Download Biology 11 - Human Anatomy Lecture

Anatomy 32 Lecture
Chapter 14 - Peripheral Nervous System
I.
Overview
A. Introduction to the PNS
B. Cranial Nerves
C. Spinal Nerves
D. Nerve Plexuses
E. Reflex Arc
II. Introduction to the _____
A. The PNS conveys impulses to and from the ____ and includes the:
1. Sensory ______________ within sensory organs
2. ____________ & their associated ganglia
3. Nerve ____________
B. __________ of the PNS are classified as either
1. _____________ nerves - arise from the brain
2. ____________ nerves - arise from the spinal cord
C. The terms sensory, motor, or mixed nerve refer to the _________ nerve impulses are
conducted
1.
2.
3.
__________ (afferent) nerves conduct impulses toward the CNS
_______ (efferent) nerves conduct impulses away from the CNS
________ nerves are composed of both sensory & mixed nerves, thus conduct
impulses to & from the CNS
III. ______________ - 12 pr. of cranial nerves emerge from the inferior brain surface and pass
through skull foramina to ennervate structures in the head, neck, and visceral organs
A. Structure & function of the cranial nerves
1. ____ pr. arise from the _________ and the other ___ pr. arise from the __________ &
brain _______
2.
Cranial nerves are designated by _________ numerals, which refer to the order the
nerves are positioned from the ________ to the ________ of the brain
3.
Most cranial nerves are ________ or mostly motor, but some associated with special
senses are __________ only. (Remember by: Some Say Marry Money, But My
Brother Says Big Bras Matter More)
4.
Cell bodies of sensory neurons are located in ___________ outside the brain and SC
B. The ___ Cranial Nerves (Remember by: On Occasion Our Trusty Truck Acts Funny,
Very Good Vehicle AnyHow)
1.
_________ - Sensory fibers arise from the olfactory epithelium in nasal cavity, pass
through the cribiform plate to synapse in the olfactory _______ and extend
posteriorly as the olfactory ____ beneath the frontal lobe; carry impulses for sense of
smell
2
2.
_______ - Sensory fibers arise from the retina, pass through the optic foramen,
converge and partially cross over forming the optic ________, continue as optic
_______, enter the thalamus and are relayed to the occipital lobe; carry impulses for
vision
3.
___________ - Mixed fibers extend from the midbrain near the pons, through the
superior orbital fissure to enervate ______ muscles
4.
____________ - Mixed fibers emerge from the midbrain , pass ventrally through the
superior orbital fissures with oculomotor nerves to the ______ muscles (superior
oblique)
5.
___________ - largest cranial nerve (mixed), extends from pons to face and forms 3
divisions:
a.
____________ - sensory fibers run from the face to pons via superior orbital
fissure; conveys impulses from _____, nose, & scalp
b.
_____________ - sensory fibers run from face to pons via foramen rotundum;
conveys impulses from nasal mucosa, palate, upper _________ & lip
c.
___________ - mixed fibers pass through skull via foramen ovale; conveys
sensory impulses from lower teeth, ______, motor impulses to muscles of
mastication
6.
__________ - mixed fibers leave inferior pons & enter orbit via superior orbital
fissure to _____; supplies motor fibers to lateral rectus muscle and sensory fibers
from the muscle proprioceptors
7.
_____ - mixed fibers emerge from pons, lateral to abducens and exit via stylomastoid
foramen, then branches into the temporal, zygomatic, buccal, mandibular, and
cervical; conveys impulses to & from muscles of ______ expression, facial glands &
tongue
8.
______________ - sensory fibers arise in the inner _____ and pass through internal
auditory meatus to enter pons; forms 2 divisions:
a.
b.
9.
