Brainscape's Knowledge GenomeTM

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


See full index

Neurology > Lecture 25 Embryology and Congenital Malformation > Flashcards

Lecture 25 Embryology and Congenital Malformation Flashcards

1
Q

Where does the nervous system develop from

A

The embryonic ectoderm

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

What week does the CNS appear

A

3rd week

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

Define the neural plate

A

thickening of ectoderm anterior to the primitive node

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

Define the Neural folds

A

Edges of the neural plate thicken and move upwards to form the neural folds

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

Neural fold migrate towards each other to form what?

A

Neural tube

Remains open at anterior and posterior ends

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

When does the anterior (cranial/rostral) neuropore close

A

Dat 25

18-20 somite stage

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

When does the posterior (caudal) neuropore close

A

Day 27

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

Where is neural tube closure initiated

A

Several points along A-P axis

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

When does neural tube closure begin

A

Day 18

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

When is neural tube closure completed

A

Day 27 (end of 4th week)

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

How many closure sites are there in humans

A

Up to 5

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

Failure of neural tube to close properly leads to what neural tube defects

A

Anencephaly
Encephalocoele
Spina bifida

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

How common is Anencephaly

A

1:1500

4 x more common in women

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

What causes Anencephaly

A

Failure of anterior neuropore to close
Skull fails to form
Brain tissue degenerates
incompatible with life

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

Define Craniorachischisis

A

Failure of neural tube closure along entire neuraxis

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

How common is Encephalocoele

A

1:4000 births

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

What is Encephalocoele

A

Herniation of cerebral tissue though a defect in the skull

Failure in closure of rostral neural tube

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

Where is Encephalocoele most common and where else can it be found

A

Occipital region

Fronto-nasal region

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

What is the cause of Spina Bifida

A

Defective closure of the caudal neural tube. Affects tissues overlying the spinal cord. Non fusion of vertebral arches

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

What are the types of Spina bifida

A 
Spina bifida with meningomyelocele
Spina bifida with myeloschisis
Spina Bifida Occulta
Spina Bifida Cystica
Spina bifida with meningocele
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Define Spina bifida with meningomyelocele

A

This is when the neural tube has failed to close and the neural tissue is exposed on the baby’s back

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

Define Spina bifida with myeloschisis

A

The nerve tissue is here fully bare and a dermal or meningeal covering is absent

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

Define Spina Bifida Occulta

A

Most minor form

Failure of embryonic halves of vertebral arch to grow normal and fuse

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

What are the features of Spina Bifida Occulta

A

No clinical symptoms

Dimple with small tuft of hair

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

What vertebral level does spina bifida occult occur

A

L5 and L6

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

What is Spina Bifida Cystica

A

Protrusion of spinal cord and/or meninges through the defect in the vertebral arches

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

How common is Spina Bifida Cystica

A

1:1000

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

What is Spina bifida with meningocele

A

Rarest form

Protrusion of meninges and CSF

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

What is Spina bifida with meningomyelocle associated with

A

Hydrocephalus

Neurological deficits- loss of sensation and muscle paralysis(loss of sensation and muscle paralysis)

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

What is the most severe form of spina bifida

A

Myeloschisis- • Spinal cord in affected area open due to failure of neural folds to fuse

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

When does the brain vesicles develop

A

Begins with closure of anterior neuropore (~day 25; 18 – 20 somite stage)

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

How is Spina bifida prevented

A

Folic acid supplements

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

How is Spina bifida diagnoses pre-natal

A

Maternal blood screening- AFP from foetal liver (16-20 weeks)
Aminocentesis (AFP in amniotic fluid)
US- anencephaly (12 weeks ) and spina bifida (16-20 weeks )

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

The forebrain develops from what vesicle

A

Prosencephalon

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

The Midbrain develops from what vesicle

A

Mesencephalon

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

The hindbrain develops from what vesicle

A

Rhombencephalon

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

What week does the 3 primary brain vesicles develop

A

4th week

38
Q

What week does the 5 secondary brain vesicles develop

A

5th week

39
Q

What is the Prosencephalon (Forebrain) made up in the 5th week

A

Telencephaln

Diencephalon

40
Q

What is the Rhombencephalon (hindbrain) made up of in the 5th week

A

Metencephalon

Myelencephalon

41
Q

When does the cephalic flexure develop and where is located

A

between midbrain (mesencephalon) and hindbrain (rhombencephalon)

42
Q

When does the cervical flexure develop and where is it located

A

End of 4th week

Between hind brain and spinal cord

43
Q

When does the Pontine flexure develop and where is it located

A 
5th week
In hindbrain (Rhombencephalon) between mesencephalon and Myelencephalon
44
Q

What develops from the telencephalon (forebrain)

A

Cerebral hemispheres
Hippocampus
Basal ganglia

45
Q

What develops from the Diencephalon (forebrain)

A

Thalamus
Hypothalamus
Pituitary gland
Pineal

46
Q

What develops from the Mesencephalon (midbrain)

A

Superior and inferior colliculi

47
Q

What develops from the Mesencephalon (hind brain)

A

Cerebellum, Pons

48
Q

What develops from the Myelencephalon (hind brain)

A

Medulla

49
Q

What forms the ventricular system

A

Lumen of neural tube

50
Q

The lateral ventricle is formed where

A

Telencephalon

51
Q

The 3rd ventricle is formed from

A

Diencephalon

52
Q

The cerebral aqueduct (of sylvius) develops where

A

Mesencephalon

53
Q

Where does the 4th ventricle is located

A

Mesencephalon

Myelencephalon

54
Q

What connects the lateral and 3rd ventricle

A

Intraventricular foramina (of Monro)

