Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology > Nervous system > Flashcards

Nervous system Flashcards

1
Q

What is a membrane potential?

A

Difference in the concentration of different ions across the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What ions contribute to the resting membrane potential

A

Na+
K+
A- - anions which have a negative charge due to amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Concentration of ions inside cell

A 
Na+ = 15mM
K+= 150mM 
A- = 60mM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Concentration of ions outside the cell

A 
Na+ = 150mM
K+ = 5mM
A- = 0
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What contributes most to the membrane potential?

A

Potassium ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is resting potential?

A

-70mV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the stages of an action potential?

A 
Resting potential
Stimulus
Threshold
Action potential
Repolarisation
Hyperpolarisation 
Returns to resting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Sodium voltage gated channel proteins

A

have 2 separate gates - inactivation and activation

in resting state the inactivation gate is open but the activation gate is closed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Process of action potential generation

A
  1. Stimulus causes sodium ion channels to open and sodium moves into the cell
  2. Once threshold is reached the sodium voltage gated channel is activated and both gates open
  3. there is an influx of sodium ions
  4. causes depolarisation and more channels to open, increasing depolarisation
  5. Potassium channels open and there is an outflow of potassium ions
  6. Inactivation gate of voltage gated sodium ion channels close
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Repolarisation

A

The leaky sodium ion channels and potassium ion channels allow outflow of sodium and potassium ions causing repolarisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Hyperpolarisation

A

Outflow of potassium ions can be large enough to cause hyperpolarisation so the cell becomes more negative than resting potential. The potassium ion voltage gated channels close and the membrane potential is restored by the sodium/ potassium pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Types of refractory period

A
  1. Absolute

2. Relative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Absolute refractory period

A

No stimulus can initiate a second action potential because the inactivated sodium gate is closed/ cannot reopen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Relative refractory period

A

period of time when a second action potential can only be initiated with there is a larger than normal stimulus are this is when the potassium channels are still open and so there is hyperpolarisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How are action potentials propagated?

A

Influx of sodium ions causes adjacent voltage gated channels to open and cause the action potential to travel along the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Continuous conduction

A

step by step depolarisation and repolarisation of the adjacent segment of the membrane . Occurs in unmyelinated neurons and muscle fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

saltatory conduction

A

Occurs in myelinated neurons becaus there is an uneven distribution of voltage gated channel proteins - few where there is myelin sheath and many at nodes of ranvier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does saltatory conduction work?

A

An electric current flows through the ECF surrounding the myelin and through the cytosol from one node to the next causing the sodium ion channels to open at the next node.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is special about saltatory conduction

A

The action potential leaps from one node to the next and so is energy efficient as there are smaller regions of depolarisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what factors affect the speed of propagation?

A

Myelination
axon diameter - larger diameter the faster rate of conduction due to larger surface area
temperature - quicker when warmer due to rate of diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the different types of neurotransmitter?

A

Excitatory and inhibitory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Excitatory neurotransmitter

A

One that causes depolarisation of the post-synaptic membrane - brings it closer to threshold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Inhibitory neurontransmitter

A

Causes hyperpolarisation of the post synaptic membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Main neurotransmitters

A 
Glutamate
Serotonin
Dopamine
Histamine
ATP
Acetylcholine
Noradrenaline
Glycine 
Neuropeptides
GABA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Glutamate

A

Main excitatory in CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

GABA

A

Main inhibitory in adult brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Glycine

A

Main inhibitory in spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Acetylcholine

A

excitatory at NMJ and inhibitory at heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Receptors of acetlycholine

A

Nicotinic and muscarinic
Nicotinic at NMJ
Muscarinic is inhibitory only at heart muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Histamine

A

Excitatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Noradrenaline

A

Excitatory and inhibitory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Receptors of noradrenaline

A

Alpha 1&2

Beta 1-3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Neuropeptides

A

excitatory and inhibitory - they assist neurotransmitters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

ATP

A

Excitatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Serotonin

A

Inhibitory and excitatory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How many receptors does serotonin have?

A

13 - all GPCRs except 5-HT3

main controller of mood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Dopamine

A

Excitatory and inhibitory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Dopamine receptors

A

D1-5 linked to schizophrenia and parkinsons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What neurotransmitter works in the sympathetic NS post-ganglionic?

A

Noradrenaline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Formation of noradrenaline

A

Tyrosine-DOPA-Dopamine-Noradrenaline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What controls the presynaptic levels of serotonin, noradrenaline, adrenaline and dopamine at the presynaptic membrane?

A

Monoamine oxidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What neurotransmitter works at an adrenal medullary cell assisting adrenal catecholamine release?

A

Adrenaline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Formation of adrenaline

A

Tyrosine-DOPA-Dopamine-Noradrenaline-Adrenaline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What inhibits noradrenaline release?

