Week 14 Quiz

The brain gives off 31 pairs of cranial nerves, and the spinal cord gives off 12 pairs of spinal nerves.

True or false.

• True
• False

A pain receptor in a fingertip sends a signal along a nerve to the spinal cord. How is that signal described?

Select one.

• Efferent, because it travels away from the fingertip
• Afferent, because it arrives at the central nervous system
• Efferent, because it is carried by a spinal nerve
• Somatic, because it is a command to skeletal muscle

Every spinal nerve is a mixed nerve, carrying both sensory and motor axons in one bundle.

True or false.

• True
• False

Which of these is a command carried by the autonomic nervous system rather than the somatic nervous system?

Select one.

• Lifting a fork to take a bite of food
• Blinking on purpose to clear the eyes
• Pulling a hand back in a withdrawal reflex
• Smooth muscle in the stomach wall churning

During a hard climb up a stairwell, which autonomic branch speeds the heart, and where do its neurons leave the central nervous system?

Select one.

• The sympathetic division, from the thoracic and upper lumbar cord
• The parasympathetic division, from the brainstem and the sacral cord
• The sympathetic division, from the brainstem and the sacral cord
• The parasympathetic division, from the thoracic and upper lumbar cord

Select every effect of the parasympathetic division.

Select every option that applies.

• A slower heart rate
• Dilated pupils
• Constricted pupils
• Paused digestion
• Active digestion

On the course's illustrative heart-rate table, the resting average is 62 beats per minute and the right-after-activity average is 98 beats per minute. What is the rise, and which branch produces it?

Select one.

• 26 beats per minute, produced by the sympathetic branch
• 36 beats per minute, produced by the parasympathetic branch
• 36 beats per minute, produced by the sympathetic branch
• 160 beats per minute, produced by the sympathetic branch

Which cranial nerve runs far beyond the head and carries the parasympathetic calming supply to the heart and gut?

Select one.

• The vagus nerve, cranial nerve X
• The optic nerve, cranial nerve II
• The vestibulocochlear nerve, cranial nerve VIII
• The olfactory nerve, cranial nerve I

Most organs, such as the heart, receive both autonomic branches. Why does this dual innervation make the autonomic system one of homeostasis's main tools?

Select one.

• It lets the autonomic system sense each change, acting as the receptor of the loop
• It gives one effector a push in each direction, so a variable can be moved either way
• It keeps the autonomic system switched off except in emergencies, apart from homeostasis
• It lets skeletal muscle make chosen corrections whenever a variable drifts

In the gas-pedal-and-brake model of the autonomic branches, the parasympathetic division is the gas pedal that speeds the heart during exercise.

True or false.

• True
• False