chapter 11

Question 1

homeostasis

Answer 1

state of relative stability within the body

Question 2

nervous system

Answer 2

Brain, spinal cord and nerves, control sensory input, integration, and motor output.

Question 3

Central nervous system

Answer 3

Brain, spinal cord it integrates and processes information sent by nervous system

Question 4

Peripheral nervous system

Answer 4

Motor neurons, and sensory neurons

Question 5

Somatic system

Answer 5

five senses

Question 6

autonomic system

Answer 6

smooth and cardiac muscles

Question 7

parasympathetic system

Answer 7

rest

Question 7

sympathetic system

Answer 7

stress (fight - or - flight)

Question 8

Neurons

Answer 8

basic structural and functional units of nervous system specialized to respond to physical and chemical stimuli, to conduct electrochemical signals, release chemicals that regulate various body processes.

Question 8

Glial cells

Answer 8

More than neurons 10 to 1. nourish the neuron, remove their waste and defend against infections (supporting framework)

Question 9

sensory neurons

Answer 9

Gather info from sensory receptors and transmit these impulses to control nervous system.

Question 10

motor neuron

Answer 10

transports information from the central nervous system to other parts of the body.

Question 11

interneuron

Answer 11

entirely in central nervous system.

Question 12

reflex arc

Answer 12

Sudden, unlearned, involuntary response to certain stimuli. contains simple connections of neurons
Sensory receptors in the skin senses and sends a stimuli to sensory neuron, which then activates the interneuron, which then activates the motor neuron to instruct the muscle to contract and withdraw the hand.

Question 13

dendrite

Answer 13

Short, branching terminals that receive nerve impulses from other neurons or sensory receptors. have high surface area and relays impulse to the cell body.

Question 14

cell body

Answer 14

Contains nucleus, site of cell’s metabolic reactions. processes input from dendrite, if input is large enough it relays impulse to axon where action potential takes place.

Question 15

axon

Answer 15

Axon conducts impulses away from the cell body. They are pretty long depending on the type of neuron and they communicate with corresponding cells, glands with releasing chemicals in the surrounding fluid.

Question 16

mylein sheath

Answer 16

Axon enclosed in fatty, insulating layer, white in color and it protects the neuron and speeds the rate of nerve impulse transmission.

Question 17

Schwann cells

Answer 17

Type of glial cells, form myelin by wrapping themselves around the axon.

Question 18

Resting membrane potential

Answer 18

Potential difference across the membrane of a resting neuron. -70mv

Question 19

Polarization

Answer 19

Process of generating the resting membrane potential
-large protein stuck inside the cell
-leaky potassium channels
-sodium/potassium pump (pumps 3 sodium out while pimping 2 potassium in)
-impermeable to small ions like chloride

Question 19

Action potential

Answer 19

When the node of ranvier gets depolarized to less than -55 mv, threshold potential is reached so the impulse goes all the way up. (all of none)

Question 20

Depolarization

Answer 20

If transmembrane potential becomes less then -70 mv.

Question 21

Threshold potential

Answer 21

The potential difference of -55 which has to be reached before generating an action potential

Question 22

nerve impulse

Answer 22

series of action potentials.

Question 22

Whole process

Answer 22

when an impulse is received by the dendrite of the neuron and is then transmitted to the cell body, if the impulse is great enough it is sent to the axon, where some sodium channels start to open, if the impulse is high enough and threshold level of -55 mv is reached then more sodium channels open and the impulse goes all the way up creating an action potential. Sodium channels then close and potassium channels open and potassium is moved to the outside of the membrane called repolarization. Even more of the potassium channels open and hyperpolarization occurs makes it up to -90 mv. then potassium channels close and the sodium potassium pump does its work. this period is called the refractory period and no action potential can be generated.

Question 23

Saltatory conduction

Answer 23

action potential jump from one node of Ranvier to another.

Question 24

Multiple sclerosis

Answer 24

autoimmune disease which breaks down its own mylein

Question 25

Synapse

Answer 25

connection between two neurons or neuron and effector.

Question 26

neuromuscular junction

Answer 26

synapse between motor neuron and muscle cell

Question 27

Synapse process

Answer 27

Impulse travels the lengths of axon and reaches the synapse terminal. the presynaptic neuron releases the neurotransmitters in the synaptic cleft from the synaptic vesicles. Neurotransmitters then go in to synaptic cleft and attach to specific receptor proteins on the postsynaptic membrane.

Question 28

Excitatory and inhibitory synapse response

Answer 28

excitatory - opens sodium channels
inhibitory - opens potassium channels

Question 29

Acetylcholine

Answer 29

a neurotransmitter broken down by enzyme called acetylcholinesterase and it returns it to presynaptic vesicles.