L 23 - Digestion and Absorption

Question 1

What are the two types of villus cells?

Answer 1

1. Goblet cells = mucus secreting 2. Columnar absorptive cells

Question 2

What are the three Crypt cell types?

Answer 2

1. Columnar cells 2. Paneth cells 3. Stem cells

Question 3

What is the histological difference when comparing Jejunum and Ileum to the Duodenum?

Answer 3

J and I: longer villi and no brunner’s glands

Question 4

What layer are the crypts of Lieberkuhn located?

Answer 4

in the lamina propria of the mucosa - open between base of villi

Question 5

Which cells are only found in ruminants and horses?

Answer 5

Paneth cells = produce immune mediators and peptidases

Question 6

What are the 3 specialisations for absorption in the small intestine?

Answer 6

1. Plicae 2. villi 3. microvilli

Question 7

What fold at the apical of the cell membrane and are known as the “brush border”?

Answer 7

Microvilli

Question 8

What are plicae?

Answer 8

mucosal/submucosal folds

Question 9

What are enterocytes and where are they found?

Answer 9

Simple columnar epi cells found in the small intestines - absorptive cells -ovoid basal nucleus

Question 10

What is the brush border on microvilli made out of ?

Answer 10

Glycocalyx

Question 11

What type of cells are these?

Answer 11

Paneth cells: only found in horses and ruminants - prominent eosiniphillic granules: = antibacterial role (peptidase and lysozymes)

Question 12

What type of cells are theses from?

Answer 12

Duodenal Brunner’s glands - found in the submucosa -empty into the base of crypts -secretions: - mucuous = dogs and ruminants - serous = horses and pigs

Question 13

What cells secret chloride?

Answer 13

Columnar cells

Question 14

What type of cells are these?

Answer 14

Goblet cells: - produce mucus so it stains poorly interspersed between columnar and villus - less numerous at tips of villi

Question 15

Which cells produce mucus in the small intestine?

Answer 15

1. goblet cells on villi 2. submucosal glands = brunner’s glands in duodenum 3. submucosal glands = mucous in dogs and pigs

Question 16

Where are digestive enzymes secreted from in the small intestines?

Answer 16

Surface columnar absorptive cells 2. paneth cells (in ruminants and horses)

Question 17

Describe the histology of the large intestine

Answer 17

1. longer, less coiled simple tubular intestinal glands with MANY GOBLET CELLS = lots of mucus 2. NO submucosal glands 3. NO paneth cells

Question 18

What factors will inhibit Na absorption?

Answer 18

1. increase in cAMP (prostaglandins, cholera toxin) 2. increase in cGMP (E coli toxic agent) 3. increase in intracellular calcium (acetyl choline)

Question 19

What uses primary active transport ?

Answer 19

Amino acids

Question 20

What uses secondary active transport and facilitated diffusion?

Answer 20

Monosaccharides

Question 21

What uses Diffusion?

Answer 21

Monoglycerides