_____________ - transmits impulses for sense of hearing
_____________ - transmits impulses for equilibrium
_______________ - mixed fibers emerge from medulla, through jugular foramen, to
throat; sends motor impulses to _________ muscles, sensory from pharynx &
posterior ________
10. _________ - only CN to extend beyond head & neck; mixed fibers emerge from the
medulla, through jugular foramen, descend through neck into thorax & abdomen;
branches enervate pharynx, larynx, tongue & visceral _________
11. ________- mixed fibers formed by union of cranial root (from lateral medulla) &
spinal root (C1-C5); enters skull via jugular foramen; cranial enervates larynx,
pharynx, & soft palate, spinal enervates trapezius & sternocleidomastoid to move
______
12. _____________ - mixed fibers arise from medulla, exit skull via hypoglossal canal
to ennervate intrisic & extrinsic ________ muscles
3
IV. __________________
A. Each of ___ pr. of spinal nerves is formed by the union of a dorsal and ventral spinal
______ that emerges from the SC through an intervertebral foramen to innervate a part of
the body
B. Spinal nerves are named according to the __________ they emerge through
1. 8 pr. __________ - C1 is between occipital bone & atlas; C2-C7 leave above their
cervical bone, C8 and the rest leave below namesake vertebrae
2.
3.
4.
5.
12 pr. _________ (T1-T12)
5 pr. _________ (L1-L5)
5 pr. _________ (S1-S5)
1 pr. ___________ (C0)
C. A spinal nerve is a _______ nerve attached to spinal cord by a
1. __________ (posterior) ______, which contains the dorsal root _____________ - a
collection of sensory cell bodies. ________ neurons carry impulses from sensory
receptors to the CNS
2.
___________ (anterior) _______ is composed of _______ fibers that convey impulses
away from the CNS to effectors
D. After spinal nerves exit a root, they divide into peripheral ______
1. ______ ________ contains mixed nerves that innervate muscles, joints, & skin of the
posterior neck & trunk.
2.
_________________ contains mixed nerves that innervate the muscles & skin of the
anterior & lateral neck & trunk, as well as the limbs.
3.
Rami ______________ are two spinal nerve branches from the ventral ramus to a
sympathetic trunk ___________, part of the autonomic nervous system.
Communicantes are mixed nerves.
V. Nerve Plexuses
A. Except for T2-T12 (intercostal nerves), the ___________ of spinal nerves split again &
again as nerve networks called plexuses.
B. There are four _________; nerves emerging from the plexuses are named according to
the structures they innervate or the course they take.
1.
_________ plexus - formed by the ventral rami of C1-C4 and part of C5.
a.
b.
2.
Branches innervate the skin & muscles of the _______, head, & shoulders
Fibers from the 3rd-5th cervical nerves become the ________ nerve, which
innervates the diaphragm
___________ plexus - formed by C5-T1; passes over the 1st rib behind the clavicle
and enters the axilla; innervates the upper extremities, and some shoulder & neck
muscles. Major subdivisions include:
a. ________ - five ventral rami (C5-T1), which unite to form three
b. ________ – upper, middle, and lower; each trunk divides into
4
c. _________ – anterior and posterior, then each of the 6 divisions merge to form three
d. ______ – posterior, medial, and lateral, which form the following nerve _________
1) __________ – from the posterior cord, posterior to the humerus neck; innervates
the shoulder
2) ___________ – from the posterior cord, wraps around the humerus in the radial
groove; innervates the triceps and forearm extensors
3) ____________ – from the medial cord, lies between the radial and ulnar nerves;
innervates anterior forearm flexors
4) ________ (funny bone nerve) – from the medial cord, descends along the medial
humerus, over the medial epicondyle, then along the medial ulna; innervates the
wrist and many hand flexors
5) Musculo____________ – from the lateral cord, descends along the anterior arm
to just below the elbow; innervates elbow flexors and lateral forearm
3.
____________ plexus - formed by L1-L4; innervates lower abdomen, anterior &
medial lower extremity. Major nerves include:
a.
b.
4.
