sci_mod16

Question 1

The system of nerves which carries instructions from the CNS to the body’s smooth muscles, cardiac muscle and glands

Answer 1

Autonomic nervous system

Question 2

The system of nerves which carries information from the body’s receptors to the CNS

Answer 2

Sensory nervous system

Question 3

The system of nerves which carries instructions from the CNS to the skeletal muscles

Answer 3

Motor nervous system

Question 4

What are the two main types of cells in the human nervous system?

Answer 4

Neurons and neuroglia are the two principal kinds of cells in the human nervous system.

Question 5

What do dendrites do?

Answer 5

Dendrites carry electrical signals to the cell body.

Question 6

What do axons do?

Answer 6

Axons carry electrical signals away from the cell body.

Question 7

What is a synapse?

Answer 7

A synapse is a small gap between the axon of a neuron and the receiving end of another cell.

Question 8

Explain how a signal crosses from the axon of a neuron to the receiving cell.

Answer 8

When the electrical signal reaches the end of the axon, neurotransmitters are released which travel across the synapse. Once they reach the receiving cell, they create a new electrical signal.

Question 9

What is the function of neuroglia?

Answer 9

Neuroglia support the neurons by performing tasks which make it possible for the neurons to do their job.

Question 10

A nerve runs down the leg, carrying signals to the foot. Is it a part of the PNS or the CNS?

Answer 10

The nerve is a part of the PNS. The PNS contains all nerves that run off of the spinal cord. If it is in the leg, it is off the spinal cord.

Question 11

What two main structures make up the CNS?

Answer 11

The CNS is made up of the brain and the spinal cord.

Question 12

What two things protect the brain?

Answer 12

The skull and the cerebrospinal fluid protect the brain.

Question 13

What protects the spinal cord?

Answer 13

The vertebral column protects the spinal cord. You could also say “the backbone.”

Question 14

What is the brain’s gray matter composed of?

Answer 14

Gray matter is made up mostly of neuron cell bodies.

Question 15

What is the brain’s white matter composed of?

Answer 15

White matter is made up mostly of the axons of neurons.

Question 16

What is the function of the corpus callosum?

Answer 16

The corpus callosum allows the two sides of the brain to communicate with one another.

Question 17

What does the cerebellum primarily control?

Answer 17

The cerebellum is mostly in charge of voluntary muscle movements, especially fine movements.

Question 18

What part of the brain deals mostly with the higher level thinking skills?

Answer 18

The cerebrum is in charge of most higher level thinking skills.

Question 19

Do the two sides of the brain do exactly the same things?

Answer 19

The two sides of the brain do not do exactly the same things. The left side of the cerebrum, for example, tends to be responsible for speaking, logic, and math. The right side is more involved with spatial relationships, recognition, and music.

Question 20

What side of the PNS does the left side of the brain control?

Answer 20

The left side of the brain controls the right side of the PNS.

Question 21

What is the blood-brain barrier and why is it important?

Answer 21

The blood-brain barrier is a system that insulates the brain from the blood. It is important because many of the chemicals in our blood are toxic to brain cells. The blood-brain barrier selectively transports “good” chemicals into the brain and leaves the “bad” chemicals in the capillaries, insulated from the brain.

Question 22

What does the sympathetic division of the autonomic nervous system do?

Answer 22

The sympathetic division increases the rate and strength of the heartbeat and raises the blood pressure. It also stimulates the liver to release more glucose in the blood, producing quick energy for the “fight or flight” response that we experience when we are frightened or angry.

Question 23

What does the parasympathetic division of the autonomic nervous system do?

Answer 23

The parasympathetic system slows the heart rate and lowers the blood pressure. In addition, it takes care of certain “housekeeping” activities such as causing the stomach to churn while it is digesting a meal.

Question 24

What are the four basic tastes that we can detect?

Answer 24

Humans detect four basic tastes: salty, sour, sweet, and bitter.

Question 25

What portion of the tongue is least sensitive to taste? Why is it so insensitive?

Answer 25

The tongue is least sensitive to taste at the center, because there are few taste buds there.

Question 26

When we smell something, what are we actually detecting?

Answer 26

When we smell, we are actually detecting chemicals which are in the air.

Question 27

What is the function of the eye’s pupil?

Answer 27

The pupil regulates how much light gets into the eye.

Question 28

What is the function of the eye’s lens?

Answer 28

The lens focuses light on the retina.

Question 29

What is the function of the eye’s ciliary muscle?

Answer 29

The ciliary muscle deforms the lens, changing its focus.

Question 30

What cells of the retina detect light?

Answer 30

The rods and cones detect light.

Question 31

What causes an eye’s blind spot?

Answer 31

Where the optic nerve enters the eye, there are no rods and cones. Without the rods and cones, light cannot be detected on that part of the retina.

Question 32

Which part of the body has the most nerves related to touch: the fingers or the arm?

Answer 32

Experiment 16.6 demonstrated that the fingers are more touch sensitive, which means they have more touch-related nerves.

Question 33

What is the function of the ear drum?

Answer 33

The ear drum converts vibrations in the air into vibrations of the ossicles, which moves the cochlea back and forth.

Question 34

What is the function of the cochlea?

Answer 34

The cochlea converts the back and forth motion of the ossicles into electrical signals which can be received by the brain and interpreted as sound.