lecture 26: digestive sys

Question 1

esophagus

Answer 1

entering inferior to vena cava, and superiorly to the aorta

esophageal hiatus: hole in diaphragm, opening for esophagus

Question 2

lower esophageal sphincter

Answer 2

esophagus enters stomach

Question 3

true/false

the esophagus enters the abdomen anterior to the IVC

Answer 3

should be posterior; false

Question 4

location of stomach

Answer 4

deep to border of ribs
inferior to diaphragm
stomach

Question 5

structure of stomach

Answer 5

“J-shaped”
- lesser curvature (right)
- greater curvature (left)

parts:
- esophagus
- cardiac sphincter
- cardia
- fundus
- body
- pyloric antrum
- pyloric canal
- pyloric sphincter
- duodenum

Question 6

function of stomach

Answer 6

• food storage
• mechanical and chemical breakdown: chemical breakdown by gastric juice

gastric juice:
- hydrochloric acid, lipase, pepsin
- chyme = gastric juice mixed w gastric content (food)

Question 7

which abdominopelvic region is the stomach located

Answer 7

epigastric region

Question 8

true or false
the greater curvature of the stomach is located closer to the left side of the body

Answer 8

true

Question 9

location of the small intestine

Answer 9

• coiled
• central/inferior abdomen
• inferior to stomach
• surrounded by large intestine
  begins: pyloric sphincter (valve)
  ends: opens into large intestine

Question 10

purpose of plicae circulares/villi/microvilli

Answer 10

• plicae circulares prevents a “garden hose” like behaviour; contents slowed by spiralling around lumen, increases contact w the intestinal walls
• increase surface area
• allows for more absorption and digestion of food

Question 11

3 parts of the small intestine

Answer 11

Duodenum
Jejunum
Ileum

Question 12

duodenum

Answer 12

shortest ~25-35cm
“c-shaped”, concaves left
function:
- receives chyme from stomach
- receives digestive secretions from pancreas
- receives bile from liver
“mixing bowl”

Question 13

jejunum

Answer 13

~1m
mostly in upper left abdomen
function:
- most of the chemical digestion and nutrient absorption, largest plicae circulares

Question 14

ileum

Answer 14

longest ~2m
mostly lower right abdomen
enters large intestine thru ileocecal valve
function:
- further digests food
- peyer’s patches; prevent infection by regulating pathogens

Question 15

what part of the digestive sys does the most chemical digestion and nutrient absorption

Answer 15

jejunum

Question 16

digestion and absorption of nutrients

Answer 16

• carbohydrates, proteins, fats, and nucleic acids
• mucosa aid with absorption, come into contact w chyme and digestive juices
• peristalsis propels chyme

Question 17

location of large intestine

Answer 17

begins: ileocecal valve
ends: anus
- inferior to stomach and liver
- surrounds small intestine

Question 18

size of large intestine

Answer 18

~6.5cm diameter
~1.5m length
**shorter than small intestine

Question 19

colon

Answer 19

water/electrolyte removal
ascending, transverse, descending, and sigmoid colon
has teniae coli (3 bands), haustra gives the puckered appearance

Question 20

rectum

Answer 20

receives stool from colon
holds in stool until excretion

Question 21

function of large intestine

Answer 21

absorption (water/electrolytes)
compaction
defecation
**think garbage compactor