Test 3 Histology Gi System 2

Front 1

What are the GENERAL layers of the Digestive Tract from outside the tube in?

Back 1

1. Serosa or Adventitia
2. Muscularis Externa
3. Submucosa
4. Mucosa

Front 2

What is the Adventitia?

Back 2

A layer of loose CT that is NOT covered by Mesothelium.

Front 3

What is the Serosa?

Back 3

A thin layer of CT (loose or dense) that IS covered by Mesothelium.

Front 4

What is the difference between Adventitia and Serosa? Where would you likely find each?

Back 4

The serosa and the adventitia both make up the outer layer of the digestive tract. The adventitia is NOT surrounded by mesothelium, such as in the esophagus. Almost everything else is Serosa, which IS covered by mesothelium.

Front 5

What makes up the Muscularis Externa?

Back 5

Usually has two layers of smooth muscle:
Inner Circular
Outer Longitudinal
(Can also have 3 thick layers depending on location in GI.)

Front 6

This part of the wall of the digestive tract is responsible for peristalsis.

Back 6

Muscularis Externa

Front 7

What important neuro structure is located in the Muscularis Externa?

Back 7

Auerbach's (Myenteric) Plexus
(an autonomic nerve plexus)

Front 8

The ANS innervation of the Muscularis Externa is mainly ____. Therefore, you will see what in this layer?

Back 8

Mainly Parasympathetic
So you see lots of soma in this layer (because they are synapsing here.)

Front 9

The submucosa of the digestive tract may contain ____ tissue and ____.

Back 9

Lymphoid Tissue
Glands

Front 10

What nerve plexus is located in the Submucosal layer of the digestive tract?

Back 10

Meissner's (Submucosal) Plexus

Front 11

Meissner's Plexus is located in what layer?
This autonomic plexus is mainly ____ so you would see what?

Back 11

Submucosa of digestive tract
Sympathetic
Very few soma

Front 12

Lots of change and variation can occur in this layer of the digestive tract.

Back 12

Submucosa

Front 13

What are the three layers of the mucosa from inside the digestive tract to outside?

Back 13

1. Epithelial Lining
2. Lamina Propria
3. Muscularis Mucosa

Front 14

What is the structure of the epithelial lining of the mucosa?

Back 14

Variable.
Usually Simple Columnar but can also be Stratified Squamous Non-keratinized in esophagus and anus.

Front 15

What may be contained in the lamina propria of the mucosa of the digestive tract?

Back 15

Glands

Front 16

What is the structure of the Muscularis Mucosa layer of the Mucosa of the digestive tract?
What is the function of this layer?

Back 16

Structure:
Two or three thin layers of smooth muscle arranged as inner circular and outer longitudinal.
Function:
Control the movement of the actual mucosa.

Front 17

What are the layers of the esophagus from outside in?

Back 17

1. Adventitia
2. Muscularis Externa
3. Submucosa
4. Mucosa

Front 18

What is the structure of the Muscularis Externa in the esophagus?

Back 18

Upper one-third has skeletal muscle (swallowing can be initiated voluntarily). The middle one-third has a mix of skeletal and smooth muscle. The lower one-third is just smooth muscle.

Front 19

What is found in the Submucosa of the Esophagus?
Why are these structures important?

Back 19

Serous-mucus glands called esophageal glands are found throughout the length of the esophagus.
These are important because their mucus provides lubrication for swallowing food.

Front 20

What layers make up the mucosa of the esophagus?

Back 20

Epithelium
Lamina Propria
Muscularis Mucosa

Front 21

What type of epithelium makes up the mucosa of the esophagus?

Back 21

Stratified Squamous NON-keratinized

Front 22

What structure would you find in the Lamina Propria of the esophagus and where would these be?

Back 22

Mucus secreting glands called esophageal cardiac glands.
These are located near the stomach.

Front 23

What is the structure of the muscularis mucosa of the esophagus?

Back 23

A SINGLE layer of longitudinal smooth muscle.

