Neuro Flashcards

1
Q

What do oligodendrocytes myelinated?

A

Brain

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2
Q

What do Schwann cells myelinate?

A

PNS

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3
Q

What is a lemnisci?

A

narrow strips of fibres

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4
Q

Define funiculi?

A

Rope or cord

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5
Q

Define Fasciculi?

A

Bundle

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6
Q

Define nuclei

A

Collection of nerve cell bodies within the CNS

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7
Q

Define ganglia

A

Collection of nerve cell bodies outside the CNS and some in the CNS (In a capsule)

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8
Q

What sort of information is carried on afferent fibres?

A

Sensory fibres towards CNS

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9
Q

What sort of information is carried on efferent fibres?

A

Motor fibres away from the CNS

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10
Q

Which direction is rostral?

A

Towards the nose (Anterior)

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11
Q

Which direction is caudal?

A

Towards tail (posterior)

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12
Q

What is the function of the frontal lobe?

A

Voluntary movement on opposite side of the body

Dominant frontal lobe controls speech and writing

Intellectual functioning, thought processes, reasoning and memory

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13
Q

What is the function of the parietal lobe?

A

receives and interprets sensations including pain, touch, pressure and proprioception

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14
Q

What is the function of the temporal lobe?

A

understanding spoken word (Wernicke’s)

Memory and emotion

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15
Q

What is the function of the occipital lobe

A

Understanding visual images and meaning of written words

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16
Q

What are the components of the basal ganglia?

A

Caudate nucleus
Putamen
Globus Pallidus

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17
Q

What are the components of the striatum

A

Caudate nucleus and putamen

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18
Q

What are the components of the lentiform nucleus

A

Globus pallidus and the putamen

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19
Q

What is the function of the cerebellum?

A

Co-ordinates movement and balance

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20
Q

Where does the superior cerebellar peduncle attach to?

A

Midbrain

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21
Q

Where does the middle cerebellar peduncle attach to?

A

Pons

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22
Q

Where does the inferior cerebellar peduncle attach to?

A

Medulla

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23
Q

What are the two specialised cell types found in the CNS

A

Nerve cells (Pyramidal, stellate, Golgi, Purkinje)

Neuroglia (Astrocytes, oligodendrocytes and microglia)

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24
Q

By which week does the neural tube normally close?

A

4th week

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25
Q

What condition results from failure of the neural tube to close in the spinal cord?

A

Spina bifida

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26
Q

What condition results from failure of the neural tube to close in the cephalic region?

A

Anencephalus

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27
Q

Describe the process of neuralation

A

Ectoderm thickens in midline in 3rd week to form neural plate

Ectoderm undergoes differential mitosis to form mid-line groove called neural groove

Groove deepens and tdetaches from ectoderm to become neural tube

Lateral to the neural plate lie presumptive neural crest cells which run dorsolaterally along the neural groove

Rostral portion of neural tube (Forms brain) grows faster than caudal portion (Forms spinal cord)

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28
Q

What do the neural crest cells go on to form?

A
Sensory (dorsal root) ganglia of the spinal cord and CN V, VII, IX and X
Schwann cells 
Pigment cells 
Adrenal medulla 
Bony skull 
Meninges 
Dermis
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29
Q

By 5th week of development, what are the three primary brain vesicles called?

A

Prosencephalon (Forebrain)

Mesencephalon (Midbrain)

Rhombencephalon (Hindbrain)

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30
Q

What secondary brain vesicle does the prosencephalon become?

A

Telencephalon and diencephalon

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31
Q

What secondary brain vesicle does the mesencephalon become?

A

Mesencephalon

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32
Q

What secondary brain vesicle does the rhombencephalon become?

A

Metencephalon and Myelencephalon

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33
Q

What does the telencephalon form?

A

Cerebral hemispheres and lateral ventricles

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34
Q

What does the diencephalon form?

A

Thalamus
Hypothalamus
Third ventricle

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35
Q

What does the mesencephalon form?

A

Midbrain (Colliculi)

Aqueduct

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36
Q

What does the metencephalon become?

A

Cerebellum, Pons and upper part of 4th ventricle

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37
Q

What does the myelencephalon become?

A

Medulla oblongata and Lower part of 4th ventricle

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38
Q

Describe the function of the hippocampus

A

Episodic memory
Construction of mental images
Short term memory
spatial memory and navigation

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39
Q

What are the basic components of all neurones

A

dendrites
cell body
axon
presynaptic terminal

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40
Q

What stain is used for myelin?

A

Luxor fast blue

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41
Q

What stain is used for Nissl (RER)?

A

Cresol violet

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42
Q

Describe the composition of myelin

A

70% lipid and 30% protein

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43
Q

Where are myelinated axons most commonly found?

A

Somatic nerves

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44
Q

Where are unmyelinated axons commonly found?

A

Post-ganglionic autonomic fibres, fine sensory fibres, olfactory neurones and interneurones

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45
Q

What is the function of glial cells?

A

Provide physical and metabolic support to neurones

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46
Q

How many axons can oligodendrocytes myelinate?

A

Multiple

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47
Q

How many axons can Schwann cells myelinate

A

Single

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48
Q

What is the function of astrocytes?

A

Regulate composition of extracellular fluid in CNS by removing K+ ions and neurotransmitters

Take up glutamate and convert it to glutamine and release it so can be taken back up by neurones and converted to glutamate for re-use

Stimulate the formation of tight junctions as part of the BBB

Sustain neurones metabolically by providing glucose and removing ammonia

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49
Q

What are microglia and what is their function?

A

Specialised macrophage like cells that perform immune functions in the CNS

  • Phagocytose debris/microbes
  • contribute to synaptic plasticity
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50
Q

What is the function of ependymal cells?

A

Line ventricles of the brain and regulate the production and flow of CSF

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51
Q

Which cells make up the BBB?

A

Endothelial cells, pericytes and astrocytes

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52
Q

What are the features of the blood brain barrier

A

Endothelial tight junctions
Astrocyte end feet
Pericytes
Continuous basement membrane

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53
Q

What is the name given to areas of the brain that lack a BBB?

A

Circumentricular organs ie. posterior pituitary

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54
Q

Where does the CSF circulate

A

Subarachnoid space

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55
Q

What is the volume of the CSF?

A

120mls

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56
Q

What is found in the CSF?

A

Protein, urea, glucose and salts

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57
Q

Where is the CSF produced?

A

By ependymal cells in the choroid plexus

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58
Q

How is CSF reabsorbed?

A

Via arachnoid granulations

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59
Q

Describe what happens in hydrocephalus?

A

Abnormal accumulation of CSF in the brain which leads to a build up of pressure often due to a blocked cerebral aqueduct

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60
Q

What is normal resting potential

A

-70mV

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61
Q

Which transporter is Important in driving neuronal membrane concentration gradients?

A

Na+/K+ ATPase pumps 3 Na+ out for every 2 K+ ions in via active transport

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62
Q

Where are Na+ ions concentrated in terms of the axonal membrane?

A

Outside the membrane

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63
Q

Where are K+ ions concentrated in terms of the axonal membrane?

