chapter 13 peripheral nervous system and reflex activity
In order for you to realize there has been a sensory change, it has to reach the __________ level of processing. receptor abstraction perceptual circuit
perceptual
The final level of neural integration in the somatosensory system is the __________ level. receptor perceptual abstraction circuit
perceptual
Choose the true statement. The flexor reflex is initiated by painful stimuli. The knee jerk reflex is an example of a superficial reflex. The abdominal reflex is an example of a tendon reflex. Stretch reflexes are hyperactive in comatose patients.
The flexor reflex is initiated by painful stimuli.
Three main levels of neural integration operate in the somatosensory system. Which level involves the spinal cord? perceptual level circuit level integrative level receptor level
circuit level
1. nociceptors 2. chemoreceptors 3. photoreceptors 4. mechanoreceptors 5. thermoreceptors
1. pain 2. chemicals in solution 3. light energy 4. stretch 5. temperature
Which of the receptor types might function as a nociceptor? Various general sensory receptors. A C E All of the listed responses are correct.
A (Nociceptors respond to potentially damaging stimuli, such as noxious chemicals or extremes of temperature or pH. Nociceptors are generally associated with free nerve endings of specialized neurons.)
Which of these receptor types functions as an exteroceptor? Various general sensory receptors. C D E All of the listed responses are correct.
All of the listed responses are correct. (All of the structures illustrated are sensitive to stimuli arising outside the body.)
A herniated lumbar disc could interfere with ______. skin sensations from the lateral thigh skin sensations from the medial thigh adduction of the thigh All of the listed responses are correct.
All of the listed responses are correct. (the branches of lumbar plexus include the following nerves: femoral, obturator, lateral femoral cutaneous, iliohypogastric, ilioinguinal, and genitofemoral. A herniated lumbar disc could affect any nerves arising from the lumbar plexus.)
Choose the FALSE statement about nerves. Axons make up a majority of the matter in a nerve. Nerves can carry only sensory information, only motor information, or a mixture of sensory and motor information. Nerves consist of parallel bundles of myelinated and nonmyelinated axons. Nerve axons are surrounded by a loose connective tissue layer called the endoneurium.
Axons make up a majority of the matter in a nerve.
Which of the receptor types shown here functions exclusively as a proprioceptor? Various general sensory receptors. B C D All of the listed responses are correct.
B (Proprioceptors are sensitive to stimuli associated with body movements. The muscle spindle shown in B is responsive to muscle stretch.)
Which pathway(s) compose the autonomic nervous system? Comparison of peripheral neural pathways of somatic and autonomic nervous systems. A only B only C only B and C
B and C (Efferent pathways of the ANS are characterized by a two-neuron chain from the CNS to the effector organ. Both B and C show such an arrangement consisting of both pre- and postganglionic neurons.)
If the phrenic nerve were severed, what would be the most immediate effect? The ability to swallow would be blocked. The sense of smell would be blocked. Breathing would stop. The upper limbs would be paralyzed.
Breathing would stop.
CNS nerve fibers regenerate because of the actions of Schwann cells. True False
False (PNS nerve fibers regenerate because of the actions of Schwann cells.)
__________ are receptors that can respond to painful stimuli. Mechanoreceptors Chemoreceptors Nociceptors Photoreceptors
Nociceptors (Nociceptors respond to potentially damaging stimuli that result in pain.)
Which of the following statements about cranial nerves is FALSE? The cranial nerves are limited to the head and neck region. There are 12 pairs of cranial nerves. Most cranial nerves serve structures in the head and neck. In most cases, cranial nerves are named for the structures they serve or for their functions.
The cranial nerves are limited to the head and neck region
Which of the following is FALSE regarding the sciatic nerve? The sciatic nerve is the thickest and longest nerve in the body. The sciatic nerve supplies the entire lower limb except the anteromedial thigh. The sciatic nerve is the largest branch of the sacral plexus. The sciatic nerve is a single nerve.
The sciatic nerve is a single nerve.
__________ MOSTLY do NOT exhibit the property of adaptation. Photoreceptors Tonic receptors Phasic receptors Sensory receptors
Tonic receptors (Tonic receptors provide a sustained response with little or no adaptation. Nociceptors and MOST proprioceptors are tonic receptors because of the protective importance of the information.)
Which of the following cranial nerves carries only motor information? trigeminal optic olfactory abducens
abducens
Proprioceptors advise the brain of __________. body movements chemical imbalances temperature of the skin pain localization
body movements
Which of the following structures is NOT a part of the peripheral nervous system (PNS)? ganglia motor endings brain sensory receptors
brain
Sciatica has no direct affect on ______. perception of sensory information from the skin that covers the front of the leg perception of sensory information from the skin that covers the back of the leg control of the adductor longus control of the semimembranosus
control of the adductor longus (This muscle is innervated by the obturator nerve, which is a branch of the lumbar plexus.)
