What is the first structure of a reflex arc?

What is the first structure of a reflex arc? 

A. effector (muscles or glands)
B. receptor
C. sensory neuron
D. motor neuron


Answer: receptor

Nerves that serve the leg come from the

Nerves that serve the leg come from the 

A. sacral plexus.
B. brachial plexus.
C. lumbar plexus.
D. both the sacral and lumbar plexuses.


Answer: both the sacral and lumbar plexuses

Nerves that serve the arm come from the _______ plexus.

Nerves that serve the arm come from the _______ plexus. 

A. cervical
B. brachial
C. lumbar
D. sacral


Answer: brachial

Reflex arcs

Reflex arcs 

A. require the actions of the brain.
B. do not utilize somatic motor nerves.
C. generally rely on the actions of the hypothalamus.
D. may have a single synapse.


Answer: may have a single synapse

Which of the following spinal nerve groups is incorrect?

Which of the following spinal nerve groups is incorrect? 

A. cervical - 7
B. thoracic - 12
C. lumbar - 5
D. sacral - 5


Answer: cervical - 7

If the dorsal root of a spinal nerve were to be cut, the individual would

If the dorsal root of a spinal nerve were to be cut, the individual would 

A. have no motor responses for that nerve.
B. have no sensory perception from that nerve.
C. have no reflexes involving that nerve.
D. Both have no sensory perception from that nerve and have no reflexes involving that nerve are correct.


Answer: Both have no sensory perception from that nerve and have no reflexes involving that nerve are correct