A&P exam 13
lumbar plexus
arises from L1-L2
patellar reflex
example of stretch reflex
contracting
the muscle activates the golgi tendon organs
receptor level
the sensor receptors
cords
lateral, medial, and posterior fiber bundles
sciatic
the major nerve of the sacral plexus
encapsulated simple receptors
-meissner's corpuscles -pacinian corpuscles -muscle spindles, Golgi tendon organs, and Ruffini's corpuscles
segmental, projection, precommand
3 levels of motor control
Trigeminal nerve Both (general sensations)
Cranial nerve V sensory or motor function?
amitotic
Damage to nerve tissue is serious because mature neurons are
dorsal root; skin; spinal cord
First-order neurons: soma reside in ________________ and conduct impulses from the __________ to the _____________
adapt quickly
Receptors responding to pressure, touch, and smell
Thalamus; cortex
Third-order neurons: located in the _____________ and conduct impulses to the _____________ of the cerebrum
roots-trunks-divisions-cords
What are the four major branches of the brachial plexus in order?
ventral; efferent
____________ roots arise from the anterior horn and contain motor _____________ fibers
31; head
_____________________ pairs of mixed nerves arise from the spinal cord and supply all parts of the body except the __________
pattern recognition
ability to recognize patterns in stimuli (e.g., melody, familiar face)
Babinski's sign
abnormal plantar reflex indicating corticospinal damage where the great toe dorsiflexes and the smaller toes fan laterally
stretching the muscles
activates the muscle spindle
PNS
all neural structures outside the brain and spinal cord
divisions
anterior and posterior serve the front and back of the limb
nerve plexuses
are found in the cervical, brachial, lumbar, and sacral regions
receptors
are structurally classified as either simple or complex encapsulated and unencapsulated varieties
sacral plexus
arises from L4-S4
antagonist
as a result, the contracting muscle relaxes and the _________________ contracts
circuit level
ascending pathways
median of brachial plexus
branches to most of the flexor muscles of arm
chains of three neurons
conduct sensory impulses upward to the brain
projection level
consists of brain stem motor areas and helps control reflex and fixed-pattern activity
segmental level
consists of the spinal cord and circuits control locomotion and specific, oft-repeated motor activity
olfactory nerve sensory-smell
cranial nerve I sensory or motor function?
Optic nerve sensory-vision
cranial nerve II sensory or motor function?
oculomotor nerve motor
cranial nerve III sensory or motor function?
Trochlear nerve motor
cranial nerve IV sensory or motor function?
glossopharyngeal nerve both (sensory-taste)
cranial nerve IX sensory or motor function?
Abducens nerve motor
cranial nerve VI sensory or motor function?
Facial nerve both (sensory-taste)
cranial nerve VII sensory or motor function?
vestibulocochlear nerve both (sensory-hearing and balance)
cranial nerve VIII sensory or motor function?
Vagus nerve both (sensory-taste)
cranial nerve X sensory or motor function?
Accessory nerve motor
cranial nerve XI sensory or motor function?
Hypoglossal nerve motor
cranial nerve XI sensory or motor function?
pain receptors and proprioception
do not exhibit adaptation
roots
five ventral rami (c5-T1)
golgi tendon organs
for skeletal muscles to perform normally: ________________ (proprioceptors) must constantly inform the brain as to the state of the muscle
muscle spindles
for skeletal muscles to perform normally: stretch reflexes initiated by ____________________ must maintain healthy muscle tone
schwann cells
form regeneration tube and secrete growth factors
unencapsulated simple receptors
free dendrite nerve endings -merkel (tactile) discs -hair follicle receptors
8
how many cervical nerves are there?
1
how many coccygeal nerves are there?
5
how many lumbar nerves are there?
5
how many sacral nerves are there?
