Brainscape's Knowledge GenomeTM

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


See full index

MD4001 > Orientation Week > Flashcards

Orientation Week Flashcards

1
Q

How does information arrive at the cell body of an excitable cell?

A

Via dendrites

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

What happens to the information that arrives at the cell body of an excitable cell?

A

Its assimilated and processed

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

What happens to the processed information in the cell body?

A

Digitised into action potentials which are transmitted along the axon

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

The larger the diameter of the axon, the ______ the resistance is. And so larger axons have faster _______ charge movement?

A
  • Lower

- Passive

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

The more surface area there is on an axon, the _____ its capacity to store charge across its membrane?

A

Higher

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

What is the fastest speed a libra can carry a signal at?

A

250 mph

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

What does the voltage dependent Na channel help to set up?

A

Refractory period of action potential

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

Where are Schwann cells found?

A

Peripheral nervous system

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

Where are Oligodendrocytes found?

A

Central nervous system

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

Describe local currents in a myelinated axon?

A

Saltatory (jumping) conduction

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

In a myelinated axon where is the only place an action potential can occur?

A

Node of Ranvier

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

What approximate size is the synaptic gap?

A

20nm

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

What helps the binding of the vesicle and cell membrane at the bouton?

A

SNARE proteins

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

What catalyses membrane fusion at the bouton?

A

Ca2+-bound synaptotagmin

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

What 3 things can happen to inactivate neurotransmitters?

A
  1. Diffusion
  2. Re-uptake
  3. Enzymal inactivation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the 2 different types of receptors?

A
  1. Ionotropic (directly gate ion flow)

2. Metabotropic (indirectly gate ion flow or active other pathways)

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

How do most receptors code the duration and magnitude of external signals?

A

Using a generator potential

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

What does stronger external signals sent to receptors result in?

A

Higher frequency of action potentials in the axon

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

What are stretch reflexes mediated by?

A

Sense organs within muscles known as muscle spindles

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

Describe the 3 parts of the spindle fibre mechanism?

A
  1. Contractile (gamma MN’s) & elastic portion
  2. Less elastic/contractive sensory portion
  3. Contractile (gamma MN’s) & elastic portion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In peripheral spinal nerves what does rootles converge to become?

A

Roots

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

In peripheral spinal nerves what does the ventral & dorsal roots converge to become?

A

Spinal nerve (mixed, motor & sensory)

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

Is a ventral root sensory or motor?

A

Motor (efferent)

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

In peripheral spinal nerves what does the spinal nerve divide into?

A

Ventral & dorsal rami (mixed, motor & sensory nerve fibres)

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

What are the 5 steps to withdrawal when a lit match is help to a bare foot?

A
  1. Aδ & C fibres in skin detect noxious stimulus
  2. Aδ & C fibres synapse with inhibitor interneurons
  3. Aδ & C synapse with α-motor neurons for flexor muscles
  4. α-motor neurons to the extensor muscle are inhibited
  5. α-motor neurons to the flexor muscles are excited & flexors contract, resulting in withdrawal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

List the 4 different neurons in the spinal nerve from posterior to anterior?

A
  1. Somatic sensory neuron
  2. Visceral sensory neuron
  3. Visceral motor neuron
  4. Somatic motor neuron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What resides in the grey matter of the spinal cord?

A

Cell bodies

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

What resides in the white matter of the spinal cord?

A

Axons

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

What resides in the ventral horn (grey matter) of the spinal cord?

A

Somatic motor cell bodies

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

What resides in the lateral horn (T1-L2, grey matter) of the spinal cord?

A

Visceral cell bodies

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

What resides in the dorsal horn (grey matter) of the spinal cord?

A

Somatic sensory nerves/interneurons (cell bodies in dorsal root ganglion)

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

What is the terminology for the collection of nerve fibres (white matter) in PNS & spinal cord?

A
  • Fascicle/bundle (nerve)

- Tract

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

What is the terminology for the collection of cell bodies (grey matter) in PNS & spinal cord?

A
  • Ganglia

- Horns

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

What are the different vascular supplies of the spinal cord?

A
  • 2 posterior spinal arteries (with veins)
  • 1 anterior spinal artery (with veins)
  • Segmental medullary arteries “supporting” the spinal arteries
  • Internal vertebral venous plexus (extradural/epidural space)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Whats the clinical problem with the spinal cord venous system?

