Tongue, esophagus, stomach

Question 1

Describe the three layers of the mucosa?

Answer 1

Epithelial lining, corium (CT), Muscularis mucosa

Question 2

What control the movement of the mucosa?

Answer 2

Muscularis Mucosa

Question 3

How are the muscles in the muscularis mucosa is arranged?

Answer 3

Inner circular, outer longitudinal

Question 4

What is the local nervous system of the GIT and where its located? and what their functions?

Answer 4

• Enteric plexus (Messiner plexus ) located in the sub-mucosa , mainly control the secreatory activity and the motility of the mucosa.
• Myenteric plexus ( Aurebach’s plexus) Located in the Muscularis externa, control the motility of the GIT

Question 5

What is the lining of the dorsal surface of the tongue?

Answer 5

stratified squamous parakeratinized to keratinized epithelium,

Question 6

What is the lining of the ventral surface of the tongue?

Answer 6

stratified squamous nonkeratinized epithelium.

Question 7

What is the core muscle of the tongue?

Answer 7

skeletal muscle

Question 8

The anterior 2/3 of the tongue is separated from the posterior 1/2 of the tongue by? and its apex ends at ?

Answer 8

Sulcus Terminalis

Foramen Cecum

Question 9

List the names of all the tongue papillae, their features?

Answer 9

a. Filiform papillae are short, narrow, highly keratinized
structures lacking taste buds.
b. Fungiform papillae are mushroom-shaped structures
interspersed among the filiform papillae; they contain
occasional taste buds.
c. Foliate papillae are shallow longitudinal furrows on the lateral aspect of the posterior region of the anterior two-thirds of the tongue. Their taste buds degenerate shortly after the second year of life.
d. Circumvallate papillae are 10 to 15 large circular papillae,each of which is surrounded by a moat-like furrow. They lie just anterior to the sulcus terminalis and possess taste buds.

Question 10

Which papillae does not posses tatse buds?

Answer 10

Filiform Papillae

Question 11

Which papilla lose its taste buds in the 2nd year of life (degenerated)

Answer 11

Foliate papillae

Question 12

Tastes buds are composed of what ?

Answer 12

• 60 to 80 spindle-shaped cells

- Each taste bud has a small opening, the taste pore

Question 13

Taste hairs are……

Answer 13

Microvilli

Question 14

Microvilli project into….

Answer 14

The oral cavity

The moat- like groove of the circumvalet papillae

Question 15

How many cells are identified in the taste buds? and what are their functions?

Answer 15

Four different cells may be recognized:
- dark cells ,
- light cells
-intermediate cells (type III cells) have short life
spans; the fourth type are the short, regenerative, basal
cells.

Question 16

Which type of stem cells are the basal regenerative cells?

Answer 16

Pluripotent

Question 17

What is the life span of taste buds cells?

Answer 17

The process of going from a newly formed dark cell to a dead intermediate cell takes about 10 days.

Question 18

Where is the site of nerve innervation in the taste bud?

Answer 18

basal cells synapses with afferent nerve fibers that deliver the taste information to the central nervous system.

Question 19

What are the morphological regions of the GIT?

Answer 19

the esophagus, stomach, small intestine (duodenum, jejunum, and ileum), and large intestine (cecum,
colon, rectum, anal canal, and appendix).

Question 20

What are the common histological layers of the GIT

Answer 20

• Mucosa
• Submucosa
• Musclaris Externa
• Serosa or Adventita

Question 21

What is the main controlling nervous system of the GIT and what modifies it?

Answer 21

Enteric Plexus, Myenteric Plexus

- Sympathetic and Parasympathetic

Question 22

What is the pace maker of the GIT and where its located? and how do they contract?

Answer 22

Interstitial cells of Cajal
Located in the Muscularis Externa
They are contract rhythmically

Question 23

What is the function of the Auerbach’s Myenteric plexus? And where its located?

Answer 23

• regulates the activity of the muscularis externa.

