Module 8 : Normal Fetal Anatomy - Brain Flashcards
(59 cards)
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»_space; foramen of Monroe (INTERVENTRICULAR FORAMEN)»_space; third ventricle»_space; aqueduct of sylvius (CEREBRAL AQUADUCT)»_space; fourth ventricle»_space; foramen of magendie and luschka»_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
lateral ventricles
- largest
| - each body has three horns
26
lateral ventricles location
- in the cerebral hemispheres
27
latera ventricles - horns
- anterior (frontal horns)
+ no choroid plexus locates anterior to foramen of monro
- posterior (occipital) horn
- inferior (temporal) horn
28
lateral ventricles - trigone
- aka atria
| - junction of body , occipital and temporal horns form trigone
29
third ventricle - communication
- thin
- communicates with lateral ventricles via foramen of monro (interventricular foramen)
- communicates with fourth ventricle via aqueduct of sylvius (cerebral aqueduct)
30
third ventricles - location
- located between the thalami and inferior to the corpus callosum
31
fourth ventricle - location
- located within the brain stem
- anterior to the cerebellum
- continuous with the central canal and the spinal cord via the foramen of magendie
32
fourth ventricle - communication
- communicates with the subarachnoid spaces of the meninges via the foramen of luschka
33
choroid plexus - function
- produces CSF
34
choroid plexus location - lateral ventricles
- in the body of the lateral ventricles
35
choroid plexus location - third ventricle
- in the roof of the third ventricle
36
choroid plexus location - fourth ventricle
- superior side walls of the fourth ventricle
37
corpus callosum
- bridge of WHITE matter nerve fibres that connects the right and left cerebral hemispheres
38
corpus callosum - location
- found deep in longitudinal fissure
- difficult to see in utero
- seen in neonates while scanning over the anterior fontanelle
39
corpus callosum - four parts
```
- front to back
+ rostrum
+ genu
+ body
+ splenium
```
40
meninges
- 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
sulci
- grooves in the cerebral hemisphers
- allow for more cerebral cortex grey matter to develop
+ increases surface area of brain
42
gyri
convolutions of the cerebral surface (bumps)
43
cavum septum pellucidi
- 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
cavum septum pellucidum - ultrasound
- want to see the box NOT the equal sign
45
cavum vergae
- found at the posterior tip of the septi pellucidi
| - closes around 26 weeks
46
cisterna magna - location
- located between the cerebellum and the occipital bone
47
cisterna magna - fucntion
- contains CSF
- visualized in normal fetus
- can be absent in fetus with spina bifida
- larges cistern in brain
48
cisterna magna normal measurement
- < 10mm
49
cisterna magna - ultrasound
- sometimes Linear echoes can be seen within it these are dural folds that attach to the falx cerebelli
50
cisterna magna enlarged
- marker for Down syndrome
51
cisterna magna absent
- marker for spina bifida
52
falx cerebri
- double layer of dura mater that separates the cerebral hemispheres
- layer of the meninges
- FALX CEREBRI RUNS WITHIN THE LONGITUDINAL FISSURE ( INTERHEMISPHERIC FISSURE)
53
thalamus
- 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
cerebellum - location
- beneath the occipital lobes of the brain
- in the posterior fossa
- posterior to the pons and medulla oblongata
55
cerebellum - hemispheres
- two lateral hemispheres separated by the cerebellar vermis and falx cerebelli
56
cerebellum - function
- coordination of movement
57
cerebellar vermix - ultrasound
- bright echogenic
58
tentorium
- 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
circle of willis
- 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
