lect 12 pt 2

What happens when you smell a plate of cookies?

Sensory receptors in your nose detect the smell and send sensory information to the brain. The brain processes the information and may decide that you want to eat the cookies.

How does the brain help you find the cookies?

The brain sends motor signals to your neck muscles to move your head so your eyes can scan the surroundings.

What happens when you visually locate the cookies?

Vision provides another sensory input that travels to the brain for processing. The brain then sends motor signals to your leg muscles to move toward the plate.

What does the cookie example demonstrate?

Sensory information flows into the CNS, where it is processed, and motor information flows outward to produce a response.

What happens when food stretches the stomach?

Stretch receptors in the stomach detect the stretching and send sensory information to the brain.

How does the nervous system respond to stomach stretching?

The brain processes the information and sends motor signals back to the stomach. These signals cause smooth muscle in the stomach to contract and churn the food.

What is the visceral motor system also called?

The autonomic nervous system.

What are the two divisions of the autonomic nervous system mentioned in the lecture?

The sympathetic and parasympathetic divisions.

When are visceral signals generally consciously noticed?

Visceral signals are generally unnoticed unless they become strong or abnormal.

What is stomach overdistention?

It occurs when the stomach becomes excessively stretched, such as after overeating. The stretching may become consciously noticeable and uncomfortable.

Why might excessive stomach stretching become consciously noticeable?

Awareness may help prevent further eating when the stomach is already excessively full, which could cause problems for the body.

What other examples of unusually noticeable visceral signals were discussed?

Bowel cramping, bladder fullness, and visceral pain.

Why does bowel cramping become noticeable?

It can indicate that something is wrong or that you need to use the bathroom.

Why does bladder fullness become consciously noticeable?

It signals that you need to voluntarily move to an appropriate place to empty your bladder.

What is referred visceral pain?

Referred pain is pain that is felt somewhere different from where it actually originates.

What example of referred visceral pain did the instructor give?

During a heart attack, a person may experience pain in the left arm even though the pain originates from the heart muscle.

Why might heart pain be felt in the arm?

The instructor explains that the nervous signal can travel along nerves associated with the arm, causing the pain to be perceived there.

What are the two main types of nervous tissue cells?

Neurons and support cells.

What is the primary function of neurons?

Neurons are specialized for information transfer.

How are neurons structurally classified?

They are classified by the number of processes projecting from their cell bodies.

What is a unipolar neuron?

A neuron with one process projecting from its cell body.

What is a bipolar neuron?

A neuron with two processes projecting from its cell body.

What is a multipolar neuron?

A neuron with three or more processes projecting from its cell body.

What are the two structural divisions of the nervous system?

The central nervous system (CNS) and the peripheral nervous system (PNS).

What structures make up the CNS?

The brain and spinal cord.

What is the peripheral nervous system?

The PNS consists of nervous structures outside the brain and spinal cord, including nerves and ganglia.

What types of nerves are included in the PNS, according to the lecture?

Cranial nerves, spinal nerves, and peripheral nerves, along with ganglia.

How do the functional and structural classifications of the nervous system differ?

Functionally, the nervous system is divided into sensory and motor pathways; structurally, it is divided into the CNS and PNS.

How are neurons functionally classified?

They are classified according to the direction of the nerve impulse relative to the CNS, producing sensory neurons, motor neurons, and interneurons.