A

Inside the membrane

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64
Q

Why is the resting axonal membrane more permeable to K+ than Na+

A

Because there are very few voltage gated Na+ channels open meaning few Na+ ions diffuse back into the axons whereas K+ voltage gated channels are also closed by K+ leak channels are open allowing K+ to move into the axon

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65
Q

Describe what happens during an action potential

A
  1. Neurotransmitter binds specific ligand gated ion channels on post synaptic membrane causing Na+ influx
  2. Na+ influx causes initial depolarisation which stimulates more voltage gated Na+ channels to open
  3. When the depolarisation reaches the threshold potential of -55mV, depolarisation becomes a positive feedback loop with more Na+ influx causing more depolarisation
  4. At +30mV, Na+ channels close and K+ channels open causing repolarisation
  5. Return to negative potential causes K+ channels to close but they do this slowly allowing continued outflow of K+ which causes hyperpolarisation
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66
Q

Why are refractory periods important?

A

Limit the number of action potentials an excitable membrane can produce and makes them separated so that individual signals pass down the axon

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67
Q

What two factors influence the speed of propagation?

A

Fibre diameter and myelination

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68
Q

Why does myelination increase propagation speeds?

A

Less leakage of charge across myelin so local current spreads further

APs only occur at nodes of Ranvier where the concentration of Na+ channels is high enabling saltatory conduction to occur

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69
Q

What is the propagation speed in unmyelinated fibres

A

0.5m/s

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70
Q

What is the propagation speed in myelinated axons

A

100m/s

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71
Q

Describe the pathophysiology of multiple sclerosis

A

Degeneration of myelin and development of scar tissue which disrupts and blocks neurotransmission in myelinated axons

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72
Q

What are the symptoms of multiple sclerosis?

A
Uncontrolled eye movements 
Slurred speech 
Partial/Complete paralysis 
Tremor 
Loss of co-ordination 
Weakness
Sensory numbness, prickling, pain
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73
Q

What happens at an excitatory synapse?

A

Membrane potential of the postsynaptic neurone is brought closer to threshold

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74
Q

What happens at an inhibitory synapse?

A

The membrane potential of the post synaptic neurone is driven further (hyper polarised) or stabilised at resting potential

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75
Q

What are the two types of synapse?

A

Excitatory

Chemical

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76
Q

Describe how electrical synapses work?

A

Plasma membrane of pre and postsynaptic cells are joined by gap junctions

these enable local currents from arriving action potentials to flow across the junction, depolarising them membrane of the second neurone to threshold

This occurs rapidly and enables synchronised transmission

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77
Q

Where are electrical synapses most commonly found?

A

Brainstem neurons ie. brainstem and hypothalamus

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78
Q

Describe the structure of chemical synapses?

A

Plasma mem of pre and post joined by synaptic cleft

Axon of pre ends in swelling, axon terminal, which holds vesicles of neurotransmitters

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79
Q

Describe how a chemical synapse works?

A

AP reaches the pre-synaptic terminal and causes Ca2+ influx

Ca2+ ions cause vesicle to move to pre membrane and discharge

Neurotrans move across cleft and attach to receptor on post synaptic mem

Neurotrans removed from synaptic cleft (astrocytes)

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80
Q

What are the 5 processes of synaptic transmission

A
  1. Manufacture (intracellular biochemical processes)
  2. Storage - vesicles
  3. Release - AP
  4. Interact with post synaptic receptors
  5. Inactivation
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81
Q

What are the two main acetylcholine receptors

A

muscarinic

Nicotinic

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82
Q

What enzyme is responsible for the breakdown of acetylcholine in the synaptic cleft

A

Acetylcholinesterase into choline and acetate

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83
Q

What is temporal summation

A

Input signals arrive from the same presynaptic cell at different times and the potentials summate since there are a greater number of open ion channels

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84
Q

What is spatial summation?

A

Where two inputs occur at different locations in the post synaptic neurone

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85
Q

What are the 3 most common fates of neurotransmitters in the synaptic cleft

A
  1. Actively transported back into presynaptic axon terminal
  2. Diffuse away from receptor site
  3. Are enzymatically transformed into inactive substances and some transported into presynaptic terminal for re-use
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86
Q

How do anaesthetics work?

A

Procaine and lignocaine most common

Work by interrupting axonal neurotransmission by blocking Na+ channels thereby preventing neurones from depolarising so threshold isn’t met and no AP is developed to be propagated

Results in pain relief since pain isn’t transmitted

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87
Q

What molecules combine in the cytoplasm to produce acetylcholine?

A

Choline

Acetyl co-enzyme A

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88
Q

Why is L-DOPA given to Parkinson’s Patients?

A

Because L-DOPA is the precursor molecule to dopamine and is freely taken up across the BBB so can enter serotonergic neurones which contain the enzymes needed to convert it to dopamine

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89
Q

What is the hearing range of a human?

A

20-20,000Hz

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90
Q

What is the function of the outer ear?

A

To collect sound, amplify and direct it

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91
Q

What is the function of the middle ear?

A

Transmission of sound

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92
Q

What is the function of the inner ear?

A

Conversion of sound into neural impulses

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93
Q

Describe the path of the external ear

A

Sound enters through the exterior part of the ear, the pinna

From here it enters the external auditory meatus and travels to the tympanic membrane where air molecules will push against the membrane causing it to vibrate at same frequency as the sound wave

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94
Q

Does the tympanic membrane vibrate slowly or quickly to low frequency sounds?

A

Slowly

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95
Q

What is the middle ear?

A

Air filled cavity in the temporal bone of the skull

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96
Q

Which nerve provides sensation to the middle ear

A

Glossopharyngeal

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97
Q

By which structure is the middle ear exposed to atmospheric pressure?

A

Eustachian tube which connects the middle ear to the pharynx

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98
Q

When does the Eustachian tube open?

A

Normally closed unless muscle movements occur during yawning, sneezing and swallowing

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99
Q

Why do changes in altitude cause ear pain?

A

because altitude change causes difference in pressure between the middle and external ear. This pressure can cause the tympanic membrane to stretch causing pain but can be relieved by yawning/swallowing which causes the Eustachian tube to open allowing pressure in the middle ear to equilibrate with atmospheric pressure

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100
Q

Name the three ossicle bones

A

Malleus
Incus
Stapes

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101
Q

Describe the transfer of tympanic membrane vibrations to the inner ear

A

Vibrations of TM are passed to the inner ear by the ossicles which act as a piston, coupling TM vibrations to the oval window which is much smaller than TM so force per area is greater which is required to transmit sound through fluid filled cochlear

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102
Q

How can the amount of energy transmitted to the inner be lessened?

A

Contraction of the tensor tympani and stapedius muscles which act reflexively to continuous loud noise to protect the inner ear

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103
Q

Which ossicle does the tensor tympani attach to?

A

Malleus

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104
Q

Which ossicle does stapedius attach to?

A

Stapes

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105
Q

What is the innervation of the tensor tympani muscle

A

Mandibular division of Trigeminal nerve

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106
Q

What is the innervation of the stapedius muscle

A

Facial nerve

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107
Q

What is the name given to the inner ear?

A

Cochlea - fluid filled space in the temporal bone

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108
Q

The cochlea is divided lengthways by what membranous tube structure?

A

Cochlea duct (SCALA MEDIA)

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109
Q

What is the fluid of the cochlea duct (scala media) called and what is its composition?

A

Endolymph which is high in K+ and Low in Na+

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110
Q

What is the name given to the fluid that fills the compartments either side of the cochlea duct?

A

perilymph - similar composition to CSF

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111
Q

What structure begins at the oval window and lies above the cochlear duct?

