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Phase 1 Notes > Neuro > Flashcards

Neuro Flashcards

1
Q

What is the forebrain also known as?

A

Prosencephalon

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2
Q

What is the midbrain also known as?

A

Mesencephalon

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3
Q

What is the hindbrain also known as?

A

Rhombencephalon

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4
Q

What is the brain also known as?

A

Encephalon

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5
Q

Rostral to caudal

A

Nose to tail

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6
Q

What does grey matter contain?

A

What neurone cell bodies

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7
Q

What does white matter contain?

A

Myelin axons

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8
Q

What are bundles of organised white matter called?

A

Fasiculus

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9
Q

Describe association fibres

A

Stay in each hemisphere

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10
Q

Describe commissural fibres

A

Fibres connect hemispheres e.g. corpus callosum

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11
Q

Describe projection fibres

A

Carry impulses up and down

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12
Q

What are the functions of the insula?

A

Disguise, emotion, self-awareness, homeostasis etc

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13
Q

What are the functions of the frontal lobes?

A

Motor, problem solving, memory, language speaking, judgement etc

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14
Q

What are the functions of the temporal lobes?

A

Understanding language, memory, primary auditory cortex, semantic processing

Auditory and recognition of faces and objects

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15
Q

What are the functions of the parietal lobes?

A

Somatosensory - pain, touch, temperature
Dominant (usually left) - perception, language and mathematics
Right - visuospatial

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16
Q

What are the functions of the occipital lobes?

A

Visual

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17
Q

How many layers does the neocortex have?

A

6

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18
Q

What is brodmann areas?

A

Mapping of the subdivisions of the cortex

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19
Q

Describe the brain asymmetry

A

Right protrudes anterior, left posterior

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20
Q

What is Broca’s area responsible for?

A

Language production

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21
Q

What is the function of Wernicke’s area?

A

Language understanding

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22
Q

What is the function of sinuses?

A

Drains used blood back to the brain and ventricles

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23
Q

Describe the coronal plane

A

Ear to ear

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24
Q

Describe the axial plane

A

Horizontal

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25
Q

Describe the Sagittal plane

A

Between eyes

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26
Q

Describe evolution of the brain

A

More complex threat detection and avoidance behaviour
->
Requires additional neural systems

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27
Q

What does the CNS contain?

A

Brain
Spinal chord

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28
Q

What does the PNS contain?

A

All other nerves

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29
Q

Describe the somatic nervous system

A

Interacts with the external environment

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30
Q

Describe the autonomic system

A

Unconscious regulation of the body’s internal environment

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31
Q

Name the 4 regions of the spine

A

Cervical
Thoracic
Lumbar
Sacral

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32
Q

Describe the dorsal and ventral roots of the spinal chord

A

Afferent (sensory) nerves have cell bodies in dorsal root ganglia and synapse win the ventral horn wither to an inter neurone or motor.

Efferent (motor) nerves travel in the ventral roots

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33
Q

What is the function of the cerebellum?

A

Balance and coordination

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34
Q

What is the function of the thalamus?

A

Sensory relay station (for all but smell)
Regulates sleep and arousal

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35
Q

What is the function of the hypothalamus?

A

Homeostasis, endocrine, body cycles etc

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36
Q

What is the function of the fornix?

A

Carries signals from hippocampus to mammillary bodies
Learning and memory - spatial navigation

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37
Q

What is the function of the caudate?

A

Planning + execution of movement
Memory, cognition, emotion etc

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38
Q

What is the function of the putamen?

A

Regulation of movement, cognition and reward

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39
Q

What is the function of the amygdala?

A

Emotional learning and behaviour, especially fear

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40
Q

What is the function of the cortical grey matter?

A

Higher processes- memory, thinking, problem solving, reasoning, consciousness, emotions etc
Sensory processing
Movement

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41
Q

2 scans to identify brain structures

A

CT - quicker
MRI - more tissue detail

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42
Q

What is the function of the medulla?

A

Sleep/wakefulness
Movement, circulatory, respiratory, excretory reflexes

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43
Q

What is the function of the PONS?

A

Relays cortex to midbrain and cerebellum
Pattern generators e.g. for walking

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44
Q

What are colliculus in the midbrain?

A

Superior - visual/orienting frequency maps
Inferior - frequency maps

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45
Q

What are the 3 sections of the midbrain?

A

Periaqueductal gray
Red nucleus
Substantia nigra

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46
Q

What is the function of Periaqueductal grey?

A

Defensive behaviour, pain and reproduction

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47
Q

What is the function of the red nucleus?

A

Pre-cortical motor control projects to spinal chord

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48
Q

What is the function of the substantia nigra?

A

Basal ganglia input
(Parkinson’s)

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49
Q

What is the function of the hippocampus?

A

Spatial and long term memory

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50
Q

What is the function of mammillary bodies?

A

Formation of recollective memory - amnesia

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51
Q

What is the function of the cingulate gyrus?

A

Behavioural outcomes to autonomic control - schizophrenia

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52
Q

Name some differentiated Glia cell types

A

Oligodendrocytes
Microglia
Astrocytes

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53
Q

Describe neurones

A

Input via dendrites and specialised axon propagates action potentials

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54
Q

2 types of synapses

A

Chemical - via neurotransmitters
Electrical - flow of ions directly through channels

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55
Q

Describe chemical synapses

A

Axon potential depolarises synaptic membrane which opens and leads to calcium influx. This triggers release of neurotransmitters.

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56
Q

Describe electrical synapses

A

Connexins form connexons = forms gap junction protein channels.

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57
Q

Describe neural plasticity

A

Changes in neuronal/synaptic structure/function for learning and memory in response to neural activity

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58
Q

List some neuronal heterogeneity

A

Size
Morphology
Neurotransmitters
Electrical properties

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59
Q

What are oligodendrocytes?

A

Unique to vertebrates, forms myelin sheath around axon for rapid conduction. Nodes of rangier allow for saltatory conduction.

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60
Q

Describe the myelin sheath

A

Formed from wrapping of Oligodendrocyte membranes
70% lipid, 30% protein
Myelin basic proteins can be detected

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61
Q

Describe microglia

A

Resident resting, motile immune cells of the CNS. Once activated, become amoeboid and is phagocytic

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62
Q

Describe astrocytes

A

Star like, highly heterogeneous cells. Most numerous glia and contains common marker protein (GFAP)

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63
Q

What is the function of astrocytes

A

Contributes to blood brain barrier containing aquaporins. Removes excess neurotransmitters from synapses and changes cerebral blood flow activity.

