Problem:

Question 1: Our case study involves a variety of reflexes. Of these, which one was the most obvious?

(a) myotatic reflex,

(b) pupillary light reflex, or

(c) regional allocation of arterial blood.

Question 2: A reflex is an involuntary, neuron-mediated response to a stimulus. What stimulus induces the pupillary light reflex?

(a) sudden motion in the peripheral visual field,

(b) excessive retinal illumination, or

(c) insufficient retinal illumination.

Question 3: Reflexes depend upon central integration. Where does this occur for the pupillary light reflex?

(a) sensory cortex,

(b) midbrain, or

(c) brainstem.

Question 4: Which cranial nerve pair enables sensory input for the pupillary light reflex?

(a) cranial nerve pair II, optic,

(b) cranial nerve pair III, oculomotor,

(c) cranial nerve pair IV, trochlear, or

(d) cranial nerve pair VI, abducens.

Question 5: Which cranial nerve pair is responsible for the motor output that enables the pupillary light reflex?

(a) cranial nerve pair II, optic,

(b) cranial nerve pair III, oculomotor,

(c) cranial nerve pair IV, trochlear, or

(d) cranial nerve pair VI, abducens.

Question 6: Where are the cholinergic, post-ganglionic motor neurons that enable the pupillary light reflex?

(a) pretectal nuclei,

(b) Edinger-Wesphal nuclei, or

(c) ciliary ganglia.

Question 7: Each optic nerve is a large bundle of axons that project from the retina through the optic chiasma and into the brain. These axons project from retinal:

(a) photopreceptors,

(b) bipolar neurons, or

(c) ganglion cells.

Question 8: If retinal ganglion cells, in essence, are miniaturized sensory neurons, then what neurotransmitter do they secrete?

(a) acetylcholine,

(b) glutamate, or

(c) glycine.

Question 9: Consider the axons within the optic nerves and optic fiber tracts of our model animal. What scale would be needed to measure the length of these axons?

(a) millimeters,

(b) centimeters, or

(c) meters.

Question 10: Vision is a representation of an animal's immediate environment arising from neurosecretion within the visual cortex. Effective vision depends upon the rapid transfer of sensory information. With this in mind, what would axons within the optic nerves look like?

(a) small diameter, non-myelinated,

(b) small diameter, myelinated, or

(c) large diameter, myelinated.

Give reasoning with your answer.