55
Q

When does CSF begin to be produced

A

5th week

56
Q

Where is the CSF produced

A

Choroid plexus (3rd, 4th, lateral ventricles)

57
Q

Where does the CSF drain into

A

Subarachnoid space via openings in roof of 4th ventricle and absorbed by arachnoid villi

58
Q

Define Hydrocephalus

A

Accumulation of CSF due to frequently due to blocked aqueduct. prevents CSF from lateral and 3rd ventricles passing into the 4th ventricle and can’t drain it properly

59
Q

What are the clinical features of Hydrocephalus

A

Enlarged brain and cranium

60
Q

What are the causes of Hydrocephalus

A

Genetic
Prenatal viral infection
Intraventricular haemorrhage
Spina Bifida Cystica

61
Q

What is the purpose of cellular differentiation in the neural tube

A

Need to make neuronal cells (neuron and glia) and connect cells together. begins early embryogenesis

62
Q

Describe the lining of neural tube

A
  • Initially a single layer of rapidly dividing neuroepithelial cells.
  • Pseudostratified epithelium.
  • Divide at ventricular surface.
63
Q

What produces most cells of the CNS

A

Neuroepithelium

64
Q

What doe Neuroepithelial cells develop into

A

Neuron
Astrocytes (protoplasmi, fibrous)
Oligodendrocyte

65
Q

What produces Microglia

A

Mesenchymal cells that migrate into CNS

66
Q

What forms the PNS neurone and glia

A

Neural crest

67
Q

Name some Neural Crest derivatives

A
  • Sensory neurons
  • Autonomic neurons (sympathetic and parasympathetic ganglia)
  • Schwann cells + satellite cells of ganglia
  • Aortic plexuses (nerves surrounding the aorta)
  • Endocrine cells (chromaffin cells of adrenal medulla; calcitonin producing cells of carotid body; parafollicular cells of thyroid).
  • Enteric nervous system
  • Pigment cells (melanocytes) – all pigment except RPE
  • Leptomeninges of anterior brain (prosencephalon and part of mesencephalon)
  • Non-neural head structures (including bone, cartilage and connective tissue).
  • Teeth (dental papilla; odontoblasts)
  • Iris muscle and pigment; ciliary muscles
  • Corneal stroma
  • Inner ear development
  • Regions of the heart + walls of large arteries
  • “4th germ layer”
68
Q

Neural crest extend 2 processes

A

Peripheral process–> body

Central process–> dorsal horn of spinal cord

69
Q

Motor component of spinal cord is derived from where

A

Neural tube

70
Q

Describe the position of the spinal cord 3 months into development

A

Extends entire length of vertebral column

71
Q

Vertebral column and dura mater grow more rapidly than what? what is the result

A

Spinal cord
Spinal cord at high levels )newborn L2/L3)
Adult -L1

72
Q

Spinal nerves become elongated and form

A

Cuada equina

73
Q

The Pia mater forms what structure

A

Terminal filum

74
Q

What is the purpose of cortical folding

A

Saves space

brings together brain regions that would otherwise be far apart and optimises brain wiring and organisation

75
Q

What is the the initial appearance of the cerebral hemisphere and what causes it to change

A

Initially smooth

Sulci and Gyri cause it to become a more complex pattern

76
Q

At what week is the cerebral hemisphere smooth

A

14 weeks

77
Q

At what week does the cortical folding begin

A

26 weeks

78
Q

Define Lissencephaly

A

Rare brain disorder where the brain is smooth due to gyro and sulk failing to develop.

79
Q

What causes Lissencephaly

A

Defective neuronal migration

80
Q

What is the consequence of Lissencephaly

A

Severe mental impairment, failure to thrive, seizures and abnormal muscle tone. Die before 10 Y.O

81
Q

Define Polymicrogyria

A

Excessive number of small gyri

mental retardation, seizes, motor deficits

82
Q

What is Micorcephaly and what causes it

A

Reduced brain and skull size

Genetics, drugs, infection (zika)

83
Q

What are the clinical signs of Microcephaly

A

Intellectual impairment, delayed motor functions/speech, hyperactivity, seizures, balance/co-ordination problems etc.

84
Q

What is Aegenesis Corpus Callosum

A

complete or partial absence of the corpus callosum.

85
Q

What are the clinical signs of Aegenesis Corpus Callosum

A
  • Effects range from subtle – severe

* Cognitive and social difficulties  intellectual impairment, seizures, hypotonia

86
Q

What is Porencephaly

A

CSF filled cysts and cavities,

87
Q

What is the cause and consequence of Porencephaly

A

Usually from stroke or infection

Delayed growth and development, seizures, hypotonia, intellectual impairment

88
Q

What is Schizencephaly

A

Large clefts or slits in the brain

89
Q

What causes Schizencephaly

A

Genetic
In utero stroke
Infection
Paralysis, seizures, intellectual impairment, development delay

90
Q

What is Diastematomyelia

A

• Spinal cord split longitudinally into 2 parts

91
Q

What is Diastematomyelia associated with

A

Vertebral abnormalities

Scoliosis, weakness of lower extremities, hairy patch over lower back, foot deformities, loss of sensation.

92
Q

Name some causes of intellectual impairment

A 
Genetic- Down's Syndrome
Radiation
Infectious agents(rubella, , toxoplasmosis, cytomegalovirus)
Birth trauma
Postnatal insults
Maternal alcohol abuse

Neurology (44 decks)

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