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Flashcards in Embryology Deck (64)
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1

The ventral mesentery suspends the gut tube to anterior body wall, and extends from caudal foregut to proximal duodenum.  What are the three derivatives of it?

Lesser omentum (hepatogastric, hepatoduodenal ligaments)
Falciform ligament
Coronary and triangular ligaments

2

What are the three types of peritonealization?

Primary retroperitoneal

Secondary retroperitoneal

Peritonealized

3

What are three examples of primary retroperitoneal structures?

kidneys, ureters, bladder

4

What are four examples of secondary retroperitoneal structures?

  1. duodenum
  2. ascending colon
  3. descending colon
  4. pancreas

5

What are some examples of peritonealized structures?

  1. stomach
  2. spleen
  3. duodenum parts 1 and 4
  4. jejunum
  5. ileum
  6. transverse colon
  7. sigmoid colon

6

What is different about secondary retroperitoneal structures?

Originate in peritoneum and move retroperitoneally during development.

7

The septum transversum is a plate of mesoderm which separates thoracic and peritoneal cavities.  What does it form?

  • Will form bulk of diaphragm; muscle and central tendon of diaphragm.

8

Does the septum transversum seperate the thoracic and abdominal cavities?

 

What does it develop from?

Septum transversum does not completely separate thoracic and abdominal cavities; leaves openings on either side of the foregut called pericardioperitoneal canals.

 

Cervical somites 3,4,5

9

What are the two openings created by the septum transversum on either side of the foregut?

pericardioperitoneal  canals

10

Pleuropericardial membranes will separate ....

pleural and pericardial cavities.  

11

Pleuroperitoneal membranes will separate...

 pleural and peritoneal cavities.

12

What sources contribute to the diaphragm?

Septum transversum - central tendon + muscle

Pleuroperitoneal membranes: Central tendon

13

What is the motor innervation of the diaphragm?

phrenic nerve

14

Describe the positional changes of the diaphragm.  When is the diaphragm at LV1?

The muscle of the diaphragm forms from cervical somites 3-5.
Differential growth of the body leads to a descent of the diaphragm into the thorax.
By week 8; diaphragm is at level of 1st lumbar vertebra.

15

What is the sensory innervation of the diaphragm?

– phrenic nerve to central tendon; intercostal nn to muscular diaphragm.

 

16

What are the congenital anomalies of the body wall?

  1. Congenital diaphragmatic hernias 

  2. Eventration of the diaphragm 

17

What are the types of congenital diaphragmatic hernias?

  1. Posterolateral defect (Bochdalek hernia)

  2. Parasternal hernia (Morgagni hernia)

18

Describe posterolateral defect hernia.

What is this a common cause of?

  • Incomplete formation of pleuroperitoneal membranes; most often on left.
  • Small intestine, and/or other viscera, herniate through defect into pleural cavity.
  • The lungs and heart are compressed ; common cause of pulmonary hypoplasia.  

19

Describe parasternal hernias

Anterior defect in muscular portion of diaphragm.
Small, sometimes not detected until child is several years old.

20

What is eventration of the diaphragm due to?  What does this lead to?

  • Weakness (usually unilateral) of diaphram due to failure of myotome migration.
  • Allows abdominal visceral to ‘‘ballon’’ into the thoracic cavity.

21

What does the endoderm bequeth to the GI tract?

epithelium and glands

22

What does mesoderm develop into for the GI system?

CT and smooth muscle

23

What does extoderm contribute to the GI system?

epithelium at ends of tube (mouth, lower 1/3 of anal canal)

24

The rostral and caudal ends of the gut tube are originally closed by what membranes?  Rupture during what weeks?

Rostral - oropharyngeal, week 4

Caudal - Cloacal, week 7

25

What are the compoinents of the foregut?

1.Pharynx
2.Esophagus
3.Stomach
4.½ duodenum
5.Spleen
6.Pancreas
7.Liver
8.gallbladder
 

26

What are the components of the midgut?


1.½ duodenum
2.Jejunum
3.Ileum
4.Cecum/appendix
5.Ascending colon
6.2/3 transverse colon
 

27

What are the components of the hind gut?


1.1/3 transverse colon
2.Descending colon
3.Sigmoid colon
4.Rectum
5.Proximal anal canal
 

28

What artery supplies the foregut?

celiac artery

29

What artery supplies the midgut?

superior mesenteric artery

30

What artery supplies the hindgut?

Inferior mesenteric artery