Spinal Cord, Peripheral Nervous System, And Cranial Nerves Flashcards
1
Q
Structural and Nutritional Support of CNS and PNS
A
- CNS: astrocyte
- PNS: Satellite cells
- look at slides for what it looks like
2
Q
Myelination in CNS and PNS
A
- CNS: oligodendrocyte
- PNS: Schwann cells/neurolemmacyte
- look at slides for what they look like
3
Q
Phagocytes
A
- CNS: microglia
- PNS: —
- look at slides for what they look like
4
Q
Line ventricles
A
- CNS: ependymal cells
- PNS: —
- look at slides for what they look like
5
Q
Spinal Cord
A
- functions: sensory and motor innervation of body
- 2-way conduction of signals btw body and brain
- major center for reflexes (don’t need brain. Sensory neuron tells motor neuron to activate)
- project white matter, so axons are gonna travel in the spinal cord and are gonna conduct signals btw the body and brain
- begins at foramen magnum
- terminates at L1/L2 as conus medullaris
- Filum terminals extends from conus medullaris to coccyx; anchors spinal cord
6
Q
Mixed spinal nerve
A
- each spinal cord segment has a mixed spinal nerve with dorsal and ventral roots
7
Q
Cauda equina
A
- collection of spinal nerves traveling inferiorly to exit at associated intervertebral foramen
8
Q
Spinal cord meninges
A
- epidural space: filled with fat and veins (not present in cranial cavity!) (blue things = veins)
- dura mater = toughest
- subdural space (potential space)
- arachnoid mater = spidery
- subarachnoid space filled with CSF
- Pia mater = deepest
9
Q
Spinal cord segment
A
- the spinal cord transmits nerve signals from the motor cortex to the body, and from afferent fibers of sensory neurons to the sensory cortex of the brain
- in each segment a pair of spinal nerves is formed
- each segment corresponds w/ a vertebra
- 31 spinal cord segments
10
Q
How is gray and white matter presented in spinal cords?
A
- gray matter = deep
- white matter = superficial
11
Q
Spinal Cord Gray Matter: Posterior/dorsal horn
A
- receives sensory neuronal input
12
Q
Spinal Cord Gray Matter: Anterior/Ventral Horn
A
- houses somatic motor cell bodies
- mostly skeletal muscles
13
Q
Dorsal Root Ganglion
A
- sensory cell bodies found here
14
Q
Lateral Horn
A
- smooth muscles (organs)
- houses visceral motor* cell bodies
15
Q
Spinal Cord Roots
A
- roots emerge from dorsal and ventral horns
- one way pathway for neurons signals
- going out of ventral root and in thru the dorsal root
16
Q
Posterior/dorsal root
A
- sensory (afferent) axons AND CELL BODIES found in dorsal root
17
Q
Anterior Root
A
- motor (efferent) axons found here
- motor signals travel from cell body thru axon
18
Q
Dorsal and Ventral Roots come tgthr to form a ____
A
- mixed spinal nerve
19
Q
Mixed spinal nerve splits to form ____
A
- dorsal (posterior) and ventral (anterior) rami
20
Q
Summary of Formation of Spinal Nerves
A
21
Q
Spinal cord in vertebral column
A
- spinal nerves are named after their adjacent vertebra
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
22
Q
Spinal nerves in situ
A
- dorsal rami: innervate muscles and skin surrounding vertebral column
- ventral rami will form plexuses
- spinal nerve travels thru intervertebral foramen
23
Q
Nerve Plexuses
A
- a nerve plexus is a network of nerves…formed by ventral rami only
- all spinal nerves except T2-T12 (travel btw ribs and form intercostal nerves) branch and rejoin
- each muscle in a limb receives its nerve supply from more that one spinal nerve… damage to one spinal nerve cannot completely paralyze any limb muscles
24
Q
Cervical Plexus
A
- C1-C4
- phrenic nerve (C3,C4,C5) — travel down thru our thorax and innervate a muscle called the diaphragm
- innervates the muscles of the neck and the diaphragm
25
Q
Brachial Plexus
A
- partly in neck, partly in axilla (armpit region)
- gives rise to most nerves of the upper limb
- mixing of ventral rami (C5-C8) and most of the ventral ramus of T1
27
Q
Terminal Branches of Brachial Plexus: Axillary Nerve (C5-C6)
A
- motor innervation: deltoid muscle (and teres minor)
- sensory innervation: shoulder joint and skin on part of deltoid (pictured below)
- sending axons to the skin, right around the area that we’re sending axons to the muscles
28
Q
Terminal Branches of Brachial Plexus: Musculocutaneous nerve (C5-C7)
A
- motor innervation: anterior compartment of arm
- sensory innervation: skin sensation for lateral forearm
29
Q
Terminal Branches of Brachial Plexus: Radial Nerve (C5-8)
A
- sensory innervation: skin over dorso-lateral arm, forearm, and hand
- motor innervation: posterior compartment of arm and forearm (extensors)
30
Q
Terminal Branches of Brachial Plexus: Median Nerve (C5-8)
A
- sensory innervation: skin of lateral palm and digits 1-3 and lateral side of digit 4
- motor innervation: anterior compartment of forearm (with ulnar)
- intrinsic muscles of the thumb
31
Q
Terminal Branches of Brachial Plexus: Ulnar Nerve (C8-T1)
A
- sensory innervation: skin of medial hand, medial side of digit 4, all of digit 5