A

Presynaptic reuptake

Catechol-o-methyltransferase (COMT) which breaks it down at postsynaptic neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Serotonin formation

A

Tryptophan-5hydroxytryptophan-5hydroxytryptamine (5-HT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What does serotonin act on?

A

CNS
Gut
CVS
Blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Serotonin role in CNS

A 
Mood
memory
aggression
appetite
sleep
addiction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Serotonin role in Gut

A

increased motility

emesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Serotonin role in CVS

A

Vasoconstriction

increases heart rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Serotonin role in blood

A

Platelet activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Alpha 1 adrenergic receptor

A

Arterioles and bladder
Vasoconstriction and constriction
Affected by adrenaline and noradrenaline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Alpha 2 adrenergic receptor

A

Central and presynaptic Inhibition and inhibition of release of adrenaline and noradrenaline

53
Q

Beta 1 adrenergic receptor

A

Heart

Increases heart rate and contractility. Affected by adrenaline and noradrenaline

54
Q

Beta 2 adrenergic receptor

A

Bronchi and muscle blood vessels and uterus
causes bronchodilation and dilation of muscle blood vessels and relaxation of uterus
Affected by adrenaline only

55
Q

Beta 3 adrenergic receptors

A

Fat cells - lipolysis
Thermogenesis
Affected by adrenaline and noradrenaline

56
Q

Catecholamines

A

Adrenline and noradrenaline

57
Q

GPCR classification

A

Gs
Gi
Gq

58
Q

Gs receptor

A

Adrenergic Beta 1 and heart
Stimulates adenylate cyclase to increase cAMP concentration and activate protein Kinase A. Increases rate and strength of contractions

59
Q

Gi receptor

A

cholinergic muscarinic 2 in heart . Inhibits adenylate cyclase decrease cAMP. Decreases rate and strength of contractions

60
Q

Gq receptor

A

Adrenergic alpha 1 in blood vessels. IP3 opens calcium ion channels and activates protein kinase C. Causes vasoconstriction

61
Q

Peripheral neurotransmitters

A

Acetylcholine

Noradrenaline

62
Q

CNS neurotransmitters

A 
Acetylcholine
Noradrenaline
Dopamine
Serotonin
GABA
Glutamate
Endorphins/ enkephalins
Substance P
Glycine
63
Q

Role of acetylcholine

A

motor function regulation
emotion
arousal

64
Q

Role of noradrenaline

A

memory
arousal
circadian rhythm
endorphin release in spinal cord which inhibits nociception

65
Q

Role of dopamine

A

Motor function regulation
memory
emesis
regulation of hormone release

66
Q

Role of serotonin

A 
mood
memory
appetite
sleep
endorphin release in spinal cord and inhibits  nociception
67
Q

GABA receptors

A

GABA a - chlorine channel linked

GABA b - GPCR

68
Q

Glutamate receptors

A

NMDA and non-NMDA - KA and AMPA

69
Q

what do Endorphins/ Enkephalins do?

A

Inhibits nociception in dorsal horn of spinal cord

70
Q

Substance P

A

amplifies nociception in the dorsal horn of spinal cord

71
Q

What are the types of sensory cells/ receptors

A 
Chemoreceptors
Thermoreceptors
Mechanoreceptors
Photoreceptors
Baroreceptors
Hydroreceptors
Magnetoreceptors
Nociceptors
Osmoreceptors
Proprioceptors
72
Q

Autonomic

A

regulates functions with little or no voluntary control, via a pair of opposing systems = sympathetic and parasympathetic

73
Q

Parasympathetic NS

A

Comfort

74
Q

Sympathetic NS

A

Crisis

75
Q

What tissues can be innervated by the autonomic NS

A 
smooth muscle
cardiac muscle
exocrine glands
endocrine glands
fat cells
76
Q

What does the parasympathetic nervous system affect?

A 
Pupils
salivary glands
heart rate
bronchi
gut
bladder
77
Q

What does PSNS do to pupils?

A

constricts

78
Q

What does PSNS do to salivary glands?

A

stimulates

79
Q

What does PSNS do to heart rate?

A

decreases

80
Q

What does PSNS do to bronchi?

A

constricts

81
Q

What does PSNS do to gut?

A

stimulates peristalsis and gastric acid secretion

82
Q

What does PSNS do to bladder?

A

stimulates contraction, allows urine to be passed

83
Q

What are the pathways of the parasympathetic NS?

A

Craniosacral

84
Q

What does the sympathetic NS affect?

A 
Arterioles
sweat glands
pupils
salivary glands
heart rate
bronchi
gut
bladder
85
Q

What does SNS do to arterioles?

A

constricts

86
Q

What does SNS do to sweat glands?

A

stimulates via ACh receptors

87
Q

What does SNS do to pupils?

A

dilates

88
Q

What does SNS do to salivary glands?

A

inhibits

89
Q

What does SNS do to heart rate?

A

increases

90
Q

What does SNS do to bronchi?