A

They do not have valves & pressure gradients permit blood flow which increases infection & metastasis spread

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

Whats the role of the anterior white commissure in the spinal cord?

A
  • Pain & temp fibres cross

- Anterior corticospinal tract fibres cross

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

Whats the role of the fasciculus gracilis in the spinal cord?

A

Sensory (fine touch, vibration, proprioception) from ipsilateral lower limb

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

Whats the role of the fascicles cuneatus in the spinal cord?

A

Sensory (fine touch, vibration, proprioception) from ipsilateral upper limb

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

Whats the role of spinocerebellar tract in the spinal cord?

A

Proprioception from limbs to cerebellum

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

Whats the role of the lateral corticospinal tract in the spinal cord?

A

Motor to ipsilateral anterior horn

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

Whats the role of the spinothalamic tract in the spinal cord?

A

Pain & temp from contralateral side of the body

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

Whats the role of the anterior corticospinal tract in the spinal cord?

A

Motor to ipsilateral & contralateral anterior horn

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

What do peripheral nerves do?

A

Link spinal cord & brain to peripheral tissue

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

What is the arterial anastomosis in the spinal cord?

A

Extra & intervertebral arteries

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

What is the main arterial supply in the brain?

A

Intracranial arteries

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

What is the difference between the venous system in the spinal cord & in the brain?

A
  • Spinal cord: venous plexus

- Brain: venous sinuses

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

What sign/s does a spinal cord pathology cause?

A

Lower motor neuron & Upper motor neuron signs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What sign/s does a intracranial pathology cause?

A

Only Upper motor neuron signs

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

Describe the location of an Upper motor neuron?

A

Above ventral horn/cranial nuclei, brain, brainstem & spinal cord

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

Describe the location of a lower motor neuron?

A

Ventral horn & below. Cranial or spinal nerve, roots, rami, plexus

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

What are typical signs of upper motor neuron lesions?

A
  • Increased muscle tone (spasticity)
  • Muscle weakness, but no wasting
  • Hyperreflexia
  • No fasciculations
  • Extensor plantar response (+ babinski)
  • Clonus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What are typical signs of lower motor neuron lesions?

A
  • Decreased muscle tone
  • Muscle weakness & wasting (atrophy)
  • Hyporeflexia/areflexia
  • Fasciculations
  • No pathological plantar response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What does the Central Nervous system do?

A

Processes/integrates/learns and sends information

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What are neurons?

A

Separate cells that communicate by releasing chemicals by secretion at the ends of cell processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the purpose of microtubules in the axon?

A

Vesicle transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Describe the different parts of an axon from top to bottom?

A
  • Dendrites
  • Cell body
  • Nucleus (+ nucleolus)
  • Axon hillock
  • Axon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What does repeated stimulation of neuronal pathways modify?

A

Function of dendritic spines (long term potentiation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Where does processing occur in the brain & spinal cord?

A

Grey matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Where does communication occur in the brain & spinal cord?

A

White matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is horizontal plane also known as in imaging (CT & MRI)?

A

Axial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What makes up the central nervous system?

A

Brain & Spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What does diencephalon stand for?

A

“Between brain”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What are the 4 lobes of the brain?

A
  1. Frontal
  2. Parietal
  3. Occipital
  4. Temporal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What lies on the floor of the lateral fissure of the brain?

A

Insula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What does the central sulcus in the brain separate?

A

Precentral gyrus & postcentral gyrus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What is another name for cerebral hemispheres?

A

Telencephalon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What lies within the diencephalon?

A

Thalamus & Hypothalamus etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What are the 3 parts of the brain stem?

A
  1. Midbrain
  2. Pons
  3. Medulla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What are the 5 fluid filled ventricles inside the brain?

A
  1. Lateral (x2)
  2. Interventricular foramen
  3. Third (head)
  4. Fourth (body)
  5. Cerebral aqueduct (neck)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What lies directly above the corpus callosum?

A

Cingulate gyrus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What is the largest bundle of white matter?

A

Corpus callosum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

How many cranial nerves are there?

A

12 (most exit ventrally)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What 2 joints in the skull allow some form of movement ?