In carpal tunnel syndrome, there may be tingling and numbness in the thumb due to compression of the ______. thumb muscles cutaneous branches of the median nerve None of the listed responses is correct. muscular branches of the posterior cord that supply the median nerve
cutaneous branches of the median nerve
The hyperalgesia that is common in phantom limb pain could potentially be blocked if a new drug was developed that could prevent (without triggering any side-effects) the ______. diffusion of enkephalins across synaptic clefts release of enkephalins diffusion of calcium ions through NMDA receptors binding of enkephalins to NMDA receptors
diffusion of calcium ions through NMDA receptors
Which connective tissue layer directly surrounds individual axons in a nerve? perineurium endomysium endoneurium epineurium
endoneurium
Most central nervous system axons are able to regenerate following injury. True False
false
Damage to the ulnar nerve could result in the inability to ______. All of the listed responses are correct. supinate or pronate the forearm extend the forearm flex the wrist
flex the wrist
The first two pairs of cranial nerves attach to the __________. spinal cord forebrain brain stem medulla oblongata
forebrain
Part complete The circular structures shown within pathways B and C represent which of the following? Comparison of peripheral neural pathways of somatic and autonomic nervous systems. nuclei ganglia rami tracts
ganglia
Which of the following have nonencapsulated (free) nerve endings? tactile (Meissner's) corpuscles muscle spindles lamellar (Pacinian) corpuscles hair follicle receptors
hair follicle receptors
Simple receptors that are particularly abundant in epithelia and connective tissue tend to __________. only have encapsulated nerve endings be mechanoreceptors be sense organs have nonencapsulated (free) nerve endings
have nonencapsulated (free) nerve endings
If "wrist drop" were to appear, there would also be an increased probability of ______. inability to pronate the forearm inability to flex the fingers inability to contract the biceps brachii inability to extend the forearm
inability to extend the forearm (Wrist drop occurs due to paralysis of the radial nerve. This nerve provides innervations to the triceps brachii muscle, which is the prime mover of forearm extension.)
Which type of sensory receptor allows us to feel an insect landing on our skin? thermoreceptor mechanoreceptor nociceptor chemoreceptor
mechanoreceptor (Mechanoreceptors respond to mechanical force such as pressure, vibration, stretch, and touch, allowing us to feel an insect landing on our skin.)
The pinching motion (with opposed thumb and forefinger) is highly dependent upon impulses transmitted by the __________. musculocutaneous nerve axillary nerve median nerve ulnar nerve
median nerve
In carpal tunnel syndrome, the __________ is compressed. median nerve musculocutaneous nerve radial nerve axillary nerve
median nerve (The median nerve descends through the arm and forearm before passing through the wrist. Compression of this nerve in the anterior wrist causes carpal tunnel syndrome.)
Spinal nerves are all classified as __________. mixed nerves sensory nerves motor nerves afferent nerves
mixed nerves
Hiccups could occur if there was irritation or damage to the ______. motor branches of ventral rami associated with the C3-C5 region of the spinal cord cutaneous branches of rami associated with the C3-C5 region of the spinal cord afferent neurons of spinal nerves associated with the C3-C5 region of the spinal cord dorsal rami of spinal nerves associated with the C3-C5 region of the spinal cord
motor branches of ventral rami associated with the C3-C5 region of the spinal cord
Fast-adapting receptors are called __________. threshold receptors phasic receptors sensory receptors tonic receptors
phasic receptors
Which of the following structures is involved in the projection level of motor control? cerebellum primary motor cortex cerebral basal nuclei spinal cord
primary motor cortex
The lowest level of motor control is the __________. upper motor level projection level segmental level precommand level
segmental level
In a reflex arc, the __________ transmits afferent impulses to the central nervous system. receptor integration center sensory neuron effector
sensory neuron
The brachial plexus can be palpated at the lower lateral border of the sternocleidomastoid muscle. Injury to the brachial plexus could cause weakness or paralysis to all of the following EXCEPT the ______. sternocleidomastoid muscle tbiceps brachii muscle deltoid muscle muscles that flex the wrist and fingers
sternocleidomastoid muscle
The knee-jerk reflex is an example of a __________. flexor reflex superficial reflex tendon reflex stretch reflex
stretch reflex (The most familiar clinical example of a stretch reflex is the knee-jerk reflex. The overall goal of a stretch reflex is to maintain a muscle's length and in turn maintain body position. For example, the knee-jerk reflex, during which the knee extensors contract in response to being stretched, helps keep your knees from buckling when you are standing upright.)
Which of the following releases the neurotransmitter norepinephrine? Comparison of peripheral neural pathways of somatic and autonomic nervous systems. terminus of a somatic motor neuron terminus of a parasympathetic postganglionic neuron terminus of a sympathetic preganglionic neuron terminus of a sympathetic postganglionic neuron
terminus of a sympathetic postganglionic neuron (In cases of dual innervation, release of norepinephrine at synapses within effector organs is characteristic of the sympathetic division (B). Sympathetic postganglionic neurons release acetylcholine in areas that receive only sympathetic fibers.)
Which of the following is NOT used to classify sensory receptors? the type of stimulus they detect location the number of dendritic endings present structural complexity
the number of dendritic endings present
All spinal nerves are mixed nerves. True False
true
Most nerves are able to transmit impulses both to and from the central nervous system. True False
true
Which cranial nerve transmits auditory information? vestibulocochlear vagus abducens optic
vestibulocochlear
A nerve that carries autonomic signals away from the central nervous system is classified as a __________. visceral afferent visceral efferent somatic efferent somatic afferent
visceral efferent
