Lecture 23: LARGE INTESTINE AND LIVER

Question 1

Why is the large intestine called the large intestine?

Answer 1

Because of its large diameter

Question 2

What does the large intestine consist of?

Answer 2

Cecum, colon and rectum

Question 3

What does the ileum empty into?

Answer 3

The cecum

Question 4

What is the colon divided into?

Answer 4

Ascending, transverse, descending and sigmoidal

Question 5

What is between the ascending and transverse colon?

Answer 5

Right colic (hepatic) flexure

Question 6

What is between the transverse and descending colon?

Answer 6

Left colic (splenic) flexure

Question 7

Where are the ascending and descending colon?

Answer 7

Retroperitoneal

Question 8

Where are the transverse and sigmoidal colon?

Answer 8

Intraperitoneal

Question 9

Where is the iliocecal valve?

Answer 9

At the junction between the small and large intestine

Question 10

What does the ileocecal valve do?

Answer 10

Regulates the passage of material into the cecum and prevents back flow

Question 11

What is found in the appendix?

Answer 11

A reserve of large intestine bacteria population. Also contains lymphoid tissue so could have an immune role

Question 12

Where is the appendix found?

Answer 12

In a variety of locations

Question 13

What does inflammation of the appendix cause?

Answer 13

Appendicitis

Question 14

What does a barium enema enable?

Answer 14

X ray images of the large intestine to be taken to assess function

Question 15

What are features of the large intestine?

Answer 15

Teniae coli, haustra and omental appendices

Question 16

What are the teniae coli?

Answer 16

Bands of longitudinal smooth muscle

Question 17

What are haustra?

Answer 17

Series of pouches in the wall of the colon separated by semilunar folds

Question 18

What are omental appendices?

Answer 18

Sacs of fat for storage

Question 19

What are teniae coli a modification of?

Answer 19

The muscularis layer (inner circular is still the same)

Question 20

How many teniae coli are there?

Answer 20

Three bands of (outer) longitudinal smooth muscle

Question 21

What does the teniae coli allow?

Answer 21

Stronger contraction to move things through the large intestine

Question 22

Is there villi in the large intestine?

Answer 22

No, because the large surface area for absorption isn’t required

Question 23

What does the mucosa do in the large intestine?

Answer 23

invaginate to form intestinal glands

Question 24

What does the mucosa consist of?

Answer 24

Epithelium, lamina propria and muscularis mucosae

Question 25

Does the muscularis mucosae invaginate?

Answer 25

No

Question 26

what is the function of the mucosa of the large intestine?

Answer 26

Water and salt/electrolyte absorption

Question 27

How does the large intestine mucosa perform its function?

Answer 27

Goblet cells produce mucous (protection and lubrication)

Question 28

What marks the boundary where the epithelium changes?

Answer 28

Anal columns

Question 29

What is the epithelium before the anal column?

Answer 29

Simple columnar

Question 30

What is the epithelium after the anal columns?

Answer 30

Stratified squamous which becomes continuous with the epidermis of the skin

Question 31

Why does the anal canal have stratified squamous epithelium?

Answer 31

For protection from abrasion

Question 32

What is the internal anal sphincter?

Answer 32

Smooth muscle under involuntary control

Question 33

What is the external anal sphincter?

Answer 33

Skeletal muscle under voluntary control

Question 34

What does movement of faeces into the rectum do?

Answer 34

Stimulates stretch receptors

Question 35

What happens to the internal anal sphincter when the stretch receptors are stimulated?

Answer 35

They relax (involuntary)

Question 36

What happens to the external anal sphincter when the stretch receptors are stimulated?

Answer 36

It is contracting until a conscious decision to defacate is made and it relaxes

Question 37

Where is the liver found?

Answer 37

In the superior right quadrant of the abdominopelvic cavity

Question 38

what is the function of the liver?

Answer 38

It has lots but primarily produces bile which is stored in the gall bladder found under the liver

Question 39

How much of cardiac output does the liver receive?

Answer 39

Approximately 25%

Question 40

Where s 1/3 of the livers blood supply from?

Answer 40

The hepatic artery which branches off the abdominal artery

Question 41

Where is the rest of the livers blood supply from?

Answer 41

The hepatic portal vein which carries nutrient rich, deoxygenated blood from the small intestines to be processed by hepatocytes

Question 42

What do the hepatic portal vein, hepatic artery and bile duct travel through?

Answer 42

The lesser omentum

Question 43

What is the liver made up of?

Answer 43

Functional hexagonal units called lobules

Question 44

What are liver cells called?

Answer 44

Hepatocytes

Question 45

How are hepatocytes arranged?

Answer 45

In rows

Question 46

What do hepatocytes do?

Answer 46

Produce bile

Question 47

What are between rows of hepatocytes?

Answer 47

Liver sinusoids

Question 48

What is between hepatocytes?

Answer 48

Bile canalicul (channels to reach the duct)

Question 49

What is a portal triad made of?

Answer 49

Branch of hepatic artery, branch of portal vein and a bile duct

Question 50

Where does blood flow in the liver?

Answer 50

Towards the central vein

Question 51

What happens with blood in the liver?

Answer 51

It is processed by the hepatocytes (removes toxins) which produce bile

Question 52

Where is bile secreted?

Answer 52

Into canaliculi and travels to the bile duct

Question 53

What do central veins drain into?

Answer 53

The hepatic vein which drains into the inferior vena cava

Question 54

Where does bile from the live travel?

Answer 54

To the gall bladder where it is stored and concentrated

Question 55

What does the bile duct join with?

Answer 55

The pancreatic duct at hepatopancreatic ampulla to form the hepatopancreatic duct