Neurophysiology

Question 1

leak

Answer 1

selectively permeable channels that are always open. Responsible for mainatining resting membrane potential

Question 2

Chemically

Answer 2

open when bound to specific chemicals e.g. ACH. Responsible for maintaining synaptics potentials, the incoming signals to the neuron

Question 3

Voltage

Answer 3

open in response to electrical changes in TMP e.g. Na, K, Ca ions. Responsible for the production & propagation of action potential, the outgoing signal from the neuron

Question 4

Mechanically-gated channels

Answer 4

open in response to physical distortion of membrane potential

Question 5

Trans-membrane potential

Answer 5

the amount of electrical charge(-70mV) difference between the 2 sides of the membrane when the neuron is at rest(not excited)

Question 6

Notes: A

Answer 6

A resting neuron has - interior & + exterior. The charge of a resting neuron membrane is -70mV

Question 7

Notes: B

Answer 7

K+ is major internal ion along w/ fewer PO4 -2 & SO4 -2 ions

Question 8

Notes: C

Answer 8

Na+ is major external ion along w/ fewer Cl- ions

Question 9

Notes: D

Answer 9

Ion dist. determined by selective ion leak channels & pumps. K+ more permeable than Na+ due to higher number of K+ channels.

Question 10

Notes: E

Answer 10

As Na+ moves into the cell, depolarization occurs & an electrical signla is produced. Cells that can produce an electrical signal are called excitable cells

Question 11

Resting potential

Answer 11

The TMP (-70mV) of a neuron at rest (not generating an electrical signal). Regulated by leak channe;s

Question 12

Graded Potential

Answer 12

a decrease in the TMP w/ distance from the stimulus. Regulated by chemically gated channels

Question 13

Local currents

Answer 13

Movement of positive ions parallel to the membrane. Internal ions Na move in response tot he negative charges along the inner surface of the membrane

Question 14

Action Potential (a.k.a Nervous Impulse/ Electrical Signal)

Answer 14

changes in TMO(increases to +30 mV) transmitted (propageted) along axon

Question 15

Continuous propagation

Answer 15

occurs in unmyelinated axons. A series of local current membrane depolarizations propagate the action potential down the axon membrane

Question 16

Saltatory propagation

Answer 16

occurs in myelinated axons. Ions cannot flow through myelin so ions cross at nodes

Question 17

Chemical synapse

Answer 17

rely upon neurotransmitters

Question 18

Electrical synapse

Answer 18

rely upon direct transmission of electrical impulse from one neuron to neuron another via physical contact of membrannes (no neurotransmitters) via gap junctions

Question 19

Synapse Transmission

Answer 19

Action potentials(nerve impulses/ information/ messages) must be transmitted across the synapse tp the next neuron

Question 20

Nervous system functions- sensory

Answer 20

recieve stimuli from environ. via sensory receptors in PNS e.g. temp, soun

Question 21

Nervous system functions- integration

Answer 21

CNS processes all sensory signals & creates sensations, memory, thoughts or actions

Question 22

Nervous system functions- motor

Answer 22

CNS sends impulses to stimulate movement in effectors outside of nervous syste e.g., muscles, gland

Question 23

NS Components- neurons

Answer 23

produce & transmit & interpret nervous impulses

Question 24

NS Components- neuroglia

Answer 24

supportive cells around neuron, it nourish, insulate & structural support neuron

Question 25

NS Components- synapses

Answer 25

gaps between adjoining neurons

Question 26

NS Components- neurotransmitter

Answer 26

chemical that carry stimulus across synapse

Question 27

NS Components- CNS

Answer 27

brain & spinal cord

Question 28

NS Components- PNS

Answer 28

cranial & spinal nerves

Question 29

Nervous system divisions