Brainscape's Knowledge GenomeTM

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


See full index

Yr 2.0 Sem 4 > Nervous System & NeuroPsych 1-5 > Flashcards

Nervous System & NeuroPsych 1-5 Flashcards

1
Q

4 Differentiate between the two types of photoreceptors in the retina

A

Rods - low light levels (scotopic vision), BandW, low spatial acuity
Cones - higher light levels, (photopic vision), Colour vision, high spatial acuity

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

4 List the 8 layers of the retina, deep to surface

A 
(In the New Generation It's Opthalmologists Examining Patient's Retinal epitheiliums) 
Inner limiting membrane
Nerve fibre layer
Ganglion cell layer
Inner plexiform layer
Outer nuclear layer
External limiting membrane
Photoreceptor layer
Retinal pigment epitheilium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

4 What is function of the choroid layer of the eye?

A

Vascular supply

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

4 Why do patients with albinism often have to wear dark glasses?

A

No melanin - which in pigmented layer of retina would normally absorb some light, thus even normal light levels are bright for them, due to glare.

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

4 What do the horizontal cells of the retina do?

A

Help integrate and regulate the input from multiple photoreceptor cells, facilitating vision in high or low light

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

4 Which part of the retina is related to the blind spot of vision?

A

Optic disc, where optic nerve enters retina and there are no photoreceptor cells

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

4 What is amaurosis fugax?

A

Painless temporary loss of vision in one or both eyes

(Latin: fugax meaning fleeting, Greek: amaurosis meaning darkening, dark, or obscure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

4 What is the fovea centralis?

A

Small, central pit in retina composed of closely packed cones and specialized for maximum visual acuity.

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

4 What type nerve lesion would cause monocular blindness?

A

Unilateral lesion of (ipsilateral) optic nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

4 What is bitemporal hemianopia?

A

Tunnel vision (as input from nasal fibres lost)

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

4 What 2 structures are located closest to the optic chiasm?

A

Pituitary gland

Anterior Communicating Artery

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

4 Name the 5 main components of the visual pathway

A

Optic nerve, optic chiasm, lateral geniculate nucleus, optic radiation and primary visual cortex

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

4 What are the 2 most common causes of optic nerve lesions in children?

A

Optic nerve glioma or blastoma

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

4 In what age group are optic sheath meningiomas most common in?

A

Middle aged (mean age at presentation 40 years, also more common in women)

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

4 Why would damage to the optic chiasm cause “tunnel vision”?

A

Nasal fibres of optic nerves cross over at optic chiasm and so are damaged. These are responsible for the temporal or lateral field of vision. Temporal fibres which give nasal field of vision run laterally so are spared., thus preserving central vision.

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

4 What’s homonomous hemianopia?

A

When you lose either left or right side of field of vision in both eyes.

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

4 What is the most common category of cause of homonomous hemianopia?

A

Vascular (i.e. stroke)

[others include neoplasia and trauma]

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

4 What sight defect would a lesion of the left optic tract cause?

A

Right homonomous hemianopia (loss of R side field of vision in both eyes)

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

4 What type of sight defects does damgage to optic radiations cause?

A

Quadrantanopias

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

4 What is the blood supply to the occipital lobe of the brain?

A

◦ Posterior cerebral artery

◦ Middle cerebral artery (occipital pole)

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

4 Why would central vision be spared in the case of a stroke affecting the posterior cerebral artery?

A

Occipital pole which represents macula is supplied by the middle cerebral artery so will still have adequate blood supply.