A

dilates via circulating adrenaline

91
Q

What does SNS do to gut?

A

inhibits peristalsis

92
Q

What does SNS do to bladder?

A

inhibits contraction - cannot pass urine

93
Q

What are the pathways of the sympathetic NS?

A

Thoracolumbar - only input between T1 and L2

94
Q

Which cranial nerves are autonomic?

A

oculomotor, facial, glossopharyngeal and vagus

95
Q

Parasympathetic pathway

A

2 neurones

long pre-ganglionic and short post-ganglionic

96
Q

Sympathetic pathway

A

2 neurone pathway

short pre-ganglionic and long post-ganglionic

97
Q

Ganglia of sympathetic NS

A

ascends to supply head, descends to supply pelvis
directly innervates adrenal medulla
directly from pre-ganglionic neurone
releases adrenaline

98
Q

Horner’s syndrome

A

Damage to the sympathetic nerves of face causing miosis, ptosis, lack of sweating and facial flushing. could be a sign of cancer at the top of the thorax.

99
Q

What is miosis?

A

Pupil constriction

100
Q

What is ptosis?

A

Droopy eyelid

101
Q

Autonomic neurotransmitterS

A

acetylcholine

noradrenaline

102
Q

Muscarinic 1 receptor

A

autonomic ganglia, synaptic transmission

103
Q

Muscarinic 2 receptor

A

stomach - acid secretion

104
Q

Muscarinic 3 receptor

A 
bronchi - constriction
bladder - contraction
gut - increases peristalsis
eye - accommodation
salivary glands - saliva secretion 
stomach - acid secretion
105
Q

Muscarinic 4 receptor

A

CNS - multiple roles

106
Q

Muscarinic 5 receptor

A

CNS - multiple roles

107
Q

Atropine

A

blocks muscarinic receptor to increase heart rate

108
Q

Isoprenaline

A

can be used to activate beta 1 receptors

109
Q

how to treat Hyperhidrosis

A

can be treated locally by botox injections which prevent synaptic ACh release

110
Q

Pilocarpine

A

selective M3 agonist used to treat glaucoma by constricting the pupil

111
Q

Anaphylaxis

A

results in profound histamine induced hypotension and bronchospasm - adrenaline is used to treat it as it stimulates both alpha 1 and beta 2

112
Q

Ear drum

A

Tympanic membrane

113
Q

Middle ear

A 
Made up of 3 bones 
oval window
round window
stapedius muscle
tensor tympanic muscle 
eustachian tube
114
Q

bones of middle ear

A

OSSICLES
malleus
incus
stapes

115
Q

Membranes of ear

A

vestibular
basilar
tectorial

116
Q

Organ of Corti

A

on top of the basilar membrane and beneath the tectorial membrane with hair cells on the surface which have stereocilia
the organ of corti is embedded in endolymph

117
Q

Fluid spaces

A

Scala vestibuli - perilymph
Scala tympani - perilymph
Scala media - endolymph
electrochemical potential between the spaces

118
Q

Hair cells

A

inner hair cells - responsible for transducing the mechanical energy
outer hair cells
stereocilia

119
Q

How is an action potential generated in the ear?

A

waves of vibration in scala media causes membranes to move and hair cells bend - moving ions and creating an action potential

120
Q

What happens in the hair cells when an action potential is generated in the ear

A

as the membranes move the hair cells move. The hair cells have thick bases containing potassium solution and stereocilia on the top which is bathed in endolymph which is rich in potassium ions. When the stereocilia move the tip links stretch and mechanical gates channels open and potassium diffuses, opening calcium ion channels to open and cause neurotransmitter release forming an action potential .

121
Q

Pitch

A

Varied frequencies which are detected at different positions along the basilar membrane

122
Q

Mechanism of damage from noise

A

damage to hair cells/ cilia
inflammation
excitotoxicity

123
Q

Acoustic reflex

A

method to try and dampen the sound
tensor tympani attached to the tympanic membrane and stapedius to the stapes
the muscles contract in response to loud noise
contraction of stapedius pulls stapes and reduces the intensity of the sound reaching the cochlea

124
Q

Ineffectiveness of acoustic reflex

A

muscles fatigue quickly

125
Q

Rinnes test

A

normal result = air conduction>bone conduction
sensorineural deafness = air conduction>bone conduction
conductive deafness = bone conduction> air conduction

126
Q

Webers test

A

normal = sound heard equally in both ears
sensorineural deafness = sound is louder on side of intact ear
conductive deafness = sound is louder on side of affected ear

127
Q

vestibular apparatus

A 
near to cochlea:
semi circular canals
utricle
saccule
contains endolymoh and perilymph
128
Q

balance

A

rotation of head movements can be detected in all planes as the semi circular canals are in all 3 planes.each canal is an ampulla which contains the crista ampullaris

129
Q

Crista ampullaris

A

the sensing mechanism linked to vestibular nerve

Physiology (46 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions