Topic 15: Digestive System - Large Intestine

Question 1

From where does the large intestine extend from and to?

Answer 1

from ileocaecal valve to anus

Question 2

Does the large intestine have any folds?

Answer 2

• no villi or folds
• in lecture, it is for reabsorption of water to produce dry fecal matter

Question 3

What are the 5 parts of the large intestine?

Answer 3

1. caecum
2. Appendix
3. colon
4. rectum
5. Anus

Question 4

What are the parts of the colon? (6)

Answer 4

1. ascending (right side)
2. hepatic fixture (90 degree turn near liver)
3. Transverse (right to left side)
4. Splenic flexure (90 degree turn near spleen)
5. descending (left side)
6. Sigmoid (medially)

Question 5

Which part of the colon is incomplete?

Answer 5

• muscularis externa longitidinal layer incomplete, called the taeniae coli

Question 6

What does contraction of the taeniae coli form?

Answer 6

• puches called houstra

Question 7

The taeniae coli contains epiploic appendages. What are they? (2)

Answer 7

• fat filled pouches
• function unknown

Question 8

What is the structure of the rectum? (3)

Answer 8

• no taeniae coli
• anal canal lasts 3 cm

Question 9

What is the structure of the anus?

Answer 9

• 2 anal sphincters:
• internal sphincter
• external sphincter

Question 10

What type of muscle is the internal sphincter of the anus made of?

Answer 10

• smooth muscle
  hence involuntary control

Question 11

What type of muscle is the external sphincter of the anus made of?

Answer 11

• skeletal muscle
• voluntary control