Peripheral Nervous System

43) A region of skin has a great number of sensory neurons, and each neuron has a relatively small receptive field. The two-point discrimination threshold for this skin region might be:

A) 5 mm.

27) Which plexus provides motor and sensory innervation to the upper limb?

A) brachial plexus

26) During a boxing match, Sammy was hit on the side of the neck. He stopped breathing temporarily due to damage to the:

A) cervical plexus.

28) The phrenic nerve is a member of the:

A) cervical plexus.

8) What connective tissue sheath wraps the axon of a neuron?

A) endoneurium

63) In the crossed-extension reflex, if the right leg flexes, then the left leg:

A) extends.

37) Potentially damaging stimuli that result in pain are selectively detected by:

A) nociceptors.

23) Which of the following carries sensory information only?

A) posterior (dorsal) root

4) Which division of the peripheral nervous system (PNS) detects stimuli and carries them to the central nervous system (CNS)?

A) sensory

33) Olfactory receptors depolarize in response to an odorant, turning a stimulus into an electrical signal. This conversion is known as:

A) sensory transduction.

2) You feel a mosquito land on your arm. This stimulus is carried to the central nervous system (CNS) by the:

A) somatic sensory division.

64) What cranial nerves are involved in the sensory and the motor roles for the corneal blink reflex?

A) trigeminal nerve (V) as sensory; facial nerve (VII) as motor

15) The cranial nerves that have neural connections with the tongue include all of the following EXCEPT:

A) trochlear nerve (IV).

60) What reflex causes muscle relaxation?

B) Golgi tendon reflex

54) Which of the following does NOT characterize a reflex?

B) Neural integration of a reflex usually occurs in the PNS.

34) Sensory transduction occurs in:

B) PNS sensory neurons.

12) The vagus nerve is represented by Roman numeral:

B) X.

42) The speed of nerve impulse transmission through the axon of a sensory neuron will be quickest in:

B) a large-diameter, myelinated axon.

55) Which of the following must occur first in a reflex arc?

B) detection by receptor and delivery of stimulus

9) Bundles of axons within a nerve are known as:

B) fascicles.

61) The inability to produce a gag reflex could indicate a problem with the:

B) glossopharyngeal nerve (IX) or vagus nerve (X).

40) Which mechanoreceptor detects deep pressure?

B) lamellated corpuscle

20) Where does the motor portion of the facial nerve (VIII) originate?

B) nuclei in the pons and medulla

16) Which cranial nerve detects smell?

B) olfactory nerve (I)

25) A network of nerves is known as a:

B) plexus.

41) Mechanoreceptors might detect which of the following sensations?

B) pressure

35) Sensory receptors that adapt to stimuli after a certain period of time are:

B) rapidly adapting receptors.

1) Which division detects stimuli of the general senses and special senses?

B) somatic sensory division

51) What type of motor neuron stimulates skeletal muscle fibers to contract by the excitation-contraction mechanism?

B) α-motor neuron

53) Place the following steps in order for motor control. 1. Upper motor neurons stimulate lower motor neurons. 2. Sensory information is relayed back to the cerebellum so movement can be modified if needed. 3. Upper motor neurons in the premotor cortex select a motor program. 4. Lower motor neurons stimulate a skeletal muscle to contract. 5. The basal nuclei enable the thalamus to stimulate upper motor neurons of the primary cortex.

C) 3, 5, 1, 4, 2

22) Which of the following is INCORRECT about the numbers of spinal nerves?

C) 7 pairs of cervical spinal nerves

48) What part of the nervous system integrates and interprets information from PNS sensory neurons?

C) central nervous system (CNS)

62) Which of the following complements the flexion (withdrawal) reflex?

C) crossed-extension reflex

45) Regions of skin supplied by a spinal nerve for somatic sensation are known as:

C) dermatomes.

38) Photoreceptors are found only in the:

C) eye.

59) Determine the polysynaptic reflex from this list of examples.

C) flexion (withdrawal) reflex

18) Ms. Parker has damage to the sensory root of the facial nerve (VII). Which of the following symptoms matches this information?

C) inability to taste

31) What do most of the anterior rami of the thoracic spinal nerves serve?

C) intercostal nerves

49) What connects the upper motor neurons to lower motor neurons?