A

Scala vestibuli

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112
Q

What structure connects the middle ear to the round window and lies below the cochlea duct?

A

Scala tympani

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113
Q

What is the name given to the part of the inner ear where the Scala tympani and vestibuli are continuous with one another?

A

Helicotraema

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114
Q

Describe the transmission of sound in the inner ear?

A

Oval window moves in and out of the scala vestibuli which creates waves of pressure which are transmitted across the cochlea duct towards the helicotraema and the scala tympani. Pressure differences across the duct cause the basilar membrane to vibrate

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115
Q

Where does the organ of Corti lie?

A

on the basilar membrane which sits on the cochlear duct side closest to the scala tympani

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116
Q

Describe the properties of the base of the basilar membrane and what frequency is it sensitive to?

A

Narrow and stiff so sensitive to high frequency sounds

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117
Q

Describe the properties of the apex of the basilar membrane and what frequency is it sensitive to?

A

Wider and less stiff so sensitive to low frequency sounds

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118
Q

What are the receptor cells of the organ of Corti called

A

Hair cells - mechanoreceptors with stereo cilia

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119
Q

How many rows of inner hair cells do we have?

A

Single row

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120
Q

How many rows of outer hair cells do we have?

A

4-5 rows

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121
Q

Where do the inner hair cells extend to?

A

Extend into the endolymph and covert pressure waves caused by fluid movement in cochlear duct into receptor potentials

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122
Q

Where are the stereo cilia of the outer hair cells embedded?

A

Embedded in the overlying tectorial membrane and mechanically alter its movement at each point along basilar membrane

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123
Q

What happens when pressure waves displace the basilar membrane?

A
  1. The hair cells move in relation to the stationary tectorial membrane causing the stereo cilia to bend
  2. When stereo cilia bend towards the tallest member of the bundle, the fibrous connections called tip links pull open mechanically gated K+ channels causing an influx of K+ and Ca2+ from the endolymph depolarising the membrane
  3. Change in voltage triggers opening of voltage gated Ca2+ channels near base of the cell which triggers neurotransmitter release
  4. Bending of hair cells in opposite direction slackens the tip links, closing the channels and causing the cell to depolarise
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124
Q

What is the neurotransmitter released from hair cells?

A

Glutamate

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125
Q

Where does glutamate from hair cells bind to?

A

Protein binding sites on afferent neurones

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126
Q

Where do action potentials generated from oscillating hair cells go?

A

axons join to form the cochlear branch of the vestibulocochlear nerve

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127
Q

Greater frequency of action potentials generated in afferent nerve fibres from stereocili occurs when…

A

The sound wave has greater energy (Loudness)

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128
Q

The cochlear nerve fibres that lie within the cochlea and make direct contact with the hair cells are known as…

A

Spiral ganglion

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129
Q

The cochlear nerve joins the brainstem at the level of

A

Rostral medulla

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130
Q

After its bifurcation fro the rostral medulla, Where does the cochlear nerve end?

A

Dorsal and ventral cochlear nuclei which lie close to the inferior cerebral peduncle

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131
Q

From the cochlear nuclei, where do the second order neurones project to?

A

Superior olivary nucleus

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132
Q

Describe the pathway of auditory information from the superior olivary nucleus to the primary auditory cortex

A

From superior olivary nucleus, the fibres travel to the inferior colliculus of the midbrain

From here, the inferior brachium nerve carries information to the medial geniculate body of the thalamus and from there the fibres travel through the internal capsule to the primary auditory cortex on the temporal lobe

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133
Q

What functional area of the brain surrounds the primary auditory cortex?

A

Wernicke’s area

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134
Q

What is the function of Wernicke’s area

A

processing of language

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135
Q

Inferior colliculus and medial geniculate body are important for what sense

A

Hearing

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136
Q

The superior colliculus and lateral geniculate body are important for what sense?

A

Vision

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137
Q

Which cranial nerve runs through the middle ear and is important for taste messages from the tongue to the brain

A

Chorda tympani branch of the facial nerve

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138
Q

Other than the vestibulochochlear nerve, which other CN exits the cranial cavity through the internal acoustic meatus?

A

Facial nerve

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139
Q

Other than in the cochlea, where else can hair cells be found in the inner ear?

A

Vestibular apparatus

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140
Q

The vestibular apparatus is filled with what fluid?

A

Endolymph

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141
Q

What do the hair cells of the vestibular system detect?

A

Motion and position of the head

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142
Q

What does the vestibule apparatus consist of? T

A

3 membranous semi-circular canals and two sac like swellings, utricle and saccule which all lie in the temporal bone

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143
Q

What do the semicircular canals detect?

A

Angular acceleration during rotation of the head along 3 perpendicular axes

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144
Q

When are the semicircular canals of the head activated

A

When nodding head up and down
When shaking head from side to side
When tipping head so ear touches the shoulder

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145
Q

stereocilia in the semicircular canals are encapsulated in a gelatinous mass in the ampulla called the

A

Capula

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146
Q

Describe how the semicircular canals detect angular acceleration

A

When head moves the semicircular canals and hair cells move with it but the endolymph in the duct is not attached to skull and due to inertia remains in its original position

The moving ampulla is thus pushed against stationary fluid which causes the stereo cilia to bend and alter their rate of glutamate release

Each hair cell receptor has one direction of maximum glutamate release so when stereo cilia bend in that direct the receptor cell depolarises and when they bend in the other direction the hyper polarisation

When the head continously rotates at steady velocity, the duct fluid begins to move at same rate as the rest of the head and the stereo cilia return to resting position so hair cells are only stimulated during acceleration and deceleration

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147
Q

What is the function of the utricle and the saccule

A

To provide information about the linear and vertical acceleration of the head and about changes in head position relative to gravity

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148
Q

What do the hair cells of the utricle respond to?

A

Hair cells in utricle stand almost straight up (pointing up from floor) when standing so they respond when the head is tipped away from a horizontal plane (Head tilt) or to linear acceleration in the horizontal plane

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149
Q

What do the hair cells of the saccule respond to?

A

Hair cells of saccule project at right angles (pointing out from wall) to the utricle and respond when you move from lying to a standing position or vertical accelerations like on a trampoline

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150
Q

Describe how the utricle and saccule convert information in nerve impulses

A

Otolith membrane is gelatinous and contains calcium carbonate crystal (Otoliths) which are heavy and sit on top of hair cells.
Otoliths make the gelatinous substance heavier than the surrounding endolymph so when the otolithic material moves (ie. Linear acceleration) it pulls agains the hair cells so the stereo cilia bend and action potentials are propagated along the vestibular nerve.
when the head is still or at a continuous acceleration, the otoliths don’t move so APs are constant

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151
Q

Where to the fibres of the vestibular nerve terminate?

A

in the vestibular nuclei of the rostral medulla

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152
Q

What is the vestibular information used for?

A

Control of eye movement
Proprioception
Reflexes maintaining upright posture and balance

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153
Q

What is the name given to the sensory epithelium in the saccule and the utricle?

A

Maculae

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154
Q

What are the 3 planes of the semicircular canals

A

Horizontal
Posterior
Superior

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155
Q

What do the semi-circular canals detect

A

Angular acceleration (Rotation)

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156
Q

What neurotransmitters are released by the hair cells in the utricle and saccule

A

Glutamate and aspartate

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157
Q

Which cranial nerves do the vestibular nuclei connect to to control the vesticularoccular reflex

A

Occulomotor

Abducens

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158
Q

Utricle provides information about what?

