Chapter 12 A&P HW

Question 1

What does the somatic nervous system do?

Answer 1

provides motor signals and conscious control to skeletal muscles

Question 2

Does the somatic nervous system control voluntary or involuntary actions?

Answer 2

voluntary

Question 3

Does the autonomic nervous system control voluntary or involuntary actions?

Answer 3

involuntary

Question 4

Does the enteric nervous system control voluntary or involuntary actions?

Answer 4

involuntary

Question 5

What does integration do?

Answer 5

processes information by analyzing it and deciding upon an appropriate response

Question 6

What are some functions of the nervous system?

Answer 6

detecting stimuli, processing information, sending responses to muscles or glands

Question 7

Is gray matter myelinated or unmyelinated?

Answer 7

unmyelinated

Question 8

Is white matter myelinated or unmyelinated?

Answer 8

myelinated

Question 9

What is the other name for myelin sheath gaps?

Answer 9

node of Ranvier

Question 10

What are sensory impulses carried to the central nervous system by?

Answer 10

afferent neurons

Question 11

What is a cluster of neuronal cell bodies in the CNS called?

Answer 11

nucleus

Question 12

What type of central nervous system tissue contains neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglial cells?

Answer 12

gray matter

Question 13

What is a graded potential?

Answer 13

a small deviation from resting membrane potential that occurs because ligand-gated or mechanically-gated channels open or close

Question 14

What causes a resting nerve fiber to be polarized?

Answer 14

the concentration of Na+ is higher on the outside and K+ is higher on the inside

Question 15

What type of communication are graded potentials used for?

Answer 15

localized and short duration

Question 16

What type of channel allows for more potassium to exit the neuron and helps in maintaining the resting membrane potential?

Answer 16

leak channel

Question 17

Which electrical signal can allow for rapid long-distance communication within the nervous system?

Answer 17

nerve action potential

Question 18

What is the difference in electrical charges on either side of the cell membrane called?

Answer 18

membrane potential

Question 19

Movement of ions through an open channel is due to what?

Answer 19

diffusion

Question 20

What is the membrane transport protein that uses ATP to move ions against their concentration gradient called?

Answer 20

pump

Question 21

True or false: to establish and maintain resting membrane potential, more potassium ions move out of the cell than sodium ions move into the cell

Answer 21

true

Question 22

What is it called when the inside of the membrane becomes less negative?

Answer 22

the membrane potential is depolarized

Question 23

What principle states that a stimulus either causes an action potential or does not cause an action potential?

Answer 23

all-or-none principle

Question 24

What happens when the accumulation of graded potentials in the trigger zone reaches threshold?

Answer 24

voltage-gated channels open

Question 25

True or false: the depolarization of one area of the cell membrane provides enough positive charge to cause neighboring voltage-gated channels to reach threshold allowing the action potential to spread across the membrane

Answer 25

true

Question 26

What maintains resting membrane potential?

Answer 26

leak channels and sodium-potassium pumps

Question 27

What results in the depolarization of the cell membrane?

Answer 27

voltage-gated sodium channels open allowing sodium ions to enter the cell to cancel the negative charges on the inside of the membrane

Question 28

Does the voltage diminish with distance in a graded potential?

Answer 28

yes

Question 29

What is the typical resting membrane potential of a neuron?

Answer 29

-70mV

Question 30

Why are N+/K+-ATPase pumps considered to be an electrogenic pump?

Answer 30

they contribute to the negativity of the resting membrane potential

Question 31

Where do graded potentials typically occur?

Answer 31

dendrites and cell body

Question 32

What does a depolarizing graded potential do?

Answer 32

makes the membrane less polarized

Question 33

What happens during repolarization?

Answer 33

K+ flows out of the cell

Question 34

How does size affect the speed of conduction of action potentials?

Answer 34

the larger the diameter of axons, the faster conduction of action potentials

Question 35

How does temperature affect the speed of conduction of action potentials?

Answer 35

warmer temperatures allow for faster conduction

Question 36

How does more stimuli affect action potentials?

Answer 36

increasing application of stimuli increases frequency of action potentials

Question 37

What is continuous conduction?

Answer 37

step-by-step depolarization and repolarization of each adjacent segment of the axolemma

Question 38

What is saltatory conduction?

Answer 38

the impulse jumps from each node of Ranvier to node of Ranvier

Question 39

How does myelination affect the speed of propagation of action potentials?

Answer 39

myelination increases the speed

Question 40

How can the nervous system distinguish between a light and heavy touch?

Answer 40

the frequency of impulses sent to sensory centers is changing