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64
Q

Name 3 specialised astrocytes

A

Radial glia - for development
Bergmann glia - cerebellum
Muller cells - retina

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65
Q

What is Motor neurone disease?

A

Adult onset neurodegenerative disease of loss of upper and lower motor neurones.

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66
Q

What is multiple sclerosis?

A

Autoimmune demyelination of ogliodendrocytes.

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67
Q

What are commissures?

A

Tracts that cross midlines

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68
Q

PNS axons are myelinated by what cells?

A

Schwann cells

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69
Q

Name the layers of the blood brain barrier

A

Endothelial
Basement membrane (fenestrations)
Astrocytes
Pericytes

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70
Q

Which organs lack normal blood brain barrier?

A

Circumventricular organs:
Post pituitary
Subformical organ

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71
Q

What are ependymal cells?

A

Line ventricular and central canal of spinal chord.
(Ciliated epithelial)

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72
Q

What is the function of ependymal cells?

A

CSF production, flow and absorption
Allows solute exchange between tissue and CSF

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73
Q

What is the main site of CSF production?

A

Choroid plexus (modified ependymal cells)

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74
Q

What waves are used in MRI?

A

Radio frequency

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75
Q

What is fMRI?

A

Scanner is sensitive to iron - active cells use oxygenated blood and therefore ‘reveals’ iron.

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76
Q

What does PET scan stand for?

A

Positron Emission Tomography

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77
Q

How does a PET scan work?

A

Contrast agent specifically targets biological process, is attached to radioisotope. Radiation emitted is detected

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78
Q

What does EEG measure?

A

Regional brain activity

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79
Q

How does TMS / TDCS work?

A

Induces an electrical current in the brain which switches off parts.

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80
Q

What are the 3 guiding principles for research involving animals?

A

Replacement
Refinement
Reduction

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81
Q

What are some possibilities of invasive methods? (Scanning)

A

Make direct measurement of activity
Determine connectivity between structures and flow of information
Lesion specific ctructures

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82
Q

During neurodevelopment, describe the main action of neurones.

A

Neurones arise in the germinal matrix, migrate to the cortisol sub plate and makes connections. Waiting until birth.

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83
Q

Describe neurodevelopment

A

Cranial to caudal
Proximal to distal
Simple to complex

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84
Q

Folic acid reduces risk of…

A

Spina bifida

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85
Q

What is anacephaly

A

No development of brain (baby dies)

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86
Q

Red flags for babies

A

Any loss of skil
Visually not following an object
Hearing loss
Squinting after 3-4 months
Cannot hold object after 5 months
No speech by 18 months
Not walking by 18 months(boys)
/ 2 years(girls)

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87
Q

Define sounds

A

The displacement of air particles following a sinusoidal pattern of compression and rarefacation

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88
Q

What range can we hear?

A

20-20000Hz

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89
Q

Describe the 4 components of the auditory system

A

Outer ear - air
Middle ear - air
Inner ear - fluid
Central auditory pathways

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90
Q

What are the components of the outer ear?

A

Pinna - cartilaginous structure
Ear canal - 1/3 cart, 2/3 bone
Tympanic membrane:
- 1/2 pats flaccid a (2 layers)
- Pats tens a (3layers)

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91
Q

What are the components of the middle ear?

A

Bones - malleus, incus, stapes
Muscles - tensor tympani, stapedius
Eustachian tube

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92
Q

What is the role of the middle ear?

A

Energy transfer from air to fluid
Amplification of airborne sound to make it louder

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93
Q

What is the role of muscles in the middle ear?

A

Protection of the inner ear from acoustic trauma
Deadens the sound of chewing

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94
Q

What is the role of the eustachian tube in the middle ear?

A

Ventilation and drainage of secretions equalises pressure

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95
Q

Describe the inner ear

A

Cochlear - 2.5 turns fluid filled bony tubes for hearing
Labyrinth - for balance

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96
Q

Describe the cochlear

A

3 compartments:
Scala tympani
Scala media
Scala vestibule
(Outer two encompassed in bone)

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97
Q

Describe the 2 cochlear fluids

A

Endlymph (Scala media)
- High K+
Perilymph (Scala Ty + ves)
- Na+ rich

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98
Q

Describe the process of the cochlear

A
  1. Pressure waves move basilar membrane to organ of corti
  2. Hair cells inside organ of cortisone and each one is gunned at different frequencies.
  3. Hair attached to the tectorial membrane depolarises endolymph
  4. Neurotransmitters released send signals.
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99
Q

Inner vs outer hair in organ of corti

A

Inner - mechanical transduction
Outer - fine tuning

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100
Q

Describe waves to sparks of inner hair cells. (Cochlear)

A

Movement or sterocilia opens K+ channels (depol) which open Ca+ channels and release neurotransmitters (Glutamate).
Repolarisation of K+

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101
Q

Frequency vs intensity

A

Pitch - nerves in location
Loudness - firing rate of nerves

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102
Q

From cochlear to brain

A

Auditory fibre
Spiral ganglion
Cochlear nerve
Central auditory pathway
(E.C.O.L.I.)

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103
Q

How does brain stem localise sound?

A

Depending on time differences of sound arriving from right and left ear to see position of sound.

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104
Q

Names of hearing loss

A

Defective outer/middle ear
= Conductive hearing loss
Defective Inner ear
= Sensorineural hearing loss

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105
Q

Name the 3 types of muscle

A

Smooth (visceral, voluntary)
Skeletal (striated, involuntary)
Cardiac

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106
Q

Describe histology of skeletal muscle

A

Myofibres surrounded by connective tissue:
-Epimysium
-Perimysiu-Endomysium
Basement membrane
Capillary to each cell
Each fibre innervated by a nerve

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107
Q

Describe neurones to skeletal muscle

A

Primary motor cortex
Through basal ganglia systems and cerebellar systems
To anterior horn cell (lower motor neurone)
To muscle

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108
Q

Pathology of lower motor neurone

A

Motor neurone disease

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109
Q

Pathology of Cerebellar system

A

Peripheral neuropathies

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110
Q

Pathology of muscle

A

Primary muscle disease (myopathies)

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111
Q

Describe enzyme histochemistry of muscle tissue

A

Frozen sections warmed up reactivates enzymes and electron microscopy shows different colours.

