Lecture 3: The Peripheral Nervous System and Cranial Nerves Flashcards
What are the three ways to categorize the peripheral nervous system?
- Motor or sensory
- General (widespread) or Specialized (local)
- Somatic (outer tube) or Visceral (inner tube)
What is the sensory receptors of the peripheral nervous system for:
-pick up stimuli from inside and outside the body, then initiate impulses in sensory axons
What is the motor endings of the peripheral nervous system for:
-the axon terminals of motor neurons that innervate the effectors
What are the group of nerves of the peripheral nervous system made up of:
-bundles of peripheral axons
What do mixed nerves contain:
-contain both sensory and motor axons
Cranial nerves are purely _______ or purely ______ in function.
- sensory
- motor
What are the ganglia of the peripheral nervous system:
-cluster of peripheral neuronal cell bodies
What are the somatic sensors:
- touch
- pain
- pressure
- vibration
- temperature
- proprioception in the skind, body wall, and limbs
What are the special somatic sensory:
- hearing
- equilibrium
- vision
What are the visceral sensory:
- Stretch
- pain
- temperature
- chemical changes,
- irritation in viscera, nausea, and hunger
What are the special visceral sensory:
- Taste
- Smell
What is the somatic sensory:
GENERAL:
-Motor innervation of all skeletal muscle
Where do motor axons innervate skeletal muscle fibers at neuromuscular junction:
-motor end plates
What is noriepinephrine breakdown is done by:
-MOA
A thin layer of connective tissue which wraps around each nerve fiber is:
-endoneurium
A loose connective tissue between nerve fibers:
epineurium
A connective tissue which wraps around bundles of nerves
Perineurium
What SENSORY receptor of the peripheral nervous system detect mechanical deformation of the receptor or of cells adjacent to the receptor:
-mechanoreceptors
What SENSORY receptor of the peripheral nervous system detects pain, damage to tissue (physical or chemical)
Nociocceptors
What SENSORY receptor of the peripheral nervous system detects light on the retina:
Electromagnetic receptors
What SENSORY receptor of the peripheral nervous system detects taste, smell, oxygenation, osmolality:
chemoreceptors
Receptor types based on morphology found in the dermis and slowly adapt to change in pressure:
Ruffini Endings
Receptor types based on morphology found in hairless portion of skin and highly discriminat tactile receptors:
meisner corpuscles
Receptor types based on morphology for vibration is:
Pacinian corpuscles
Receptor types based on morphology of encapsulated receptors that perceive muscle stretch:
Neuromuscular spindles and neurotendonous organs of golgi
What is the spinal cord artery one on each side, arises from vertebral arteries and extends to cauda equina:
-Posterior Spinal artery
What is the spinal cord artery that also arises from vertebral artery, extends to filum terminale:
-Anterior spinal artery
The spinal cord artery blood supply is reinforced by intercostals in the thoracic region, and also by lumbar arteries in the lumbar region:
-radicular arteries
What spinal cord supplies most of the spinal cord:
Anterior spinal artery
T/F: The Cauda equina is also known as the horse’s tail.
TRUE
_____ roots sensory fibers arising from cell bodies in _______ root ganglia.
-Dorsal
-Dorsal
(Sensory-Afferent-Dorsal)
______ roots motor fibers arising from anterior gray coumn of spinal cord.
Ventral
Motor-Efferent-Ventral
What ventral rami do not form a plexus:
Thoracic
What is a nerve plexus:
-networks of successive ventral rami that exchange fibers (cisscross and redistribute)
What nerve roots form the cervical plexus:
C1 to C4
What does the cervical plexus innervate:
-muscle and skin of the neck and shoulder
What is the phrenic nerve:
- C3 to C5
- Sole motor supply of the diaphragm
What is the branchial plexus:
- C5 to T1
- Innervate the upper extremity
What are the nerve names that are in the brachial plexus:
- Musculocutaneous (are flexors)
- Median (anterior forearm muscles and lateral palm)
- Ulnar (Anteromedial muscles of forearm and medial hand)
- Axillary (to deltoid and teres minor)
- Radial (to posterior part of limb)
- Radial
What is the lumbar plexus:
-L1 to L4
What does the lumbar plexus (L1 to L4) innervate:
- Lies within the psoas major muscle
- Innervates anterior and medial muscles of thigh through femoral and obturator nerves respectively
- Femoral nerve also innervates skin on anterior thigh (includes quads and medial leg)
What is the sacral plexus:
- L4 to S4
- Supplies muscles and skin of posterior thigh and almost all of the leg
The large sacral nerves belongs to what plexus and innervates what:
- Tibial nerve (Most of hamstrings, calf, and sole)
- Common fibular nerve (muscles of anterior and lateral leg and skin)
- Other branches supply pelvic girdle (gluteus muscle) and perineum (pudendal nerve)
______ tracts are those which travel toward the brrain are sensory.
Ascending
______ tracts are those which travel away from the brain are motor.
Descending
Spinothalamic tract tells us the impulse origin from the _____ to the ______ and is it afferent or efferent?