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

4 What are the 3 main things that must happen for our eyes to adjust to see something close up?

A

(3 Cs)
Convergence of eyes
pupillary Constriction
increased Convexity of lens to increase refractive power

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

4 What are the 3 main muscles required for the accommodation reflex?

A

Medial rectus
Constrictor pupillae
Ciliary Muscle

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

4 Is the brain involved in the accommodation reflex?

A

Yes (cerebral cortex must be involved)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

4 Why does the pupil constrict in the accommodation reflex?

A

Pupillary constriction allows eye to focus on close objects

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

4 Which arteries supply the anterior and posterior parts of the Circle of Willis?

A

Internal Carotid Arteries - anterior

Vertebral arteries- posterior

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

4 What is the name of the vessel that completes the Circle of Willis anteriorly?

A

Anterior communicating artery (links the 2 anterior cerebral arteries)

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

4 Which vessel supplies most of the so-called anterior part (most anterior part of frontal lobe + midline parts of parietal lobes) of the cerebrum?

A

Anterior cerebral artery

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

5 Why do upper motor nerve lesions affecting the face spare the forehead?

A

Bilateral innervation of superior part of facial nucleus whereas neurones supplying the rest of the face travel contralaterally. Thus if innervation is lost from one side of the CNS, the forehead is unaffected as it still has functional innervation from the other, unaffected side.

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

5 Where are the cell bodies of lower motor neurons located?

A

Ventral horn of spinal cord
or
Cranial nerve motor nuclei in brainstem

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

5 Why does an upper motor neuron lesion cause hyperactivity in the lower motor neuron and muscle supplied?

A

Net effect of upper motor neurons on lower motor neurons is inhibitory

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

5 Where are the cell bodies of the upper motor neurons found?

A

Motor cortex i.e. the pre-frontal gyrus

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

5 What is the most common site of an upper motor neuron lesion?

A

The internal capsule

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

5 Where do upper motor neurons decussate?

A

In the medulla

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

5 List 5 signs of a lower motor neuron lesion

A 
Weakness
Areflexia
Wasting
Hypotonia
Fasciulation
(Well Aren't We Happy Flappers)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

5 Within which tract do upper motor neurons descend through the spinal cord?

A

Lateral corticospinal tract

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

5 List the structures through which upper motor neurons descend before reaching the medullary pyramids

A

Corona radiata
Internal Capsule
Cerebral peduncle in midbrain
Pons

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

5 What do the nerves of the corticobulbar / corticonuclear tract synapse with?

A

Lower motor neurons in the cranial nerve nuclei (i.e. nerves supplying face)

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

1 What does white matter of the CNS consist of?

A

Axons and their supporting cells

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

1 Which anatomical landmark of the brain is the primary visual cortex associated with?

A

Calacrine sulcus

41
Q

1 What function is associated with the parahippocampal gyrus?

A

Memory encoding (it is the key cortical region for this)

42
Q

1 Where is the cingulate gyrus located?

A

Curved round the corpus callosum

43
Q

1 Which type of CNS tissue is more vascular?

A

Grey matter

44
Q

1st yr 1 How does the neural tube of the embryo develop?

A

Gastrulation produces notocord.
Notocord induces neurulation in overlying ectoderm.
Neural plate forms and its lateral edges elevate becoming the neural folds between which is the neural groove.
Neural folds approach each other in the midline, fusing to form neural tube.

45
Q

1 At what point of embryonic development does the neural tube become completely closed?

A

By day 28-32

46
Q

1 What is the most common site of a spina bifida?

A

Lumbosacral region

47
Q

1 What would a failure of the neural tube to close cranially cause?

A

Ancephaly (this is incompatible with life)

48
Q

1 What is rachischisis?

A

Severe form of spina bifida resulting from failure of neural fold elevation (almost always fatal)

49
Q

1 What advice is given to help prevent neural tube defects?

A

That all women of childbearing age / that are trying to conceive take folic acid supplements (3 months pre-conceptually + during 1st trimester)

50
Q

1 What maternal blood test can be used to detect neural tube defects in a developing foetus?

A

Serum alpha fetoprotein - this will be raised in NTD

51
Q

1 Explain why the cauda equina forms embryologically

A

Vertebral column grows faster than spinal cord after 3rd month of development. Spinal roots must therefore elongate because they still exit at their inter-vertebral foramen.