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112
Q

2 types of muscle fibre types

A

Slow twitch - type 1, oxidative, fatigue resistant
Fast twitch - fatigue rapidly but generates large peak of energy
- 2A - Glycolytic + oxidative
- 2B - glycolytic

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113
Q

Define a motor unit

A

A motor neuron and the fibres it innervates (all of same type)
Fibre type dependent on neurone and size of motor unit varies between muscles.

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114
Q

Describe denervating diseases

A

Loss of innervation causes fibre atrophy, but sprouting from adjacent motor units allow reinnervation. Conversion of fibres result in fibre type grouping

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115
Q

What is a sarcomere?

A

Basic unit of contraction in a muscle fibre

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116
Q

Name the different bands in a sarcomere

A

Z disc
I band
H band
A band

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117
Q

Describe the sliding filament theory (muscle contraction)

A

Myosin head binds to actin
ATP binds and is hydrolysed allowing myosin head to release and move further along chain.

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118
Q

What is creatine phosphate?

A

Short term energy store.
Creatine Kinase sticks P- to form CP

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119
Q

What is mitochondrial cytopathies?

A

Maternally inherited mitochondrial DNA is damaged/ mutated.
Heteroplasmy = only some DNA mutated gives symptom variation

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120
Q

How to diagnose mitochondrial cytopathies

A

In muscle biopsies = ragged red flag or abnormal morphology

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121
Q

What are dystroglycans?

A

Link Intracellular proteins of sarcolemma to external matrix protein for stability

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122
Q

What are dystrophies?

A

Genetically determined, destructive and mainly progressive disorders of the muscle

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123
Q

Describe neuromuscular transmission

A

Depolarisation of presynaptic membrane releases ACh which binds to receptors and propogates action potential across the t-tubules. Ca2+ is released.

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124
Q

What is myasthenia graves?

A

An autoimmune neuromuscular transmission disease where Anti-AChR antibodies reduce ACh receptors

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125
Q

What is damage to motor or sensory neurones called?

A

Neuronpathies

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126
Q

What is damage to axons called?

A

Axonopathies

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127
Q

What is selective damage to myelin sheaths called?

A

Demyelination

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128
Q

Describe axonal regeneration

A

Axonal sprouts form from proximal part of damaged axon and grows along columns of proliferating Schwann cells to remyelinate

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129
Q

What are extraocular muscles?

A

Muscles in the eye orbits

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130
Q

Name all 7 extraocular muscles

A

Levator palpebrae superioris
Medial rectus
Lateral rectus
Superior rectus
Inferior rectus
Superior oblique
Inferior oblique

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131
Q

Which 3 cranial nerves are involved in movement of eye?

A

3 - oculomotor
4 - trochlear
6 - abducens

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132
Q

Which cranial nerves supply which extraocular muscles?

A

4 - superior oblique
6 - lateral rectus
3 - rest

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133
Q

What is the origin of the extraocular muscles?

A

Attached to orbital bones and insert into sclera (apart from LPS into upper eyelid)

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134
Q

Looking straight, orbital axis does not coincide with optical axis so…

A

Direction of muscle fibres don’t coincide with optical acis

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135
Q

Movement of levator palpebrae superioris

A

Elevates upper eye lid

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136
Q

What is ptosis?

A

Drooping of eyelid (3rd nerve injury)

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137
Q

Movement of the medial rectus

A

Moves eye medially

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138
Q

Movement of the lateral rectus

A

Moves eye laterally

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139
Q

What can oculmotor nerve lesion lead to?

A

Weak medial rectus so eye deviates laterally and experiences double vision (diplopia)

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140
Q

What can abducens nerve lesion lead to?

A

Lateral rectus weakness so eye deviates medially and experiences double vision (diplopia)

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141
Q

Movement of the superior rectus

A

Up and laterally

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142
Q

Movement of the inferior rectus

A

Down and laterally

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143
Q

Movement of the superior oblique

A

Medially and down

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144
Q

Movement of the inferior oblique

A

Medially and up

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145
Q

How to examine medial and lateral rectus

A

Move finger horizontally:
Medial - moves eye medially
Lateral - moves eye laterally

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146
Q

How to examine superior and inferior rectus?

A

Move finger laterally
SR - should follow finger up
IR - should follow finger down

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147
Q

How to test superior and inferior oblique

A

Move inferior medially
SO - will follow finger down
IO - will follow finger up

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148
Q

What are the vestibular structures?

A

3 semicircular (90degrees) canal and in semicircular ducts that contain fluids. Endolymph (fluid) drains into utricle (sac) and saccule.

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149
Q

What is the function of the semicircular ducts?

A

Balance:
When head moves in one direction, endolymph moves to the opposite. Cupula and hair cells in the ampulla bend and send info via CN 8 to nuclei in the medulla.

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150
Q

Describe vestibular nuclei

A

Nuclei of brain stem makes connection with nuclei of CN 3,4,6 to control posture, balance and position.

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151
Q

What is the oculocephalic reflex?

A

Maintaining fixed gaze when head is moving.
(Absent reflex indicates brain stem lesion)

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152
Q

What is materialism?

A

Mental states are actually physical

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153
Q

Define dualism

A

Mental and physical states are both real

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154
Q

Define idealism

A

Physical states are really mental

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155
Q

What are some challenges to dualism?

A

Inexplicable symptoms
Impact of environment / societ

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156
Q

Neurology vs Psychiatry

A

N - focus on diagnosis of abnormal brain chemistry, genetics, structure et
P - focus on diagnosis and formulation e.g. interaction with environment, psychological, cultural issues etc

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157
Q

Schizophrenia symptoms

A

Delusions
Hallucinations
Thought disorders
Negative symptoms:
Withdrawn, reduce self care and social contact

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158
Q

What are some biological correlations to schizophrenia?

A

.Smaller brain volumes
.Functional imaging - dysfunction in regions associated with hallucinating
.Dopamine theory - blockers as treatment
.Genetics

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159
Q

What are some non-biological correlations to schizophrenia?

A

More common in:
Urban areas
Ethnic minorities
Association with trauma
High expressed emotion, loss

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160
Q

Adv of classification of mental disorders

A

Inform public health for allocation of resources
Promote feelings of understood
Provide framework for research

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161
Q

Disv of classification of mental disorders

A

Can lead to stigma and prejudice
Oversimplification

162
Q

Define emotion

A

Strong feeling deriving from one’s circumstances, mood or relationship with others.

163
Q

What is the role of emotion?

