Module 8 : Normal Fetal Anatomy - Brain Flashcards Preview

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Flashcards in Module 8 : Normal Fetal Anatomy - Brain Deck (59)
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1
Q

embryology of brain

A
  • develops from a thickened area of the ectoderm called neural plate at 4.5 weeks LMP
2
Q

when does cranial end closes when

A
  • day 38 (LMP)
3
Q

when’d does caudal when

A
  • day 40 (LMP)
4
Q

parts of the neural tube

A
  • rostral end is the cephalic end
  • caudal end is inferior part
  • rostral and caudal area is most common to have defects
5
Q

rostral differentiation

A
  • differentiates into three primary vesicles
    + prosencephalon
    + mesencephalon
    + rhombencephalon
6
Q

prosenceohalon

A
  • forebrain
  • divides into
    + telencephalon
    + diencephalon
7
Q

prosencephalon - telencephalon

A
  • cerebral hemispheres
8
Q

prosencephalon - diencephalon

A
  • thalamus and hypothalamus
9
Q

mesencephalon

A
  • midbrain
  • smallest portion of brain
  • creates the cerebral peduncles
  • located anterior to aqueduct of sylvius
  • anterior to cerebellum vermis
  • posterior to thalami
10
Q

rhombencephalon

A
  • hindbrain
  • cerebellum and pons (metencephalon)
  • medulla oblongata (myelencephalon)
11
Q

cerebellum and pons (metencephalon)

A
  • pons located between the midbrain and medulla oblongata
  • pons connects the cerebrum to the cerebellum
  • pons means bridge
12
Q

medulla oblongata (myelencephalon)

A
  • extends from pons to spinal cord

- regulates heart rate and respiratory rhythm and blood pressure

13
Q

rhombencephalon - ultrasound

A
  • very first identified structure in embryo

- at 7 or 8 weeks

14
Q

cerebrum - function

A
  • learned behaviour and personality
15
Q

cerebrum - lobes

A
  • 2 frontal lobes
  • 2 parietal lobes
  • 2 temporal lobes
  • 2 occipital lobes
  • 2 insula
16
Q

frontal lobe - function

A
  • personality

- voluntary function

17
Q

parietal lobe - function

A
  • peripheral sensory
18
Q

temporal lobe - function

A
  • smell
  • taste
  • hearing
19
Q

occipital lobe - function

A
  • vision
20
Q

insula lobe - function

A
  • motor and sensory function of organs
  • don’t see on surface
  • medial aspect of brain
21
Q

ventricles

A
  • 4 connecting cavities within the cerebral hemispheres and brain stem
  • continuous with the spinal cord cavity
  • all cavities contain CSF and choroid plexus
22
Q

ventricular system

A

lateral ventricles&raquo_space; foramen of Monroe (INTERVENTRICULAR FORAMEN)&raquo_space; third ventricle&raquo_space; aqueduct of sylvius (CEREBRAL AQUADUCT)&raquo_space; fourth ventricle&raquo_space; foramen of magendie and luschka&raquo_space; spinal cord

23
Q

foramen of magendi

A
  • medial aspect og fourht ventricle

- connects to spinal cord

24
Q

foramen of luschka

A
  • 2 foramen
  • lateral aspect of the fourth ventricle
  • connects with the meniginges of the brain
25
Q

lateral ventricles

A
  • largest

- each body has three horns

26
Q

lateral ventricles location

A
  • in the cerebral hemispheres
27
Q

latera ventricles - horns

A
  • anterior (frontal horns)
    + no choroid plexus locates anterior to foramen of monro
  • posterior (occipital) horn
  • inferior (temporal) horn
28
Q

lateral ventricles - trigone

A
  • aka atria

- junction of body , occipital and temporal horns form trigone

29
Q

third ventricle - communication

A
  • thin
  • communicates with lateral ventricles via foramen of monro (interventricular foramen)
  • communicates with fourth ventricle via aqueduct of sylvius (cerebral aqueduct)
30
Q

