digestive tract 2 duodenum to anus

Question 1

what is the peritoneum

Answer 1

continuous sheet of serous membrane

Question 2

what does the serous membrane secrete

Answer 2

serum and forms the mucous membrane

Question 3

what does the parietal peritoneum line

Answer 3

lines the abdominal and pelvic cavities- it wraps around them

Question 4

what does the visceral peritoneum cover

Answer 4

covers most abdominal organs

it folds in on itself

Question 5

what is the peritoneal cavity

Answer 5

potential space between two peritoneum

Question 6

what is introperitoneal

Answer 6

sit in peritoneal

Question 7

what is retroperitoneal

Answer 7

behind peritoneal

Question 8

what are mesenteries

Answer 8

the peritoneal folds

Question 9

what are the functions of mesenteries

Answer 9

• connect organs to each other

- connect organs to the abdominal wall to stop organs from moving around and colliding into each other

Question 10

what is the omentum

Answer 10

it covers all organs in the abdominal cavity

it is the largest piece of peritoneal

Question 11

what is mesentery proper

Answer 11

mesentrial sheet that has a lot of blood vessels

Question 12

what occurs in the small intestine

Answer 12

90% of nutrient absorption occurs here

Question 13

subdivisions of the small intestine

Answer 13

duodenum (30cm)
jejunum (2.5m)
ileum (3.5m)

Question 14

what is the duodenum

Answer 14

c shaped structure adjacent to head of pancreas
extends from pyloric sphincter to jejenum
has an alkaline environment of pH9

Question 15

characteristics of the superior part of the duodenum

Answer 15

short, only section of duodenum peritonised (within the peritoneal lining)

Question 16

characteristics of the descending part of the duodenum

Answer 16

it has major and minor duodenal papillae

Question 17

what is the jejenum

Answer 17

• extends from the duodenojejunal flexure to the ileum
• it is completely peritonised
• has villi

Question 18

what is the ileum

Answer 18

• extends from the jejunum to the large intestine to the ileocecal junction
• completely peritonised
• no villi
• smaller in diameter

Question 19

what are plicae circularis

Answer 19

circular folds formed by mucosa and submucosa
unlike rugae, these are permanent
have projections - villi
these plicae villi is less prominent distally in the small intestine

Question 20

how does the intestinal walls change

Answer 20

diameter and thickness of intestinal walls decrease

Question 21

where is most of the mucus

Answer 21

in the submucosa of the duodenum - secreting duodenal (Brunner) glands that help maintain alkaline environment

Question 22

where are most of the lymphoid follicles

Answer 22

in the submucosa of ileum -Peyer patches

Question 23

lining of villi

Answer 23

covered with simple columnar epithelium (4 types):

1. absorptive: digestive enzymes
2. goblet: mucus secretion
3. granular or paneth: lyzozyme
4. endocrine: hormones

Question 24

intestinal glands

Answer 24

where the 4 different types of villa are produced

located at the bottom of villi

Question 25

locations of types of cells in villi

Answer 25

absorptive and goblet migrate to cover the surface of the villi granular and endocrine remain in the bottom

Question 26

what is the lacteal

Answer 26

is a lymphatic capillary that absorbs dietary fats in the villi of the small intestine.

Question 27

what is the function of the lymphs

Answer 27

drainage of water

Question 28

functions of the large intestine

Answer 28

- re-absoprtion of water - compact intestinal contents into faeces - absorption of vitamins - storage of faecal material

Question 29

length of large intestinal

Answer 29

extends from ileocecal junction to anus

Question 30

what is the illeocecal sphincter

Answer 30

opening between ileum and large intestine | guarded by fold of mucous membrane

Question 31

how is the mucosa in the large intestine

Answer 31

simple columnar epithelium | has no villi or plicae circularae

Question 32

what are crypts

Answer 32

straight tubular glands formed by the mucosal lining

Question 33

types of cells in crypts

Answer 33

absorptive, granular and goblet (predominant)

Question 34

muscle layers of large intestine

Answer 34

longitudinal and circular layers

Question 35

what are taeniae (teniae) coli

Answer 35

3 bands formed by the longitudinal layer of large intestine

Question 36

what are the haustra

Answer 36

gathering of colon into pouches formed by the contractions of taeniae coli permits expansion and elongation of intestine

Question 37

serosa

Answer 37

contains fat-filled pouches

Question 38

epiploic appendages (mental appendages)

Answer 38

fat-filled pouches within the serosa | attaches to peritoneum

Question 39

what is peristalsis

Answer 39

series of wave-like muscle contractions that move food to different processing stations in the digestive tract begins in the oesophagus when a bolus of food is swallowed

Question 40

what is the rectum

Answer 40

terminal part of the large intestine | folds inside

Question 41

what are rectal valves

Answer 41

transverse rectal folds in rectum

Question 42

how is the rectal mucosa

Answer 42

simple columnar epithelium with tubular glands housing large numbers of mucus-secreting goblet cells

Question 43

what is the muscularis

Answer 43

thick muscular tunic in rectum

Question 44

what is the anal canal

Answer 44

final part of rectum

Question 45

mucosa in anal canal

Answer 45

superior part simple columnar | inferior part stratified squamous epithelium

Question 46

what are anal columns

Answer 46

epithelium arranged in longitudinal folds (arteries and veins) anal sinuses between columns exude mucus

Question 47

what is the internal anal sphincter

Answer 47

formed by the thickening of the layer muscularis | movement is involuntary

Question 48

what is the anal sphincter

Answer 48

formed by skeletal muscle | voluntary movement

Question 49

major sphincters of the GI tract

Answer 49

formed by thickening of inner circular muscle layer (muscularis) - upper and lower oesophageal sphincters - pyloric sphincters - ileocaecal valve - internal and external anal sphincter