A
  • Temporomandibular joint

- Atlanto-occipital joint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What 3 different types of bones make up the skull?

A
  1. Flat
  2. Irregular
  3. Pneumatised
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What is a Pneumatised bone?

A

Bones with air spaces such as the frontal, temporal, sphenoid & ethmoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What are the 4 functions of the skull?

A
  1. Protection
  2. Attachment for muscles
  3. Framework for the head
  4. Gives our identity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What are the 3 divisions of the skull?

A
  1. Neurocranium
  2. Viscerocranium (facial skeleton)
  3. Mandible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

How many bones are there in an adult skull?

A

22

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What is the neurocranium?

A

Bony case of brain including cranial meninges with a dome-like roof (calvaria) & floor (cranial base)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What is the viscerocranium?

A

Anterior part of the cranium that consists of bones surrounding the oral cavity, nasal cavity & most of the orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What 6 bones make up the Neurocranium?

4 singular midline & 2 bilateral paired bones

A
  1. Frontal
  2. Parietal (x2)
  3. Occipital
  4. Sphenoid
  5. Temporal (x2)
  6. Ethmoid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What 9 bones make up the Viscerocranium?

15 irregular, 3 singular midline & 6 bilateral paired bones

A
  1. Ethmoid
  2. Palatine (x2)
  3. Lacrimal (x2)
  4. Nasal (x2)
  5. Zygomatic (x2)
  6. Vomer
  7. Inferior nasal concha (x2)
  8. Maxilla (x2)
  9. Mandible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What are the 3 main features of the Viscerocranium?

A
  1. Zygomatic arch
  2. Mandible
  3. Infratemporal fossa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What are the 4 main features of the Neurocranium?

A
  1. External acoustic meatus
  2. Styloid process
  3. Mastoid process
  4. Temporal fossa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

What are the borders of the temporal fossa?

A
  1. Sup & Post- sup & inf temporal lines
  2. Ant- frontal process of zygomatic bone
  3. Inf- infratemporal crest deep to zygomatic arch
  4. Floor- pterion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

What is the Pterion?

A

H-shaped junction of sutures (frontal, parietal, temporal, sphenoid) which is structurally weak & vulnerable to injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What does the Pterion overlie?

A

Anterior branch of middle meningeal artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

What can trauma to the Pterion lead to?

A

Extradural/epidural haematoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What are the 4 flat bones of the calavaria fused by?

A

Coronal, sagittal & lambdoid sutures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

Describe Fontanelles?

A
  • Space between the bones of the skull in infant/fetus, where ossification is not complete & sutures not fully formed
  • Main one is between the frontal & parietal bones (anterior fontanelle)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

When do corners of frontal & parietal bones fuse?

A

By 18months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Describe the suture joint?

A
  • Fibrous

- Limited or no movement (synarthrosis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

What 3 foramen’s in the anterior skull are involved in the divisions of the trigeminal nerve (CN V)?

A
  1. Supra-orbital notch
  2. Infra-orbital foramen
  3. Mental foramen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

What are the 8 important craniometric points from posterior to anterior of the skull?

A
  1. Asterion
  2. Inion (protrude)
  3. Lambda
  4. Vertex
  5. Bregma
  6. Pterion
  7. Glabella (protrude)
  8. Nasion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

What are the 7 foramen’s in the inferior external view of the cranial base?

A
  1. Foramen magnum
  2. Jugular foramen
  3. Carotid canal
  4. Foramen lacerum
  5. Foramen ovale
  6. Foramen spinosum
  7. Hypoglossal canal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

What are the borders of the Infratemporal fossa?

A
  • Lat: ramus of mandible
  • Med: lat pterygoid plate of sphenoid
  • Ant: post maxilla
  • Post: Tympanic plate, mastoid & styloid processes
  • Sup: infratemporal crest of sphenoid
  • Inf: angle of mandible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

What is the shallowest part of the cranial base?

A

Anterior cranial fossa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

How do olfactory bulbs (CN I) receive nerve fibres from the nasal cavity?

A

Foramina of cribriform plate (olfaction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

How can cribriform fractures present?

A

CSF rhinorrhoea

100
Q

What 3 bones make up the anterior cranial fossa?

A
  1. Frontal
  2. Ethmoid
  3. Sphenoid
101
Q

What 2 bones make up the middle cranial fossa?

