Intro To Nervous System

Question 1

CNS

Answer 1

brain and spinal cord

Question 2

PNS

Answer 2

autonomic nervous system and motor pathways

Question 3

Main goal of information pathway

Answer 3

sense changes in the environment and respond appropriately

Question 4

Afferent Peripheral

Answer 4

at/towards CNS, how sensory information is received and transmitted into animals body

Question 5

Integration

Answer 5

takes place in CNS

Question 6

Efferent Peripheral

Answer 6

away from CNS, carries signals through nerves to muscles (motor response pathway) or internal organs (autonomic nervous systems) to elicit response

Question 7

Neurons

Answer 7

what transmit electrical signals

Question 8

cell body

Answer 8

houses nucleus

Question 9

plasma membrane

Answer 9

surrounds cell

Question 10

dendrites

Answer 10

finger-like projections originating from neuron cell body that receives sensory stimuli/signals (neurotransmitters) from other neurons

Question 11

Action potential

Answer 11

generation of electrical signals sent in one direction down nerve axon to axon terminal (triggered by activation of dendrites)

Question 12

Synapse

Answer 12

connection between two neurons, or a neuron or another cell, at axon terminal. Responsible for transmitting electrical signals across neurons through the entire body

Question 13

myelin sheath

Answer 13

layer of fat covering axon, helps action potentials move faster down the axon

Question 14

glial cells

Answer 14

surround neurons (not part of the neuron), support and insulate neurons

Question 15

oligodendrocytes and Schwann cells

Answer 15

glial cells that produce myelin for the CNS and PNS

Question 16

Steps of Action Potentials (4)

Answer 16

1) Rest. Higher sodium concentration outside the neuron compared to inside where there is a higher potassium concentration. Sodium-potassium ATPase pump maintains levels using energy to pump ions against the concentration gradients. Sodium and potassium ions in neurons plasma membrane closed, ions can’t flow down concentration gradients. Resting membrane potential of -70mV
2) dendrite stimulated. Sodium channels open and it rushes into the neuron towards a lower concentration inside the neuron (down concentration gradient). Depolarization: membrane potential to +30mV
3) membrane potential reaches +40mV, potassium channels open, rushes out of neuron towards a lower potassium concentration outside the cell (down concentration gradient). Repolarization: membrane potential is -90mV
4) sodium-potassium pump moves sodium back outside the cell and potassium inside of the cell to reestablish resting membrane potential of -70mV

Question 17

Locations of action potential in order

Answer 17

dendrites, axon, axon terminal, release of neurotransmitters at synapse

Question 18

all-or-nothing

Answer 18

when triggered, action potentials always reach +40mV.

Question 19

neurotransmitters

Answer 19

chemicals released from neuron in response to an action potential

Question 20

presynaptic neuron

Answer 20

neuron releasing the neurotransmitter

Question 21

synaptic cleft

Answer 21

space between presynaptic and postsynaptic neuron that the neurotransmitter travels

Question 22

Receptors

Answer 22

where neurotransmitters bind on the post-synaptic neuron
Ach and NE (E too)

Question 23

Acetylcholine

Answer 23

Ach, excitatory or inhibitory depending on location of release

Question 24

Norepinephrine

Answer 24

NE, fight or flight, response of the sympathetic nervous system

Question 25

afferent sensory

Answer 25

action potentials activated here, PNS, synapse and release neurotransmitters to nerves in integrating CNS

Question 26

efferent peripheral nervous system

Answer 26

action potentials via neurotransmitters sent to activate muscles or organs for an appropriate response