- is situated between the muscle layers ( muscularis externa)

Question 24

The muscularis externa motility is controlled by?

Answer 24

Auerbach’s Myenteric plexus

Question 25

Intraperitoneal organs are covered by?

Answer 25

Serosa

Question 26

Retroperitoneal organs are covered by?

Answer 26

Adventitia ( dense irregular connective tissue)

Question 27

What is the epithelial lining of the esophagus?

Answer 27

stratified squamous nonkeratinized epithelium.

Question 28

How many layer of muscles in the muscularis mucosa of the esophagus?

Answer 28

single longitudinal layer of smooth muscle.

Question 29

The esophageal lamina propria and submucosa contain….?

Answer 29

mucus-secreting esophageal and cardiac glands.

Question 30

What is the muscular composition of the esophageal muscularis externa?

Answer 30

- upper third is composed only of skeletal muscle - the middle third is composed of a combination of smooth and skeletal muscle - the lower third is composed only of smooth muscle.

Question 31

How many physiological sphincter the esophagus have? Name them and what is their function and location?

Answer 31

2 (pharyngoesophageal and the gastroesophageal) - in the muscularis externa - ensure that the bolus is transported in one direction only toward the stomach.

Question 32

What is the epithelial lining of the stomach?

Answer 32

a simple columnar epithelium

Question 33

What are the histological changes that occur in the gastro-esophageal junction?

Answer 33

1- The stratified squamous epithelium of the esophagus changes ,abruptly into simple columnar. 2- The C.T. lamina propria of the mucosa of the stomach contains branched tubular glands. 3- esophageal glands present in its submucosa, stop or continue for a short distance in the submucosa of the stomach. 4- The musculosa becomes more thick in the stomach due to appearance of an inner oblique layer of muscles.

Question 34

How many layers of muscles in the stomach musculosa (muscularis externa)?

Answer 34

3 | an outer longitudinal layer, a middle circular layer, and inner oblique layer.

Question 35

What is the external layer of the stomach and the esophagus?

Answer 35

The external layer of esophagus is adventitia but in stomach is serosa.

Question 36

What are the anatomical division of the stomach?

Answer 36

cardia, fundus, body and pylorus

Question 37

Which divisions of the stomach are histologically identical?

Answer 37

the fundus and body

Question 38

What are rugae and which layers from them? When do the appear and disappear?

Answer 38

- longitudinal folds of the mucosa and submucosa | - which disappear in the distended stomach.

Question 39

The gastric pit (foveola) is formed by …. And it’s the opening of …?

Answer 39

epithelial lining of the stomach invaginates into the mucosa, the gastric glands.

Question 40

Which mechanism protects the stomach from auto-digestion?

Answer 40

Epithelium lining the lumen;secrete a thick layer of visible mucus that protects the stomach from auto digestion.

Question 41

The mucosa of the fundus of the stomach is composed of?

Answer 41

Epithelial lining Lamina propria Muscularis mucosa

Question 42

Which junctions are formed btw stomach epithelia?

Answer 42

zonulae occludentes and | zonulae adherentes

Question 43

Gastric glands or fundic gland are located in ?

Answer 43

In the lamina propria of the mucus layer.

Question 44

Describe the location, arrangement and division of the fundic gland?

Answer 44

- Each fundic gland extends from the muscularis mucosa to the base of the gastric pit.

Question 45

List the different cells in the gastric gland and their functions?

