Mod 2- Digestive System Flashcards
4 general layers of the GI channel
- Mucosa
- Submucosa
- Muscularis externa
- Serosa
what makes up the mucosa layer
- inner layer made of loose connective tissue (lamina propria)
- has lymph vessles/glands
- has two layers of smooth muscle (muscular mucosal)
what makes up the submucosa layer
- dense, irregular fibroelastic connective tissue
- submucosal nerve plexus (controls motility)
- blood and lymph vessels
what makes up the muscular externa and what is found there
- inner circular and outer longitudinal smooth muscle (for peristaltic activity)
- Auebach myentric plexus
function of serosa (and adventitia)
no function
-invested in peritoneum (covers it)
what innervates the Gi cannel
Enteric nervous system (messners and auerbachs)
Parasympathetic and sympathesic
what are the 2 sphincters of the GI canal
high- pharyngoesophageal
low- external and internal gastroesphogeal
at what portion of the esophagus would you likely see 2 diff types of muscle
usually middle third of esophagus
what 3 structures make up the esophageal wall
Mucosa- non keratinized strat squamous
Musculature- inner circular and outer longitudinal
Adevntia
what enzymes are released in the stomach
Pepsin, rennin and gastric lipase
what are the 4 gastric glands that line the mucosa of the stomach
- Mucous cells
- Parietal cells
- chief cells
- endocrine cells
what does the stomach secrete a day
-water
-hcl
-gastric intrincic factor
enzymes
mucus
how are the glands of the stomach structured and what are the 6 things found in it
each fundic gland extends from the muscular mucosal to the base of the gastric pit and contains :
Surface lining cells regenerative cells Mucous parietal chief enteroedocrine
Function of surface lining cells
produce soluble mucus which mixes w plus to reduce friction
function of regenerative cells
replace all specialized cells in the gastric pit
function of parietal cells
manufacture HCL and gastric intrinsic factor
function of chief cells
manufacture enzymes such as precursor to pepsin
function of enteroendocrine
manufacture endocrine etc
3 phases of HCL production
- in anticipation of food
- Parietal cells have recptors for gastrin, histamine and when they bine HCL released
What does helicopter-bacter pylori affect and what are some of the symptoms
-damages cells in gastric pit
symptoms- heartburn, chest/abdominal pain, bloating etc
what portion of the small intestine receives enzymes, buffer from pancreas and bile from liver
duodenum
what are Pilcae circulares
- permenant structures
- increase surface area of absorption (along w microvilli)
what cells are found in the duodenum
- Surface absorptive cells
- goblet cells
- DNES
- Mcells
- Regenerative
- Paneth
what are Brunners glands and what portion of small intestine are they found in
Duodenum
-secrete alkaline mucus into crypts of lieberkuhn , neutralize acid from stomach