A

Linear acceleration and head tilt

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159
Q

Saccule provides information about

A

Vertical acceleration

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160
Q

What frequency range is the human ear most sensitive to?

A

1500-4000Hz

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161
Q

The cochlear twists around what bony strcuture?

A

Modiolus

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162
Q

What ligament connects the stapes to the oval window?

A

Annular ligament

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163
Q

Which membrane separates the scala vestibuli and the scala media

A

Reissners membrane

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164
Q

Which membrane separates the scala tympani and the scala media

A

Basilar membrane

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165
Q

Reticular lamina and basilar membrane are connected by what

A

Rods of Corti

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166
Q

Which hair cell (Inner or outer) has the most afferent nerve connections

A

Inner

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167
Q

Inner cells have an important function in

A

Detecting sound

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168
Q

Outer hair cells have an important function in

A

Modifying sound

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169
Q

What is the name of the biggest stereo cilia in a bundle

A

Kinocillium

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170
Q

What are the three tunica (Layers) of the eye?

A

Fibrous tunic
Vascular Tunic (Uvea)
Sensory Tunic

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171
Q

What are the components of the fibrous tunic

A

Sclera

Cornea

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172
Q

What are the components of the vascular tunic

A
Choroid 
Iris 
Ciliary body 
 - Ciliary muscle 
 - Ciliary processes
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173
Q

What are the components of the sensory tunic

A

Retina

Vitreous humor

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174
Q

What is the function of the cornea

A

Allows the passion of light for refraction

Must be transparent

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175
Q

What is the function of sclera?

A

White capsule that offers protection due to collagen component
Serves as insertion point for external eye muscles

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176
Q

What Is the effect of parasympathetic innervation on the iris

A

causes the sphincter pupillae muscle to contract

177
Q

What is the effect of the sympathetic innervation on the iris

A

Causes the dilator pupillae to dilate

178
Q

What is the anterior segment of the eye?

A

From the cornea to the lens

179
Q

What are the two compartments of the anterior segment of the eye

A

Posterior chamber

Anterior chamber

180
Q

What Is the posterior segment of the eye

A

From the posterior lens to the retina

181
Q

What is the function of the choroid

A

Pigmented so when light hits retina and becomes scattered the choroid absorbs it

182
Q

What are the two components of the lens

A

Crystallin lens fibres

Lens epithelium

183
Q

What are the two components of the retina

A

Neural retinal layer

Epithelial retinal layer

184
Q

What happens in a retinal detachment

A

The neural and epithelial layers of the retina become separated allowing vitreous humour to seep in between the layers

185
Q

Which part of the eye is involved in the accommodation reflex?

A

Cilliary muscle

186
Q

What does the iris do?

A

Controls the size of the pupil which lets light into the eye

187
Q

What does the dilator papillae muscle do?

A

Dilates the pupil (Sympathetic)

188
Q

What does the spinchter papillae do?

A

Cnstricts the pupil (Parasympathetic)

189
Q

What does the ciliary body do other than accommodation reflex?

A

Contains glandular epithelium which produces aqueous humour

190
Q

What is the important roles of the aqueous humour

A

Maintains intra-ocular pressure (15mmHg)

191
Q

What structure produces vitreous humour?

A

Retina

192
Q

What are the two muscles attached to the tarsal plate?

A

Levatator palpibra superioris

Obicularis oculi

193
Q

Where in the eye are photoreceptors absent?

A

Optic disc (Blind spot)

194
Q

What is the function of rod cells?

A

Important for vision in dim light and peripheral vision

195
Q

What is the function of cone cells

A

Colour vision

196
Q

What is the function of cone cells

A

Colour vision

197
Q

What are the three layers of the tear film?

A

Anterior lipid layer
Middle aqueous layer
posterior mucous layer

198
Q

Where is the anterior lipid layer of the tear film secreted from?

A

Meibomium gland

199
Q

Where is the middle aqueous layer of the tear film secreted from

A

Lacrimal glands

200
Q

Where is the posterior mucous layer of the tear film secreted from?

A

Goblet cells

201
Q

What is the function of the anterior lipid layer of the tear film

A

Provides hydrophobic layer to prevent the aqueous layer evaporating

202
Q

What is the function of the middle aqueous layer of the tear film?

A

Regulates transport through the cornea and prevents infection

203
Q

What is the function of the posterior mucous layer of the tear film?

A

Provides hydrophilic layer that allows even distribution of the tear film

204
Q

What are the 12 layers through which a photon must travel through the eye?

A
  1. Tear film
  2. Cornea and refraction
  3. Aqueous humour
  4. Lens
  5. Vitreous humor
  6. Ganglion cell
  7. Amacrine cell
  8. Bipolar cell
  9. Horizontal cell
  10. Cone cell
  11. Rod cell
  12. Pigmented epithelium
205
Q

What branches of the internal carotid artery supply the eye?

A
Ophthalmic artery 
Central retinal artery 
Ciliary arteries 
Lacrimal artery 
Ethmoidal and eyelid artery
206
Q

What branch of the external carotid artery supplies the eye

A

facial artery

207
Q

Which fibres cross at the optic chiasm

A

Nasal portion of the retina, carrying the temporary visual field

208
Q

Where in the thalamus do optic tracts join too?

A

Lateral geniculate nucleus

209
Q

Outline the order of the visual pathway from eye to visual cortex

A
Eye
Optic nerve 
Optic chiasm 
Optic tract 
lateral geniculate body 
Optic radiation 
Visual cortex
210
Q

What is the name of the optic radiation that passes through the parietal lobe?

A

Baums loop

211
Q

What is the name given to optic radiation that passes through the temporal lobe?

A

Meyer’s Loop

212
Q

What information do the superior retinal fibres of the optic radiation carry

A

inferior portions of the retina

213
Q

What information do the inferior retinal fibres of the optic radiation carry?

A

Superior portions of the retina

214
Q

Which lobe of the brain do the superior retinal fibres pass through?

A

temporal lobe

215
Q

Which lobe of the brain do the inferior retinal fibres of the optic radiation pass through?

A

Parietal lobe

216
Q

What is the effect of a lesion on the right optic nerve

A

Right anopia

Right monocular blindness

217
Q

What is the effect of a lesion on the left optic nerve?

A

Left anopia

Left monocular blindness

218
Q

What is the effect of a lesion at the optic chiasm?

A

Loss of temporal visual fields = Bitemporal hemianopia

219
Q

What is the effect of a lesion on the right optic tract?

A

Loss of temporal field of left eye and nasal field of right eye
= Right homonymous hemianopia

220
Q

What is the effect of a lesion on left Meyer’s Loop?

A

Carries information from inferior retina on superior visual field so causes of loss of vision in superior nasal field of left eye and superior temporal field of right eye

221
Q

What is the effect of a lesion to left Baum’s Loop?

