Straighterline A&P Chapter 12 Questions And Answers With Complete Solutions

There are _____ enlargements of the spinal cord where nerves supplying the extremities enter and leave. correct answer: two The spinal cord correct answer: links the peripheral nervous system to the brain The spinal cord begins at the correct answer: foramen magnum The conus medullaris correct answer: is a tapered, cone like region immediately inferior to the lumbar enlargement. The spinal cord ends at the correct answer: 2nd lumbar vertebrae The thickest of the meninges is the correct answer: dura mater The sac surrounding the spinal cord is the correct answer: thecal sac The middle, thin, spider-like meninx is the correct answer: arachnoid mater What space, found between the vertebral wall and the dura mater, is the area for injecting anesthesia for childbirth? correct answer: epidural space During a spinal tap, cerebrospinal fluid is obtained from which of the following locations? correct answer: subarachnoid space What structure anchors the thecal sac and conus medullaris to the coccyx? correct answer: filum terminale Where is cerebrospinal fluid found around the spinal cord? correct answer: subarachnoid space Which of the following is false? A. The dorsal root of the spinal cord conveys sensory (afferent) nerve impulses to the spinal cord. B. The posterior horn of the cord contains the cell bodies of motor neurons. C. The ventral root is formed by the axons of neurons in the lateral and anterior horns. D. The dorsal and ventral roots unite to form spinal nerves. E. The ventral root of the spinal cord conveys motor (efferent) nerve impulses away from the spinal cord. correct answer: B. The posterior horn of the cord contains the cell bodies of motor neurons The ventral root of a spinal nerve contains correct answer: only motor fibers The sensory root of a spinal nerve is also referred to as correct answer: dorsal root The motor root of a spinal nerve is also referred to as the correct answer: ventral root The cross-sectional view of the spinal cord reveals white matter on the correct answer: outside, gray matter on the inside, and a ventral motor root. In the spinal cord, white matter is organized into correct answer: columns and the gray matter into horns. What structure makes the dorsal root different from the ventral root? correct answer: the dorsal root has a ganglion What is found in the dorsal root ganglion? correct answer: The cell bodies of pseudo-unipolar sensory neurons. What is found the lateral gray horns of the spinal cord? correct answer: the cell bodies of autonomic motor neurons Structurally, the simplest reflex is the correct answer: stretch reflex Reflex arcs correct answer: are capable of receiving a stimulus and yielding a response. Which portion of a reflex arc is most likely to be located entirely within the central nervous system? correct answer: interneuron Reflexes correct answer: are homeostatic Reflexes function in A. removing the body from painful stimuli. B. keeping the body from falling. C. maintaining blood pressure. D. maintaining blood CO2 levels. E. All of these choices are correct. correct answer: E. All of these choices are correct. Place the following parts of a reflex arc in the correct order beginning with the sensory receptor. (1) motor neuron (2) interneuron (3) effector (4) sensory neuron (5) sensory receptor correct answer: 5, 4, 2, 1, 3 The sensory receptor of the stretch reflex is the correct answer: muscle spindle Stretch reflexes correct answer: aid in maintaining proper posture. Which of the following events in a stretch reflex occurs last? A. alpha motor neurons transmit action potentials to muscle causing contraction B. muscle spindle detects stretch of muscle C. afferent neurons conduct action potentials to the spinal cord D. afferent neurons synapse with alpha motor neurons E. muscle is stretched correct answer: A. alpha motor neurons transmit action potentials to muscle causing contraction Muscle spindles correct answer: are innervated by gamma motor neurons. Muscles and glands that are capable of producing a response when stimulated by motor neurons are called correct answer: effectors The knee-jerk reflex involves which of the following? A. sensory and motor neurons B. sensory, association and motor neurons C. sensory, motor and inhibitory interneurons D. sensory and association neurons E. the brain correct answer: sensory and motor neurons Gamma motor neurons correct answer: regulate the sensitivity of the muscle spindle. The muscles of the back contract to straighten so that you sit at a more erect posture and subsequently the muscles are suddenly stretched as you nod off. Which of the following best represents the sequence of events when you start to nod off? (1) muscles