Gastrointestinal System Q4

Question 1

ID structures

Answer 1

Question 2

What are the 3 layers of the mucosa?

Answer 2

Epithelium, lamina propria, and muscularis mucosa.

Question 3

What layer is deep to the mucosa and what type of tissue is it?

Answer 3

Submucosa. Dense irregular CT.

Question 4

What three layers make up the muscularis externa layer?

Answer 4

Inner circular layer, myenteric nerve plexus, and outer longitudinal layer.

Question 5

What is the structure found between the inner circular and the outer longitudinal layers of the muscularis externa?

Answer 5

Enteric plexus.

Question 6

What is the outer layer of the GI tract?

Answer 6

It is adventitia CT but when covered with mesothelium it is serosa.

Question 7

When will an organ have adventitia?

Answer 7

When it is connecting to another organ.

Question 8

What is mesothelium?

Answer 8

Simple squamous epithelium lining CT of GI tract whenever organs are not touching.

Question 9

What are the three layers of the pharynx?

Answer 9

1- Mucosa made of non-keratinized stratified squamous and lamina propria. (no muscularis mucosa/submucosa)

2- Muscularis externa: Circular and longitudinal

3: Adventitia: outer CT.

Question 10

How can you tell the vagina apart from the esophagus?

Answer 10

The presence of esophageal glands in the submucosa and lamina propria.

Question 11

What is the structure where the esophagus and stomach meet and what is this structure formed by??

Answer 11

The esophageal sphincter. Formed from the smooth muscle of the muscularis externa.

Question 12

At the junction of the esophagus and stomach, what type of epithelium will be present?

Answer 12

It will transition from stratified squamous to simple columnar.

Question 13

What is the function of lipase and pepsin?

Answer 13

Lipase is to break down carbohydrates and pepsin to break down proteins.

Question 14

What are the “indentations” in the mucosa of the stomach?

Answer 14

Gastric pits that lead to gastric glands.

Question 15

What layer of the stomach contracts to break mix the chyme?

Answer 15

Muscularis externa.

Question 16

In the cardia, body/fundus, and pylorus explain the differences in the pits and glands.

Answer 16

Cardia pits shorter than glands. Body/Fundus long glands but pits more defined than cardia. Pylorus longer pits and shorter glands.

Question 17

What are the type of glands of the cardia?

Answer 17

Mucous glands

Question 18

What type of cells are in the glands of the body/fundus?

Answer 18

Cheif cells which secret pepsin and lipase, and parietal cells that secret gastric acid and intrinsic factor.

Question 19

What are the primary type of glands in the pylorus?

Answer 19

Mucous glands.

Question 20

What do D cells of the stomach release?

Answer 20

Somatostatin.

Question 21

What do G cells of the stomach release?

Answer 21

Gastrin stimulating acid.

Question 22

Where are the stem cells of the glands found?

Answer 22

At the top in the isthmus.

Question 23

What is the difference between surface mucous cells and mucous neck cells?

Answer 23

Surface secrete alkaline fluid while neck secrete acidic fluid.

Question 24

Where do cheif cells secrete their enzymes?

Answer 24

Lumen side of the gut.

Question 25

What cells are part of the DNES? Where do their secretions go?

Answer 25

G cells. diffuse neuroendocrine system cells secrete all sorts of things. Into the blood to be able to communicate to the rest of the body.

Question 26

What nerve is responsible for the regulation of HCl secretion?

Answer 26

Vagus nerve.

Question 27

Where is the site of most chemical digestion?

Answer 27

Duodenum.

Question 28

Where does the absorption of bile-lipid micelles take place?

Answer 28

Ileum.

Question 29

What three structures are responsible for increasing the surface area of the small intestine?

Answer 29

Plica circulares (3x), vili (10x), and microvili (20x).

Question 30

What layers make up plica circulares?

Answer 30

Mucosa and submucosa.

Question 31

What makes up the vili?

Answer 31

Lamina propria and covered in simple columnar epithelium.

Question 32

What makes up the microvili?

Answer 32

The folding of individual cell membranes.

Question 33

What do brunners glands secrete and where are they located?

Answer 33

Found in the duodenum and secrete mucus.

Question 34

What are peyer's patches made of?

Answer 34

Lymphoid tissue.

Question 35

What is MALT refering to?

Answer 35

Mucosal Associated Lymphatic Tissue where specialized epithelial cells endocytos antigens to bring to lymphocytes and dendritic cells.

Question 36

What are enterocytes?

Answer 36

Absorptive columnar cells.

Question 37

How does the absorption of lipids take place?

Answer 37

Bile acids emulsify them to be broken down by gastric lipase then allowing them to diffuse across membrane to SER and to RER to LYMPHATICS and end up in the tissues.

Question 38

How does the absorption of protein and carbohydrates take place?

Answer 38

enterocytes release disaccharidases and amino peptidases breaking down into monosac and amino acids allowing to be absorbed via active co transport and released into CAPILLARIES.

Question 39

What is the effect of cholera?

Answer 39

Pushes Cl into the lumen of the gut destrying the osmotic gradient and water absorption.

Question 40

What cells are the innate immune cells and what do they release?

Answer 40

Paneth cells located in the crypts of lieberkuhn and release lysozyme, phospholipase A, and defensins.

Question 41

What is the function of enteroendocrine cells?

Answer 41

Help the GI tract keep track of how much of what is where by secreting scretin, CCK, and GIP.

Question 42

What is the function of the submucosa and muscularis externa for intestinal motility?

Answer 42

Submucosa moves vili and plica ciruclarae for mixing and the mucularis externa primary source of motility.

Question 43

What is the myenteric plexus?

Answer 43

collection of sympathetic and parasympathetic nerve fibers that regulate GI.