Large Bowel

Question 1

What 5 parts is the large bowel made up of?

How long is it?

What is its structure? Fill in the missing labels on the diagram below:

What is its function?

Answer 1

Colon, caecum, appendix, rectum and

Begins from the right side of the body?

Question 2

The colon can be divided into which 4 colons? Descrobe each of them in terms of location:

Answer 2

Ascending

Transverse

Descending - coming towards the splenic flexure to the sigmoid colon

Sigmoid -

Question 3

What is the the blood supply to the bowel?

WHich part of the gut is most sensitive to ischaemia and why?

Answer 3

Large bowel supplied by the superior and inferior mesenteric artery (SMA and IMA)

Distal something uspplied by distal mesenteric artery?

Question 4

What is found on the outside of the peritenium of the colon?

What causes the appearance of a pouch in the large bowel?

Answer 4

Fatty tags on the peritonium (function largely unkown although said to have protective functions),

Question 5

What is the function of the colon?

Question 6

What is the rectum?

Why does the structure of the rectum change from that of the colon?

Answer 6

Ca distinguidh between solid, liquid and gas

Question 7

What is the anal canal and what is its structure? Fill in the missing labels on the diagram below:

Answer 7

Have voluntary control over only one of those sphincters

Question 8

What are the different layers of the large bowel? Fill in the missing labels below:

Answer 8

Mucosa -

Submucosa

Submucosal space - harbours all the glands / secretion glands

Muscularis - 2 types, circular and longitudinal muscles

Serosa - sits on top of the muscularis and secures the area?

Question 9

Within the mucosa, what are the different types of cells found?

Are there villi in the large bowel?

What is the organisation of these cells?

Answer 9

Enterocytes and goblet cells

No paneth cells

No villi but contains microvilli - where the rest of the water absorption occurs

Looks smooth on gross level, but microvilli = different lengths on the enterocytes??

Stem cells found in the crypts

Question 10

What are goblet cells and where are they found in the small bowel?

Why is increased mucus secretion required?

What is the function of the mucus?

What stimulates mucus secretion?

Question 11

missed a slide

Question 12

missed a slide

Question 13

What is the function of the microvilli in the large bowel?

What is found surrounding the microvilli and what is the function of that substance?

Answer 13

Glycocalyx?

Question 14

What is the muscularis layer of the large bowel divided into? What are their structures?

Answer 14

Inner circular muscle layer - ovoid stuff

Outer longitudinal muscle layer - thinner than of the small bowel?

Question 15

How does material move through the colon? (motility)

What sort of speed does material travel and why?

Answer 15

Allows and promotes more time for absorption of electrolytes and water

Question 16

What is the mass movement of the large bowel?

Question 17

What is the nerve supply to the large bowel to control the motility?

Question 18

missed a slide

Question 19

What is the hormonal control of the large bowel absorption and motility?

Question 20

How does the large bowel carry out its function of defacation? (2 slides)

Answer 20

COntrolled by the sacral spinal cord?

Internal sphincter relaxes?

Question 21

What are faeces made up of?

What gives it its colour?

What does the smell come from?

Question 22

What is large bowel flora and what is its importance?

Answer 22

flora = microbiome

All mammals have a symbioti relationship between

Diverse, highly metabolic active community

Question 23

What are the 5 major roles of the intestinal flora (microbiome)?

Question 24

What is fibre?

How can fibre be broken down?

Why is this important?

Question 25

What are the most common types of flora / bacteria found in the colon?

Question 26

What 5 conditions can the gut microbiome be linked to?

Question 27

What are the benefits of stool transport?