Histology of Stomach and small intestines

Question 1

List the tissular organization of the digest system starting from the innermost layer

Answer 1

Mucosa
Submucosa
Muscularis Externa
Serousa

Question 2

What kind of tissue is the submucosa made up of

Answer 2

Dense irregular connective tissue

Question 3

What controls motricity of mucosa and secretory activity of mucosal gland in the submucosa

Answer 3

Meissner’s plexus(parasympathetic neurons)

Question 4

Which 2 muscles comprises the muscularis externa

Answer 4

Circular smooth muscle( inner layer)
Outer Longitudinal smooth muscle

Question 5

Which plexus is present between the circular and longitudinal layer of the muscularis externa

Answer 5

Myenteric ( Auerbach’s) Plexus

Question 6

What type of fibres does the Auerbach’s plexus contain

Answer 6

Parasympathetic fibers

Question 7

What kind of tissue makes up the Serosa of the digestive tract

Answer 7

Loose connective tissue- surrounding visceral organs

Question 8

What kind of enzymes does the stomach secrete

Answer 8

Protein-digesting enzymes called Proteases

Question 9

Name the four sections of the stomach and their functions

Answer 9

Cardia- Where the contents of the esophagus empty into the stomach
Fundus- Formed by the upper curvature of the organ
Body or Corpus- The main central region
Pylorus- The lower section of the organ that facilitates emptying the contents into the small intestines

Question 10

What is the epithelium of the stomach

Answer 10

Simple columnar epithelium

Question 11

What is the epithelium of the oesophagus

Answer 11

Stratified squamous epithelium

Question 12

Define Rugae:

Answer 12

Longitudinal folds of mucosa and submucosa
note : all stomach regions have rugae

Question 13

Rugae are temporary and disappear when stomach distended with fluid or solid material; True or FALSE

Answer 13

True

Question 14

The stomach only has 3 histological regions name them:

Answer 14

Fundus and body
Cardia
Pylorus

Question 15

Which region of the stomach are gastric glands located:

Answer 15

Fundus and body

Question 16

There are 2 main cell types in the gastric glands located in the lamina propria of the mucosal layer; name them

Answer 16

Acidophilic parietal cells: in upper portions of glands
Basophilic Chief( zygomatic) cells- Lower portion of the glands

Question 17

There are 3 layers of smooth muscle located in the Muscularis externa of the stomach; name them:

Answer 17

Inner oblique(not complete)
Middle circular
Outer Longitudinal

Question 18

Describe the 3 regions of the gastric glands

Answer 18

Isthmus- junction of gastric pit with gastric gland; composed of acidophillic parietal cells
Neck- parietal cells
Base (fundus)- composed of chief (zymogenic cells), basophilic

Question 19

3 Main types of cells in glands

Answer 19

Mucous neck cells: Round, basal nuclei
Parietal cells: large, pyramidal shape, round nuclei, acidophilic cytoplasm
Chief (zymogenic) cells: basophillic

Question 20

What so parietal cells secrete

Answer 20

Intrinsic factor and HCL

Question 21

Chief cells secrete

Answer 21

Pepsinogen and gastric lipase

Question 22

What are G cells

Answer 22

Enteroendocrine cells that secrete gastrin into the blood

Question 23

The gastric pits in the pyloric is deeper than in the body or fundus; True of False

Answer 23

True

Question 24

There is only one type of cell in the pyloric region of the stomach; name it

Answer 24

Tall columnar cell

Question 25

What separates the pylorus from the duodenum

Answer 25

Pyloric Sphincter- by thickened circular layer of muscularis externa of the stomach

Question 26

What kind of epithelium is in the duodenum

Answer 26

Intestinal epithelium- goblet cells and columnar cells with microvilli

Question 27

What type of glands are located in the submucosa of the upper duodenum

Answer 27

Brunner's Gland (Duodenal glands)

Question 28

When there is an overproduction of serotonin from enteroendocrine cells what is the result?

Answer 28

Ans: Tumors called Carcinogens are produced

Question 29

What colour staining would an Isthmus of gland generate?

Answer 29

Ans: Clear

Question 30

What are enteroendocrine cells

Answer 30

Aka APUD cells; secrete different peptides and proteins with hormonal activity

Question 31

Where is serotonin secreted

Answer 31

Fundus

Question 32

What is the primary function of the small intestines aka small bowel

Answer 32

absorption of nutrients and minerals found in food

Question 33

Average length of small intestines found in adult male and female

Answer 33

Male: 6.9m; 22ft 6 inches Female: 7.1m; 23ft 4 inches

Question 34

What is the diameter of the small intestines

Answer 34

Approximately 2.5 - 3cm

Question 35

Name he 3 structural parts that divide the small intestines

Answer 35

Duodenum Jejunum Ileum

Question 36

Name the cells and glands located within the small intestines

Answer 36

Intestinal Glands(Crypts of Lieberkuhn) Goblet Cells Absorptive cells Duodenal (Brunner's) glands Enterendocrine cells (APUD) Paneth cells Peyer's patches M cells

Question 37

Which cell type is the most common in the intestinal epithelium

Answer 37

Absorptive cells

Question 38

Brunner's glands are tubular acinar true or false

Answer 38

True

Question 39

Which cells contains granukes releasing antimicrobial substances, protects stem cells and are involved in innate immunity

Answer 39

Paneth Cells

Question 40

Function of M cells

Answer 40

Phagocytose luminal antigens and present them to lymphocytes and macrophages (APCs)

Question 41

Which parts of the duodenum ae serous and which are adventitia

Answer 41

1st part- Serous 2nd - 4t part: Adventitia

Question 42

Which muscles make up the muscularis externa for the duodenum, jejunum and ileum

Answer 42

Longitudinal and Circular layers with Auerbach's plexus in between

Question 43

Name the only section of the intestines where you can find Brunner's Glands and Meissner's plexus

Answer 43

Duodenum

Question 44

Which section of the small intestines has Peyer's Patches

Answer 44

Ileum

Question 45

What are Peyer's Patches

Answer 45

Aggregations of lymphatic nodules

Question 46

Which part of the small intestines is the smallest and is the site for which most absorption takes place

Answer 46

Duodenum

Question 47

The duodenum begins with the duodenal bulb and end with the ligament of Treitz; True or False

Answer 47

True

Question 48

How long is the duodenum

Answer 48

25-38cm (10-15inches)

Question 49

How long is the Jejunum

Answer 49

2.5m

Question 50

Which section of the small intestines has the longest villi

Answer 50

Jejunum

Question 51

Which aspect of the small intestines specializes in the absorption of monosaccharides

Answer 51

jejunum

Question 52

What separates the ileum from the caecum

Answer 52

Ileocecal valve

Question 53

How long is the ileum and what is it's pH

Answer 53

2-4m long 7 and 8 pH

Question 54

What are the functions of the Ileum

Answer 54

absorb vitamin B12 and bile salts

Question 55

What are Lacteals

Answer 55

Small lymph vessels Absorb fatty acids and glycerol