GI Embrology/Histology (Reybolds)

Question 1

Mucosa of digestive tract is made of three parts which are?

Answer 1

1. Epithelium-barrier; alters surface area; permits movement of nutrients, water, electrolytes
2. Lamina propia- LCT that contains glands, vessels for transport, components of the immune system
3. Muscularis mucosea- thin layer of smooth muscle cells in circular and longitudinal arrangement.

Question 2

Oral cavity, pharynx, esophagus mechanism and epit?

Answer 2

mechanical stresses; simple squamous

Question 3

Stomach, small intestine, most of large intestine function and epi?

Answer 3

Absorption; simple columnar epi with muscous cells

Question 4

Digestive tract tube 4 layers?

Answer 4

1. mucosa
2. submucosa
3. muscularis externa
4. Serosa or adventitia

Question 5

submuscosa

Answer 5

control of & contribution to mucosal function.

-Irregular LCT and DCT, blood and lymph vessels, nerves, and glands

Question 6

Muscularis externa

Answer 6

Generates peristalsis. Inner circular smooth muscle layer, CT layer, outer longitudinal smooth muscle layer.

Question 7

Serosa or adventitia

Answer 7

Reduces frictional forces.

serosa in esophagus, stomach, small intestine, portions of large intestine

Question 8

Mechanical process examples:

Answer 8

oral cavity, teeth, tongue

stomach (via muscular contractions)

Question 9

Chemical process examples

Answer 9

stomach (breakdown of materials by acid and enzymes)

Question 10

For differentiation of organs know that __ and __ communicate with each other.

Answer 10

Mesoderm and endoderm

Question 11

Liver forces stomach to rotate how many degrees?

Answer 11

90 degrees

Question 12

vovulus

Answer 12

Situation where there is kinking/mis-rotation; pinching off of gut.

Question 13

Meckel’s diverticulum

Answer 13

contents of small intestine coming out of belly button. Vitelline duct should differentiate but if it doesn’t it becomes meckel’s diverticulum.

Question 14

Meckel’s diverticulum due to

Answer 14

vitelline duct persists in the abdominal wall forming open omphalomesenteric fistula/cyst/ligament connecting the small bowel and umbilicus.

Question 15

Liver germ layer

Answer 15

endoderm

Question 16

Pancreas germ layer

Answer 16

endoderm

Question 17

Annular pancreas

Answer 17

Defect where you have mismigration, where ventral bud does not migrate to the correct direction but opposite thereby constricting the GI tract.

Question 18

Omphalocele

Answer 18

Herniation of abdominal viscera through an enlarged umbilical ring.

Question 19

Gastroschisis

Answer 19

Herniation. birth defect of the abdominal (belly) wall. The baby’s intestines stick outside of the baby’s body, through a hole beside the belly button. The hole can be small or large and sometimes other organs, such as the stomach and liver, can also stick outside of the baby’s body.N

Question 20

buccal phase

Answer 20

cheewing, manipulating, forming bolus

Question 21

voluntary phase

Answer 21

pharyngeal and esophageal phase.