Brainscape's Knowledge GenomeTM

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


See full index

Semester 3 > Extra Yaffas Notes > Flashcards

Extra Yaffas Notes Flashcards

1
Q

where do the neural crest arise from

A

the dorsal neural tube along the entire length of the spinal cord and hindbrain

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

what gene to neural crest cells express

A

Hox genes that are limited to various spinal cord and hindbrain domains

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

what do all neural crest cells begin as

A

neuroepithelial cells and thus have all the cellular junctions and adhesive interaction that jeep epithelial cells inlace

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

what do neural crest cells have to do to move

A

must down regulate expression of these adhesive genes and undergo an epithelial-to-mesenchymal transition

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

what transcription factors to neural crest cells express

A

bHLH family members Snail1 and Snail 2 which repress expression of intercellular junctional proteins and epithelial adhesion molecules

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

when the neural crest cells reach their final destination what happens

A

they cease to express Snail1/Snail2 and other transcription factors that favour the mesenchymal migratory state

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

what do a minatory of nerve and glial cells in the CNS use as migratory guides

A

existing axon pathways

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

how do neuroblasts reach their final destination

A

use the long process of radial glia as scaffolds, travelling along the radial glial fibres in order to reach their final destinations

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

what is the nervous system patterned along

A

both the DV and AP axes

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

what is the DV axis set up by

A

by the TGF-beta family and Shh

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

what is the AP axis set up by

A

retinoic acid, FGF, and homeotic genes

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

what is dysraphism

A

incomplete fusion - where there is continuity between the posterior neuroextoderm and the cutaneous ectoderm

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

when is the abnormal increase in maternal serum alpha fetoprotein detected

A

16-18 weeks

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

what does maternal serum screening not detect

A

closed defects and is less sensitive in women taking sodium valproate

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

when can anencephaly be detected

A

12th weel

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

when can SB be detected

A

16-20weels

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

what is the banana sign

A

refers to the shape of the cerebellum, owing to caudal tail displacement

18
Q

when does the lemon sign disappear

A

24 weeks

19
Q

what is the treatment for adults with type 1 oe 2 chairi malformations

A

posterior fossa decompression surgery to create more space for the cerebella, and to relieve pressure on the spinal cord

20
Q

what is the absent brain replaced by in anencephaly

A

malformed cystic tissue

21
Q

what is a cephalocele

A

herniation of cranial contents through a skull defect

22
Q

what are the several subtypes of cephaloceles

A
  1. cranial meningocele: contains ony meninges
  2. encephalocele: contains brain tissue
  3. ventriculocele: contains part of the ventricle within the herniated portion of the brain
23
Q

what are cephaloceles also associated with

A

other brain abnormalities such as agenesis pf the corpus callosum or abnormal gyration

24
Q

what is holoprosencephaly

A

occurs when the embryonic prosencephalon does not undergo segmentation and cleavage - into telencephalon and diencephalon

25
Q

what is abnormal in holoprosencephaly

A

the anterior midline brain, cranium and face are abnormal

26
Q

what is the holoprosencephaly caused by

A

defects of the sonic hedgehog gene

27
Q

what can hydrocephalus result from

A
  1. excess CSF production
  2. decrease in reabsorption via the arachnoid granulations
  3. obstruction of flow at any point in the ventricles or subarachnoid space
28
Q

what is hydrocephalus catagorised into in clinical practice

A
  1. communicating hydrocephalus: this is caused by impaired CSF reabsorption in the arachnoid granulations, obstruction of flow in the subarachnoid space, or excess CSF production
  2. obstructive (non communicating) hydrocephalus: caused by obstruction of flow within the ventricular system
29
Q

which nerve may be affected in hydrocephalus

A

the sixth cranial nerve - affects eyes

30
Q

what is bipolar type 1

A

this is defined as one of more manic or mixed (signs of mania and depression) episodes - severe bipolar

31
Q

what is bipolar 2

A

this is defined as a depressive episode with at least one episode of hypomania - milder form of bipolar

32
Q

what is the average onset age of bipolar

A

21

33
Q

sodium valporate (Depakote) mode of action

A

1) maybe increasing gamma levels in the brain
2) altering the properties of voltage dependent sodium channels

34
Q

mechanism of valproate in more detail

A

Valproic Acid dissociates to the valproate ion in the GI tract and then binds to and inhibits GABA transaminase.
The drug’s anticonvulsant activity may be related to increased brain concentrations of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter in the CNS, by inhibiting enzymes that catabolize (break down) GABA or block the reuptake of GABA into glia and nerve endings.
Valproic Acid may also work by suppressing repetitive neuronal firing through inhibition of voltage-sensitive sodium channels.

35
Q

what are glia

A

connective tissue of the nervous system, consisting of several different types of cell associated with neurones

36
Q

by what ratio do glia outnumber neurones

A

3 to 1

37
Q

what roles do glial cells play in the nervous system

A
  • maintaining the ionic Millieu of nerve cells
  • modulating the rate of nerve signal propagation
  • modulating synaptic action by controlling the uptake of neurotransmitters at or near the synaptic cleft
  • aiding in recovery from neural injury
38
Q

what are the three types of glial cells in the CNS

A
  1. astrocytes
  2. oligodendrocytes
  3. microglial cells
39
Q

what are astrocytes

A

these are restricted to the brain and spinal cord. have elaborate local processes that give these cells a star like appearance. the main function of astrocytes is to maintain, an appropriate chemical environment for neuronal signalling and maintain the blood brain barrier

40
Q

what are oligodendrocytes

A

these are restricted to the brain and spinal cord, lay down a laminated, lipid rich wrapping called myelin around some axons. in the PNSs, the cells that elaborate myelin are called Schwann cells

41
Q

what are microglial ells

A

primary scavenger cells that remove cellular debris from sites of injury or normal cell turnover. in addition, microglia, like their macrophage counterparts, secrete signalling molecules - particularly a wide range of cytokines that are also produced by immune system cells that can modulate local inflammation and influence cell survival or death

42
Q

what happens to the number of microglia following brain damage

A

the number of microglia increases at site of injury drastically. some of these cell proliferate from microglia resident in the brain, while others come from macrophages that migrate to the injured area and enter the brain via local disruptions to the blood brain barrier

Semester 3 (94 decks)

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