A
  1. Sphenoid

2. Temporal

102
Q

Where does the pituitary gland lie?

A

Hypophyseal (pituitary) fossa

103
Q

What 3 bones make up the posterior cranial fossa?

A
  1. Sphenoid
  2. Occipital
  3. Temporal
104
Q

Describe the temporomandibular joint?

A
  • Glenoid fossa of temporal & condylar process of mandible
  • Synovial joint
  • Fibrocartilage cover
105
Q

Whats the most common clinical problem with the temporomandibular joint?

A

Anterior dislocation

106
Q

What are the 2 ligaments in the temporomandibular joint?

A
  1. Sphenomandibular ligament

2. Lateral ligament (prevents post dislocation)

107
Q

When is the temporomandibular most unstable?

A

During depression

108
Q

What are the 4 assessment tools for cognitive assessment?

A
  1. 4AT
  2. Mini Mental state examination (MMSE)
  3. Montreal cognitive assessment (MOCA)
  4. Addenbrookes cognitive examination (ACE III)
109
Q

What is the 4 “A”s test?

A

Initial assessment for delirium & severe cognitive impairment

110
Q

What are the 4 “A”s?

A
  1. Alertness
  2. AMT 4
  3. Attention
  4. Acute change or fluctuating course
111
Q

What is delirium?

A

Mental confusion that can happen if someone becomes medically unwell (common 1:10 hospital patients)

112
Q

Describe the Montreal Cognitive Assessment (MoCA)?

A
  • Better identifying mild levels of impairment

- Less bias ethnicity/age/education

113
Q

What are the 5 cognitive domains of ACE II test?

A
  1. Attention
  2. Memory
  3. Verbal fluency
  4. Language
  5. Visuospatial abilities
114
Q

What is confabulation?

A

Presenting false information with no intent to deceive

115
Q

Give 2 illnesses in which confabulation occurs?

A
  1. Korsakoff’s syndrome

2. Alzheimer’s dementia

116
Q

What are the 7 skills in neuro history taking?

A
  1. Clarifying
  2. Being curious
  3. Sifting & sorting
  4. Analysing info
  5. Recognising value of negatives
  6. Observing how things are said, not just listening
  7. Succinctly documenting story
117
Q

What are some questions you can ask a patient when taking a neuro history?

A
  • Have you noticed any changes in your writing?
  • Any differences in the way you walk?
  • Increased difficulty doing up buttons?
118
Q

How common are medically unexplained symptoms in neuro history taking?

A

30%

119
Q

What are 6 common neurological presentations?

A
  1. Altered cognitive ability
  2. Fits, faints, funny turns
  3. Headache
  4. Weakness or movement disorders
  5. Numbness or sensory disorders
  6. Visual impairments
120
Q

What are some questions you could ask a patient for them to describe the most recent episode?

A
  • What was happening before?
  • What factors might have lowered the seizure threshold?
  • What position was the patient in?
  • Any prodromal symptoms?
  • What happened during the episode and after?
121
Q

What can focal weakness suggest?

A

Neurological origin

122
Q

What are 2 examples of proximal muscle weakness?

A
  • Rising from sitting

- Drying hair

123
Q

What are 2 examples of distal muscle weakness?

A
  • Standing on tip toes

- Fine finger movements

124
Q

Give an example of an illness in which there is too little movement?

A

Parkinson’s disease (stiffness)

125
Q

Give an example of an illness in which there is too much movement?

A
  • Chorea (“fidgety jerks”)

- Choreoathetosis (decreased tone, rapid)

126
Q

What does ADLs stand for?

A

Activities of Daily Living

127
Q

When should a child be able to walk & talk?

A

1 to walk, 2 to talk

128
Q

What systems enquiry would you go through in a neuro history?

A
  • Psychological (depressed)
  • ANS (bowel, bladder, sexual, light headaches)
  • Infection
129
Q

What are 6 cranial nerve screening questions?

A
  1. Change in your sense of smell?
  2. Vision? Double vision?
  3. Dry eyes? Dry mouth? Change in taste?
  4. Hearing? Dizziness?
  5. Change in voice?
  6. Articulation?
130
Q

Is it ectoderm, endoderm or mesoderm which makes the CNS?

A

Ectoderm

131
Q

Describe the steps of the early development of the CNS?