of the back are stretched (2) the muscle spindle is stretched (3) action potentials in sensory neurons of the muscle spindles increase (4) action potentials in alpha motor neurons of skeletal muscle fibers increase (5) skeletal muscle of the back contract correct answer: 1, 2, 3, 4, 5 Doctor Johansson wants to test a patient's reflexes by briskly striking the patellar tendon with a reflex hammer. Which reflex is Dr. Johansson testing? correct answer: the knee-jerk reflex The reflex that prevents excessive tension in a muscle is the correct answer: Golgi tendon reflex Sam is curling very heavy weights and suddenly drops them. Which reflex forced this action by Sam to prevent tendon damage? correct answer: Golgi tendon reflex Stimulation of the Golgi tendon organs result in which of the following changes in the reflex arc? A. stimulation of a stimulatory association neuron B. stimulation of an inhibitory neuron C. decreased action potentials in alpha motor neurons D. contraction of skeletal muscle fibers E. stimulation of an inhibitory neuron and decreased action potentials in alpha motor neurons correct answer: E. stimulation of an inhibitory neuron and decreased action potentials in alpha motor neurons A reflex that protects limbs by removing them from painful stimuli is the correct answer: withdrawal reflex Reciprocal innervation correct answer: reinforces the withdrawal reflex. Initiating the withdrawal reflex in both legs at the same time would cause one to correct answer: fall Because the stretch reflexes can be traced back along certain spinal nerve routes, correct answer: it is possible to determine what level of the spinal cord may have been damaged. The adaptive significance of the crossed extensor reflex when a person steps on a tack is to correct answer: prevent the person from falling down The endoneurium correct answer: surrounds individual axons and their Schwann cells. The epineurium correct answer: bundles fascicles into nerves. The perineurium correct answer: bundles axons into fascicles Which of the following statements concerning the structure of spinal nerves is true? A. The ventral root contains motor or efferent fibers. B. The ventral root has a prominent root ganglion. C. Rootlets from the surface of the spinal cord form the dorsal and ventral rami. D. Each spinal nerve is formed by the union of a cranial nerve and a spinal nerve. E. Spinal nerves do not have specific cutaneous distributions. correct answer: A. The ventral root contains motor or efferent fibers. 49. Which of the following combinations indicates the correct distribution of spinal nerve pairs? A. 7 cervical - 12 thoracic - 6 lumbar - 5 sacral - 1 coccygeal B. 7 cervical - 12 thoracic - 5 lumbar - 6 sacral - 1 coccygeal C. 8 cervical - 12 thoracic - 6 lumbar - 4 sacral - 1 coccygeal D. 8 cervical - 12 thoracic - 5 lumbar - 5 sacral - 1 coccygeal E. 7 cervical - 13 thoracic - 6 lumbar - 5 sacral - 1 coccygeal correct answer: D. 8 cervical - 12 thoracic - 5 lumbar - 5 sacral - 1 coccygeal A collapsed intervertebral foramen could affect all of the following spinal nerves EXCEPT A. C2-C8 B. T1-T12 C. L1-L5 D. C1 correct answer: D. C1 There are ________ cervical spinal nerves. correct answer: eight A man was in an accident and severed his spinal cord between C6 and C7. Which of the following would NOT occur? A. loss of sensation in the trunk below the shoulders, the lower limbs and portions of the arms B. loss of use of the phrenic nerves and paralysis of the diaphragm C. loss of movement in the lower limbs D. loss of the use of the intercostals nerves, and breathing would be affected because the intercostals muscles would be paralyzed E. loss of sensation and movement in the jaw correct answer: B. loss of use of the phrenic nerves and paralysis of the diaphragm Damage to which of these nerves would be most life-threatening? A. median nerves B. phrenic nerves C. lumbar nerves D. sciatic nerves E. radial nerves correct answer: B. phrenic nerves The brachial plexus supplies nerves that function to contract which of the following? A. the diaphragm B. intercostal muscles C. muscles of the arm and forearm D. muscles of the lower limb E. abdominal muscles correct answer: C. muscles of the arm and forearm Dermatomal maps are important clinically because they correct answer: can be used to help locate nerve damage. The cutaneous sensory distribution of a spinal nerve can be mapped as a correct answer: dermatome Ventral rami of some spinal nerves join with each other to form a correct answer: plexus If the ventral root of a spinal nerve were cut, the regions innervated by that spinal nerve would experience complete loss of correct answer: movement The branch of a spinal nerve that innervates deep muscles on the dorsal thorax is the