The nervous system

Question 1

Glial cells- general function

Answer 1

• surround the axon and dendrites of neurons

- provide physical and metabolic support

Question 2

astrocyte function

Answer 2

• regulate composition of the extracellular fluid in the CNS by removing K+ and neurotransmitters around synapses
• stimulate formation of tight junctions between cells that make up the walls around capillaries
• sustain neurons metabolically (provide nutrients and remove waste
• secrete growth factors

Question 3

ogliodendrocyte

Answer 3

form mylein sheath in the CNS

Question 4

shwann cells

Answer 4

form mylein sheath in the PNS

Question 5

microglia

Answer 5

microphage like cells that peform immune function in the CNS

Question 6

Mylein

Answer 6

-concentric lipid rich layers

Question 7

direction of calcium, cloride, sodium and pottasium

Answer 7

in, in, in, out

Question 8

glutamate

Answer 8

excitatory neurotransmitter important for learning and memory

Question 9

somatic stimuli

Answer 9

• muscle length and tension

- propioception

Question 10

visceral stimuli

Answer 10

Blood pressure, ph of blood and spinal fluid, oxygen content of blood, lung inflation, osmolarity of body fluids, temperature, glucose levels of blood

Question 11

somatic senses

Answer 11

touch, temperature, pain, itch, propioception

Question 12

special senses

Answer 12

vision, hearing, taste, smell, equilibrium

Question 13

temporal summation

Answer 13

two potentials arriving in a short space of time, rate is increased

Question 14

spatial summation

Answer 14

many ion channels are opened at once

Question 15

Graded Potential

Answer 15

• changes in membrane potential (hyperpolarising or depolarising) that are confined to a relatively small area of the plasma membrane
• magnitude can vary and is related to initiation event
• function as signals only over short distances (unless summation occurs)

Question 16

NMDA receptor

Answer 16

• opens in response to glutamate, allowing Na and Ca influx

Question 17

Snare proteins

Answer 17

initiate movement of vesicles to the membrane during exocytosis of neurotransmitters

Question 18

PNS: somatic

Answer 18

• control of skeletal muscle via motor neurones

Question 19

PNS: Sensory

Answer 19

• relays information to the CNS about the internal and external environment via afferent pathways

Question 20

PNS: autonomic

Answer 20

• regulates smooth muscle and gland function

Question 21

somatic excitation pathway

Answer 21

• consists of one cholinergic neurone; no synapses or ganglia
• synapses at a skeletal muscle neuromuscular junction consisting of axon terminals and motor end plates (region of skeletal muscle fibre containing many receptors)
• receptors are always nicotinic choliergic

Question 22

ACh nicotinic receptor action

Answer 22

non selective iontropic opening, net excitation

Question 23

slowly adapting receptors

Answer 23

neurones which persistently fire action potentials throughout period of stimulation

Question 24

Rapidly adapting receptors

Answer 24

only respond when conditions are altered

Question 25

Sympathetic pathway

Answer 25

• short preganglionic neurone: releases ACh which binds to nicotinic receptors
• long post ganglionic: releases noradrenaline binds to g protein coupled receptor

Question 26

parasympathetic pathway

Answer 26

long pre-ganglionic neurone: releases ACh which binds to a nicotinic receptor
Short post-ganglionic neurone: Releases ACH that binds to muscarinic receptors on the post-synaptic membrane

Question 27

Simple receptor

Answer 27

neurones with free nerve endings

Question 28

complex receptor

Answer 28

nerve enclosed in connective tissue capsule

Question 29

Complex non neural cells

Answer 29

cells that release neurotransmitters onto sensory neurones, initiating an action potential