A
  • The plate will make a tube (neurulation)
  • Day 19+ midline groove apparent
  • Neurulation induced by the bar shaped tissue (notochord)
132
Q

What happens to the CNS development in 20-21days (end of 3rd week)?

A

Cells on plate edge thicken forming folds and a groove

133
Q

What happens to the CNS development into the 4th week?

A

Plate edges roll over and the cells fuse to make a tunnel

134
Q

When does the rostral neuropore close?

A

25 days

135
Q

When does the caudal neuropore close?

A

27 days

136
Q

Describe Anencephaly?

A
  • Failure of rostral neuropore to close
  • Born without forebrain
  • Unreactive to light & sound
  • Stillborn
  • May have respiration & respond to touch & sound
137
Q

What are some risk factors for neural tube defects?

A
  • Previous anencephaly
  • Diabetes
  • Epilepsy drugs
138
Q

Give a birth defect caused by failure of caudal neuropore to close?

A

Spina bifida

139
Q

What maternal supplement can reduce risk of neural tube defect?

A

Folate

140
Q

What 2 things are associated with Spina bifida?

A
  1. Displaced cerebellum

2. Hydrocephalus

141
Q

What 3 types of diseases can Alpha fetoprotein (AFP) detect?

A
  • Neural tube defects
  • Some cancers
  • Liver disease
142
Q

What neural tube swelling (vesicle) forms the forebrain?

A

Prosencephalon

143
Q

What neural tube swelling (vesicle) forms the midbrain?

A

Mesencephalon

144
Q

What neural tube swelling (vesicle) forms the hindbrain?

A

Rhombencephalon

145
Q

Describe the growth of the forebrain?

A

Grows 2 lateral expansions connected to a central slit like space

146
Q

Describe the growth of the midbrain?

A

Slower than forebrain, remains as single central tube

147
Q

Describe the growth of the hindbrain?

A

Develops into (rest of) brainstem & cerebellum with a central ventricle expanding

148
Q

What are the different lumens formed in the fore, mid and hindbrain?

A
  • FOREBRAIN: 2 lateral ventricles, 3rd ventricle
  • MIDBRAIN: cerebral aqueduct
  • HINDBRAIN: 4th ventricle
149
Q

Describe the walls of the forebrain?

A
  • Telencephalon (endbrain) cerebral hemispheres x2

- Diencephalon (“between brain”) includes thalamus

150
Q

Describe the walls of the hindbrain?

A
  • Metencephalon (pons, cerebellum)

- Myelencephalon (medulla)

151
Q

What are the different grooves in the brain?

A
  • Lateral fissure
  • Central sulcus
  • Pre-occipital notch
  • Parieto-occipital sulcus
152
Q

Where does the insula lie?

A

Floor of the lateral fissure

153
Q

What is the purpose of the gyri in the brain?

A

Increase surface & volume of grey matter

154
Q

What 4 structures lie within the C-shaped lateral ventricles?

A
  1. Corpus callosum
  2. Fornix
  3. Interventricular foramen (fluid filled)
  4. Hippocampus
155
Q

What is the purpose of the Hippocampus?

A

Memory

156
Q

What is the purpose of the fornix?

A

Connects hippocampus with anterior structures

157
Q

What does the internal capsule do?

A

Basal ganglia split by ascending & descending bundle (lies between caudate nucleus & lentiform nucleus)

158
Q

Where is the sensory grey matter before & after the 4th ventricle forms?

A
  • BEFORE: in dorsal position

- AFTER: more lateral

159
Q

Where does the cerebellum develop?

A

Dorsal wall of neural tube

160
Q

How many cranial nerves are there?

A

12 (most exit ventrally)

161
Q

What does the caudal neural tube become?

A

Spinal cord

162
Q

What are the 3 layers of the caudal neural tube?

A
  1. VENTRICULAR: progenitor cells- neurons/glia
  2. MANTLE: neutron bodies/glia
  3. MARGINAL: processes of neurons
163
Q

What are the 3 regions of the developing spinal cord?

A
  1. Sulcus limitans
  2. Alar lamina (posterior basal lamina)
  3. Basal lamina (anterior basal lamina)
164
Q

How does the CNS connect to the PNS?