A

Carries information from superior retina on inferior visual field resulting in loss of vision in inferior temporal field of right eye and inferior nasal field of left eye

222
Q

What is the name given t internal rotation of the eye? (Towards the midline)

A

Intorsion

223
Q

What is the name given to external rotation of the eye?(Away from the midline)

A

Extorsion

224
Q

What are the 6 ocular eye muscles

A
Superior rectus 
Inferior rectus 
Lateral rectus 
Medial rectus 
Superior oblique 
Inferior Oblique
225
Q

What are the 6 ocular eye muscles

A
Superior rectus 
Inferior rectus 
Lateral rectus 
Medial rectus 
Superior oblique 
Inferior Oblique
226
Q

Which muscles of the eye are supplied by oculomotor nerve?

A

Superior rectus
Medial Rectus
Inferior rectus
Inferior oblique

227
Q

Which muscles of the eye are supplied by abducens nerve?

A

Lateral rectus

228
Q

Which muscle of the eye is supplied by the trochlear nerve?

A

Superior Oblique

229
Q

Where are the nuclei of oculomotor and trochlear CN located?

A

In the periaqueductal grey

230
Q

What does the somatic nervous system innervate?

A

Skeletal muscle

231
Q

Do neurones of the somatic nervous system synapse before the skeletal muscle?

A

No

232
Q

What is the only neurotransmitter involved in the somatic nervous system?

A

Acetylcholine

233
Q

What does the autonomic nervous system innervate?

A

Smooth and cardiac muscle, glands, neurones in the GIT

234
Q

Where is the first synapse of an autonomic nerve

A

First nerve synapses outside the CNS in a cell cluster called autonomic ganglion

235
Q

Whats the name of autonomic nerve between the CNS and the ganglia?

A

Preganglionic fibres

236
Q

Whats the name of the autonomic nerve between the ganglion and the effector cells?

A

Postganglionic fibres

237
Q

What is the neurotransmitter of the pregnaglionic fibres

A

Acetyl choline

238
Q

What is the neurotransmitter of the postganglionic fibres

A

Acetylcholine (Excitatory) or noradrenaline (Inhibitory)

239
Q

What are the two divisions of the autonomic nervous system?

A

Sympathetic and Parasympathetic

240
Q

Where do the sympathetic nerves leave the spinal cord?

A

Between T1 and L2

241
Q

Where do the ganglia of the sympathetic neurones lie?

A

Close to the spinal cord

242
Q

What neurotransmitter is used by the preganglionic sympathetic fibres?

A

Acetylcholine acts at nicotinic receptors

243
Q

What neurotransmitter is is used at the effect cell synapse in sympathetic fibres?

A

Noradrenaline acts at adrenergic receptors

244
Q

What are the effects of the sympathetic nervous system?

A
Increased HR
Increased force of contraction 
Vasoconstriction 
bronchodilation
Reduced gastric secretion
Male ejaculation 
Reduced gastric motility 
Sphincter contraction
245
Q

Where do parasympathetic nerves leave the spinal cord?

A

Brainstem and sacral regions of spinal cord

246
Q

Which cranial nerves are parasympathetic

A

3, 7, 9 and 10 (1973)

247
Q

Where do the ganglia of parasympathetic nerves lie?

A

Close to the organs that the postganglionic fibres innervate

248
Q

What is the neurotransmitter used by preganglionic parasympathetic fibres

A

Acetylcholine at nicotinic receptors

249
Q

What is the neurotransmitter used by postganglionic parasympathetic fibres

A

Acetylcholine at muscarinic receptors

250
Q

What are the effects of the parasympathetic nervous system?

A
Decreased heart rate
Decreased force of contraction 
Vasodilation
Bronchoconstrition 
Increased gastric motility 
Increased gastric secretion 
Male erection 
Sphincter relaxation
251
Q

Describe the gross structure of a muscle

A
Muscle attached to bone by a tendon 
Muscle comprises several fasciculi 
Fasiculi comprise several muscle fibres 
Muscle fibres comprise myofibrils 
Myofibrils contrain actin and myosin myofilaments
252
Q

Define a motor unit?

A

An alpha motor neurone and all the extrafusal skeletal muscle fibres it innervates

253
Q

Where are the alpha motor neurones that innervate distal muscles located in the spinal cord?

A

Laterally

254
Q

Where are the alpha motor neurones that innervate the proximal muscle located in the spinal cord?

A

medially

255
Q

What is a major difference between neuromuscular junctions and synaptic junctions

A

At NMJ, every action potential in a motor neurone produces an action potential in a muscle fibre whereas at synaptic junctions, multiple EPSPs are required in order for threshold to be reached
All NMJs are excitatory

256
Q

What is a muscle spindle?

A

A receptor consisting of peripheral endings of afferent nerve fibres wrapped around modified muscle fibres that monitor muscle length and rate of change of muscle length

257
Q

What are the modified muscle fibres in a muscle spindle called

A

Intrafusal fibres

258
Q

What innervates intrafusal fibres?

A

Gamma motor neurones

259
Q

What does a muscle spindle detect?

A

The change in length of the muscle

Rate of change in length of the muscle

260
Q

What is the name of the muscle fibres that form the bulk of the muscle and are important in generating force and movement

A

Extrafusal fibres

261
Q

What are the two types of stretch receptor found in the muscle spindle?

A

Nuclear chain receptors

Nuclear bag receptors

262
Q

What is the function of nuclear chain receptors?

A

To detect how much the muscle has been stretched

263
Q

What is the function of the nuclear bag receptors?

A

To detect the magnitude of stretch and the speed at which it occurred

264
Q

What happens when a muscle spindle is stretched?

A

Activates receptor endings

Causes the stretch reflex (Muscle contracts) and reciprocal inhibition of the antagonistic muscle

265
Q

What is the only known monosynaptic reflex?

A

Stretch reflex because the afferent nerve fibres in the stretched muscle synapse directly onto motor neurones without interneurones

266
Q

Why is a muscle contraction (Shortening) an issue for the muscle spindle detection?

A

Because the stretch on the intramural fibres shortens so slackening on spindle receptor reduces action potentials along afferent neurone so can’t indicate further changes in muscle length while it is shortening

267
Q

What mechanism exists to allow the muscle spindle to detect muscle length even when shortening?

A

Alpha-gamma coactivation - Two ends of the intrafusal muscle fibres contract during shortening of extrafusal fibres to maintain tension in central region of intrafusal fibres

268
Q

which motor neurones control the extrafusal muscle fibres?

A

Alpha motor neurones

269
Q

Which motor neurones control the intrafusal muscle fibres?

A

Gamma motor neurones

270
Q

What are the three factors that determine muscle tension

A

The load
Muscle length
Muscle fatigue

271
Q

Where is the golgi tendon organ located?

A

In the tendon of the muscle

272
Q

How does the golgi tendon organ work?

A

Afferent neurone endings wrap around collagen bundles so when the muscle is stretched of extrafusal muscle contracts, the collagen bundles straighten and distort the receptor endings, activating them

273
Q

What type of sensory afferent nerves are associated with the middle third of the muscle spindle?

A

Fast Type 1a

274
Q

`Which type of sensory afferent neves are associated with the superior and inferior third of the muscle spindle?

A

Slow type 2

275
Q

What type of sensory afferent nerve is associated with the glogi tendon organ?

A

Type 1b fibres that run to the anterior horn of spinal cord

276
Q

What is the effect of activation of the golgi tendon organ?

A

Autogenic inhibition where the 1b afferent nerves will inhibit the alpha motor neurones of the contracting muscle to prevent overload of the muscle

277
Q

Define muscle tone

A

degree of contraction of a muscle or the proportion of Motor units active at one time

278
Q

What will a muscle of high tone feel like?

