Systemic embryology and congenital malformations Flashcards Preview

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Flashcards in Systemic embryology and congenital malformations Deck (26)
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1
Q

Three layers in trilaminar embryonic disc

A

Ectoderm, mesoderm, endoderm

2
Q

Parts of body from ectodermal germ layer

A

Skin/ear/nose/eye

Contact with outside world

3
Q

How does neural tube form?

A

Ectoderm - neuroectoderm

4
Q

3 parts of mesodermal germ layer

A

Paraxial, intermediate, lateral plate

5
Q

What are neuromeres?

A

Somitomeres in association with neural plate

6
Q

What do neuromeres do?

A

Contribute to connective tissue in head

7
Q

What are somites?

A

Somitomeres on either side of neural tube

8
Q

What are somites made from?

A

Paraxial mesoderm

9
Q

At what rate do new somites appear?

A

3 pairs per day

10
Q

How many somites formed at end of 5th week?

A

42-44

11
Q

What does intermediate mesoderm form?

A

Urogenital system - primordial germ cells, gametes and gonads

12
Q

What does lateral plate mesoderm split into?

A

Somatic (parietal) and visceral (splanchnic)

13
Q

What does parietal layer do?

A

Lines body walls

14
Q

What does lateral plate mesoderm form?

A

Skin, ribs, limbs, blood cells, blood vessels

15
Q

What does endodermal germ layer form?

A

GI tract, bladder, urethra, auditory tube,

16
Q

What is morphogenesis?

A

Form shaping process in embryo - differential tissue growth

17
Q

What is dysmorphogenesis?

A

developing abnormally, outside arbitrary range

18
Q

What is deformation?

A

Secondary morphologic defects that are imposed upon an organ or body part due to mechanical forces over a prolonged period - an indirect effect e.g. club feet

19
Q

Symtoms of Down’s syndrome

A
  • Trisomy 21
  • Flat facial feature with small nose
  • Reduced muscle tone (hypotonia)
  • Upwards/downward slant to eye
  • Large tongue that sticks out
  • Single deep dcrease across palm
  • Hyper-flexibility of joints
20
Q

Symptoms of foetal alcohol syndrome

A
  • Short palpebral fissure lengths
  • Smooth philtrum
  • Thin upper lip
  • Brain damage
21
Q

What is teratology?

A

Study of birth defects/congenital malformations

22
Q

Where is inhibin A produced?

A

Foetus and placenta

23
Q

Sacrococcygeal teratomas

A

Remnants of primitive streak persist and form tumours

24
Q

Situs inversus

A

Transposition of visceral organs

25
Q

Sirenomelia

A

Legs stuck together like mermaid

26
Q

Caudal dysplasia

A

due to mesodermal insufficiency in caudal-most region of embryo which contributes to formation of lower limbs, urogenital system and lumbosacral vertebrae
- Affected child exhibits a variable range of defects including: hypoplasia and fusion of lower limbs, vertebral abnormalities, renal agensis, imperforate anus, abnormalities or genital organs