A

Motivator for learning
Thoughts
For best obtaining rewards/avoiding punishment

164
Q

Name 4 theories of emotion

A

Basic
Appraisal
Psychological constructionist
Bayesian model

165
Q

Describe neuroanatomy of emotion

A

Limbic system is network of connections

166
Q

3 steps of emotion

A

Identification (smell, taste, sight)
Appraisal (Amygdala, orbitofrontal cortex)
Reactivity (cingulate cortex)

167
Q

Describe the orbitofrontal cortex (appraisal)

A

Medial: reward
Lateral: punishment

168
Q

Describe the amygdala (appraisal)

A

Conditioned response to harmful stimuli
Facial expression recognition

169
Q

Describe the cingulate cortex (action-outcome learning)

A

Anterior: outcome (reward+punish)
Posterior: action
Mid: action

170
Q

What happens at the ventromedial prefrontal cortex?

A

Reward related decision making

171
Q

What are autonomic responses regulated by?

A

OFC
Amygdala

172
Q

What happens at the inferior frontal gyrus?

A

Behavioural suppression

173
Q

What happens at the precuneus?

A

Autobiographical memory, spatial navigation

174
Q

What happens at the PCC?

A

Self reflection + image, retrieves autobiographical memories.

175
Q

Where does the nervous system develop from?

A

Ectoderm

176
Q

Describe development of spinal chord until 4 weeks.

A
  1. Signals from notochord causes inward folding of ectoderm at the neural plate.
  2. Ectoderm thickens in midline and ends fuse to form neural tube.
177
Q

Describe development of spinal chord after 4 weeks.

A

Lateral to neural grove lie presumptive neural crest cells that migrate to different organ systems.
These form neurones, Schwann cells, melanocytes, osteoblasts, adipocytes and Chondrocytes.

178
Q

Describe some abnormalities of the spinal chord

A

Neural tube usually closes at 4th embryonic week.
Failure to close Cephalic region
= Anacephaly
Failure to close spinal region
= spina bifida

179
Q

What are neural tube defects?

A

Failure to close spinal chord at 4th embryonic week

180
Q

What does prosencephalon form?

A

Cerebral hemisphere, thalamic structure

181
Q

What does the mesencephalon form?

A

Midbrain

182
Q

What does the rhombencephalon form?

A

Medulla, pons, cerebellum

183
Q

Describe development of brain

A

Stem cells from ventricular zone migrate to outer surfaces.

184
Q

Micro vs Macrocephaly

A

Micro - reduced head circumference (bottom 2.5% of population)
Macro - increased head circumference (top 2.5%)

185
Q

Which is more severe? Micro vs macrocephaly?

A

Macrocephaly

186
Q

What is the function of CSF?

A

Cushion the brain and help circulate metabolites

187
Q

What is hydrocephalus?

A

Accumulation of CSF with increased inter cranial pressure.
Can cause macrocephaly

188
Q

Define sensation

A

A mental process resulting from immediate external stimulation of sense organ
(Touch, smell, taste, sight)

189
Q

Define perception

A

Ability to become aware of something following sensory stimulation.
(Tactile, olfactory, visual, auditory)

190
Q

*What is a perceptual set?

A

The psychological factors that determine how you perceive your environment.
Believing is seeing

191
Q

Sensation vs perception

A

Bottom up
Vs
Top down

192
Q

*Factors that affect perceptual set

A

Context, culture, expectations, mood & motivation

193
Q

What are Gestalt principles?

A

Principles of human perception that describe how humans group similar elements

194
Q

What is the thatcher effect?

A

The interpretation of faces even when the faces are weird

195
Q

Define illusion

A

Misinterpreted perception of a sensory experience

196
Q

Define hallucinations

A

Apparent perception of something not present

197
Q

What is the percentage of people who have experienced hallucinations?

A

5%

198
Q

Out of people who experienced hallucinations, what % is due to mental conditions?

A

30%

199
Q

Some causes of hallucinations

A

Neurological conditions
Drugs
Derilium
Sleep deprivation
Psychiatric illness

200
Q

Hallucination is a form of what process?

A

Top - Down

201
Q

What is the bio-psycho-social model?

A

Important for managing mental illnesses.

202
Q

Hallucinations are experienced uniquely due to …

A

The perceptual set

203
Q

What does the prosencephalon contain?

A

Cerebral hemispheres, basal ganglia

204
Q

What does the diencephalon contain?

A

Thalamus, Hypothalamus, subthalamus, epithalamus

205
Q

What is the mesencephalon?

A

Midbrain

206
Q

What does the rhombencephalon contain?

A

Pons
Medulla
Cerebellum

207
Q

What divides the frontal and parietal lobes?

A

Central sulcus

208
Q

What separates the frontal and temporal lobes?

A

Sylvia’s fissure / Lateral sulcus

209
Q

Name a white matter tract

A

Corona radiata

210
Q

Mental illness vs psychological dysfunction

A

Car broken
Vs
Car fine but don’t know how to drive it well

211
Q

Name 4 major neurotransmitters

A

Noradrenaline
Dopamine
Serotonin
Acetylcholine

212
Q

Adrenaline vs noradrenaline

A

A - can’t pass blood brain barrier
N - produced in brain. (Causes stress)

213
Q

What is CBT

A

Cognitive Behavioural Therapy

214
Q

Why do we have 2 eyes?

A

Allows us to see 3D
Widens our visual field

215
Q

What happens when the eyes don’t move together?

A

Diclopea (double vision)

216
Q

How many layers in the eye?

A

3
Outer - sclera and cornea
Middle - choroid
Inner - retina

217
Q

What is the function of the sclera?

A

Tough fibrous coat made of collagen to maintain shape and protect from trauma and infection.

218
Q

What is the function of the cornea?

A

Parallel fibres of collagen transparent to allow light through. Responsible for 2/3 refractive power

219
Q

How many layers in sclera / cornea?

A

5

220
Q

Describe layers in sclera / cornea?

A

Epithelium - Can regenerate after abrasion
Bowman’s layer
Stromatolites - for clarity
Descemets layer
Endothelium - Keeps cornea hydrated and supplies nutrients
(Not regenerated when hurt)

221
Q

What parts of middle layer?

A

Iris
Ciliary body
Choroid

222
Q

Describe function of iris

A

Contains dilator and sphincter pupillae muscles
Aqueous humour maintains pressure in anterior chamber

223
Q

Describe function of ciliary body

A

Glandular epithelium produce aqueous humour
Attached to lens by suspensory ligament so controls accommodation

224
Q

Describe function of choroid

A

Blood supply to 1/3 of retina

225
Q

What is the function of the retina?