third ventricles - location

A
  • located between the thalami and inferior to the corpus callosum
31
Q

fourth ventricle - location

A
  • located within the brain stem
  • anterior to the cerebellum
  • continuous with the central canal and the spinal cord via the foramen of magendie
32
Q

fourth ventricle - communication

A
  • communicates with the subarachnoid spaces of the meninges via the foramen of luschka
33
Q

choroid plexus - function

A
  • produces CSF
34
Q

choroid plexus location - lateral ventricles

A
  • in the body of the lateral ventricles
35
Q

choroid plexus location - third ventricle

A
  • in the roof of the third ventricle
36
Q

choroid plexus location - fourth ventricle

A
  • superior side walls of the fourth ventricle
37
Q

corpus callosum

A
  • bridge of WHITE matter nerve fibres that connects the right and left cerebral hemispheres
38
Q

corpus callosum - location

A
  • found deep in longitudinal fissure
  • difficult to see in utero
  • seen in neonates while scanning over the anterior fontanelle
39
Q

corpus callosum - four parts

A
- front to back 
  \+ rostrum 
  \+ genu
  \+ body
  \+ splenium
40
Q

meninges

A
  • protective areas of the brain
  • from inner to outer
    + pia mater
    + arachnoid mater
    + dura mater
  • surrounds the brain all the convolutions (gyri) and grooves (sulci)
41
Q

sulci

A
  • grooves in the cerebral hemisphers
  • allow for more cerebral cortex grey matter to develop
    + increases surface area of brain
42
Q

gyri

A

convolutions of the cerebral surface (bumps)

43
Q

cavum septum pellucidi

A
  • anterior and slightly superior to thalamus
  • separates the anterior horns of the lateral ventricle
  • important landmark fo the BPD where the cranium is measured
44
Q

cavum septum pellucidum - ultrasound

A
  • want to see the box NOT the equal sign
45
Q

cavum vergae

A
  • found at the posterior tip of the septi pellucidi

- closes around 26 weeks

46
Q

cisterna magna - location

A
  • located between the cerebellum and the occipital bone
47
Q

cisterna magna - fucntion

A
  • contains CSF
  • visualized in normal fetus
  • can be absent in fetus with spina bifida
  • larges cistern in brain
48
Q

cisterna magna normal measurement

A
  • < 10mm
49
Q

cisterna magna - ultrasound

A
  • sometimes Linear echoes can be seen within it these are dural folds that attach to the falx cerebelli
50
Q

cisterna magna enlarged

A
  • marker for Down syndrome
51
Q

cisterna magna absent

A
  • marker for spina bifida
52
Q

falx cerebri

A
  • double layer of dura mater that separates the cerebral hemispheres
  • layer of the meninges
  • FALX CEREBRI RUNS WITHIN THE LONGITUDINAL FISSURE ( INTERHEMISPHERIC FISSURE)
53
Q

thalamus

A
  • part of diencephalon
  • main relay centre for sensory impulses
  • impulses form the right side of the body gp through the thalamus to the left cerebral hemispheres
  • GREY MATTER
  • posterior to cavum septum pellucidi
54
Q

cerebellum - location

A
  • beneath the occipital lobes of the brain
  • in the posterior fossa
  • posterior to the pons and medulla oblongata
55
Q

cerebellum - hemispheres

A
  • two lateral hemispheres separated by the cerebellar vermis and falx cerebelli
56
Q

cerebellum - function

A
  • coordination of movement
57
Q

cerebellar vermix - ultrasound

A
  • bright echogenic
58
Q

tentorium

A
  • dura mater that separates the occipital lobes of the cerebrum from the cerebellum
  • seen best on the neonatal cranial ultrasounds
  • cerebellum is underneath
  • Christmas tree look
59
Q

circle of willis

A
  • middle cerebral artery is closest to the transducer
  • 0 angulation
  • in asymmetric IUGR
    + middle cerebral artery less resistive diastolic flow
    + increase flow to make sure oxygen getting to the brain
  • no doppler when fetus is breathing