- spine
- brain
- afferent
Corticospinal tract tells us the impulse origin is from the b_____ to the ______ and is it afferent or efferent?
- brain
- Spine
- efferent
What fasciculus belong to the dorsal column medial lemniscus: (sensory or motor)
- Gracile fasciculus
- Cuneate fasiculus
-SENSORY
What Fasciculus belong to the Anteriolateral system: (Sensory or Motor)
- Lateral spinothalamic tract
- Anterior spinothalamic tract
-SENSORY
How does the dorsal column-medial lemniscus tract run up the spine and to the brain:
- Spinal Cord
- Crosses the medulla
- travels to the thalamus via medial lemnisscus (which are large, fast, meylinated nerve fibers)
What type of function does the dorsal column medial lemniscus do:
- touch sensation
- vibration
- proprioception (stereogensesis)
- Fine pressure
How does the anterolateral system tract run up the spine and to the brain:
- Dorsal horn of spinal grey mater
- Crosses to opposite side of cord
- Ascends to the brain stem and thalamus
(Smaller, slower, myelinated)
What function does the anterolateral system serve?
- Pain
- Temperature
- Crude touch
- Tickle/itch
- Sexual sensation
What function does the lateral spinothalamic tract serve?
-pain and temperature
What function does the ventral spinothalamic tract serve:
-crude touch
What function does the fasciculus gracilus and cuneatus (found in the dorsal horn) serve:
- fine touch,
- proprioception
- joint sense
What function does the spinocerebellar tract serve:
-unconscious anesthesia
What function does the lateral and ventral corticospinal tract serve:
-Voluntary movements
The afferent pathways have three neuron paths. What are they:
- Primary neuron originates in periphery and terminates in spinal cord.
- Secondary neurons in spinal cord cross to controalateral side and ascencd (ie anterolateral system whcih is comprised of LSTT & ASTT) to terminate in thalamus.
- Third order neurons project to specific cortex in brain
The characteristic of defects of an upper motor neuron:
- Spastic paralysis (NO MUSCLE ATROPY)
- Fasiculation NOT present
- Hyperreflexia
- Babinski PRESENT
THe characteristic of defects of a lower motor neuron:
- Flaccid paralysis (ATROPHY)
- Fasiculation PRESENT
- Hyporeflexia
- Babinski NOT present
The filaments of the olfactory nerve cross the ______ plate or the _______ bone.
- cribriform
- ethmoid
Cranial nerve two involves the __ optic nerves that unite to form an optic _____, fibers cross and form an optic tract on either side.
- 2
- chasm
T/F: Most fibers of the optic tract terminate on the thalamus, and then relay fibers run to visual cortex on the occipitl lobe.
TRUE
Cranial nerve III nucleus on the _____ part of midbrain, and extends to run the _________ eye muscle.
- ventral
- external
Cranial nerve IV cells are on the _____ and motor to superior ________ muscles of the eye.
- midbrain
- oblique
Cranial nerve V called the _______ serve three branches that carry afferent impulses from the skin and mucosa of the head and teeth to cell bodies situated on the _____.
- Trigiminal
- pons
What areas do the trigiminal nerve (Cranial nerve V) serve:
- opthalmic
- maxillary
- mandibular
- mastication (small nerve)
Cranial nerve VI called the ______ gives motor to the _____ ______ muscle.
- abducen
- lateral rectus
Cranial nerve VII called the ______ originate on the lower part of ____ and extend via several branches to muscle of the _____ expression. The cranial nerve VII also give sense to the _____ 2/3 of the tongue
- facial
- pons
- facial
- anterior
Cranial nerve VIII called the _____ have two division called the ______ and the _______.
- vestibular
- vestibular
- cochlear
Cranial nerve IX called the ______ glossopharyngeal has SENSORY fibers from the external ear and post ______ 1/3 of tongue and pharynx. The MOTOR fibers to muscles of the ______.
- glossopharyngeal
- posterior
- pharynx
Cranial nerve X called the ______ has both _____ and ______ fibers. The sensory fibers are many, but the motor fibers are to the ____ and ____ viscera and to the muscles of _______ (pharynx and larynx).
- vagus
- sensory
- motor
- thoracic
- abd.
- swallowing
Cranial nerve XI called the spinal _______. Motor fiber originate on the _____ cord to the _____ and ________.
- accessory
- cervical
- trapezius
- sternocleidomastoid
The spinal accessory (Cranial nerve XI) have part of the fibers originate in the cells of the MEDULLA (______ _______) and eventually join forces with the _____ for abdominal and thoracic viscera.
- nuclei ambiguous
- vagus
Cranial nerve XII called the _______ originate at the cell nucleus in _______ to the muscles of the tongue
- hypoglossal
- medulla
T/F: The largest of the cranial nerves is the trigeminal nerve or cranial nerve III.
FALSE (….cranial nerve V.)
