Small intestine

Question 1

What are the 3 sections of the small intestine

Answer 1

-duodenum (L. duodecem)​
- jejunum (L. jejunus)​
- ileum (L. ileum)​

Question 2

What is the function of the small intestine

Answer 2

Primary site for digestion and absorption

Question 3

Where is the peritoneum

Answer 3

Wraps around all of inside of abdominal cavity, holds everything in place

Question 4

What does partially retroperitoneal mean

Answer 4

Only covered by the peritoneum on it’s anterior side (front), but not posterior

Question 5

Approximately how long is the duodenum

Answer 5

25-30cm

Question 6

How long is the ileum

Answer 6

3.5m

Question 7

Which part of the small intestine is usually empty at post mortem

Answer 7

Jejunum due to terminal peristalsis

Question 8

Where does the small intestine start

Answer 8

Pylorus

Question 9

How long is the small intestine

Answer 9

Approx 6m

Question 10

What is the structure of the mesothelium (serous membrane)

Answer 10

2 layers that are continuous with each other made up of simple squamous epithelial cells

Question 11

What layer of the peritoneum is sensitive to pressure, pain and temp

Answer 11

Parietal

Question 12

What is the omentum

Answer 12

Sheets of visceral peritoneum extending from the stomach and proximal duodenum to other abdominal organs

Question 13

What is the mesentery

Answer 13

A double layer of visceral peritoneum which connects to posterior abdominal wall.

Question 14

What are intraperitoneal organs

Answer 14

Organs enveloped by the visceral peritoneum

Question 15

Where are Brunner’s glands found

Answer 15

Above where the pancreatic and biliary secretions enter the duodenum

Question 16

What is the purpose of Brunner’s glands within the duodenum

Answer 16

Secrete alkaline and mucous secretions to protect the duodenum from acidity of chyme, provide optimal condition for intestinal enzymes to be active and for lubrication

Question 17

Where does the duodenum end

Answer 17

At the duodenojejunal junction

Question 18

What does the sphincter of Oddi do

Answer 18

This muscular valve controls the flow of bile and pancreatic juice, or enzymes as they pass into the duodenum

Question 19

Where is the minor duodenal papilla

Answer 19

If present, 2cm proximal to the major duodenal papilla

Question 20

What is cholecystokinin (CCK)

Answer 20

A peptide hormone and helps digest fat and protein.

Question 21

What secretes CCK

Answer 21

Cells of the duodenum and highest secretions occur when there is fatty acids in the chyme entering the duodenum

Question 22

What does CCK do

Answer 22

Inhibits gastric emptying but increases the release of pancreatic enzymes, as well as increases the production of bile, contraction of the gall bladder and relaxes the Sphincter of Oddi resulting in better fat digestion

Question 23

What are the four parts of the duodenum

Answer 23

Superior
Descending
Inferior
Ascending

Question 24

Where would a duodenal ulcer likely be found

Answer 24

Superior section within the posterior wall

Question 25

Which site of the duodenum does the major duodenal papilla lie

Answer 25

Descending

Question 26

Which portion of the duodenum passes over the inferior vena cava and aorta and lies behind the superior mesenteric artery

Answer 26

Inferior

Question 27

Which vessels supply the pancreas

Answer 27

Coeliac trunk Mesenteric artery

Question 28

What does superior and inferior mean

Answer 28

Above and below

Question 29

What is an ulcer

Answer 29

A breakdown of epithelial tissue

Question 30

What can relieve the upper abdominal pain of an ulcer

Answer 30

Eating

Question 31

If sudden intense abdominal pain, fever and nausea occur with a duodenal ulcer what might this indicate

Answer 31

Perforation of the ulcer and peritonitis

Question 32

What is the treatment for a ruptured ulcer

Answer 32

Surgery

Question 33

Where does the small intestine end

Answer 33

At the ileocaecal junction where the ileum and large intestine meet

Question 34

What are the main functions of the 3 sections of the small intestine

Answer 34

Duodenum -mainly digestion Jejunum -digestion -absorption Ileum -mainly absorption of nutrients

Question 35

What are the tissue layers within the walls of the jejunum and ileum

Answer 35

Lumen Mucosa -epithelium -lamina propria -muscularis mucosae Submucosa Muscularis externa -innermost oblique -inner circular -outer longitudinal Adventitia (serosa)

Question 36

What are goblet cells

Answer 36

exocrine glands which secrete mucin

Question 37

Where are hormones secreted and new stem cells found

Answer 37

Crypts of Lieberkühn

Question 38

What cells are found in the mucosal lining of the GI

Answer 38

Enterocytes Goblet cells Crypts of Lieberkühn

Question 39

What are Enterocytes

Answer 39

Tall columnar epithelium which have an absorptive function

Question 40

What is a plexus

Answer 40

A network of nerves or vessels in the body

Question 41

Which system do the nerves in the submucous plexus come from

Answer 41

Parasympathetic nervous system

Question 42

What innervates the muscle layers in the GI

Answer 42

Myenteric plexus

Question 43

Which plexus has both parasympathetic and sympathetic innervation

Answer 43

Myenteric

Question 44

What increases the surface area of the small intestine by about 2-3x

Answer 44

The plicae circulares -Permanent circular folds of mucous membranes

Question 45

Where are plicae circulares most numerous

Answer 45

The latter part of the duodenum through the upper part of the jejunum

Question 46

What can increase the surface area of the small intestine by 600x

Answer 46

Microvilli

Question 47

What is the name for 2 layers of mesothelium

Answer 47

Serosa

Question 48

What feature make the jejunum identifiable

Answer 48

Thick intestinal wall Longer vasa recta (straight arteries) Less arcades (arterial loops) Red in colour

Question 49

How can the ileum be described

Answer 49

Thin intestinal wall Shorter vasa recta (straight arteries) More arcades Pink in colour

Question 50

How is the ileum adapted for greater absorption

Answer 50

Shorter and more branched

Question 51

Where are the Peyer's patch most common

Answer 51

Ileum

Question 52

How does circular muscle aid in the breakdown of chyme

Answer 52

Carries out local contraction and breakdown

Question 53

How does chyme move along

Answer 53

Longitudinal muscle and villi

Question 54

What is the ileo-caecal junction

Answer 54

A muscular sphincter between the last part of the small intestine and the start of the large intestine

Question 55

Where can both Vit B12 and Bile acid be absorbed

Answer 55

Ileo-caecal junction

Question 56

What defects affect the intestines

Answer 56

-Dietary deficiencies (intolerances) -Malabsorption syndromes can lead to deficiencies that affect blood (anaemia) -Coeliac disease -Crohn's disease -Cystic fibrosis

Question 57

What defect occurs in the small intestine which is identified using the rule of 2's

Answer 57

Meckel's diverticulum

Question 58

What are the Rule of 2's

Answer 58

Used to identify Meckel's diverticulum -Usually present before age 2 -2%of population affected -Within 2 ft from ileo-caecal valve -2inches long 2 types of mucosa

Question 59

What are the 2 types of mucosa present in Meckel's diverticulum

Answer 59

Gastric, pancreatic or colonic

Question 60

What is peritonitis and why may a Meckel's diverticulum cause this

Answer 60

Inflammation of the peritoneum If gastric tissue secreting HCL is present (from parietal cells), it may erode the ileal mucosa, resulting in perforation and subsequent peritonitis