Front 24

Stomach-
Think _____ Epithelium?

Back 24

SIMPLE COLUMNAR

Front 25

What are the gross regions of the stomach? What are the histologic regions?

Back 25

Gross regions:
1. Cardia
2. Fundus
3. Body
4. Pylorus
Histologic Regions:
1. Cardiac
2. Fundic
3. Pyloric

Front 26

What layers of the stomach do rugae involve?

Back 26

Mucosa and Submucosa

Front 27

What are the main layers that make up the stomach from inside out?

Back 27

Mucosa
Submucosa
Muscularis Externa
Serosa

Front 28

What type of cells make up the surface of the mucosa of the stomach? What do these cells produce and why?

Back 28

Simple Columnar
Produce mucus and bicarbonate ions to protect the stomach from acid.

Front 29

Although the epithelium does not normally absorb substances from the stomach lumen, some ___, ____ and ____ pass across this layer.

Back 29

Water
Salts
Lipid-Soluble Drugs

Front 30

_____ and ____ damage the surface cells of the stomach and diffuse into the lamina propria where they enter ____.

Back 30

Alcohol and Aspirin
Blood vessels

Front 31

What are the layers of the mucosa in the stomach?

Back 31

Epithelial
Lamina Propria
Muscularis Mucosa

Front 32

What are gastric pits? What are they lined with?

Back 32

Gastric pits are invaginations of the surface epithelium into the lamina propria (in the stomach).
They are lined with surface mucous cells (Simple Columnar).

Front 33

What type of glands are Gastric Glands?

Back 33

Branched Tubular Glands

Front 34

Where are Gastric Glands located?

Back 34

Located at the bottom of the pits in the lamina propria.

Front 35

What are the three types of Gastric Glands? What do they correspond to?

Back 35

1. Cardiac Glands
2. Gastric (Fundic) Glands
3. Pyloric Glands

Front 36

Cardiac Glands
Where are they found?
What nearby glands are they similar to?

Back 36

Found in the cardia of the stomach.
Similar to the esophageal glands (which provide lubrication for swallowing.)

Front 37

What do Cardiac Glands secrete?

Back 37

Mostoly mucus cells.
Secrete mucus and lysozyme (a bacteriocidal enzyme).

Front 38

What type of cels are located in the upper part of cardiac glands and what do these give rise to?

Back 38

Undifferentiated cells in the upper part of the gland give rise to the mature cell types of the gland.

Front 39

Where are Gastric (Fundic) Glands found?

Back 39

Found in the body and the fundus of the stomach.

Front 40

Gastric glands:
The gastric pits are ____ and the glands are ____.

Back 40

Pits are short
Glands are long

Front 41

Gastric glands can be divided into what regions from top to bottom?

Back 41

(Gastric Pit -->)
1. Isthmus
2. Neck
3. Body

Front 42

What are the 5 cell types that are found in Gastric (Fundic) Glands?

Back 42

1. Undifferentiated Stem Cells
2. Mucous Neck Cells
3. Parietal Cells
4. Chief (Zymogenic) Cells
5. Enteroendocrine (Neuroendocrine) Cells

Front 43

What is the turnover rate of the gastric pit and surface mucous cells in a Gastric Gland?

Back 43

Short turnover.
3-7 Days

Front 44

What is the function of undifferentiated stem cells in the Gastric Glands?

Back 44

Replace the gastric pit cells and the surface mucous cells which have a short turnover rate from all the acid damage.

Front 45

What is the function of the Surface Mucous cells of the Gastric Glands?

Back 45

They secrete a neutral mucus that protects the stomach's surface from the acidity of the gastric fluid.

Front 46

How do the parietal cells of the Gastric Glands stain and where in the gland are they found?

Back 46

Acidophilic (due to large number of mitochondria).
Found mainly in the upper half of the gland.

Front 47

What is the function of the Parietal Cells of the Gastric Glands?