A

Transducers light to electricity

226
Q

Describe the areas of the retina

A

Macula lutea - important for central vision
Fovea central is - centre of macula
Cones
Rods

227
Q

Difference between cone and rod cells

A

Rod - Lower resolution, Black or white, synapses Many-1
Cones - Higher resolution, colour, synapses 1-1

228
Q

Describe layers in retina

A

Photoreceptors (rods+cones)
| Supported by horizontal cells
Bipolar cells
|Supported by amacrine cells
Ganglion cells
(Merges to form optic nerve)

229
Q

Describe chemical reaction of phototransduction

A

In discs of rod /cone cells:
Photon converts 11-cis-retinal to 11-trans-retinal
Enzyme uses energy from ATP to reverse

230
Q

Describe the lens

A

Biconvex
Responsible for 1/3 refractive power of eye

231
Q

What is emmetropia?

A

Perfect vision

232
Q

What is hypermetropia?

A

Refractive power too weak when looking at near objects
= long sighted

233
Q

Reasons for hypermetropia

A

Lens not flexible enough
Axial length of eyeball short
Corneal curvature too shallow

234
Q

Describe myopia

A

Refractive power too strong when looking at far objects
= short sighted

235
Q

Reasons for myopia

A

Corneal curvature too steep
Axial length of eyeball too long

236
Q

What is in the posterior segment?

A

Vitreous (more fluid) humour
Collagen
Hyaluronic acid (GAG)
Avascular viscoestalic gel

237
Q

Name the layers of the adnexaa (eye lid)

A

Lids
Conjunctiva
Tear film

238
Q

Describe the layers of the lids

A

Meibomian glands - oily secrete
Obicularis oculi - muscle closes lid (CN 3)
Tarsal plat - separates layers
Levator palpebrae superioris - Elevates lid

239
Q

Describe layers of the conjunctiva

A

Palpebrae (under eyelid)
Bulbar (on eye)
Limbal stem cells
Goblet cells
Lymphoid cells (protective)

240
Q

Describe the 3 layers of the tear film

A

Anterior lipid - Prevents evaporation
Middle aqueous - Hydrates + nutrition for cornea
Posterior mucous - Lubricates + aids even distribution

241
Q

Describe blood supply of retina

A

Outer 1/3 by choroid
Inner 2/3 by central retinal artery

242
Q

Describe retinal veins

A

Superior ophthalmic v. -> cavernous sinus -> internal jugular v.

Internal ophthalmic v. -> pterygoid venous plexus

243
Q

Why is there risk of infection spreading from eye to brain?

A

Valvless vein system to cavernous sinus

244
Q

Is there lymphatic drainage from lobe?

A

No
Only from lids and conjunctiva

245
Q

Describe the resting potential

A

Sodium-potassium pumps actively transport 3Na+ out and 2K+ into neurones. More leaky K+ channels (out) gives -70mv membrane potential.

246
Q

Describe excitatory neurotransmitters at start of post-synapse

A

Depolarises cell membrane
Increases probability of action potential
= Excitatory Post Synaptic Potential

247
Q

Describe inhibitory neurotransmitters at start of post-synapse

A

Hyperpolarises the membrane
Decreases probability of action potential
= Inhibitory Post synaptic Potential

248
Q

Depolarisation only occurs above…

A

Threshold potential

249
Q

Describe depolarisation

A

Na+ channels open and floods in down electrochemical gradient. At -50mv, depolarisation opens even more Na+ channels.

250
Q

Describe Repolarisation

A

At +30mv, Na+ channels close and K+ channels open so K+ flood out down an electrochemical gradient.

251
Q

Describe hyperpolaristion

A

A slight overshoot of Repolarisation restores resting potential through sodium-potassium pumps

252
Q

Spatial vs temporal summation to reach threshold

A

S - Multiple presynaptic neurones converge
T - Single presynaptic neurone has high frequency of neurotransmitters released.

253
Q

What increases action potential speed

A

Higher temperature- energy
Wider axon diameter
Myelin sheath - saltatory conduction

254
Q

What is Multiple sclerosis?

A

Axonal transmission failure
E.g. tremor, slurred speech, paralysis, weakness

255
Q

How wide is a synaptic cleft?

A

20-30 x10-9m wide

256
Q

Why’s is Novichok dangerous?

A

Disrupts normal synaptic neurotransmittion of acetylcholine

257
Q

How are neurotransmitters removed?

A

Enzyme degradation
Reuptake

258
Q

Describe synaptic transmission

A

Action potential opens Ca2+ channels and it floods in. This causes vesicles to fuse with membrane and release transmitters. Diffuses across synaptic cleft and binds to receptors which opens Na+ channels.

259
Q

Name 5 main processes of synaptic transmission

A
  1. Manufacture
  2. Storage (vesicles)
  3. Release
  4. Diffusion
  5. Inactivation (breakdown)
260
Q

Name 3 fast neurotransmitters

A

Acetylcholine
Glutamate
GABA

261
Q

Name 3 slow neuromodulators

A

Dopamine
Noradrenaline
Serotonin

262
Q

How do local anaesthetics work?

A

Na+ channel blockers

263
Q

What affects acetylcholine?

A

Cigarettes
Nerve gases

264
Q

What affects noradrenaline?

A

Antidepressants
Stimulants

265
Q

What affects dopamine?

A

Antipsychotic drugs
Stimulants
Anti-Parkinson drugs

266
Q

What affects serotonin?

A

Hallucinogens
Ecstasy
Antidepressant drugs

267
Q

What affects GABA (inhibitor)

A

Anaesthetics
Anticonvulsant drugs

268
Q

Name photo pigment in rod cells

A

Rhodopsin

269
Q

Name photo pigment in cone cells

A

Opsin - sensitive to light

270
Q

What is special about photoreceptors?

A

They can produce a graded response
(But ganglion is not graded)

271
Q

What describes structure of lacrimal gland?

A

Exocrine lobulated tubulo-acinar gland

272
Q

Which gland is responsible for baseline tear formation (aqueous)?

A

Lacrimal and Accessory Lacrimal glands

273
Q

Which is the outermost layer of the tear film?

A

Lipid

274
Q

What gland produces lipid in tear film?

A

Meibomian glands, Zeis, Moll

275
Q

What produces mucus in tear film?

A

Conjunctival goblet cells

276
Q

How to test stroke vs Bell’s palsy?