52
Q

1 When do the secondary embryological brain vesicles form?

A

At 5 weeks (primary form during 4th week)

53
Q

1 Name the 5 secondary embryological brain vesicles and state which structures they become in the adult brain

A 
Telencephalon - Cerebral hemispheres
Diencephalon - Thalamus
Mesencephalon - Midbrain
Metencephalon - Pons and cerebellum
Myelencephalon - Medulla oblongata
54
Q

1 Name the 2 flexures of the brain

A

Cervical and cephalic

55
Q

1 What is neonatal hydrocephalus most commonly associated with?

A

Spina bifida (also aquaductal stenosis)

56
Q

1 What are neural crest cells?

A

Cells of lateral border of the neuroectoderm tube which migrate into mesoderm and become mesenchymal

57
Q

1 What causes Hirshsprung’s disease?

A

Defect in neural crest migration affecting colon

58
Q

1 Which components of the endocrine system are neural crest derivatives?

A

C cells of thyroid gland

Adrenal medulla

59
Q

1 Why can maternal alcoholism affect the developing embryological heart?

A

Alcohol disrupts neural crest migration

Conotruncal septum which divides the outflow region of the developing heart is a neural crest derivative

60
Q

1 Briefly describe diGeorge syndrome

A

(CATCH 22)
Cardiac (aortic arch anomalies, conotruncal (TOF, truncus arterious, interrupted aorta), tricuspid atresia)
Abnormal facies (hypertelorism, ear anomalies, short down slanting palpebral fissures (antimongoloid), short philtrum)
Thymic hypoplasia (cellular immune deficiency: abnormal number and function of T-cells)
Cellular immune deficiency; Cleft palate
Hypoparathyroid w/ Hypocalcemia (causes tetany)
22 chrom defect (deletion 22q11; dx by FISH)

61
Q

2 What is the most abundant type of glial cell?

A

Astrocytes

62
Q

2 What is the function of microglia?

A

Immune response - phagocytose debris and foreign material

63
Q

2 How are neurones supplied with energy if blood glucose is low?

A

Astrocytes produce lactate which is transferred to neurones via the glucose lactate shuttle

64
Q

2 How do astrocytes help maintain a favourable environment for neurones?

A

Uptake neurotransmitters, including glutamate which becomes toxic at high concentrations
Take up K+ to maintain ionic environment

65
Q

2 Differentiate between oligodendrocytes and Schwann cells

A

Oligodendrocytes secrete myelin sheaths around multiple axons of the CNS
Schwann cells wrap themselves around single axons in the PNS and phagocytose foreign material

66
Q

2 What 3 features of brain capillaries and other local cells contribute to the blood brain barrier?

A

Tight junctions between endothelial cells
Basement membrane surrounding capillary
End feet of astrocyte processes

67
Q

2 Name the 3 chemical classes of neurotransmitters

A

Amino acids
Biogenic amines
Peptides

68
Q

2 What is the major excitatory neurotransmitter?

A

Glutamate

69
Q

2 Name the 2 main inhibitory amino acid neurotransmitters

A

GABA (brain)

Glycine (mostly brainstem and spinal cord)

70
Q

2 Which ions are NMDA receptors permeable to?

A

Na+ K+ and Ca2+

71
Q

2 How does activation of GABA and glycine receptors decrease action potential firing?

A

Integral Cl- channels open, Cl- enters cell causing hyperpolarisation after which a greater change in membrane potential is needed for action potentials so these occur less readily.

