Nervous Communication

Question 1

Dendrins

Answer 1

To cell body

Question 2

Axon

Answer 2

Away from cell body

Question 3

Motor vs sensory

Answer 3

Motor cell body at end sensory in centre
Motor = no dendrimer Sensory= dendron
Motor cell body in cns sensory cell body in pns

Question 4

Myelinated neuron

Answer 4

Insulated neuron impulse at faster speed
Node of ranvier electrical impulse jump from node to node saltatory process

Question 5

Sensory receptor

Answer 5

Acts as transducer converts stimulus into nervous impulse

Question 6

Pascinian corpuscle

Answer 6

Resting potential
Pressure -> Na channels change shape
Na channels open Na diffuse in
Depolarised -> generator potential

Question 7

Action potential

Answer 7

Stimulus cause na + channels to open na+ diffuse in
Depolarisation if pd big enough reach threshold open vgscs and more Na+ diffuse in
Repolarisation Na channels close K channels open K+ let out
Hyperpolaristaion vgpcs close
Resting potential

Question 8

Refractory period

Answer 8

K+ channels delayed close so AP doesn’t move backward unidirectional

Question 9

Propagation

Answer 9

Movement of ap along neurone
Na diffuse sideways causing vgscs in adjacent region to open along neuron

Question 10

Saltatory conduction

Answer 10

Depolarisation only occurs at nodes Ap jumps from node to node
Speedier reduce Na channels opening and closing
Less ATP

Question 11

Synapses

Answer 11

Ap reaches end of synaptic knob depolarisation causes Ca channels to open
This causes vesicles containing neurotransmitter to fuse w membrane
Neurotransmitter diffuse across cleft
Bind w receptor opening Na channels
If threshold Ap generated

Question 12

Somatic nervous system

Answer 12

Voluntary actions

Question 13

Autonomic

Answer 13

Sympathetic fight or flight
Parasympathetic rest and digest

Question 14

Brain responsible for controlling heart rate

Answer 14

Medulla oblongata

Question 15

2 centres within medulla

Answer 15

Impulse through sympathetic - accelerator nerve
Impulse through parasympathetic- vagus nerve

Question 16

Change in pH

Answer 16

Chemoreceptors
If CO2 increase carbonic acid forms decrease in pH - increase heart rate
Blood flows quicker to lungs
If blood pH increases - recept in aorta/carotid arteries reduction of impulses sent to medulla sent to SAN

Question 17

Pressure changes

Answer 17

Baroreceptors in aorta/carotid arteries detect
If too high impulse to medulla oblongata then sends impulse along parasympathetic to SAN to decrease heart rate
If too low impulse sent to medulla oblongata which sends impulse down sympathetic neuron to incr heart rate

Question 18

Neuron at rest

Answer 18

3 Na in
2K out
Potassium most permeable to facilitated diffusion
Electrochemical gradient exists
More positive ions outside the cell than inside - electrochemical gradient

Question 19

Direction of ions during depolarisation

Answer 19

Na into the cytoplasm