The text notes that humans have a few hundred different types of smell or “olfactory” receptors while dogs have about 1,000. Given this, dogs have a much greater ability to distinguish one scent from another than people do. Meanwhile, humans have sharper daytime vision than dogs and a greater ability to perceive colors in the portion of the visible light spectrum that runs from green through red. With this in mind, in what ways is a daytime walk around the neighborhood likely to be perceptually different for dogs, compared to humans?

An action potential is possible because:

a. neurons are wrapped in myelin.

b. the CNS and PNS are separate.

c. only the spinal cord has to be involved.

d. there is no charge difference across the outer membranes of resting neurons.

e. there is a charge difference across the outer membranes of resting neurons.

A neurotransmitter:

a. is stored in sending cell vesicles.

b. diffuses across the synaptic cleft.

c. binds with receptors on a receiving cell.

d. can sometimes be taken back up by a sending cell.

e. all of the above.

The autonomic nervous system (select all that apply):

a. carries out voluntary decisions.

b. is part of the central nervous system.

c. carries out involuntary regulation.

d. is divided into sympathetic and parasympathetic divisions.

e. is an efferent system.

In the brain, the site of our higher thought processes is the:

a. cerebellum.

b. cerebrum.

c. thalamus.

d. medulla oblongata.

e. hypothalamus

All sensory receptors ____ and ____.

a. respond to stimulation; transform that stimulation into a neural signal

b. respond to all forms of stimulation except smell; send messages through the spinal cord

c. are located in the spinal cord; send messages through the thalamus

d. are located in the brain; interconnect with neurons

e. respond to neurotransmitter stimulation; turn that stimulation into a neural signal

Several of the senses work by means of:

a. the brain distributing portions of its processing to the spinal cord.

b. the brain analyzing the pattern of input from many sensory receptors.

c. the brain receiving messages from sensory receptors and then sending messages back to them.

d. sensory receptors communicating first with each other, then with the brain.

e. sensory receptors responding to light.

Muscle cells are referred to as muscle _______ because of their unusual _______.

Muscle contraction works through the process of a ______ of two kinds of muscle filaments past each other within a muscle unit known as a______.

In this process, relatively thick _______ filaments pull relatively thin _______ filaments toward the center of the _______.

The three elements of the skeletal system are_______, _______, and _______.