C) interneurons

36) The stretch of a full urinary bladder is detected by a(n):

C) interoceptor.

56) What type of sensory receptors are muscle spindles and Golgi tendon organs?

C) mechanoreceptor

29) Which of the following does NOT belong to the brachial plexus?

C) phrenic nerve

46) Ms. Carroll went to her doctor's office with pain in her right shoulder blade and learned she was having a gallbladder attack. You're not surprised to hear about the unusual location of her pain since it is known as:

C) referred pain.

47) Visceral pain may be perceived as cutaneous pain, a phenomenon known as:

C) referred pain.

24) The anterior root and posterior root fuse to form a(n):

C) spinal nerve.

39) Your wrap your hands around a warm cup of hot chocolate. This sensation is detected by a:

C) thermoreceptor.

30) Striking the "funny" bone is actually stimulation (or injury) to the:

C) ulnar nerve.

14) Which cranial nerve is NOT involved in eye movement?

C) vestibulocochlear nerve (VIII)

19) Loss of balance and equilibrium can indicate damage to the:

C) vestibulocochlear nerve (VIII).

57) What is NOT true of muscle spindles?

D) Muscle spindles are found within tendons.

21) What controls the movement of rectus abdominis, a skeletal muscle on the anterior surface of the body?

D) anterior ramus

7) Which of the following houses motor neurons?

D) anterior root of spinal nerve

6) Mixed nerves house:

D) both sensory and motor neurons.

5) What is the outermost connective tissue covering of a nerve?

D) epineurium

13) Which cranial nerve is generally thought of as a mixed nerve?

D) glossopharyngeal nerve (IX)

50) What type of neuron contacts a muscle fiber and initiates a muscle contraction?

D) lower motor neuron

58) A reflex with a single synapse between the sensory and motor neurons within the spinal cord is known as a:

D) monosynaptic reflex.

10) Where is the motor response initiated?

D) motor areas of the brain

32) The longest and largest nerve in the body belongs to the sacral plexus and is known as the:

D) sciatic nerve.

44) A test known as two-point discrimination threshold measures:

D) the relative size of receptive fields.

17) An inability to swallow indicates a problem with the:

D) trigeminal nerve (V) or glossopharyngeal nerve (IX).

11) What is cranial nerve VIII?

D) vestibulocochlear nerve

3) The sympathetic nervous system and parasympathetic nervous system are divisions of the:

D) visceral motor division (autonomic nervous system).

67) The visceral motor division (autonomic nervous system) controls the body's voluntary motor functions.

FALSE

69) The first pair of cranial nerves is the optic nerve (I).

FALSE

70) The hypoglossal nerve (XII) and glossopharyngeal nerve (IX) are both involved in taste sensation.

FALSE

71) The posterior (dorsal) root of a spinal nerve and the posterior ramus are considered mixed nerves since they both carry sensory and motor information.

FALSE

75) Receptive field maps show the regions of skin and the spinal nerve that supplies somatic sensation to them.

FALSE

76) Motor control is initiated by lower motor neurons and transmitted to upper motor neurons by interneurons situated within the CNS.

FALSE

77) Upper motor neurons directly contact and stimulate skeletal muscle fibers to contract.

FALSE

79) The simple stretch reflex employs mechanoreceptors known as Golgi tendon organs to detect the degree of stretch experienced by a muscle.

FALSE

65) The somatic sensory division of the peripheral nervous system (PNS) carries stimuli from both general and special senses to the central nervous system (CNS).

TRUE

66) Cranial nerves and spinal nerves are the two types of nerves found in the peripheral nervous system (PNS).

TRUE

68) Twelve pairs of cranial nerves transmit information to and from the brain.

TRUE

72) The lumbar nerve plexuses arise from the anterior rami of L1 - L4 and innervate structures of the pelvis and lower limb.

TRUE

73) Proprioceptors are located in the musculoskeletal system where they detect the movement and position of a joint or body part.

TRUE

74) Interoceptors detect stimuli from the inside of the body, such as blood pressure, stretch of a full urinary bladder, and the body's temperature.

TRUE

78) Reflexes are programmed, automatic, and rapid responses to stimuli.

TRUE

Motor neurons pools consist of:

lower motor neurons.