correct answer: dorsal ramus Intercostal nerves are formed from the correct answer: ventral rami of thoracic spinal nerves Which of the following nerves is a branch of both the cervical plexus and the brachial plexus? A. axillary B. femoral C. phrenic D. sciatic E. splanchnic correct answer: C. phrenic Damage to the phrenic nerve would result in correct answer: difficulty breathing Spinal nerves C5-T1 make up the ____________ plexus. correct answer: brachial Which of the following nerves is part of the brachial plexus? A. peroneal B. ansa cervicalis C. ischiadic (sciatic) D. musculocutaneous E. femoral correct answer: D. musculocutaneous Improper use of crutches could cause compression of the _____ nerve. correct answer: radial When a person hits their funny bone, they cause temporary damage to the _____ nerve. correct answer: ulnar An injury to the wrist that results in edema in the carpal tunnel would compress the correct answer: median nerve Using the biceps brachii to flex the forearm requires innervation of the _____ nerve. correct answer: musculocutaneous When someone taps you on your shoulder, they stimulate the ____ nerve. correct answer: axillary If you pinch your index finger in a door, pain sensations are carried via the ____ nerve. correct answer: median Which of the following nerves is associated with the lumbosacral plexus? A. phrenicB. medianC. musculocutaneous D. ulnarE. obturator correct answer: obturator Spinal nerves exiting the cord from the level of L4 to S4 form the correct answer: sacral plexus The sciatic nerve is composed of the correct answer: tibial nerve and common fibular nerve Which nerve is involved when a dancer points his/her toes? correct answer: tibial The gastrocnemius muscle is most likely to be innervated by the _____ nerve. correct answer: tibial When a person sits on a hard surface for a period of time, his foot or leg may "go to sleep." This sensation is the result of compressing the _____ nerve. correct answer: sciatic Adduction of the thigh involves the correct answer: obturator nerve If a person fell down the steps and then developed pain down his anterior thigh into the knee, which of the following spinal nerves was probably damaged? correct answer: femoral Branches of the ____ nerve are anesthetized before a doctor performs an episiotomy for childbirth. correct answer: pudendal innervates the triceps brachii correct answer: radial nerve innervates the deltoid and teres minor muscles correct answer: axillary nerve provides motor innervation to the biceps brachii correct answer: musculocutaneous innervates two forearm muscles plus most of the intrinsic hand muscles correct answer: ulnar nerve innervates all but one of the flexor muscles of the forearm and most of the hand muscles near the thumb correct answer: median nerve loss of sensation correct answer: anesthesia inflammation of a nerve correct answer: neuritis Pain along a nerve tract correct answer: neuralgia pain radiating down the back of the thigh and leg correct answer: sciatica stiffnes in the neck and headache correct answer: meningitis innervates the muscles that adduct the thigh correct answer: obturator nerve innervates the iliopsoas, sartorius, and quadriceps femoris correct answer: femoral nerve branches to form the medial and lateral plantar nerves correct answer: tibial nerve innervates the anterior and lateral muscles of the leg correct answer: common fibular nerve innervates muscles of the pelvic floor correct answer: coccygeal plexus removing hand from a hot iron correct answer: withdrawal reflex a reflex that helps prevent falls correct answer: crossed extensor reflex partially responsible for a weight lifter suddenly dropping a weight that is too heavy correct answer: Golgi tendon reflex associated with withdrawal and stretch reflex correct answer: reciprocal innervation the knee-jerk correct answer: stretch reflex the meninx bound tightly to brain and spinal cord correct answer: pia mater most superficial and thickest meninx correct answer: dura mater functional unit of the nervous system correct answer: reflex arc separates dura mater from periosteum correct answer: epidural space the middle meninx correct answer: arachnoid mater In the PNS, nerves are held together by correct answer: epineurium Cutaneous sensory distribution of a spinal nerve can be mapped as a ________. correct answer: dermatome The largest peripheral nerve in the body is the ______ nerve. correct answer: sciatic Branches of the pudendal nerve are anesthetized during childbirth before the doctor performs a(an) _______________. correct answer: episiotomy The __________ __________ is the basic functional unit of the nervous system and is capable of receiving a stimulus and producing a response. correct answer: reflex arc