Brainscape's Knowledge GenomeTM

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


See full index

Neuro Pathology > Nervous System Embryology and Congential Malformations > Flashcards

Nervous System Embryology and Congential Malformations Flashcards

1
Q

What embryological structure 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

When does the CNS begin to develop?

A

Beginning of the 3rd week

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

How does the CNS develop?

A

Thickening of ectoderm anterior to the primitive node = neural plate
Edges thicken and move upwards to form the neural folds
Neural tube folds migrate towards each other and fuse at the midline forming the NEURAL TUBE
Neural tube intitally open at anterior and posterior ends
Anterior (cranial/rostral) neuropore closes 18-20 somatie stage (approx. 25 days)
Posterior (caudal) neuropore closes approx. day 27

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

How do brain vesicles develop?

A

Begins with closure of anterior neuropore (approx. day 25, 18-20 somite stage )

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

What happens in the neural development in the 5th week?

A 
Prosencephalon splits into 
- telencephalon 
- diencephalon 
Mesencephalon stays the same
Rhombencephalon splits into 
- metencephalon 
- myelencephalon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Flexures of the nervous system development

A 
Cephalic flexure
- end of 3rd week 
- between midbrain and hindbrain 
Cervical flexure 
- end of 4th week 
- between hindbrain and spinal cord
Pontine flexure
- 5th week 
- in hindbrain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Parts of the neural tube

A 
Telencephalon 
Diencephalon 
Mesencephalon (Midbrain) 
Rhombecephalon (hindbrain)
- Metencephalon 
- myelencephalon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the telencephalon form into?

A

Cerebral hemispheres
Hippocampus
Basal ganglia

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

What does he diencephalon form into?

A

Thalamus
Hypothalamus
Pituitary gland
Pineal

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

What does the mesencephalon form?

A

Superior and inferior colliculi

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

What does the metencephlon form?

A

Cerebellum

Pons

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

What does the myelencephalon form?

A

Medulla

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

What does the lumen of the neural tube form?

A

Ventricular system

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

What week does CSF begin to form?

A

During the 5th week

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

What is CSF produced predominately by?

A

Choroid plexus

- in 3rd and 4th and lateral ventricles

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

Where does CSF drain into?

A

Subarachnoid space via openings in roof of the 4th ventricle

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

Where is CSF absorbed into?

A

Venous system

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

Definition of hydrocephalus

A

Accumulation of CSF leading to enlarged brain and cranium

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

What is hydrocephalus frequently due to?

A

Blocked aqueduct

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

Pathology of hydrocephalus

A

CSF is prevented from lateral and 3rd ventricles passing into the 4th ventricle so cant drain properly

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

Causes of hydrocephalus

A

Genetic
Prenatal viral infection
Intraventricular haemorrhage
Spinal bifida cystica

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

What cellular differentiation needs to be done in the neural tube?

A

Neuronal cells need to be made (neurones and glia)

Connect cells together

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

What produces most of the cells of the CNS?

A

Neuroepitheliun

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

In what month does the entire length of the vertebral column extends?

A

3rd,month

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

What does the spinal nerves become elongated to form?

A

The cauda equina

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

What does the pia mater form?

A

Terminal filum (long fibrous thread)

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

What are sympathetic and parasympathetic ganglia formed by?

A

Neural crest cells

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

Where are parasympathetic ganglion found?

A

Near or within the organs they innervate

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

Where are sympathetic ganglia found?

A

Chains along side of spinal cord
Preaortic ganglia
Sympathetic organ plexuses (in e.g. heart, lungs, GI tract)

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

What are the surface or cerebral hemispheres initially like?

A

Smooth

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

What is a sulcus?

A

Groove

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

What is a gyri?

A

Elevation

33
Q

What is lissencephaly?

A

Smooth brain

34
Q

Pathology of lissencephaly

A

Defective neuronal migration

Gyri and sulci fail to develop

35
Q

Results of lissencephaly

A 
Severe mental impairment
Failure to thrive
Seizures
Abnormal muscles tone
Affected children die before 10
36
Q

What is polymyalgia?

A

Excessive number of small gyri

37
Q

Results of polymyalgia

A

Variable degree of neurological problems

  • mental retardation
  • seizures
  • motor deficits
38
Q

Causes of microcephaly

A

Genetic
Drugs
Infection (e.g. zika)

39
Q

Results of microcepahly

A 
Intellectual impairment
Delayed motor functions/speech 
Hyperactivity 
Seizures
Balance / co cordination problems
40
Q

Causes of porencephaly

A

Postnatal stroke

Infection

41
Q

What is porencephaly?

A

CSF filled cysts or cavities

42
Q

What is schizencephaly?