Back 47

Produce HCl and IF (glycoprotein).

Front 48

Why is IF necessary?

Back 48

Needed for vitamin B12 absorption in the terminal ileum.

Front 49

How do the Chief Cells (Zymogenic cells) of the Gastric glands stain and where in the gland are they found?

Back 49

Basophilic
Found mainly in the lower half of the gland.

Front 50

What is the function of Chief Cells in the Gastric Glands?

Back 50

They produce pepsinogen (the inactive zymogen of pepsin), lipase, and rennin.

Front 51

What type of cell secretes rennin and what does it do?

Back 51

Chief Cells (in Gastric Glands)
Involved in milk digestion

Front 52

How is pepsinogen converted to pepsin?

Back 52

By acidic gastric juice

Front 53

Enteroendocrine cells of the Gastric Glands:
Secrete?
Affect function of?

Back 53

Secrete:
Several GI Polypeptide Hormones (including serotonin)
Affect:
Activity of stomach, pancreas and gall bladder.

Front 54

Where are Pyloric Glands found?
They have ___ pits and ___ glands.

Back 54

Found in pyloric region of stomach.
Long pits
Short glands

Front 55

What cell type do Cardiac Glands have that Pyloric Glands lack?

Back 55

Chief (Zymogenic) Cells

Front 56

What type of cells are found in the Pyloric Glands of the stomach?

Back 56

1. Mucous cells
2. Enteroendocrine cells
3. Parietal cells
4. Undifferentiated stem cells

Front 57

What is the function of Mucous cells in the Pyloric Glands?

Back 57

Secrete mucous and lysozyme

Front 58

What different types of Enteroendocrine cells are located in the Pyloric Glands and what does each secrete?

Back 58

G Cells- Secrete Gastrin
D Cells- Secrete Somatostatin

Front 59

What is the affect of the gastrin released by G-Cells of the Pyloric glands?

Back 59

Gastrin stimulates the parietal cells in the gastric glands to secrete HCl.

Front 60

What is the affect of the somatostatin released by the D-Cells of the Pyloric glands?

Back 60

Somatostatin regulates the release of other hormones.

Front 61

Would you find more parietal cells associated with Gastric Glands or Pyloric Glands?

Back 61

Gastric Glands.
Only a limited number found in Pyloric Glands.

Front 62

Muscularis Mucosa of the stomach.
Structure?
Function?

Back 62

Consists of two or three layers of smooth muscle throughout the stomach mucosa.
Helps to empty the glands in the Lamina Propria.

Front 63

What is the overall structure shown?

Back 63

Esophagus
(Layers arent bold terms but still good for ID'ing)

Front 64

What structure is shown? (Regions?)

Back 64

Esophagus Stomach Junction
(Be able to distinguish upper and lower esophagus by muscle present.)

Front 65

What structure is shown? (Regions?)

Back 65

Esophagus Stomach Junction
(Be able to distinguish upper and lower esophagus by muscle present.)

Front 66

Where is this?
What gland is present and what layer are these from?

Back 66

Esophagus-Cardia Junction
Cardiac Glands in Lamina Propria of Mucosa.

Front 67

What area of the stomach is this?
What glands are present?

Back 67

Fundic Region
Gastric (Fundic) Glands

Front 68

What area of the stomach is this?
What glands are present?

Back 68

Fundic Region
Gastric (Fundic) Glands

Front 69

What stomach region is this?
What glands are present?
What cells of these glands are distinguishable?

Back 69

Fundic
Gastric (Fundic) Glands
Chief Cells and Parietal Cells

Front 70

What region of the stomach is this?
What kind of glands are visible? Whats the structure at the top?

Back 70

Pyloric Stomach
Pyloric Glands of the Lamina Propria
Gastric Pits

Front 71

These glands have long pits and short glands. What are they? What region of the stomach is this? What type of cells are distinguishable in these glands?

Back 71

Pyloric Glands
Pyloric Stomach
Mucous Cells (taggable)