coordination and response Flashcards
compare the features of the nervous system and the
endocrine system
1)method of communication
2)method of transmission
3)transmission speed
4)duration of effect
nervous system:
1) electrical / impulses / action potentials / wave of depolarisation
2) neurons / nerve fibres / nerve cells / axons
3) fast(er) / quick(er) / rapid
4) short(er) / temporary / seconds
endocrine system
1) hormones / chemical(s) (messengers)
2) blood (stream / plasma) / circulation
3) slow(er)
4) long(er) / permanent / minutes - years
describe the structure of a sensory neurone
1) nucleus in, cell body / soma
2) (long) dendron
3) (short) axon
4) many mitochondria (in cell body)
5) many, RER / ribosomes or presence of Nissl’s granules (in cell body)
6) synaptic, knobs / terminals / boutons
7) Schwann cells / myelin sheath
8) nodes of Ranvier
describe the function of a sensory neurone
receives, input / impulses, from receptors
describe the structure of a motor neurone
1) nucleus in cell body
2) (short), dendrites / dendrons
3) axon
4) (axon) much longer than, dendrite / dendrons
5) cell body contains, mitochondria / RER / golgi / groups of ribosomes
6) many mitochondria at, synaptic knob / terminal branch
7) synaptic vesicles
8) neurotransmitter / named neurotransmitter {linked to 7}
9) Schwann cells / myelin sheath
10) nucleus in Schwann cell
[Reject nucleus in myelin sheath]
11) node of Ranvier
AVP ) motor end plate / (dendrites) have receptors (for neurotransmitters)
describe the function of a motor neurone
1) transmit, impulses / action potentials, from, CNS / sensory neurones / relay neurones / intermediate neurones
2) to effectors / muscles / glands
what is the name of the intermediate neurones that
connect sensory neurones and motor neurones
relay neurones
outline the role of sensory receptor cells in the mammalian nervous system
1) detect / respond to, (change in) stimulus / stimuli
2) {two examples from} light / heat / sound / touch / pressure / pain / chemicals / taste / smell / tension
3) (act as) transducers / convert stimulus energy to electrical energy
4) produce, generator / receptor / action, potential
5) passes impulse, to / along, sensory neurone
Explain how an action potential is transmitted along a sensory neurone
OR
Describe and explain the transmission of an action potential in a myelinated neurone
(both questions have the same answer as mammalian neurons are myelinated)
1) Na+ channels open [Allow sodium channels]
2) Na+ enter cell [Reject enter membrane]
3) inside becomes, less negative/positive/+40mV or membrane depolarised
4) Na+ channels close ; A sodium channels
5) K+ channels open [Allow potassium channels]
6) K+ move out (of cell) [Reject of membrane]
7) inside becomes negative or membrane repolarised [Allow negative figure]
8) LOCAL CIRCUITS
9) (myelin sheath Schwann cells) insulate axon/does not allow movement of ions
10) action potential / depolarisation, ONLY at nodes (of Ranvier)/gaps
11) saltatory conduction / action potential jumps from node to node
12) one-way / unidirectional, transmission
AVP) hyperpolarisation / refractory period
Outline the role of a chemoreceptor cell in the human taste bud in detecting stimuli and in stimulating the transmission of nerve impulses in sensory neurones.
1) chemicals act as a stimulus
2) ref. to specificity of chemoreceptors
3) sodium ions diffuse into cell
4) via microvilli
5) membrane depolarised
6) receptor potential / generator potential
7) stimulates opening of calcium (ion) channels
8) calcium ions enter cell
9) causes movement of vesicles containing neurotransmitter
10) neurotransmitter released by exocytosis
11) neurotransmitter stimulates, action potential / impulses, in sensory neurone
12) chemoreceptors are transducers
AVP) threshold / all or nothing law / papilla
outline how the resting potential is maintained
1) reference to Na+/K+ pump
2) active process/ATP used
3) Na+ (pumped) out and K+ (pumped) in
4) high Na+ outside and high K+ inside axon
5) membrane slightly more leaky to K+/more K+ leaks out than Na+ leaks in/
reference to some K+ channels open
6) inside more negative than outside
describe how the changes in the membrane bring about depolarization
1) reference stimulation
2) opening of Na+ channels
3) Na+ diffuses in (across axon membrane)
4) inside more positive than outside/outside more negative than inside
5) potential across the membrane changes
Explain how the membrane is repolarised
1) reference to closing Na+ channels
2) opening of K+ channels
3) K+ diffuses out (across axon membrane)
4) (charge on the K+) restores the membrane/resting potential
5) reference to slight overshoot /hyperpolarisation
6) reference K+ channels close
Describe the importance of the refractory period in the transmission of action potentials
1) limits / controls, (maximum) frequency of action potentials
2) (action potentials / impulses) travel in one direction
Describe how a nerve impulse crosses a cholinergic synapse.
1) action potential / depolarisation, reaches presynaptic membrane
2) calcium (ion) channels open / presynaptic membrane becomes more permeable to Ca2+
3) Ca2+ flood into presynaptic neurone [Reject membrane]
4) this causes vesicles of (neuro)transmitter to move towards presynaptic membrane
5) ref. acetylcholine / ACh
6) vesicle fuses with presynaptic membrane / exocytosis
7) ACh released into synaptic cleft
8) ACh diffuses across (cleft)
9) ACh binds to receptor (proteins)
10) on postsynaptic membrane [Reject neurone]
11) proteins change shape / channels open
12) sodium ions rush into postsynaptic neurone [Reject membrane]
13) postsynaptic membrane depolarised
14) action potential / nerve impulse
AVP) action of acetylcholinesterase
describe the roles of neuromuscular junctions, the T-tubule
system and sarcoplasmic reticulum in stimulating contraction
in striated muscle
1) action potential / depolarisation / impulse, at pre-synaptic membrane
2) (voltage-gated) calcium ion channels open / calcium ions enter (cell / cytoplasm /(motor) neurone / pre-synaptic knob)
3) vesicles fuse with pre-synaptic membrane
4) acetylcholine / ACh, released, by exocytosis / into synaptic cleft
5) (ACh) binds to receptors on, muscle cell membrane / sarcolemma / motor end plate
6) sodium ion channels open / sodium ions enter (muscle cell / sarcoplasm)
7) depolarisation of, (muscle) cell surface membrane / sarcolemma
8) (depolarisation) spreads / transmitted, to / down / via, T-tubules
9) depolarisation of (adjacent) sarcoplasmic reticulum (membrane)
10) (voltage-gated) calcium ion channels open
11) calcium ions, move / diffuse, out of SR / out of cisterna(e)
12) calcium ions, move / diffuse, into, sarcoplasm / cytoplasm
13) calcium ions, start contraction / bind to troponin