A

Large clefts or slits

43
Q

Causes of schizencephaly

A

Genetic
In utero
Infection

44
Q

Results of schizencephaly

A

Paralysis
Seizures
Intellectual impairment
Developmental delay

45
Q

What is diastematomyelia?

A

Split cord manifestation where the spinal cord is split longitudinally into 2 parts

46
Q

Presentation of diastematomyelia

A 
Scoliosis
Weakness of lower extremities
Hairy patch over lower back 
Foot deformities
Loss of sensation
47
Q

Causes of intellectual impairment

A 
Genetic (e.g. Downs)
Radiation 
Infectious agents (e.g. rubella, CMV)
Birth trauma
Post natal insults
Maternal alcohol abuse
48
Q

Examples of post natal insults that would cause intellectual impairment

A

Head injury
Infections e.g. meningitis
Lead exposure

49
Q

What is closure of the neural tube essential for?

A

Normal development and function

50
Q

When does the neural tube close?

A

Begins day 18

Completed by end of 4th week (approx. day 27)

51
Q

What does failure to the neural tube to close result in? Give some examples of these

A

Neural tube defects

  • ancencephaly
  • Encephalocele
  • Spina bifida
52
Q

Pathology of ancenecephaly

A

Failure of anterior neuropore to close

53
Q

Presentation of ancenecephaly

A

Skull fails to form
Brain tissue degenerates
Incompatible with life

54
Q

What is cranioarchischisis?

A

Failure of neural tube closure along the entire neuroaxis - resulting in degeneration and death

55
Q

What is encephalocele?

A

Herniation of cerebral tissue through a defect in the skull

56
Q

Pathology of encephaloecele

A

Failure in the closure of rostral neural tube

57
Q

Types of encephaloecele

A

Fronto-nasal

Occipital

58
Q

Most common site for encephalocele

A

Occipital region

59
Q

Presentation of encephalocele

A

Variable degree of neurological deficits

Symptoms depend on location of the brain

60
Q

Pathology of spina bifida

A

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

61
Q

Types of spinda bifida

A

Spina bidifa occulta

Spina bifida Cystica

62
Q

What is the most minor form of spina bifida?

A

Spina bifida occulta

63
Q

Pathology of spina bifida occulta

A

Failure of embryonic halves of vertebral arch to grow normally and fuse
Underlying tissue is completely fine

64
Q

Where does spina bifida occulta occur?

A

L5 and L6 vertebrae

65
Q

Presentation of spina bifida occulta

A

Usually no clinical symptoms

May result in dimple with small turft of hair

66
Q

Pathology of spina bifida cystica

A

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

67
Q

Pathology of spina bifida with meningocele

A

Protrusion of meninges and CSF forming a fluid filled sac outside the spine
(Impact minimal as no neural damage)

68
Q

What is the rarest form of spina bifida?

A

Spina bifida with menigocele

69
Q

Pathology of spina bifida with meningomyelocele

A

Nerve roots and/or spinal cord included in the fluid filled CSF sac

70
Q

Presentation of spida bifida with meningomyelocele

A

Neurological deficits
Loss of sensation
Muscle paralysis
Area affected determined by level of lesion

71
Q

What is spina bifida with meningomyelocele often associated with?

A

Hydrocephalus

72
Q

What can be taken to prevent neural tube defects?

A

Folic acid supplements (400ug / day)

73
Q

Prenatal diagnosis of neural tube defects is done by….

A 
Maternal blood screening 
- AFP levels in serum
Amniocentesis 
- AFP in amniotic fluid
USS 
- anecephaly from 12 weeks
- spina bifida from 16-20 weeks
74
Q

Risk factors for neural tube defects

A 
Genetic
Nutritional 
- too little folate
- too much vitamin A 
Environmental 
- hyperthermia
- taking drugs e.g. sodium valproate
75
Q

What week does the nervous system start to develop?

A

Week 3

76
Q

Inheritance of tuberous sclerosis

A

Autosomal dominant

77
Q

Presentation of tuberous sclerosis

A

Cutaneous features
- depigmented “ash leaf” spots which fluorescence under UV light
- roughened patches of skin over lumbar spine (Shagreen patches)
- Adenoma sebaceum (angiofibroma); butterfly distribution over the nose
- fibromata beneath nails (subungual fibroma)
- Café au lait spots may be seen
Neurological features
- developmental delay
- Epilepsy
- intellectual impairment
Retinal haemorrhages
Rhabdomyomas of the heart
Gliomatous changes that occur in brain lesions
Polycystic kidneys, renal angiomyolipomata
lymphangioleiomyomatosis: multiple lung cysts

78
Q

What are axillary freckles indicative of?

A

NF type 1

Neuro Pathology (21 decks)

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