A
  • Ingrowth of neurites from DRG forms dorsal root

- Outgrowth from neurons motor grey forms ventral root

165
Q

What induces the neural plate?

A

Notochord

166
Q

What does Bone morphogenetic protein (BMP) do?

A

Inhibits neural ectoderm, promoting skin

167
Q

What 3 things blocks bone morphogenetic protein?

A
  1. Noggin
  2. Chordin
  3. Follistatin
    (all produced in the notochord)
168
Q

Where do the neural crest cells go?

A

Migrate from the neural tube epithelium and into mesoderm

169
Q

What 3 things can neural crest cells produce?

A
  1. Skull (bone)
  2. Sensory & ANS
  3. Pigment cells
170
Q

What are 2 autosomal dominant syndromes caused by a defect in neural crest development?

A
  1. Waardenburg’s syndrome

2. Treacher Collins syndrome

171
Q

Describe Waardenburg’s syndrome?

A
  • Some have Pax-3 gene deletion
  • Pigment abnormalities
  • Deafness
  • Constipation
  • Heterochromia of eyes
  • Telecanthus
172
Q

Describe Treacher Collins syndrome?

A
  • Treacle (TCOF1 gene) defect
  • Failure of formation/apoptosis of neural crest cells
  • Abnormal eye shape
  • Micrognathia
  • Conductive hearing loss
  • Underdeveloped zygoma
  • Malformed ears
173
Q

What are the 3 stages to corporal senses?

A
  1. Detection of a stimulus
  2. Transmission of stimulus information to brain
  3. Recognition (conscious/unconscious) of nature, location, intensity & duration of stimulus
174
Q

What 4 things do the cutaneous receptors detect?

A
  1. Temperature
  2. Nociception
  3. Pressure
  4. Vibration
175
Q

What are the 5 special senses?

A
  1. Sight
  2. Hearing
  3. Taste
  4. Balance & movement
  5. Olfaction
176
Q

What happens to the degree of myelination when the speed of saltatory transmission increases?

A

Myelination Increases

177
Q

Describe Free nerve endings (specialised cutaneous receptor)?

A
  • C & Aδ fibres
  • Detect Pain
  • All skin types
  • Slowly adapting with high activation threshold
178
Q

Describe Merkel’s disks (specialised cutaneous receptor)?

A
  • Aβ fibres
  • Non-encapsulated
  • Static touch & pressure
  • All skin types
  • Slowly adapting with low activation threshold
179
Q

Describe Meissner’s corpuscles (specialised cutaneous receptor)?

A
  • Aβ fibres
  • Encapsulated
  • Changes in touch & pressure
  • Glabrous skin
  • Rapidly adapting with low activation threshold
180
Q

Describe Pacini’s corpuscles (specialised cutaneous receptor)?

A
  • Aβ fibres
  • Encapsulated
  • Vibration
  • All skin types
  • Rapidly adapting with low activation threshold
181
Q

Describe Ruffini corpuscles (hair follicle receptor)?

A
  • Entangled in collagen
  • Skin stretch & direction
  • Slow adaptation & widely distributed
182
Q

What is the purpose of muscle spindles?

A
  • Measure changes in length of muscle

- Regulates length via gamma reflex loop

183
Q

How does the gamma reflex loop work in muscle spindles?

A

When intrafusal fibres are stretched (length increases) afferent fibres stimulate contraction of extrafusal fibres via alpha motor neurons

184
Q

What is the purpose of the golgi tendon organs?

A
  • Detect tension in muscle via type 1b sensory nerve endings which innervate a collagen matrix in the tendon
  • Tendon stretch –> ending depolarise & send afferent info to CNS
185
Q

What pattern do most conscious sensory tracts follow?

A

General somatosensory system (1st, 2nd, 3rd order neurons)

186
Q

What is the arrangement of the primary somatosensory cortex?

A

Topographical

187
Q

What happens to the sensory information on route to the somatosensory cortex?

A

Passes through the thalamus

188
Q

What is the purpose of the thalamus?

A

Has reciprocal connections (peduncles) to all cortical regions & can relay information, receive feedback & modulate cortical activity

189
Q

What does the grey matter in the spinal cord divide into?

A

Lamina (rexed) and these represent targets for afferent information

190
Q

What does the white matter in the spinal cord divide into?