Answer 45

``` 1- The surface-lining cells 2- Mucous neck cells a 3- Stem (regenerative)cells 4- Parietal (Oxyntic) Cells 5- Chief (Zymogenic) Cells 6- DNES Cells (APUD or Enteroendocrine Cells) ```

Question 46

What is the characteristic of an active Oxyntic (parietal) cell?

Answer 46

a deep intracellular canaliculai with microvilli.

Question 47

Which cell in the fundic gland secrete HCL?

Answer 47

Parietal (Oxyntic) Cells

Question 48

What are the secretion of the Oxyntic cell and their functions?

Answer 48

hydrochloric acid (HCl) and intrinsic factor

Question 49

Which enzyme catalyse the conversion of cytoplasmic water and CO2 to H and HCO3?

Answer 49

carbonic anhydrase

Question 50

How is the mucus neck cell is different from the surface lining cells?

Answer 50

The surface-lining cells: secrete thick mucous The surface-lining cells: secrete soluble mucus and functions to lubricate the gastric contents

Question 51

What type of stem cells is the regenerative cells in the fundic gland?

Answer 51

plueripotent divide to give progenitor cells for all the other Gastric epithelial cells.

Question 52

Where does CL and H join to form HCL?

Answer 52

in the lumen

Question 53

Which cell in the gastric gland is basophilic?

Answer 53

Chief (Zymogenic) Cells basally located nuclei, and apically situated secretory granules that house the proenzyme

Question 54

What does the gastric chief cell secrete?

Answer 54

proenzyme pepsinogen (as well as rennin and gastric lipase).

Question 55

Which nerve influence the secretion of pepsinogen?

Answer 55

vagus nerve.

Question 56

Which hormone influence the secretion of pepsinogen and what is mechanism?

Answer 56

secreten binding to receptors in their basal lamina.

Question 57

Which DNES cells secrete Serotonin and how it influences the stomach?

Answer 57

EC-cells

Question 58

Gastric carcinoids tumors arise from which cells? And what are the associated symptoms?

Answer 58

- EC-cells - overproduction of serotonin. - Serotonin increases gut motility and mucosal vasoconstriction and tissue damage.

Question 59

What are the causes of Gastric duodenal ulcers?

Answer 59

1- Bacterial infections with Helicobacter pylori. 2- Effects of non steroidal anti inflammatory drugs. (NSAID) 3- Overproduction of HCl or pepsin. 4- Lowered production or secretion of mucus or bicarbonate.

Question 60

Which taste buds cell have a short life span?

Answer 60

Intermediate cells.

Question 61

What is the function of taste buds?

Answer 61

perceive salt, sour, bitter, sweet, and umami | taste sensations.

Question 62

What type of epithelial are taste buds?

Answer 62

neuroepithelial

Question 63

When basal cells of the taste buds divide they give rise to......

Answer 63

basal cell and a dark cell. (Other gustatory cells)

Question 64

How many muscular layer in the fundus of the stomach, and how are they arranged?

Answer 64

The smooth muscle cells that compose the muscularis mucosae are arranged in three layers. The inner and outer circular and middle longitudinal layers.

Question 65

Describe the histological features of the Epithelium lining the lumen of the fundus?

Answer 65

Their apical surfaces display short microvilli coverd with glycocalyx layer Their apical cytoplasm contain mucous granules

Question 66

Which Gastric glands cell is located in the isthmus of the gland?

Answer 66

The surface-lining cells | Stem (regenerative)cells

Question 67

Which Gastric glands cell is located in the neck of the gland?

Answer 67

The surface-lining cells | Parietal (Oxyntic) Cells:

Question 68

Which Gastric glands cell is located in the base of the gland?

Answer 68

Chief (Zymogenic) Cells: | DNES Cells

Question 69

What is the function of the intrinsic factor that is released by the Oxyntic cells?

Answer 69

required for uptake of vitamin B12 in the small intestine

Question 70

What is the histological features of the Parietal (Oxyntic) Cells:?

Answer 70

Pyramid in shape active parietal cell is a deep intracellular canaliculai with microvilli.

Question 71

Where does Gastric duodenal ulcers occur?

Answer 71

between the lower esophagus and the | jejunum,

Question 72

What is Gastric duodenal ulcers ?

Answer 72

painful erosive lesions of the mucosa that may extend to deeper layers.

Question 73

Pyloric sphincter is formed by?

Answer 73

the middle circular layer is greatly thickened to form the pyloric sphincter.