Dev Of Midline Structures

Question 1

Which part of the PG is neuro and endocrine?

Answer 1

PP- neuroendocrine

AP- endocrine

Question 2

What connects the hyp and P?

Answer 2

Hypophysial vessels

Question 3

From what cell line/s is the PG derived from?

Answer 3

Ectoderm and neuroectoderm

Question 4

What is Rathke’s pouch? What does it create?

Answer 4

Out-pocketing of ectoderm of the stomatodeum, Eva GI nation of oropharynx, grows dorsally to dev forebrain
Creates AP

Question 5

What does the infundibulum create?

Answer 5

PP and stalk

Question 6

What tethers the tongue to the floor of the mouth?

Answer 6

Lingual frenulum

Question 7

What is the tongue derived from?

Answer 7

Component from each of the PAs

Question 8

Explain the dev of the tongue- the swelling and where they come from

Answer 8

• 2 lat swellings (PA1)
• 3 med swellings- PA 1= tuberculum impar, PA 2+3= cupola, PA 4= epiglottis swelling
• Lat swellings grow over tuberculum impar and cupola overgrows.
• Apoptosis to leave lingual frenulum

Question 9

Where do the intrinsic and extrinsic muscles of the tongue dev from? What innervated by?

Answer 9

Myogenic precursors from occipital somites that migrate into dev tongue
Innervated by hypoglossal

Question 10

Where does the primordia of the thyroid gland appear?

Answer 10

Floor of the pharynx= foramen cecum aperture

Question 11

How does the thyroid gland descend?

Answer 11

Bifurcates and descends as bi-lobed diverticulum connected by isthmus

Question 12

What is the thyroglossal duct? How many people have remnants?

Answer 12

Connect thyroid gland to tongue during descent. Remnants in 50% popn

Question 13

Name 2 thyroid abnormalities

Answer 13

Thyroglossal cysts and fistulas

Ectopic thyroid tissue- any point along path of descent of thyroid

Question 14

What is Treacherous-Collins syndrome? Inheritance pattern?

Answer 14

Hypoplasia of mandible and facial bones, autosomal dominant

Question 15

What is Di-George syndrome?

Answer 15

CATCH22
Abnormal dev of neural crest 
- cardiac abnormalities 
- abnormal fancies
- thymus aplasia 
- cleft palate
- hypocalcaemia- PTh glands aplasia 
- chr 22

Question 16

What is charge syndrome?

Answer 16

CHD7 heterozygous mutation
C- coloboma
H- heart defects 
A- Chantal atresia
R- growth and dev retardation
G- genital hypoplasia
E- ear defects