___________ - innervates anterior & lateral thigh, medial leg & foot
____________ - innervates medial thigh, adductors of thigh
__________ - formed by L4-S4; innervates lower back, pelvis, perineum, posterior
thigh & leg, & foot. Major nerves include:
a.
___________ - passes through the greater sciatic notch, deep to gluteus maximus
and biceps femoris; branches into two nerves
1) ____________ - posterior to tibia; innervates knee flexors and foot plantar
flexors
2) _____________ (peroneal) - lateral to fibula; innervates fibularis muscles
(Note: Sciatica involves injury to the sciatic nerve, causing pain to radiate from the
buttock down the posterior leg; may be caused by herniated disc, dislocated hip,
lumbosacral osteoarthritis, pregnancy, and gluteal muscle injection)
VI. Components of a ________________
A. A reflex arc implies an ____________, unconscious, protective response in an attempt to
maintain homeostasis
B. The five components of a reflex arc are:
1. ____________ - dendrite of a sensory neuron and the place the impulse is initiated
2. __________ neuron - relays the impulse through the dorsal root to the CNS
3. __________________ - located in the CNS and usually involves an association
neuron (interneuron); here impulses are sent through synapses to other parts of the
body
4.
5.
___________ neuron - conducts the impulse to an
____________ - usually a skeletal muscle
5
Chapter 15 - Autonomic Nervous System
I.
Introduction to the _______
A. The autonomic nervous system (ANS) is the general ___________ division of the PNS,
and contains two subdivisions
1. ______________ N.S. – involved in “fight or flight” responses
2. ________sympathetic N.S. – involved in “rest & digest” activities
B. Involuntary ___________ (smooth & cardiac muscle and glands) are regulated by
autonomic ________ impulses via the ANS
C. The autonomic motor pathway involves 2 types of ____________:
1. _______________ (presynaptic) neurons - have their cell bodies in the gray matter of
the brain or SC; release _____ neurotransmitter; their axons synapse with
2.
________________ (postsynaptic) neurons - extend from the autonomic ganglia and
synapse with an ____________ organ
3.
Autonomic _____________ are located in the head, neck, & abdomen, and on each
side of the spinal cord (paravertebral)
II. Both sympathetic & parasympathetic divisions innervate the _____ organs, but have
_____________ effects (see table in text)
A. Sympathetic (______________) division - preganglionic neurons exit the spinal cord
lateral horns from T1 to L2
1. Involved in “________ or ________” responses:
a. Dilates _______
b. Stimulates _______ glands
c. Vaso__________ blood vessels to glands and internal organs
d. __________ bronchioles and blood vessels to heart & skeletal muscles
e. Stimulates ____________ medulla to secrete epinephrine & norepinephrine into the
blood stream
f. Increases ____________ and force of contraction, as well as blood pressure
g. Stimulates break down and release of _______ from liver and
lipids from fat cells to supply _________ to blood stream
2. ______transmitters are released by neurons and adrenal glands
a. ______________ - most postganglionic sympathetic neurons release
____epinephrine
b. Epinephrine (_________) & norepinephrine are released by the adrenal glands
when stimulated by the sympathetic sys.
3. ____________ are close to the spinal cord
a. _____________ trunk ganglia alongside vertebral column
b. _____________ ganglia anterior to vertebral column
4. Preganglionic neurons are _______, postganglionic are ______
6
B. Parasympathetic (___________) division - preganglionic neurons exit from the midbrain,
brain stem and sacrum (cranial nerves III, VII, IX, & X also participate)
1. Involved in _____________ (resting & digesting) functions
a. _______ are constricted
b. Glands are stimulated to ________
c. Heart rate is ________ and steadied
d. Blood vessels to heart and bronchioles are vaso__________
e. Smooth muscle of bladder and digestive organs are contracted, promoting
_______________.
2. ___________ - acetylcholine (____) neurotransmitter is released from most
parasympathetic postganglionic neurons to effectors
3. ____________ are in or close to the organ served
4. Preganglionic neurons are ______, postganglionic are ______