exam 3

Question 1

Which of the following neurons does not have a process in the peripheral nervous system?
a. upper motor neuron
b. lower motor neuron
c. primary sensory afferent neuron
d. inhibitory interneuron
e. a and d are correct

Answer 1

upper motor neuron and inhibitory interneuron

Question 2

Which of the following neurons has a process in the peripheral nervous system?
a. upper motor neuron
b. lower motor neuron
c. primary sensory afferent neuron
d. inhibitory interneuron
e. a and d are correct

Answer 2

LMN and primary sensory afferent neuron

Question 3

There are several toxins from Clostridium bacteria that affect neuronal function. All of them are
proteolytic enzymes that specifically attack proteins in the SNARE complex. The most immediate effect of
these toxins is to prevent:

Answer 3

neurotransmitter release by exocytosis

Question 4

The colliculus is located in a part of the brain known as the midbrain. The colliculospinal tract controls
reflexive movements of the head and neck in response to visual or auditory input. This tract is responsible
for orienting to a sound in the environment. You would expect neurons in this tract to have their input
regions in the ________________ and their output regions in the ________________________.

Answer 4

colliculus, gray matter of the spinal cord

Question 5

Osmium tetroxide preferentially labels lipids dark black. Which of the following would you expect to be
prominently labeled?
a. the dorsal columns.
b. the spinal cord gray matter.
c. the cerebral cortex
d. the decussation of the pyramids
e. a and d are correct

Answer 5

dorsal columns and decussation of pyramids

Question 6

In excitation contraction coupling (EC coupling) in skeletal muscle, the predominate source of Ca2+
ions that bind to troponin-C is the:
a. sarcoplasmic reticulum
b. T-tubule
c. synaptic vesicles
d. synaptic cleft
e. mitochondria

Answer 6

SR

Question 7

In some neurodegenerative diseases the lower motor neuron cell bodies die and the remaining lower
motor neurons sprout process that innervate the neuromuscular synapses vacated by the dead lower motor
neurons. In these muscles, the size of the motor unit ____________ and the strength of the muscle
contraction generated by the activation of each of the motor neurons _____________.
a. decreases, decreases
b. decreases, increases
c. increases, decreases
d. increases, increases

Answer 7

increases, increases