A

If patient can lift forehead = stroke

277
Q

Define pain (IASP)

A

Pain is an unpleasant sensory and emotional experience associated with, or resembling that associated with actual or potential tissue damage.

278
Q

Name 4 purposes of pain

A

Immediate pain
Persisting pain
Nociception
Nociceptive pathways

279
Q

Function of immediate pain

A

Warns of imminent tissue damage = withdraw from source of injury

280
Q

Function of persisting pain

A

Encourages immobilisation of injured area to give damaged tissue best chance to heal.

281
Q

What is nociception?

A

Neural neural processes involved in producing sensation of pain

282
Q

Describe nociceptive pathways

A

Transduction in periphery, through dorsal horn of spinal chord, then to brain.

283
Q

Acute vs chronic pain

A

Acute < 12 weeks
Chronic > 12 weeks and persists beyond tissue heating time

284
Q

Name the two categories of chronic pain

A

Chronic non-cancer pain
Chronic cancer pain

285
Q

Name 3 types of pain

A

Nociceptive pain
Neuropathic pain
Nociplastic pain

286
Q

Define nociceptive pain

A

From actual or threatened damage to non-neural tissue due to activation of nociceptors.

287
Q

Define neuropathic pain

A

Caused by lesion or disease of somatosensory nervous system

288
Q

Define nociplastic pain

A

Pain from altered nociception but with no evidence of tissue damage or disease and lesions.

289
Q

Examples of neuropathic pain

A

Phantom limb pain
Diabetic neuropathy

290
Q

Define allodynia

A

Pain due to stimulus that does not normally provoke pain

291
Q

Define dysesthesia

A

Unpleasant abnormal sensation, whether spontaneous or evoked.

292
Q

Hyper vs hypoalgesia

A

Hyper - Increased pain
Hypo - Diminished pain
From a stimulus that normally invokes pain

293
Q

Describe pathway of pain via neurones

A

Peripheral receptor - Detects stimulus
1st order neurone - periphery to ipsilateral spinal chord
2nd order neurone - crosses to contralateral and ascends to thalamus
3rd order neurone - thalamus to midbrain and higher cortisol centres
(Synapses between each neurone)

294
Q

Define emotion

A

A mind and body’s integrated response to a stimulus.

295
Q

What happens when we feel emotions

A

Physiological arousal (increase in reactivity to prime us for an event)
Expressive behaviour
Conscious experience

296
Q

Izzards 10 basic emotions

A

Joy
Surprise
Sadness
Anger
Contempt
Shame
Fear
Disgust
Guilt
Excitement

297
Q

Describe hemispheric lateralisation

A

Right hemisphere = negative emotions
Left hemisphere = positive emotions

298
Q

Define mood

A

Long term emotional states, rather than discreet, fleeting feelings

299
Q

Define mood disorder

A

Longer term extremes of emotional state and challenges in regulating mood.

300
Q

Describe depression

A

Lowering of mood, reduction of energy etc.
Biological symptoms - poor sleep, appetite, concentration
Cognitive symptoms - worthlessnes, guilt, suicidal thoughts

301
Q

Describe bipolar affective disorder

A

2< episodes where mood and activity level are significantly disturbed.

302
Q

Mania vs hypomania

A

Mania = mood is elevated
Hypo = not to extent of disruption of work or social rejection

303
Q

Describe function of nociceptors

A

Transduction of physical stimulus to action potential

304
Q

Which primary afferent fibres are slower?

A

C fibre
(A-alpha is faster
A-beta
A-delta)

305
Q

Cell bodies of primary afferent neurones lie where?

A

Dorsal root ganglion (body)
Trigeminal ganglion (face/head/neck)

306
Q

What type of neurones are 1st order neurones?

A

Pseudo-unipolar

307
Q

Where do 1st order neurones synapse?

A

Dorsal horn

308
Q

Describe function is the 3 ascending tracts (sensory 2nd order white matter neurones)

A

Doral columns - fine touch, vibration
Lateral spinothalamic tract - pain, temperature
Ventral spinothalamic tract - light touch

309
Q

Describe route of 2nd order neurone

A

Axon originates from spinal chord, decussates few levels above, crosses midline in anterior commissure to form anterolateral tract

310
Q

Describe pathway of 3rd order neurones

A

Cell bodies in thalamus then travels to sensory cortex (post central gyrus)

311
Q

What is the pain matrix?

A

Parts of the brain involved in pain:
Insula - degree of pain
Amygdala - learned emotional responses
Cingulate cortex - emotion formation
Peri-aqueductal gray - modulates pain

312
Q

Define chronic pain

A

Complex abnormal pain with bio-psycho-social aspects.

313
Q

How can we treat pain?

A

Stimulate descending inhibitory pathway
Gate control (peripheral stimulation of other fibres to block pain)
Pharmacotherapy (drugs)

314
Q

Problems with long term opioid use

A

Tolerance
Immunosuppressive
Opioid induced hyperalgesia (opioid pain as well as original pain)

315
Q

What are some chemical findings of depressions

A

Increased Corticotropin production
Reduced -ve feedback in brain
Reduced GR expression

316
Q

How does stress affect the brain?

A

In the HPA Axis:
Reduces neurogenesis (new neurones)
Neurotoxic
Reduced BDNF levels
Affects dendritic formation
Affects frontal lobes and hippocampus

317
Q

Where does neurogenesis occurs?

A

6% of total dendrites, and axons grown in the hippocampus every month.

318
Q

How do antidepressants work?

A

Affects gene GR expression
Increases neurogenesis
Increases BDNF synthesis

319
Q

What is MDD?

A

Neurodegenerative disease of impaired plasticity

320
Q

What is the default mode network?

A

Resting state
- Daydreaming, internal flow of consciousness, social judgments
(Depressed find turning DMN off hard)

321
Q

What is entropy? (2nd law of thermodynamics)

A

Measure of disorder

322
Q

How does brain reduce entropy?

A

Makes predictions (top-down processing)
Can eventually form core beliefs e.g. ‘I’m fat’

323
Q

What is depression (cellular level)

A

Disease of reduced plasticity (reduced connecitvity)
Increased self-referential thinking

324
Q

Name the 5 pillars of well-being (NHS)

A
  1. Physical activity (resets HPA axis)
  2. Connect with others
  3. Learn something new (turn off DMN)
  4. Practice mindfulness (reduces DMN)
  5. Acts of generosity
325
Q

4 types of motor control

A

Voluntary
Goal-directed
Habit
Involuntary

326
Q

Describe hierarchical control architecture

A

More complex, sophisticated threat detection and avoidance requires additional and complex processing capacity
Motor -> Autonomic -> Endocrine

327
Q

Overview of sensorimotor system

A

Motor control by lower (spine to muscle) and upper (higher centres to lmn) motor neurones.

