GI embryology and Histology (6) Flashcards
What are the basic functions of the digestive system
ingestion mechanical digestion chemical digestion - secretion absorption excretion
what are the four basic layers of the digestive tract tube
- mucosa
- submucosa
- muscularis externa
- serosa or adventitia
What are the functions of the mucosa
protect, secrete, absorb
what are the different parts of the mucosa and their functions
epithelium - barrier, increase SA, movement of nutrients
Lamina propria - LCT with glands, vessels, immune system
Muscularis mucosae - smooth muscle cells
What is the epithelium like in the oral cavity, pharynx, and esophagus
it is lined by stratified squamous epithelium and uses mechanical stress
what is the epithelium like in the stomach, small intestine, and most of large intestine
it is lined by simple columnar epithelium with mucous cells, its function is absorption
What is the function of the submucosa
control and contribution to the mucosal functions
what is the function of the muscularis externa
generate peristalisis
what is the function of the serosa or adventitia
reduce frictional forces
what are the accesory organs derived from the gut tube endoderm
pharyngeal pouch derivatives lungs liver gallbladder bile ducts pancreas urogenital sinus and derivatives
What causes the stomach to rotate
the developing liver
What is gastroschisis
when the lateral walls of the abdomen fail to close completely so that intestines come out.
what is omphalocele
when the intestines fail to return into the body cavity, so they remain in the umbilicus where they were in W8 and W10. the intestines are covered in a thin umbilical sac
what is apple peel atresia
when the vitelline duct persists too long and it rotates too much
what is meckels diverticulum
a portion of the small intestine that used to be in the umbilicus, that normally resorbs, but hasn’t.
it can be an ompthalmomesenteric fistula, cyst of ligament that connects the small intestine and the umbilicus
during what weeks is part of the small intestine outside the body and in the umbilicus
W8-W10
what is a duodenal volvulus
twisting of the duodenum
what is a persistant cloaca
when the rectum, vagina, and urethra all exit in the same hole
What is anal atresa
when your rectum doesn’t have an opening
what is an annular pancreas
when the ventral and dorsal pancreases combine and form a ring around the small intestine