72
Q

2 Name 2 classes of drugs that bind to GABA receptors

A

Barbiturates

Benzodiazepines

73
Q

2 Which neurotransmitter do inhibitory inter-neurones in the spinal cord release?

A

Glycine

74
Q

2 Where does acetylcholine act in the peripheral nervous system?

A

Neuromuscular junctions
Autonomic ganglion synapses
Synapses of parasympathetic post-ganglionic neurons w/ their target tissues

75
Q

2 What functions are the cholinergic pathways of the CNS involved in?

A

Arousal, learning,

memory and motor control

76
Q

2 Why are cholinesterase inhibitors used to alleviate symptoms of Alzheimer’s disease?

A

Alzheimers causes degeneration of cholinergic neurones (in the nucleus basalis) -> ACh depletion.
Cholinesterase catalyses breakdown of ACh thus when inhibited ACh conc. will increase.

77
Q

2 Which dopaminergic pathway is involved with motor control?

A

Nigrostriatal

78
Q

2 What are the mesocortical and mesolimbic pathways of the brain involved in?

A

Mood, arousal and reward

79
Q

2 Loss of which neurones are associated with Parkinson’s disease?

A

Dopaminergic neurones of the substantia nigra

80
Q

2 What is the mechanism of action of most antipsychotics?

A

Antagonism at dopamine D2

receptors

81
Q

2 How is action in the peripheries prevented in dopamine therapy?

A

Give precursor L-DOPA combined with Carbidopa which inhibits the enzyme that converts L-DOPA to dopamine but cannot cross the blood brain barrier and so only acts peripherally.

82
Q

2 How does L-DOPA cross the blood-brain barrier?

A

Through large neutral amino acid transporter

83
Q

2 What are the 2 main functions of serotonergic pathways in the CNS?

A

Regulating sleep/wakefulness and mood

84
Q

2 What receptors would you find at glutamatergic synapses?

A

AMPA and NMDA receptors

85
Q

2 What receptors does noradrenaline act on?

A

G protein coupled alpha and beta adrenoreceptors

86
Q

2 Where are the cell bodies of noradrenaline containing neurones located?

A

Pons and medulla i.e. brainstem

87
Q

2 Where does most noradrenaline in the brain come from?

A

Locus ceruleus in brainstem

88
Q

3 What modalities of sensation are innervated by the spinothalamic system?

A

Temperature
Pain
Crude touch (including pressure and stretch)

89
Q

3 Where are the cell bodies of primary sensory neurones located?

A

Dorsal Root Ganglion the spinal cord

90
Q

3 Where would you find the axons of neurons that detect vibration, proprioception and fine touch?

A

Dorsal column of spinal cord

91
Q

3 Explain why there are not clear borders between dermatomes

A

Each neuron receives input from multiple receptors, known as its receptive field. These often overlap so that one area of skin may be supplied by 2 different neurons.

92
Q

3 At what level does the sensory system decussate?

A

Secondary sensory neurons are the ones that decussate. Their cell bodies are located in dorsal horn or medulla.

93
Q

3 Describe the general route of tertiary sensory neurons

A

From thalamus, where their cell bodies are, to the primary sensory cortex i.e. the post central gyrus

94
Q

3 Why would a central cord lesion affect different modalities of sensation differently?

A

The 2 systems that each supply a different set of sensory modalities are organised differently in the spinal cord.
In the dorsal column pathway (fine touch, vibration and proprioception) the lower body maps to the medial portion of the tract while in the spinothalamic tract (temperature, pain, crude touch and presssure) the lower body maps to the more lateral, superficial parts.

95
Q

3 Name the 2 nuclei whose axons form the medial lemiscus pathway

A

Gracile and Cuneate (both synapse with dorsal column pathway)

96
Q

3 Why does activation of mechanoreceptors alleviate pain?

A

It excites inhibitory enkephalinergic interneurones in the spinal cord

97
Q

3 Which nerve fibres are responsible for slow, diffuse, dull pain?

A

C fibres (unmyelinated)

98
Q

3 What causes Brown-Sequard syndrome?

A

Complete hemisection of spinal cord due to trauma or ischaemia (rare)

Yr 2.0 Sem 4 (4 decks)

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