328
Q

How do we achieve a range of movements?

A

Antagonist arrangement - e.g. eye
Recruitment of different muscle fibres - fast/slow twitch

329
Q

What is rigor Mortis?

A

Release of acetylcholine causes cascade of ca2+, Mg+ and ATP to be released.
After death muscles remain contracted until enzymes disrupt the actin/myosin

330
Q

Fewer muscle fibres in a motor unit gives…

A

Greater movement resolution

331
Q

What is a motor pool?

A

All lower motor neurones that innervate a single muscle

332
Q

A good CNS needs to know what about muscles

A
  1. How much tension is on the muscle
  2. What is the length (stretch) of the muscle
333
Q

What do Golgi tendon organs sense?

A

Muscle tension
(Under extreme conditions can inhibit muscle fibres to prevent damage)

334
Q

What do muscle spindles sense?

A

Length of muscle (stretch)

335
Q

What are reflexes?

A

Operate without engaging the brain for avoidance of injury and effective motor control.

336
Q

Intrafusal vs extrafusal muscle fibres

A

Extra - Normal muscle fibres
Intra - sensory fibres coiled around used to detect stretch

337
Q

Gamma vs alpha innervation

A

Gamma motor neurones to keep intrafusal fibres at set length
Alpha - for muscle contraction

338
Q

Describe reciprocal innervation

A

Contraction of one muscle induces relaxation of the other to permit smooth movement.

339
Q

Where are motor and sensory neurones?

A

Sensory - dorsal root ganglion
Motor - ventral root

340
Q

Control of gross movement has simple circuits but why is it hard to replicate?

A

Needs constant modulation based on sensory feedback to adjust activity and direct it towards its goal

341
Q

Describe ancient brain stem motor control

A

Pathways connect sensory input to motor output directly e.g. balance, respiration and posture

342
Q

How is motor control more adapted in humans?

A

Cortex sculpts commands into more developed.g. Grunts to voices

343
Q

Describe primary motor cortex

A

Top down control over muscular activity with little synapses between a corticol neurone.

344
Q

Describe general descending pathways from cortical motor areas

A

Upper motor neurones originate in pyramidal cells and synapse with lower motor neurones in spinal chord. Most innervate contralateral motor units

345
Q

Axons of the upper motor neurones form

A

The pyramidal tract

346
Q

Which areas of the brain affect motor control systems

A

Cerebellum = excitatory
Basal ganglia = Inhibitory

347
Q

Describe dorsolateral tracts

A

Contains direct corticospinal tract and indirect route via brain stem red nuclei.
Innervates contralateral spine to alpha motor neurones directly and project to distal muscles e.g. fingers

348
Q

Describe ventromedial tracts

A

Contains direct corticospinal tract and indirect route via brain stem tectum, vestibular and CN nuclei.
Diffuses Innervation to both sides and projects to proximal muscles of trunks and limbs.

349
Q

Define the basal ganglia

A

A group of structures (group of nuclei) beneath the cortex that acts as a Gatekeeper for control of the motor system. (Not fully understood)

350
Q

Describe function of basal ganglia.

A

Receives excitatory input from cortex and outputs inhibitory (GABA) response back via the thalamus at rest.
Dopamine from substantia nigra dishibits basal ganglia and increases excitation to motor cortex.

351
Q

Describe the cerebellum

A

Acts as a parallel processor enabling smooth, coordinated movements. Also important in cognitive tasks.
Contains half number of CNS neurones and 10% of brain weight.

352
Q

Describe the function of the cerebellum

A

No direct projection to LMN - modulates activity of UMN. Computes errors back to motor cortex and adjust commands while motor learning = precise control + coordination

353
Q

Name 3 inputs of cerebellum and 1 output

A

I = Corticol - copy of commands from motor, somatosensory and visual areas of cortex
I= Spinal - proprioceptive info about limb position and movement
I= Vestibular- Rotational and acceleratory head movement.
O = Thalamus -> motor cortex

354
Q

Autonomic vs somatic system

A

Involuntary, generally smooth/ cardiac muscle/ glands.

Voluntary, more organised nerves, always stimulates skeletal muscle contraction.

355
Q

Parasympathetic vs Sympathetic innervation

A

Para - CN 3,7,9,10 and Sacral 1,2
S - CN, white + grey rami, sympathetic chain (splanchnic T1-L2), other ganglia

356
Q

Autonomic vs somatic motor neurones

A

Myelinated Fibres synapse at ganglion after CNS and postganglion fibres are unmyelinated

Myelinated Fibres don’t synapse after leaving CNS

357
Q

Some examples of autonomic functions

A

Thermoregulation, exercise, digestion, sexual function

358
Q

What happens in sympathetic innervation?

A

Bronchodilator, vasoconstriction, increased heart rate and blood pressure, decreased GI motility and contraction.
(Opposite for para)

359
Q

Name 3 systems of the autonomic system

A
  1. Para (CN + Sacral)
  2. S (Adrenal amplification)
  3. Enteric NS (GI)
360
Q

Describe the adrenal amplification system

A

The adrenal glands over kidneys secrete more adrenaline which circulate and amplify fight or flight responses by about 5x

361
Q

Describe the enteric NS

A

Allows GI to function without para/sympathetic NS by allowing neurotransmitters circulating in portal system to allow digestive enzymes to be released

362
Q

Describe neurotransmitters and receptors in parasympathetic and sympathetic neurones

A

Sympathetic - Ach (Nicotinic receptor), Noradrenaline (Adrenergic receptor)

Parasympathetic- Ach (nicotinic receptor), Ach (Muscarinic receptor)

363
Q

Name some ANS inputs

A

Carotid body receptor (in bifurcation)
Atrial baroreceptors
Cardiac baroreceptors
Arteriolar receptors

364
Q

Name some primary and secondary ANS disorders

A

P - Acute, chronic
S - Diabetes, Chronic liver, renal,, alcohol induced, Guillain-Barre (inflammation), infection, brain tumours, Hypertension*, sexual+sudomotor+GI+eye disorders

365
Q

How to test autonomic nervous systems

A

Heart rate and blood pressure measurement using:
Stress test
Bp beat-by-beat
Baroreflex

Non cardiovascular test:
Pupillarometry
Sweat measurement
Skin blood flow
Gastric acid secretion

366
Q

What is the basal ganglia

A

Part of telencephalon that is not directly connected to but influences motor control.

