Bio 201: Chapter 13-The Peripheral
Nervous System and Reflex Activity
2024. Already Graded A+.
abdominal reflexes - ANS-tests the spinal cord integrity from T8-T12
autonomic (visceral) - ANS-activate effectors (smooth or cardiac muscles or glands)
axillary nerve - ANS-innervates the deltoid and teres minor muscle and the skin and
joint capsule of the shoulder
BRACHIAL PLEXUS - ANS-gives rise to all nerves that innervate the upper limbs
-ventral rami of C5-C8 and most of the T1 ramus
cervical plexus - ANS-formed by the ventral rami of C1-C4
common fibular nerve - ANS-wraps the head of the fibula
-innervated the knee joint, skin of the lateral calf & dorsum of the foot
cranial nerves - ANSI. olfactory: smell
II. optic: vision
III. oculomotor: eye movement
IV. trochlear: "pulley" for the eye
V. trigeminal: facial and chewing muscles
VI. abducens: abducts the eye
VII. facial: facial expression
VIII. vestibulocochlear: hearing & balance
IX. glossopharyngeal: toungue and pharynx
X. vagus: head, neck, thorax & abdomen
XI. accessory: accessory to the vagus nerve
XII. hypoglossal: tongue movement
crossed-extensor reflex - ANS-accompanies the flexor reflex in weight-bearing limbs
-important in maintaining balance
dermatomes - ANS-the area of skin innervated by the cutaneous branches of a single
spinal nerve
dorsal roots - ANS-contain sensory (afferent) fibers that arise from sensory neurons i
the dorsal root ganglia and conduct impulses from peripheral receptors to the spinal
cord
encapsulated dendritic endings - ANS-all mechanoreceptors
-enclosed in a connective tissue capsule
, femoral nrve - ANS-the largest, terminal nerve of this plexus
-innervates anterior thigh muscles
flexor/withdrawal reflex - ANS-initiated by a painful stimulus an causes automatic
withdrawal of the threatened body part from the stimulus
free or naked nerve endings - ANS-present everywhere in the body
-abundant in the epithelia and connective tissues
ganglia - ANS-collections of neuron cell bodies associated with nerves in the PNS
general sensory receptors - ANS- involved in tactile sensations
-proprioceptors
-either unencapsulated or encapsulated nerve endings
Golgi tendon organs - ANS-proprioceptors
-cause contracting muscles to relax
-encapsulated
golgi tendon reflexes - ANS- produce muscle relaxation and lengthening in response to
tension
hair follicle receptors - ANS-free nerve endings that wrap around hair follicles
-light touch receptors that detect the bending of hairs
Hilton's Law - ANS-any nerve serving a muscle that produces movement at a joint also
innervates the joint and the skin over that joint
intercostal nerves - ANS-the ventral rami of T1-T12
-supply the intercostal muscles lying between the ribs
Joint kinesthetic receptors - ANS-proprioceptors
-monitor stretch in the articular capsules that enclose synovial joints
-encapsulated
LUMBAR PLEXUS - ANS- arises from spinal nerves L1-L4
median nerve - ANS-innervates five intrinsic muscles of the lateral palm
Meissner's corpuscles or tactile corpuscles - ANS-found just beneath the epidermis
-numerous in hairless skin areas
-receptors for discriminative touch
-encapsulated
Merkel discs - ANS-lie deeper within the layers of the epithelium
Nervous System and Reflex Activity
2024. Already Graded A+.
abdominal reflexes - ANS-tests the spinal cord integrity from T8-T12
autonomic (visceral) - ANS-activate effectors (smooth or cardiac muscles or glands)
axillary nerve - ANS-innervates the deltoid and teres minor muscle and the skin and
joint capsule of the shoulder
BRACHIAL PLEXUS - ANS-gives rise to all nerves that innervate the upper limbs
-ventral rami of C5-C8 and most of the T1 ramus
cervical plexus - ANS-formed by the ventral rami of C1-C4
common fibular nerve - ANS-wraps the head of the fibula
-innervated the knee joint, skin of the lateral calf & dorsum of the foot
cranial nerves - ANSI. olfactory: smell
II. optic: vision
III. oculomotor: eye movement
IV. trochlear: "pulley" for the eye
V. trigeminal: facial and chewing muscles
VI. abducens: abducts the eye
VII. facial: facial expression
VIII. vestibulocochlear: hearing & balance
IX. glossopharyngeal: toungue and pharynx
X. vagus: head, neck, thorax & abdomen
XI. accessory: accessory to the vagus nerve
XII. hypoglossal: tongue movement
crossed-extensor reflex - ANS-accompanies the flexor reflex in weight-bearing limbs
-important in maintaining balance
dermatomes - ANS-the area of skin innervated by the cutaneous branches of a single
spinal nerve
dorsal roots - ANS-contain sensory (afferent) fibers that arise from sensory neurons i
the dorsal root ganglia and conduct impulses from peripheral receptors to the spinal
cord
encapsulated dendritic endings - ANS-all mechanoreceptors
-enclosed in a connective tissue capsule
, femoral nrve - ANS-the largest, terminal nerve of this plexus
-innervates anterior thigh muscles
flexor/withdrawal reflex - ANS-initiated by a painful stimulus an causes automatic
withdrawal of the threatened body part from the stimulus
free or naked nerve endings - ANS-present everywhere in the body
-abundant in the epithelia and connective tissues
ganglia - ANS-collections of neuron cell bodies associated with nerves in the PNS
general sensory receptors - ANS- involved in tactile sensations
-proprioceptors
-either unencapsulated or encapsulated nerve endings
Golgi tendon organs - ANS-proprioceptors
-cause contracting muscles to relax
-encapsulated
golgi tendon reflexes - ANS- produce muscle relaxation and lengthening in response to
tension
hair follicle receptors - ANS-free nerve endings that wrap around hair follicles
-light touch receptors that detect the bending of hairs
Hilton's Law - ANS-any nerve serving a muscle that produces movement at a joint also
innervates the joint and the skin over that joint
intercostal nerves - ANS-the ventral rami of T1-T12
-supply the intercostal muscles lying between the ribs
Joint kinesthetic receptors - ANS-proprioceptors
-monitor stretch in the articular capsules that enclose synovial joints
-encapsulated
LUMBAR PLEXUS - ANS- arises from spinal nerves L1-L4
median nerve - ANS-innervates five intrinsic muscles of the lateral palm
Meissner's corpuscles or tactile corpuscles - ANS-found just beneath the epidermis
-numerous in hairless skin areas
-receptors for discriminative touch
-encapsulated
Merkel discs - ANS-lie deeper within the layers of the epithelium