A

Tracts of axons carrying typified information

191
Q

What does fasciculus gracilis carry?

A

Information from lower body extremities

192
Q

What does fasciculus cuneatus carry?

A

Information from the upper body extremities

193
Q

What does the dorsal & ventral spinocerebellar tracts carry?

A

Proprioceptive information from muscle spindles (dorsal) & golgi organs (ventral)

194
Q

What are the 4 principle ascending pathway systems in the spinal cord?

A
  1. Dorsal column medial lemniscus pathway
  2. Anterolateral pathways
  3. Spinocerebellar pathway
    4, Trigeminal pathway (thalamus & brainstem)
195
Q

Describe the dorsal column medial lemniscal pathway?

A
  • Large diameter fast Aβ fibres
  • 1st order neuron ascend ipsilaterally in fasciculus gracilis & cuneatus & synapse with 2nd order neuron at brainstem nuclei
  • Then decussate, form part of medial lemniscus & project to ventral posterolateral lobe of thalamus –> cortex
196
Q

What does lateral inhibition rely on?

A

Reciprocal inhibition between 2 adjacent neurons where extent of inhibition from each 1 is linked to stimulus point on neuronal receptive field overlap

197
Q

What can lesions of gracile fasciculus cause and why?

A

Gait ataxia as brain is deprived of information about position of the feet

198
Q

What can lesions of the cervical cord cause?

A

Upper extremity ataxia and often patient is able to compensate with vision minimising sensory ataxia

199
Q

What is a classic sign of gait/sensory ataxia?

A

“Stamp & Stick”- Patient stamps down feet to enhance sensory input & maintains broad based stance

200
Q

What can dorsal column disease also cause?

A

Paraesthesia (tingling, numbness, crawling, deadness) in distal parts of extremities

201
Q

How can dorsal column function impairment be concluded?

A

Testing ability of proprioception

202
Q

Proprioception is NOT lost until about ___ of posterior column axons have ceased to function?

A

75%

203
Q

What 3 diseases can Romberg’s sign show?

A
  1. Dorsal column disease/lesion
  2. Vestibular disease
  3. Cerebellar disorders
204
Q

What are the dorsal column medial lemniscal pathways 2 cortical functions?

A
  1. Determine the shape by fine discriminating touch & proprioception of an object without sight
  2. Determine texture by vibration & slip receptors of an object without sight
205
Q

What is required for the dorsal column medial lemniscal cortical functions?

A

Somatosensory association area in parietal lobe functioning normally

206
Q

What can lesions of one of the somatosensory associated cortex cause?

A

Amorphosynthesis- unable to recognise complex object by feel on the opposite side to the lesion

207
Q

What are the 2 principle cell types in nervous tissue?

A
  1. Neurons

2. Supporting cells (neuroglia)

208
Q

What is the structural & functional unit of the nervous system?

A

Neuron

209
Q

What are the 3 different types of neurons?

A
  1. Multipolar
  2. (Pseudo)unipolar
  3. Bilpolar
210
Q

What is Nissl stain used for?

A
  • Stains rough endoplasmic reticulum & polyribosomes

- Important in protein synthesis

211
Q

Where is there a lack of Nissl substance usually when dying neuron?

A

Axon

212
Q

List the 6 layers of the cerebral cortex (neocortex) from top to bottom?

A
  1. Molecular
  2. External granular
  3. External pyramidal
  4. Internal granular
  5. Internal pyramidal
  6. Multiform
213
Q

Are pyramidal & granule neurons unique to the cortex?

A

NO

214
Q

List the 3 layers of the cerebellar cortex from top to bottom?

A
  1. Molecular
  2. Purkinje
  3. Granule
215
Q

What cells lie within each (3 layers) layer of the cerebellar cortex?

A
  1. Molecular: basket cells, stellate cells, fibres
  2. Purkinje: Purkinje cells
  3. Granule: granule cells, golgi cells
216
Q

Describe the Purkinje neurons in the cerebellum?

A
  • Multipolar
  • Largest cell in cerebellum
  • Pear-shaped cell bodies
  • Dendritic tree expands into molecular layer
  • Receive afferent info from other areas of CNS
217
Q

What is the function of Neuroglia cells?

A

Metabolism & support of neurons

218
Q

What are the neuroglia cells in the CNS?

