47

Lower Motor Neuron Injury

Back 47

-can occur with damage to peripheral nerves (ie. knife cut or prolapse of vertebral disc)
-Signs: flaccid paralysis of muscles, hypotonicity, loss of stretch reflex

Front 48

Upper Motor Neuron Injury

Back 48

-can occur from spinal cord injury or stroke in higher CNS region
-Signs: loss of voluntary movements, spasticity, rigor, & exaggerated/aberrant reflexes (ie. Babinski Sign)

Front 49

Somatic Afferent System

Back 49

Review Pg. 26 (summary on somatic afferent system)

Front 50

Dermatomes

Back 50

-result from segmental arrangement of sensory neurons
-Back = dorsal rami dermatomes
-Anterior = ventral rami dermatomes
-All spinal nerves have dermatomes except for C1

-T4 = Nipple Line
-T10 = Umbilicus

Front 51

Reflexes

Back 51

-can be monosynaptic, but in most cases several interneurons are involved
-Review Figure - Pg. 30

Front 52

Enteric Nervous System

Back 52

-3rd part of CNS
-intrinsic neurons of the gut located in 2 layers --> Myenteric Plexus & Submucosal Plexus
-gut capable of autonomous regulation

Front 53

Visceral Afferents

Back 53

Review Pg. 31