A

Firm, rigid an resists passive stretch h

279
Q

What will a muscle of low tone feel like?

A

Soft, flaccid and offers little resistance to passive stretch

280
Q

Define hypertonia

A

Abnormally high muscle tone

281
Q

Hypertonia is most commonly seen in what sort of motor neurone disorder

A

Upper motor neurones as they inhibit motor neurones of the descending pathways

282
Q

What is the clasp knife reflex

A

When spasticity occurs as in the muscles do not develop increased tone until they are stretched then after a brief period the contraction subsides

283
Q

The clasp knife reflex is characteristic of what type of motor neurone lesion

A

Lower motor neurone

284
Q

Define pain

A

Unpleasant sensory or emotional experience associated with actual potential tissue damage or described in terms of such damage

285
Q

Define nociceptive pain

A

Pain that arises from actual or threaten damage to non-neuronal tissue due to activation of nociceptors

286
Q

Define neuropathic pain

A

Pain initiated by primary lesion or dysfunction of the nervous system

287
Q

What is a nociceptor?

A

Free nerve endings with no form of specialisation

288
Q

What neurotransmitters are released at primary afferent with nociceptor endings

A

Substance P

Glutamate

289
Q

What substances released from damaged cells will activate nociceptors?

A
Neuropeptides
Bradykinin
Histamine 
Cytokines 
Prostaglandins
290
Q

What are the two somatosensory ascending neural pathways

A

Anterolateral (Spinothalamic path)

Dorsal column lemniscus pathway

291
Q

Describe the path of 1st,2nd and 3rd order neurones in the spinothalamic pathway

A

1st neurone enters the spinal cord on the ipsilateral side as the peripheral receptor and synapses with 2nd neurone in the CNS

2nd order neurone decussates to the contralateral side and projects in the anterolateral column to the thalamus

3rd order neurone has cell body in the thalamus and projects to the somatosensory cortex

292
Q

What information does the spinothalamic tract carry

A

Pain and temperature and crude touch

293
Q

What information does the dorsal column pathway carry

A

Proprioception, fine touch discrimination and pressure

294
Q

Describe the path of the 1st, 2nd and 3rd order neurones of the dorsal column pathway

A

Afferent neurone (1st) enters on the ipsilateral side of spinal cord to the receptor and travels ipsilaterally in the dorsal columns

synapses with 2nd order neurone in the brainstem where it decussates to contralateral side

Synpases with third order neurone in thalamus which projects to somatosensory Cortex

295
Q

Define acute pain

A

Short term pain of less than 12 weeks in duratio n

296
Q

Define chronic pain

A

Continuous long term pain for more than 12 weeks of duration

297
Q

Which primary afferent fibres are associated with the transmission of pain?

A

A delta

C fibres

298
Q

Describe the properties of alpha delta fibres in terms of their level of myelination, what information they carry, their diameter and their conduction speed

A

Thinly myelinated
Carry touch, pressure, temperature and FAST pain
Small diameter (1-5 micrometers)
Conduction speed is medium (5-40m/s)

299
Q

Describe the properties of C fibres in terms of their level of myelination, what information they carry, their diameter and their conduction speed

A

Unmyelinated
Carry SLOW pain, temperature, touch, pressure and itch
Smallest diameter (0.2-1.5 micrometers
Slowest conduction speed (0.5-2m/s)

300
Q

Where do the Adelta and C fibres synapse with second order neurones?

A

In the grey matter of the dorsal horn which is divided into reed laminae

301
Q

What neurotransmitters do the fast pain A delta fibres release?

A

Glutamate

302
Q

What neurotransmitters do the slow pain C fibres release?

A

Glutamate and substance P

303
Q

What information does the trigemini-thalamic tract carry?

A

Pain, temperature and crude touch from the face/head and neck

304
Q

What is the only sensation that doesn’t relay at the thalamus

A

Olfaction

305
Q

Which part of the brain that lies in the sylvan fissure judges the degree of pain

A

Insula

306
Q

Which part of the brain is associated with the emotional response to pain?

A

Cingulate gyrus

307
Q

What is the basal ganglia

A

Group of nuclei lying deep within the cerebral hemisphere

308
Q

What are the main components of the basal ganglia?

A

Striatum (Putamen and caudate)
Globus pallidus
Subthalamic nucleus
Substantia nigra

309
Q

Why is the substantia nigra black?

A

Due to the production of neuromelanin as a byproduct of dopamine production

310
Q

What are the main functions of the basal ganglia?

A

Purposeful behaviour and movement
Inhibits unwanted movements
Controls posture and movement
Facilitation, integration and fine tuning of movements

311
Q

Describe Parkinson’s disease in terms of what happens to muscle tone, movement and dopamine production

A

Increased muscle tone
Reduced movements
Reduced dopamine production

312
Q

Describe Huntington’s disease in terms of what happens to movement, muscle tone and dopamine production

A

Decreased muscle tone
Overshooting movement
Too much dopamine

313
Q

What is the precursor molecule to dopamine production

A

Tyrosine

314
Q

Describe how tyrosine is converted to dopamine

A

Undergoes tyrosine hydroxylation and decarboxylation into L-DOPA then into dopamine

315
Q

Describe how a lack of dopamine in PD causes lack of movement

A

Less dopamine means the external globus pallid us doesn’t inhibit the sub thalamic nucleus so it will excite the internal globus pallidus resulting in inhibition of the thalamus and decreased movement

316
Q

What are the two main functions of the limbic system?

A

Learning and regulation and transition of our emotion state into appropriate behaviour

317
Q

What are the components of the limbic system?

A
Cingulate gyrus 
Hippocampus 
Parahippocampal gyrus 
Anterior perforated substance
Uncus 
Amygdala
318
Q

The name given to the connections of the limbic system is the

A

Papez circuit

319
Q

What is the function of the hypothalamus?

A

Coordinates drive related behaviours

320
Q

What is the name given short term memory and where is it stored/formed?

A

Working memory in the prefrontal cortex

321
Q

What are the two forms of long term memory?

A

Explicit

Implicit

322
Q

What is episodic memory and where is it coded?

A

Knowledge of yourself

In the hippocampus

323
Q

What is the semantic memory and where is it coded?

A

Knowledge of stuff in the lateral temporal lobe

324
Q

What are the two types of explicit memory?

A

Semantic and episodic

325
Q

What is implicit memory

A

Unconscious memory

326
Q

What are the forms of implicit memory and where are they stored?

A

Skills/Habits = cerebellum and basal ganglia

Conditioned reflexes = cerebellum

Emotional = amygdala

327
Q

Which part of the limbic system is responsible for the formation of new memories>

A

Mammillary bodies

328
Q

What will a lesion to the anterior hypothalamus causes

A

inability to dissipate heat

329
Q

What will a lesion to the posterior hypothalamus cause

A

Inability to retain heat

330
Q

What will lesions of lateral tuberal nucleus cause?

A

Loss of hunger

331
Q

What will lesions f he ventromedial nucleus cause?

A

Loss of satiety

332
Q

What are the functions of the amgydala

A

Produces instinctive emotional output

Emotional memory

333
Q

What are the functions of the cerebellum?