A
  • Astrocytes
  • Oligodendroglia
  • Ependymal cells
  • Microglia
219
Q

What are the neuroglia cells in the PNS?

A
  • Schwann cells

- Satellite cells

220
Q

What are the 4 different types & location of Astrocytes in the CNS?

A
  1. Fibrous (white matter)
  2. Protoplasmic (grey matter)
  3. Müller glia (retina)
  4. Radial glia (specialised)
221
Q

What size of solutes are not allowed to pass the blood-brain barrier?

A

> 500daltons MW

222
Q

What is the integrity of the blood-brain barrier highly dependent on?

A

Astrocyte “end feet”

223
Q

What are Ependymal cells?

A

Ciliated cuboidal epithelial cells which line ventricle as part of plexus & secrete CSF

224
Q

What is Cerebrospinal fluid (CSF)?

A

Clear, cell-free fluid produced in choroid plexus

225
Q

What is the purpose of Microglia?

A
  • Immune function within CNS
  • Phagocytose debris in response to injury
  • Release cytokines
226
Q

What are 2 diseases which can affect oligodendrocytes in the CNS?

A
  1. Multiple sclerosis

2. Leukodystrophies

227
Q

What % of lipid does myelin consist of?

A

~80%

228
Q

Describe the action potentials in unmyelinated axons?

A

“Continuous conduction” of action potentials due to passive current flow (low conduction)

229
Q

What are examples of unmyelinated axons?

A

Sensory fibres carrying pain, temp, itch

230
Q

What are individual ganglion cells surrounded by?

A

Layer of flattened satellite (fibroblast) cells

231
Q

What are ganglia?

A

Aggregations of nerve cells outside the CNS

232
Q

Describe the arrangement of Peripheral nerve?

A

Numerous nerve fibres collected into bundles

233
Q

Peripheral nerve bundles surrounded by thick sheath of _______, each bundle then surrounded by _______, each nerve fibre surrounded by _______?

A
  1. Epineurium
  2. Perineurium
  3. Endoneurium
234
Q

Describe the histology of cell bodies of multipolar motor neurons?

A
  • Large
  • In ventral horn of spinal cord
  • Pale staining nucleus & prominent nucleolus & nissl bodies
235
Q

Can peripheral nerve be repaired after injury?

A

YES- large degree of regeneration due to intrinsic capabilities

236
Q

Can CNS axons be repaired after injury?

A

NO

237
Q

What process exists in both CNS & PNS following trauma?

A

Wallerian degeneration

238
Q

What is Wallerian degeneration?

A
  • Clears debris & lays foundation for regrowing nerve fibres
  • Not efficient in CNS resulting in failed repair
239
Q

Describe the 5 steps of Wallerian Degeneratin in the PNS?

A
  1. Schwann cells become reactive, proliferate due to injury
  2. Macrophages (& Schwann) phagocytose debris
  3. Schwann cells express/secrete growth factors & form Bands of Büngner
  4. Nerve fibres grow towards & through the Bands
  5. Nerve fibres reconnect with end organs & are remyelinated by Schwann cells
240
Q

Describe the 5 stops of Wallerian Degeneration in the CNS?

A
  1. Microglia & astrocytes become active due to injury
  2. Inflammation
  3. Macrophages remove debris (not completely)
  4. Glial scar formed by reactive astrocytes
  5. Regeneration fails as growth of transected axons is inhibited by persistent myelin debris & glial scar
241
Q

What happens to Reactive astrocytes during CNS Wallerian Degeneration after injury?

A
  • Become hypertrophic
  • Express/secrete inhibitory molecules like chondroitin sulfate proteoglycans (CSPGs)
  • Increase expression of normal molecules (GFAP)
  • Resulting in glial scar
242
Q

What does Glial scar + Myelin debris equal?

A

Area which growing axons cannot pass through

243
Q

What is the histological end result of failed CNS regeneration?

A

Growing axons turning away from the lesion &/or having reactive “end bulbs” (swellings of accumulated organelles) at their tips

244
Q

What do oligodendrocytes in the CNS do during repair?

A

Contribute to myelin debris & failed repair

245
Q

Where are glial cells of CNS & PNS segregated?

A

Glial limiting membrane at the dorsal root entry zone

MD4001 (11 decks)

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