Brainscape's Knowledge GenomeTM

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


See full index

Keeping People Healthy > Embr: signalling in development > Flashcards

Embr: signalling in development Flashcards

You may prefer our related Brainscape-certified flashcards:
People You Should Know flashcards
1
Q

What is an inducer? what does it do?

A

An inducer is a population of cells or tissue that acts on another tissue (the responder) to stimulate a specific developmental pathway in the responding tissues

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

What signalling molecules are involved in induction?

A

Protein/peptide growth factors

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

what does the notochord become in adults?

A

nucleus pulposus in IV disk

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

Describe notochord formation

A

Area under the ectoderm thickens and a transient patterning structure is formed = notochord

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

What signals are released from the Notochord?

A

Chordin and Noggin

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

Describe the roles of Chordin and noggin in neural tube development

A

Noggin: inactivates BMP4. Absence of BMP4 causes patterning of neural tube and somites.
CHordin: BMP antagonist

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

Describe the formation and closure of the neural tube

A

Notochord sends signals to the overlying ectoderm to thicken and form the neural plate.
After the plate is induced, the neural plate lengthens
Lateral edges elevate to form the neural folds.
Depressed mid region forms the neural groove
The folds approach each other in the midline and fuse = NEURAL TUBE
Tube sinks in and overlying ectoderm repairs

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

What do cells of the neural plate make up?

A

Neuroectoderm

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

What are the last areas of the neural tube to close? when do they close?

A

Top and bottom
Anterior closes - day 25
Posterior closes - day 27

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

list the 3 mechanisms involved in ending the neural plate to form the neural tube? briefly describe two

A

Cells wedging - microtubules and microfilaments change shape
Hinge points
Extrinsic forces - pushing of surface ectoderm, adhesion with notochord

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

where does closure of the neural tube begins and how does it proceed?

A

Begin in the cervical region

proceeds in caudal and cephalic directions.

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

what are neuropores?

A

open ends of the neural tube

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

What is the role of SHH in neural tube folding?

A

Notochord releases SHH to the neural tube.
Ventral cells respond by making floor plate of the neural tube.
Once this is made, the floor plate can make its own SHH and is responsible for the development of motor neurons on each side of the neural tube

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

What is a neural tube defect?

A

Result of failure or incomplete closure of the neural tube

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

What is failure of anterior neuropore closure called?

A

Anencephaly

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

What is failure of posterior neuropore closure called?

A

Spina Bifida

17
Q

In what region does Spina Bifida most commonly occur?

A

Dorsolateral region

18
Q

what are the 2 types of hinge points? where are they ?

A

Median hinge point (where neural groove was)

Dorsolateral hinge point (to close the tube off)

19
Q

Describe Spina Bifida occulta

A

less severe, hidden, vertebrae are not completely fused

20
Q

Describe Spina Bifida cystica - meningocele

A

Sac protruding from spinal cord contains spinal fluid

21
Q

Describe Spina Bifida myelomeningocele

A

Most severe, can result in paralysis or nerve root damage

22
Q

what can help prevent spina bifida?

A

folic acid

23
Q

raised levels of what protein can be used to diagnose SB?

A

Alpha-feto protein

24
Q

what signalling molecule does SHH switch off?

A

noggin

25
Q

In what area of the neural tube is the DLHP not needed? why?

A

Upper region - they come together easily themselves

26
Q

What is needed to stop DLHP in the upper region

A

We want BMP2 to inhibit DLHP. So we need to switch off noggin so that it does not inhibit BMP 2. Need lots of SHH to switch off noggin.

27
Q

In what area of the neural tube is the DLHP needed? why?

A

In the lower region as it is bigger and wider so needs help closing.

28
Q

What is needed to keep DLHP in the upper region

A

We want DLHP, so need to inhibit BMP2. For this, we need noggin and low levels of SHH

29
Q

How can SHH problems cause neural tube defects

A

High levels of SHH would mean no DLHP so can result in failure of closure of neural tube

30
Q

what re the 2 genes needed in SHH signalling

A

patched and smoothened

31
Q

Whats is the role of patched?

A

Patched is a negative regulator that inhibits smoothened. This blocks downstream signalling via Gli which would eventually transduce the SHH signal

32
Q

What happens is SHH binds to patched?

A

It no longer inhibits smoothened, so smoothened can upregulate downstream signalling so Gli can bind to DNA and transduce the SHH signal.

Keeping People Healthy (5 decks)

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