A
Maintenance of posture and balance 
Maintenance of muscle tone 
Coordination of voluntary movement 
Computes motor error and adjusts 
Precise control, fine adjustment and coordination of motor activity
334
Q

What are the three layers of the cerebellum from outermost to innermost

A

Molecular
Purkinje
Granule

335
Q

Where does the purkinje layer of the cerebellum receive input from?

A

Climbing fibres

336
Q

Where does the granule layer of the cerebellum receive input from?

A

Mossy fibres

337
Q

Where do the mossy fibres originate from and what information do they carry?

A

Come from pons and cerebral cortex via middle cerebral peduncle and carry information on the pontocerebellar pathway

338
Q

Where do the climbing fibres originate and what information do they carry?

A

From the olivocerebellar nuclei via inferior peduncle - carry proprioception and vestibular info

339
Q

What are the 4 main afferent projections to the cerebellum

A

Spinocerebellar
Olivocerebellar
Vestibulocerebellar
Pontocerebellar

340
Q

What sort of input do climbing fibres provide?

A

Excitatory input to the purkinje fibres and the deep cerebellar nuclei

341
Q

the axons of which fibres are the only axons to leave the cerebellar cortex?

A

Purkinje fibres

342
Q

What neurotransmitter do purkinje cells use?

A

GABA

343
Q

Which cerebellar peduncle does the corticopontocerebellar tract pass through

A

Middle

344
Q

Which cerebellar peduncle does the vestibulocerebellar tract pass through

A

Inferior

345
Q

Which cerebellar peduncle foes the ventral contralateral spinocerebellar tract pass through

A

Superior

346
Q

Which cerebellar peduncle foes the dorsal ipsilateral spinocerebellar tract pass through

A

Inferior

347
Q

Which tract carries information from the lower limbs to the cerebellum

A

Spinocerebellar tract

348
Q

Which two tracts carry information from the upper limbs to the cerebellum

A

Cuneocerebellar and rostral spinocerebellar tract

349
Q

Describe the components of the spinal column

A
Cervical 7
Thoracic 12 
Lumbar 5 
Sacrum 5
33 in total
350
Q

How many spinal nerves are there?

A

31

351
Q

What is the name given to C1

A

Atlas

352
Q

What is the name given to C2

A

Axis

353
Q

Which vertebra is the vertebra prominence?

A

C7

354
Q

What is unique about the structure of the cervical vertebra?

A

All have bifid spinous processes except c7

355
Q

Describe the structure of thoracic vertebra?

A

Spinous processes are thinner and descending
Circular vertebral foramen
Have costal facets

356
Q

Describe the structure of a lumbar vertebra?

A

Spinous processes are thick and broad
Vertebral body is larger as it carries more weight
Vertebral foramen is triangular

357
Q

What are the three coverings of the spinal cord from outermost to innermost

A

Dura
Subarachnoid
Pia

358
Q

Where are the two enlargements of the spinal cord?

A

Cervical (Segments C3-T1) = upper limbs

Lumbar L1-S3 = lower limbs

359
Q

Describe the anatomy of the spinal cord after it ends at L1/2

A

Tapers into a cone (Conus medullaris) and ends in a strand of tissue called filum terminale

360
Q

At what position do spinal nerves leave the cervical segments of the spinal cord

A

1 vertebra higher than their corresponding vertebra except C8 which is one below

361
Q

At what position do the spinal nerves leave the thoracic segments of the spinal cord

A

1-2 vertebra below

362
Q

At what position do the spinal nerves leave the lumbar segments of the spinal cord

A

3-4 vertebra below

363
Q

At what position do the spinal nerves leave the sacral segments of the spinal cord

A

5 below

364
Q

What do mixed spinal nerves divide into

A

Small posterior ramus

Large anterior ramus

365
Q

What are the three layers covering fasicles of nerves from outermost to innermost

A

Epineurium
Perineurium
Endoneurium

366
Q

What are the 5 ascending spinal cord tracts

A
Fasciculus gracilis 
Fasciculus cuneatus 
Dorsal spinocerebellar 
Ventral spinocerebellar 
Spinothalamic
367
Q

What are the 10 descending spinal cord tracts

A
Fasciculis proprius 
Lissauers tract 
Lateral corticospinal 
Rubrospinal 
Medial longitudinal fasciculus
medullary reticulospinal 
Lateral vestibulospinal 
Pontine reticulospinal 
Tectospinal 
Ventral corticospinal
368
Q

The fascicles cuneatus carries information about what limb

A

Upper

369
Q

The fasciculus cuneatus carries information about what limb

A

Lower

370
Q

What information does the lateral spinothalmic tract carry

A

Pain and temperature

371
Q

What information does the medial spinothalamic tract carry

A

Crude touch

372
Q

where do the first and second order neurones synapse in the spinothalamic tract

A

Substantia gelatinous of the dorsal horn

373
Q

Where do the second order neurone decussate in the spinothalamic tract

A

White anterior comissure

374
Q

Where do the second order neurone decussate in the spinothalamic tract

A

White anterior commissure

375
Q

What is the function of the descending spinal tracts

A

Control of movement, muscle tone
Spinal reflexes
Spinal autonomic function

376
Q

What are the two divisions of the descending spinal tracts

A

Pyramidal

Extrapyramidal

377
Q

What are the two divisions of the descending spinal tracts

A

Pyramidal

Extrapyramidal

378
Q

What are the three ascending spinocerebellar tracts?

A

Dorsal spinocerebellar
Ventral spinocerebellar
Cuneocerebellar

379
Q

What stimuli does the spinocerebellar tracts respond to?

A

Proprioception, touch and pressure

380
Q

Describe the course of the ventral spinocerebellar tract

A

Starts in the PNS with first order neurones in the DRG

These fibres decussate to the contralateral side through the white anterior commissure and ascend to the superior cerebellar peduncle where they synapse with the cerebellar cortex

They then cross round the back to the opposing cerebellar cortex

381
Q

Describe the path of the dorsal spinocerebellar tract

A

Begins in PNS with 1st order neurones in DRG

Enters CNS and synapses with Clarke’s Nuclei in the 7th rexed lamina (C8-L2/3)

Ascends ipsilaterally to the inferior cerebellar peduncle where it enters the cerebellar Cortex

382
Q

The ventral spinocerebellar tract carries information from which spinal levels

A

Below C8-L2/3

383
Q

Describe the path of the cuneocerebellar tract

A

1st order neurones enter the DRG and synapse in the Dorsal horn grey matter then ascend ipsilaterally to the accessory cuneate nucleus before entering the cerebellar cortex through the inferior cerebellar peduncle

384
Q

Describe the path of the spinolivcerebellar tract?

A

1st order neurones through DRG
Decussates contralterally to through the white anterior commissure then ascends to the inferior olivary nucleus where it crosses back over the midline to and enters the cerebellar cortex through the inferior cerebellar peduncle

385
Q

Describe the symptoms of brown sequard disease?

A

Ipsilateral weakness below the lesion due to damage to the corticopspinal tract

Ipsilateral loss of proprioception below the lesion because dorsal column pathway dont decussate till medulla

Contralateral loss of pain and temperature below the lesion as spinothalamic decussate at entry to spinal cord

Ipsilateral loss of proprioception, motor and fine touch

Contralateral loss of pain, temperature and crude touch

386
Q

How do you test cranial nerve 2?

A

Visual fields
Pupil reflexes
Visual acuity
Fundoscopy

387
Q

Parasympathetic fibres of the occulomotor nerve go to where?