12
how many thoracic nerves are there?
repaired
if the soma of a damaged nerve remains intact, damage can be ______________
acetylcholine
in innervation of skeletal muscle, ____________ is the neurotransmitter that diffuses across the synaptic cleft
acetylcholine; norepinephrine
in innervation of visceral muscle and glands, _______________ and _____________ are used as neurotransmitters
slower
in innervation of visceral muscle and glands, visceral responses are ___________ than somatic responses
regulate motor activity precisely start or stop movements coordinate movements with posture block unwanted movements monitor muscle tone
in the precommand level, cerebellar and basal nuclei systems:
input
in the somatosensory system, ______________ comes from exteroceptors, proprioceptors, and interoceptors
intrinsic
inborn reflexes
superficial reflexes
initiated by gentle cutaneous stimulation
radial of brachial plexus
innervates essentially all extensor muscles
axillary nerve of brachial plexus
innervates the deltoid and teres minor
reflexes
involve only peripheral nerves and the spinal cord
reflex
is a rapid, predictable motor response to a stimulus
flexor reflex
is initiated by a painful stimulus (actual or perceived) that causes automatic withdrawal of the threatened body part
plantar reflex
is initiated by stimulating the lateral aspect of the sole of the foot
dermatome
is the area of skin innervated by the cutaneous branches of a single spinal nerve
sensation
is the awareness of changes in the internal and external environment
perception
is the conscious interpretation of those stimuli
phrenic nerve
is the major motor and sensory nerve of the diaphragm
acquired
learned reflexes
perceptual level
neuronal circuits in the cerebral cortex
adaptation
occurs when sensory receptors are subjected to an unchanging stimulus
golgi tendon reflex
opposite of the stretch reflex
PNS
provides links to and from the external environment
merkel's discs, Ruffini's corpuscles
receptors responding slowly include
contracting the muscles
reduces tension on the muscle spindle
axons
regenerate damaged part
macrophages
remove debris
chemoreceptors
respond to chemicals (examples: smell, taste, changes in blood chemistry)
proprioceptors
respond to degree of stretch found in skeletal muscles, tendons, joints, ligaments, and connective tissue coverings of bones and muscles
Photoreceptors
respond to light energy (example: retina)
exteroceptors
respond to stimuli arising outside the body sensitive to touch, pressure, pain and temperature
interoceptors
respond to stimuli arising within the body sensitive to chemical changes, stretch, and temperature changes
Mechanoreceptors
respond to touch, pressure, vibration, stretch, and itch
dorsal; afferent
roots arise from sensory neurons in the ganglion and contain sensory ______________ fibers
dorsal horn; thalamus
second-order neurons: soma reside in the ________________ of the spinal cord and transmit impulses to the ____________
musculocutaneous nerve of brachial plexus
sends fibers to the biceps brachii and brachialis
Thermoreceptors
sensitive to changes in temperature
Nociceptors
sensitive to pain-causing stimuli
ulnar of brachial plexus
supplies the flexor carpi ulnaris and part of the flexor digitorum profundus
innervation of skeletal muscle
takes place at a neuromuscular junction
quadriceps
tapping the patellar tendon stretches the ___________ and starts the reflex action
Quality discrimination
the ability to identify submodalities of a sensation (e.g., sweet or sour tastes)
the simulated side is withdrawn the contralateral side is extended
the cross extensor reflex has two parts:
sciatic nerve
the longest and thickest nerve of the body
femoral; obturator
the major nerves of the lumbar plexus are the ___________ and the ______________
phrenic nerve
the most important nerve of the cervical plexus
cranial nerve X: Vagus
the only cranial nerve that extends beyond the head and neck
antagonistic
the quadriceps contract and the _____________ hamstrings relax
downward flexion of the toes
the response to plantar reflex is
lowest
the segmental level is the ___________ level of motor hierarchy
receptor level, circuit level, perceptual level
the three main levels of neural integration in the somatosensory system are:
trunks
upper, middle, and lower, which form divisions
feature abstraction
used to identify a substance that has specific texture or shape
C5-T1
what is the brachial plexus formed by?
C1-C4
what is the cervical plexus formed by?
stimulus
when processing at the receptor level, _____________ energy must be converted into a graded potential
receptor
when processing at the receptor level, the ______________ must have specificity for the stimulus energy