chapter 12 H&A

The perineurium? A. surrounds nerve cell bodies. B. surrounds individual axons and their Schwann cells. C. bundles axons into fascicles. D. bundles fascicles into nerves. E. bundles fascicles into axons.

C. bundles axons into fascicles.

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 A. 1, 2, 3, 4, 5 B. 1, 5, 2, 3, 4 C. 1, 5, 3, 2, 4 D. 5, 2, 3, 4, 1 E. 4, 5, 3, 2, 1

A. 1, 2, 3, 4, 5

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

A. alpha motor neurons transmit action potentials to muscle causing contraction

Reflex arcs? A. are capable of receiving a stimulus and yielding a response. B. are the basic structural units of the nervous system. C. occur primarily in the cerebral cortex of the brain. D. involve inhibitory neurons. E. do not involve the spinal cord.

A. are capable of receiving a stimulus and yielding a response.

Muscle spindles? A. are innervated by gamma motor neurons. B. originate in the spinal cord. C. are specialized nerve cells. D. are found encapsulated in nerve endings. E. are innervated by alpha motor neurons.

A. are innervated by gamma motor neurons.

The cutaneous sensory distribution of a spinal nerve can be mapped as a? A. dermatome. B. plexitome. C. microtome. D. myotome. E. superdome.

A. dermatome.

Structurally, the simplest reflex is the? A. stretch reflex. B. Golgi tendon reflex. C. reciprocal reflex. D. alternating reflex. E. withdrawal reflex.

A. stretch reflex.

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.

B. The posterior horn of the cord contains the cell bodies of motor neurons.

In the Golgi tendon reflex? A. muscle spindles detect tension in a tendon. B. alpha motor neurons are inhibited causing muscle relaxation. C. gamma motor neurons cause muscle contraction. D. there is reciprocal innervation to facilitate the reflex. E. alpha motor neurons are stimulated causing muscle contraction.

B. alpha motor neurons are inhibited causing muscle relaxation.

The conus medullaris? A. anchors the spinal cord to the coccyx. B. is a tapered, cone like region immediately inferior to the lumbar enlargement. C. marks the exit of nerves to the upper extremity. D. is located adjacent to the foramen magnum. E. is inferior to the cauda equina.

B. is a tapered, cone like region immediately inferior to the lumbar enlargement.

The endoneurium? A. surrounds nerve cell bodies. B. surrounds individual axons and their Schwann cells. C. bundles axons into fascicles. D. bundles fascicles into nerves. E. surrounds nerve tracts in the spinal cord

B. surrounds individual axons and their Schwann cells.

Dermatomal maps are important clinically because they? A. can be used to check for motor function. B. locate the position of cranial nerves. C. can be used to help locate nerve damage. D. indicate what muscles are innervated by each spinal nerve. E. can be used to detect cranial nerve damage.

C. can be used to help locate nerve damage.

In the spinal cord, white matter is organized into? A. horns and the gray matter into columns. B. horns and the gray matter into roots. C. columns and the gray matter into horns. D. columns and the gray matter into tracts.

C. columns and the gray matter into horns.

What space, found between the vertebral wall and the dura mater, is the area for injecting anesthesia for childbirth? A. subarachnoid space B. subdural space C. epidural space D. epipial space

C. epidural space

The spinal cord begins at the? A. cerebellum. B. medulla oblongata. C. foramen magnum. D. conus medullaris E. 1st cervical vertebrae.

C. foramen magnum.

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

C. muscles of the arm and forearm

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

D. 8 cervical - 12 thoracic - 5 lumbar - 5 sacral - 1 coccygeal

The epineurium? A. surrounds nerve cell bodies. B. surrounds individual axons and their Schwann cells. C. bundles axons into fascicles. D. bundles fascicles into nerves. E. bundles fascicles into axons.

D. bundles fascicles into nerves.

Which portion of a reflex arc is most likely to be located entirely within the central nervous system? A. sensory neuron B. motor neuron C. effector cell D. interneuron E. receptor cell

D. interneuron

The spinal cord? A. controls the reticular activating system. B. stores reflexive memory. C. forms memory engrams. D. links the peripheral nervous system to the brain. E. is characterized by conscious activity.

D. links the peripheral nervous system to the brain.

Ventral rami of some spinal nerves join with each other to form a? A. ganglion. B. dermatome. C. cord. D. plexus. E. nerve.

D. plexus.

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 A. 5, 1, 2, 3, 4 B. 5, 3, 2, 4, 1 C. 5, 4, 3, 2, 1 D. 5, 2, 3, 4, 1 E. 5, 4, 2, 1, 3

E. 5, 4, 2, 1, 3

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.

E. All of these choices are correct.

The thickest of the meninges is the? A. pia mater. B. arachnoid mater. C. subdural space. D. subarachnoid space. E. dura mater.

E. dura mater.

A reflex that protects limbs by removing them from painful stimuli is the? A. stretch reflex. B. crossed extensor reflex. C. Golgi tendon reflex. D. alternating reflex. E. withdrawal reflex

E. withdrawal reflex