A

Edinger-westphal nucleus of the tegmenjtum, ciliary muscles, sphincter papillary mucles (Dilation)

388
Q

Which cranial nerve maintains the open eyelid via the elevator palpebral superioris muscle?

A

Oculomotor

389
Q

What does the trochlear nerve innervate?

A

Superior oblique muscle

390
Q

Damage to the trochlear nerve will cause what symptoms in patients?

A

Double vision when looking down

391
Q

What are the three branches of the trigeminal nerve?

A
  1. Ophthalmic
  2. Maxillary
  3. Mandibular
392
Q

Where do the trigeminal afferents meet?

A

Meckels cave

393
Q

How do you test the function of the trigmeninal nerve?

A

Sensation the face
Muscles of the jaw
Jaw jerk reflex
Corneal reflex

394
Q

What is the somatic motor function of the facial nerve?

A

Muscles of facial expression

395
Q

What is the visceral motor function of the facial nerve?

A

Lacrimal glands

Submandibular and sublingual glands

396
Q

How do you test the motor function of the facial nerve?

A
Inspect face for weakness of asymmetry 
Drooping of lower eyelids 
Smile 
Raise eyebrows 
Puff cheeks out 
Shut eyes tight 
Frown
397
Q

How do you test the sensory function of the facial nerve?

A

Touch lateral aspect of tongue with flavoured cocktail sticks and ask patient to identify the taste

398
Q

What is the cause of bells palsy

A

Lesion of the facial nerve

399
Q

How do you test the cochlear branch of the vestibulocochlear nerve?

A

Tuning fork

400
Q

What is nystagmus a sign of?

A

Vestibular damage

401
Q

What are the two motor functions of the glossopharyngeal nerve?

A

Elevate the pharynx by supplying stylopharyngeus

Secretion of the parotid gland

402
Q

What are the sensory functions of the glossopharyngeal nerve

A
Sensation to external ear 
Posterior 1/3 of tongue - touch, pain, temp 
Pharynx - touch, patn, temp 
Eustachian tube - touch, pain, temp 
Carotid sinus, baro and chemoreception
403
Q

What are the functions of the vagus nerve

A
Taste - posterior pharynx 
Swallowing- muscles of pharynx and larynx except stylopharngeus 
CV and GI regulation 
Hunger 
Fullness 
Decreased HR and BP
404
Q

How do yo test the function of the glossopharyngeal and vagus nerves?

A

Hoarseness of voice is sign of vocal cord paralysis which is caused by damage to recurrent laryngeal nerve (Derivative of vagus)

Ask patient to say AH

  • Bilateral lesion of vagus and palate fails to rise
  • Unilateral lesion and both palate and uvula deviate away from lesion

Absence of gag reflex suggests lesion of glossopharyngeal or vagus nerves

405
Q

What does the accessory nerve supply?

A

Sternocleidomastoid

Trapezius

406
Q

How do you test the function of the accessory nerve

A

ask patient t turn head against resistance - sternoclastomastoid

Ask patient to shrug shoulders against resistance
- Trapezius

407
Q

What does the hypoglossal nerve supply?

A

The intrinsic and extrinsic muscles of the tongue

408
Q

What are the functions of the extrinsic and intrinsic musclesof the tongue

A

Speech, food manipulation and swallowing

409
Q

How do you test the function of the hypoglossal nerve

A

Ask patient to protrude tongue

LMN lesion causes tongue to deviate towards lesion

410
Q

What is the sensory and taste innervation of the posterior 1/3 of tongue?

A

Glossopharyngeal nerve

411
Q

What is the sensory sensation of the anterior 2/3 of tongue?

A

Lingual branch of the V3 from trigeminal

412
Q

What is the taste sensation of the anterior 2/3 of tongue?

A

Chorda tympani branch of facial nerve carried by lingual branch

413
Q

What passes through the cavernous sinus

A
Oculomotor 
Trigeminal 
Ophthalmic trigeminal 
Maxillary trigeminal 
Carotid (internal) 
Abducens 
Trochlear
414
Q

Which spinal levels supply the wrist and biceps reflex

A

C5 and C6

415
Q

Which spinal levels supply he triceps reflex

A

C7 and C8

416
Q

What spinal level supplies the knee jerk reflex

A

L3 and L4 keeps foot off the floor

417
Q

What spinal level supplies the ankle jerk reflex

A

S1 and S2

418
Q

What spinal level supplies everything on the front of the arm

A

C5 and C6

419
Q

What spinal level supplies everything on the back of the arm?

A

C7 and C8

420
Q

What spinal levels cause penis erection

A

S2,S3,S4 keep penis of the floor

421
Q

Damage to Broca’s area results in what sort of aphasia

A

Expressive aphasia where they understand what is being said and know what they want to say but can’t express it in meaningful words

422
Q

Damage to Wernicke’s area results in what sort of aphasia

A

Comprehension aphasia where they have difficulting understanding written or spoken language but hearing and vision not impaired
Have fluent speech but may scramble words

423
Q

What is the most common artery for a berry aneurysm to occur?

A

Anterior cerebral artery

424
Q

What are the common signs of a third nerve palsy

A

Double vision
Down and out facing eye
Ptosis
Dilated and fixed pupil

425
Q

What are the functions of the oculomotor nerve

A

Eye movement
eyelid opening
Pupil constriction
Accomodation

426
Q

What will a lesion to the trochlear nerve cause?

A

Inability to depress an adducted eye

427
Q

What will a lesion to the abducens nerve cause?

A

Inability to abduct the eye

428
Q

What are the functions of the ophthalmic division of the trigeminal nerve

A

Sensation to the anterior of head and face (Superior 1/3) including scalp, forehead, cornea and tip of nose

429
Q

What are the three main branches of the ophthalmic division of the trigeminal nerve?

A

Lacrimal
Frontal
Nasociliary

430
Q

What are the functions of the maxillary division of the trigmeninal nerve

A

Sensation to middle 1/3 of face including cheek, nose, upper lip, upper teeth and palate

431
Q

What are the functions of the mandibular division of the trigeminal nerve?

A

Senesation to inferior 1/3 of face including lower Lip, lower teeth, chin, jaw and anterior 2/3 of tongue
Motor to muscles of mastication and tensor tympani muscle

432
Q

What are the functions of the facial nerve?

A
Motor to facial movement 
Salivation (Submandibular and sublingual)
lacrimation 
Sensation from external ear 
Taste from anterior 2/3 of tongue
433
Q

What are the functions of the glossopharyngeal joint

A

Taste and sensation from posterior 1/3 of tongue
Sensation from pharynx
Salivation
Motor to the stylopharngeus muscle

434
Q

What is the function of the accessory nerve

A

Motor function to trapezius and sternocleidomastoid

435
Q

What are the 3 sensory nuclei of the trigeminal nerve

A

Mesencephalic
Central pontine
Spinal nucleus
1 motor nucleus

436
Q

What are the three nuclei of the facial nerve

A

Superior salivary nucleus
Motor nucleus of CN VII
Nucleus Fasciuculus solitarius

437
Q

What are the branches of the facial nerve from the motor nucleus

A
Temporal 
Zygomatic 
Buccal
Mandibular 
Cervical
438
Q

What are the 4 nuclei of the glossopharyngeal nerve

A

Nucleus ambigus
Inferior salivary
Spinal trigeminal tract
Solitary tract