Small and Large Intestine Flashcards
Where does most digestion and absorption occur
the small intestine
Where does the small intestine begin and end
Begins: post pyloric sphincter
Ends: ileocecal sphincter
How do you differentiate between the duodenum and the jejunum
The ligament of Treitz, this is also the landmark to differentiate between the upper and lower GI tract
What is another name for the ligament of treitz
the suspensory ligament of the duodenum
What are Brunners glands are where are they located
glands that secrete alkaline mucous that neutralize gastric acid in chyme found in the small intestine submucosa
What are the deep crevices in the mucosal lining called
crypts of Lieberkühn
What do S cells produce, where are they found, what is the fxn of these cells
Produce: secretin
Located: in the duodenum
Fxn: pH sensing cells, when pH falls below 4.5 secretion is released and pancreatic bicarb increases and HCL production is decreased
What do I cells produce, where are they found, what is the fxn of these cells
Produce: cholecystokinin (CCK)
Located: in the duodenum
Fxn: slows gastric emptying and H secretion, stimulates pancreatic juice secretion, stimulates gallbladder contraction, promotes satiety
What are Paneth cells
cells in the the small intestine that secrete lysozymes and participate in phagocytosis as needed
What are pilicae circulares
permanent ridges in the small intestine that increase service area for absorption begin in the duodenum and end in the middle of the jejunum
What is the function of the large intestine
- completes absorption
- produces certain vitamins like K
- forms feces
- excretes solid waste from the body
What are the 4 major regions of the large intestine
- cecum
- colon
- rectum
- anal canal
What separates the ileum from cecum
ileocecal sphincter
What characterizes appendicitis and how is it treated
- High fever, elevated WBC’s, begins w/ generalized umbilical pain that becomes localized in the RLQ
- treated w/ surgery
What are the 4 major regions of the colon
- ascending
- transverse
- descending
- sigmoid
What is the hepatic flexure
where the ascending colon turns and becomes the transverse colon
What is the splenic flexure
where the transverse colon turns and becomes the descending colon
What anatomical landmark, identifies the the beginning and the end of the sigmoid colon
Begins=left iliac crest and then projects medially
Ends= at the rectum ~3rd sacral vertebra
What is defined as the the terminal 1 inch of the rectum
the anal canal
What anal sphincter is voluntary and which is involuntary
Voluntary= external sphincter
Involuntary=internal sphincter
What are the anal columns
longitudinal folds in the anal canal
What are the pectinate line and what do they demarcate
line that lies at the inferior portion of the anal columns
- above the this line ie the upper 2/3rd of the anal canal that is only sensitive to stretch
- below this line ie lower 1/3rd of the anal canal is sensitive to pain, temp and touch
How do you identify internal vs external hemorrhoids
Internal= above pectinate lines
External=below pectinate lines
What are teniae coli
portions of the external longitudinal layer of the muscularis layer of the large intestine that are thickened bands
What are omental appendices and where are they found
small pouches of visceral fat attached teniae coli
Define haustra
gatherings of the large intestine caused by the teniae coli, it is what gives the colon its pouched look
True or false there are circular folds and villi in the large intestine
False
What is responsible for the chemical digestion in the colon
bacteria
What gases give odor to feces
indole, skatole, hydrogen sulfide
When does chyme become feces
when enough water is absorbed to make chyme solid
What are the 2 types of GI motility and can they occur at the same time
- Peristalsis= wavelike ripple that pushes the bolus forward
- Segmentation = mixing movement to mechanically break down food
These 2 movements can occur at the same time
Describe the defecation reflex
distention of the rectum causes baroreceptors to signal the colon and anal colon to contract