367
Q

What is the lenticular nucleus made of?

A

Putamen
Globus pallidus

368
Q

What is the striatum made of?

A

Caudate nucleus
Putamen

369
Q

What is the corpus striatum made of?

A

Caudate nucleus
Putamen
Globus pallidus

370
Q

MRI facts

A

Always on - magnetic rays
Cannot take in money, phones etc
Implants, heating, projectile hazards
-> May cause death
Need to fill form before using

371
Q

Describe beginning of motor movement

A

Motor cortex
Brain stem
Spinal chord (Ventral horn)

372
Q

Common causes and features of UMN disorder

A

Brain stem - stroke/ tumour/ MS
Spinal chord - Vit B12 deficiency, spinal chord degeneration, cord compression

Spastic, Spastic /pyramidal weakness, Brisk reflexes, + Babinski reflex

373
Q

Causes and features of LMN disorders

A

Motor neurone - MND, Polio
Motor nerve root - Guillain Barre
Motor nerve - neuro / radiculopathies
Neuro muscular junction - Myasthenia gravis
Muscle - Myositis, myopathies

Weakness (flaccid), muscle wasting, fasciculation, absent deep tendon reflex, reduced tone

374
Q

Causes and Features of peripheral nerve or neuromuscular junction disorders

A

P - Diabetes, HIV, Alcohol/Drugs, Paraneoplastic syndrome
N - Myasthenia gravis …

Weakness and muscle wasting, Poor balance, Numbness, burning, tingling, freezing pain

375
Q

What is myasthenia gravis? Describe

A

Antibody mediated immune system attacks neuromuscular junction

376
Q

Describe structure of a skeletal muscle

A

Muscle cell = fibre (one cell with nucleus)
-> myofibrils -> sarcomeres

Made of actin and myosin filaments which slide over each other for contraction

377
Q

Which systems ensure smooth and coordinated movement?

A

Extra pyramidal system - Basal ganglia
Cerebellar system
Sensory input

378
Q

Describe Parkinson’s disease

A

Neurodegenerative condition associated with loss of dopaminergic neurones so the basal ganglia is inhibited and motor cortex is uninhibited. Systems (TRAP):
Tremor
Rigidity
Akinesia / Bradykinesia
Postural instability

379
Q

Describe importance and features of cerebellar disorders

A

Important for coordination: limb movement, clear speech, smooth eye movement, maintaining posture

Features : dysarthria (slurring), Unsteadiness, nystagmus, lack of smooth fine movements.

380
Q

What can chronic pain affect?

A

Ability to work
Activities and enjoyment
Contact with others + relationships
Self confidence + sleep

381
Q

Describe 2 common patterns of pain

A

Take it easy - avoid activities due to fear = loss of contact and fitness
Boom and bust - aggrieved pain and then rest repeatedly

382
Q

3 Ps to help pain

A

Pacing - regular activity
Prioritising - spreading activities
Planning - balance choices

383
Q

Effects of muscle tension with pain

A

Muscle tenses in anticipation to pain causing aches with simple movements.
Beneficial to practice relaxation, mindfulness and distraction

384
Q

Describe sub grouping of basal ganglia in 17th century

A

Rostral (upper)
- Striatum (putamen + caudate)
- Globus pallidus
Caudal (lower)
- subthalamic nucleus
- Substantia nigra

385
Q

Describe the position of the striatum

A

Caudate nucleus runs along lateral ventricles and putamen latera, to this.
(Together = striatum)

386
Q

Describe the position of the caudal structures

A

Red nucleus is above substantia nigra.
Subthalamic nucleus is lateral.

387
Q

Which 3 circuits is the basal ganglia involved in?

A

Motor
Limbic (emotion)
Oculmotor

388
Q

Name some illnesses with basal ganglia dysfunction

A

Parkinson’s
Huntingtons
ADHD
Cerebral palsy
Wilson’s (storage disorder)

389
Q

Parkinson’s vs Huntingtons

A

P - Not enough dopamine
= Increased muscle tone and reduced movement
H - Too much dopamine
= Decreased muscle tone and overshooting movement

390
Q

Synthesis and storage of dopamine

A

L-Tyrosine = naturally occurring acid
2 enzymatic steps (-> L-DOPA ->)
= dopamine stored in synaptic vesicles cleft and released to 5 different receptors (D1-5)

391
Q

Where exactly is dopamine produced and released?

A

Dopamine is produced in the substantia nigra and travels along the axon to the synapse in the target (striatum)

392
Q

Why is there not enough dopamine in Parkinson’s?

A

Not enough dopamine transporters to transport dopamine from substantia nigra to striatum
(Very faint substantia nigra due to dead lewy bodies)

393
Q

Why is there a long presympathetic time phrase for neurogenesis cell deaths (Parkinson)?

A

2/3 dopamine transporter need to be lost before becoming sympathetic.
(May take decades)

394
Q

Describe huntingtons disease

A

Larger ventricles due to death of caudate nucleus

395
Q

Functions of cortex vs basal ganglia

A

Cortex - generates will and motor
BG - fine tuning of movement from c
(C -> BG -> C -> Move)

396
Q

How does substantia nigra and striatum fine tune movements from cortex?

A

SN - secretes dopamine so signals continue through to cortex
S - secretes GABA which inhibits signal to cortex

(Parkinson’s don’t have SN or dopamine so pauses in signals, Huntingtons is opposite)

397
Q

3 cardinal/clinical features and treatment of Parkinson’s

A

Brady/Akinesia (slow)
Tremor at rest
Rigidity (may be pain)

Treatment = supply L-DOPA, deep brain stimulation (inactivate subthalamic nucleus so less inhibitory)

398
Q

What 2 functions are dead in Parkinson’s?

A

Substantia nigra releases dopamine
- This lubricates normal loop
- This stimulates subthalamic nucleus (which inhibits loop)

So PD = Overall inhibition of basal ganglia motor output

399
Q

Clinical features and genetics of Huntingtons

A

Chorea (overshooting movements)
Dementia/ psychiatric illness
Personality change

Autosomal dominant genetic with full penetrance (tested by looking at repeats of trinucleotides >40)

400
Q

How do we calculate age of onset of Huntingtons

A

On average more repeats of trinucleotides, the younger the age of onset.
However CANT, because can’t predict for individuals.

Phase 1 Notes (9 decks)

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