- motor innervation: flexors and intrinsic hand muscles on ulnar side of anterior forearm
32
Q
Lumbar Plexus (L1-L4)
A
- branches that innervate part of the skin around the genitals and part of the skin around the abdominal region
- femoral and obturator = main 2
33
Q
Femoral Nerve (L2-4)
A
- sensory innervation: skin of antero-medial thigh and skin of medial leg and foot
- motor innervation: muscles of anterior thigh, thigh flexors, leg extensors (iliopsoas, sartorius, rectus femoris, vastus lateralis, vastus medialis (and v. intermedius))
34
Q
Obturator Nerve (L2-4)
A
- sensory innervation: skin of medial thigh
- motor innervation: muscles of medial thigh (adductors)
> adductor longus, gracilis, adductor magnus, and adductor
brevis
36
Q
Gluteal Nerves
A
- inferior gluteal nerve (L5-S1): motor innervation = gluteus Maximus
- superior gluteal nerve (L4-S1): motor innervation = gluteus medius and minimus, tensor fascia lata
> thigh abductors
38
Q
Sciatic Nerve: Tibial Nerve (L4-S3)
A
- sensory innervation: skin of postero-lateral leg. Skin of sole of foot (subdivides into plantar nerves)
- motor innervation: muscles of posterior thing and posterior leg
- hamstring muscles = tibial nerve
39
Q
Common Fibular Nerve (L4-2)
A
- sensory innervation: skin of antero-lateral leg, skin on dorsum of foot
- motor innervation: muscles of anterior leg (deep fibular) and muscles of lateral leg (superficial fibular)
41
Q
Cranial Nerves Overview
A
- part of peripheral nervous system
- sensory and motor nerve fibers that innervate the head/viscera
- all of organs in our thoracic and abdominal cavities
- originate at brain or brain stem
- named in order, anterior-posterior
- 12 pairs (CN 1-CNXII)
> 3 pairs of sensory nerves
> 5 pairs of motor nerves
> 4 pairs of mixed nerves
42
Q
Sensory of Cranial Nerves: CN I — Olfactory Nerve
A
- origin in olfactory epithelium of nasal cavity
- olfactory nerves travel thru cribriform plate
- synapse in olfactory bulb
- olfactory tract terminates in olfactory cortex (turns it in to a sensation that the brain can understand)
- neurons = collect olfactory sensations
- olfactory tract: collection if axons going to the brain
43
Q
Sensory of Cranial Nerves: CN II Optic Nerve
A
- special sense of vision
- origin in retina of eye
- axons travel posteriorly in optic tract
- some axons cross to opposite side of brain in optic chains
- terminates in primary visual cortex (in occipital lobe) = where we make sense of this electrical signal in our retina
44
Q
Sensory of Cranial Nerves: CN VIII Vestibulocochlear
A
- special senses of hearing and equilibrium (figuring out where you are in space if you need it balance yourself)
- origin in the inner ear (with petrous part of temporal bone)
- connects to brain stem at pons
- labyrinth (balance): filled with fluid
- cochlea (hearing): send axons into the brain
46
Q
Motor Cranial Nerves: CN III Occulomotor
A
- innervates all extrinsic muscles of the eye except superior oblique and lateral rectus
- origin in the midbrain
47
Q
Motor Cranial Nerves: CN IV Trochlear
A
- innervates superior oblique muscle
- eye look down and out
48
Q
Motor Cranial Nerves: CN VI Abducens
A
- innervates lateral rectus (abduct the eye)
49
Q
CN XI — Spinal Accessory Nerve
A
- sends rootlets from spinal cord up thru foramen magnum; exits again from jugular foramen
- rootlets enter cranial cavity
- innervates sternocleidomastoid and trapezius muscles
> does this after it exits jugular foramen
50
Q
CN XII — Hypoglossal
A
- originates in medulla oblongata
- innervates muscles of tongue, including genioglossus
51
Q
Mixed Cranial Nerve: CN V — Trigeminal Nerve
A
- sensation from the face into your brain
- motor innervation to muscles of mastification
52
Q
Mixed Cranial Nerve: CN VII Facial Nerve
A
- conveys special sensation (taste) from the anterior 2/3 of tongue
- motor innervation to muscles of facial expression
53
Q
Mixed Cranial Nerve: CN IX Glossopharyngeal Nerve
A
- conveys general and special sensation of taste to posterior 1/3 of tongue
- visceral sensation from carotid body -> sense blood pressure and blood gases
- motor innervation to stylopharyngeus muscle (swallowing)
- visceral motor from your salivary glands
54
Q
Mixed Cranial Nerve: CN X Vagus Nerves
A
- wanderer
- visceral sensations to organs of thorax and abdomen
- somatic motor to muscles of larynx (speaking) and pharynx (swallowing)
- visceral motor (parasympathetic) to thoracic and abdomen
56
Q
V1 Opthalmic Division of Trigeminal Nerve
A
- sensation to forehead, upper eyelid, cornea, bridge of nose
57
Q
V2 Maxillary Division of Trigeminal Nerve
A
- sensation to bottom eyelid, side of nose, upper lip, maxillary region
58
Q
V3 Mandibular Division of Trigeminal Nerve
A
- sensation to side of temple, side of ace (cheek), bottom lip and chin, mandibular teeth and anterior 2/3 tongue
- motor innervation to muscles of mastification (masseter, temporalis, pterygoids)
