The Nervous system, tissue and transmission 10,11,12

Question 1

What is the function of sensory receptors & afferent (sensory) nerves?

Answer 1

To carry information to brain and spinal cord.

Question 2

What is the function of inter-neurones?

Answer 2

integration and information processing, carried by short interneurons.

Question 3

What is the function of Motor activity /efferent (motor) nerves ?

Answer 3

Carry signals from brain and spinal cord to glands.

Question 4

name the structures of the nervous system

Answer 4

spinal chord, sensory receptors, brain, enteric plexuses, ganglia, nerves.

Question 5

What are the 2 nervous systems in order

Answer 5

1) central nervous system, (CNS)
2) peripheral nervous system (PNS)

Question 6

What does the central nervous system include?

Answer 6

Brain and spinal chord.

Question 7

what does the peripheral nervous system include?

Answer 7

all nervous tissue outside CNS. Includes somatic, autonomic and enteric nervous systems.

Question 8

Explain somatic nervous system (SNS)

Answer 8

sensory neurons in somatic receptors and motor neurons to skeletal muscle.

Question 9

explain autonomic nervous system (ANS)

Answer 9

sensory neurons from autonomic receptors and motor neorons to smooth muscle, cardiac muscle and glands.

Question 10

Enteric nervous system (ENS)

Answer 10

sensory and motor neurons of the GI tract and enteric plexuses, motor neurons to smooth muscle, glands, endocrine cells of GI tract.

Question 11

What is a neuron?

Answer 11

nerve cell, specialised for signal conduction and information processing.

Question 12

Explain neuroglia cells.

Answer 12

support, nourish, and protect neurons.
neuralgia are critical for maintaining homeostasis of interstitial fluid around neurons.

Question 13

what are dendrites?

Answer 13

branched structures emerging from cell body - recieve input.

Question 14

what are axons?

Answer 14

Conducts impulse away from body toward another neuron or effector

Question 15

where do axons emerge from?

Answer 15

Cone shaped axon hillock.

Question 16

where are axon terminals found?

Answer 16

at the end of axon with synaptic bulbs.

Question 17

what does the myelin sheath cover?

Answer 17

axons

Question 18

what is a myelin sheath?

Answer 18

many layered lipid and protein creating insulations.

Question 19

what does the myelin sheath do

Answer 19

increases speed of nerve conduction,

Question 20

what are nodes of ranvier?

Answer 20

gaps in the myelin, they are important for signal conduction.

Question 21

what can destroy myelin?

Answer 21

diseases such as multiple sclerosis.

Question 22

where is white matter primarily found?

Answer 22

myelinated axons.

Question 23

what 5 components is grey matter made of up.

Answer 23

cell bodies, dendrites, unmyelinated axons, axon terminals and neuroglia.

Question 24

what is the brain cortex (outer layer) made up of?

Answer 24

grey and white matter

Question 25

where are spinal chord white and grey matter located?

Answer 25

white matter is located externally, great matter is centrally located.

Question 26

how many types of neuroglia are there?

Answer 26

6 types.

Question 27

what does the neuroglia cell astrocyte do?

Answer 27

it is a blood brain barrier.

Question 28

what do the neuroglia cells oligodendrocytes do?

Answer 28

they create myelin in CNS

Question 29

what do the neuroglia cells microglia do?

Answer 29

act as a defence.

Question 30

what do the neuroglia ependymal cells do?

Answer 30

produce cerebrospinal fluid.

Question 31

what do the neuroglia Schwann cells do?

Answer 31

PNS cell support/myelin

Question 32

what do neuroglia satellite cells do?

Answer 32

found in PNS ganglia.

Question 35

what are nerve action potentials?

Answer 35

nerve impulses.

Question 36

what do nerve action potentials require?

Answer 36

a membrane potential - electrical charge difference across cell membrane - like a battery.

Question 37

what do ion channels do?

Answer 37

allow ions to move by diffusion.

Question 38

if no action potential then resting cell has..

Answer 38

resting membrane potential - 70mv

Question 39

talk about the resting membrane potential.

Answer 39

• contains leakage channels- cytosol high in K+ and interstitial fluid high in Na+
• leakage lets K+ through easily and Na+ poorly, inside is negative relative to outside.
  *actual RMP depends on relative leakage channels numbers.

Question 40

what is action potential

Answer 40

series of active events, channels actively open and close.

Question 40

an initial event is required to reach a voltage threshold of what?

Answer 40

50millivolts.