Histology Part 2 - Digestive System

Front 1

location of esophagus

Back 1

extends from the oropharynx to the stomach, has 3 parts: upper, middle and lower thirds.

Front 2

where are mucous glands in the esophagus

Back 2

Mucous glands are present in the submucosa of all regions, but only the upper and lower 1/3rds have mucous glands in the lamina propria

Front 3

muscularis externa in the esophagus

Back 3

upper 1/3, a continuation of the pharynx, is skeletal muscle. The lower 1/3, continuation of the stomach, is composed of smooth muscle. The middle 1/3 is a blending of the 2 varieties of muscles.

Front 4

component that guide to identifying esophagus

Back 4

muscularis externa

Front 5

Characteristics of mucosal epithelium, muscularis externa, adventitia.

Back 5

mucosal epithlium: muscularis mucosa and lamina propria.
muscularis externa: circular and longitudinal smooth muscle.
adventitia: fibroelastic connective tissue that binds the esophagus to adjoining structure

Front 6

types of epithelium of esophagus

Back 6

stratified squamous epithelium (non-keratinizing)

Front 7

features of esophagogastric junction

Back 7

1. abrupt change from stratified squamous epithelium (esophagus) to the simple columnar, mucus secreting epithelium (stomach)
2. presence of mucosal glands (cardiac glands) in the terminal esophagus (located in the submucosa in the rest of the esophagus)

Front 8

3 regions of stomach

Back 8

cardiac, fundic body and pylorus

Front 9

cardiac stomach is recognized by? fundus body of the stomach is recognized by?

Back 9

Cardiac stomach is recognized by pure mucous gastric glands. The fundus body of the stomach is recognized by fundic glands, which is continuous with gastric pits.

Front 10

rugae of the stomach is made of what 2 structural layer?

Back 10

regae are made of mucosa and submucosa.

Front 11

Grooves that subdivide the mucosal surface of stomach into slightly bulding gastric area

Back 11

mammillated area

Front 12

Cells that protect the lining of stomach from the gastric juices

Back 12

mucous cells

Front 13

Pepsinogen are secreted by?

Back 13

Chief cells

Front 14

HCl and intrinsic factor (essential for Vit B12 absorption) are secreted by?

Back 14

parietal cells

Front 15

Function HCl in the stomach?

Back 15

HCl activates the pepsinogen secreted by the chief cells into pepsin.

Front 16

Structure of pyloric junction (sphincter)

Back 16

1. thickening of the circular layer of the muscularis externa, which forms the pyloric sphincter
2. columnar enterocytes (absorptive cells) are present on the surface of the villus protrusions
3. Glnds of Brunner, neutralize the acidic chyme)

Front 17

Function of the pyloric sphincter

Back 17

controls the passage of the chyme from the stomach into the duodenum

Front 18

Function of the duodenum

Back 18

1. receives digested bolus from the stomach
2. receives digestive enzymes from the stomach, pancreas and liver
3. secretes an alkaline mucus to neutralize the acidic chyme

Front 19

structure of the duodenum

Back 19

1. 25cm in length
2. enterocytes is the main cells of the epithelial layer
3. goblet cell: secret mucus
4. Paneth cell line the intestinal crypt of Lieberkuhn
5. Brunner's glands

Front 20

Function of the jejunum

Back 20

1. chemical breakdown of the food chyme
2. absorption

Front 21

structure of the jejunum

Back 21

1. 2.5m in length
2. plicae circulares are the most numerous in the proximal part and morm most of the submucosa
3. goblet cell
4. paneth cell line the intestinal crypts of lieberkuhn
5. brunner's glands are absent

Front 22

Paneth cells functions in?

Back 22

host defense, and they are next to stem cells

Front 23

Function of ileum

Back 23

1. absorption of Vit B12 and bile salts, things not absorbed by the jejunum

Front 24

Structure of ileum

Back 24

1. 3.5m in length (longest of the small intestine)
2. the plicae circulares are smaller and fewr
3. presence of lymphatic nodules (Peyer's patches)
4. absence of Brunner's glands

Front 25

Structure that characterizes the ileum

Back 25

lymphatic nodules of the Peyer's patches

Front 26

function of the Ileocecal junction

Back 26

1. prevents retrograde movement of fecal contents back into the ileum

Front 27

structure of ileocecal junction

Back 27

1. reduction in size and number of villi
2. muscularis mucosa continues uninterrupted like submucosa and muscularis externa

Front 28

Enteric nervous system

Back 28

2 layers of neurons located on the wall of GI tract. Meissner's plexus and auerbach's (myenteric) plexus

Front 29

Meissner's plexus is located btw? Auerbach's (myenteric) plexus located btw?

Back 29

Meissner's plexus: btw submucosa and muscularis externa layers. Auerbach's (myenteric) plexus: between muscularis externa and longitudinal layer of smooth muscle.

Front 30

Function of the appendix

Back 30

1. immunologic role
2. potential B cells gains immunocompetence

Front 31

structure of appendix

Back 31

1. 2.5 - 13cm in length
2. lacks both plicae circularis and villi
3. mucosa is similar to that of the colon
4. large lymphatic nodules
5. appendix may or may not be there in some adults

Front 32

function of the colon

Back 32

1. reabsorption of electrolytes and water
2. elimination of undigested food and other waste material

Front 33

structure of the colon

Back 33

1. 1.5m in length
2. simple columnar epithelium made of goblet cells, absorptive cells, and enteroendocrine cells
3. paneth cells are absent
4. teniae coli: expansions of parts of outer longitudinal layer of the mascularis externa
5. crypts of Lieberjuhn

Front 34

T/F
Stomach has crypts, no villi.
Small intestine has villi, no crypts.

Back 34

true

Front 35

structure of the rectum

Back 35

mucosa of the rectum is the same as that of the colon: columnar epithelium

Front 36

structures of the anal canal

Back 36

1. stratified epithelium, nonkeratinized (upper portion of the anal canal)
2. keratinized stratified squamous epithelium at the lower portion of anal canal
3. the lower portion of the anus is associated with sebaceous flands and hair follicles

Front 37

anocutaneuous junction

Back 37

1. muscularis mucosa ends at the junction
2. the smooth muscles of the circular level of the muscularis externa thickens to become the internal anal sphincter
3. the external sphincter is formed by the striated muscles of the pelvic Fl and perineum
4. sebaceuous glands

Front 38

crypt of Lieberkuhn are found where?

Back 38

It's found in the small intestine and colon

Front 39

liver function

Back 39

1. has both exocrine and endocrine functions
2. hemopoiesis beginning in the 3rd month of gestation

Front 40

liver: 2 largest what?

Back 40

largest internal organ and largest mass of glandular tissue in the body

Front 41

structure of liver

Back 41

1. receives blood from the hepatic portal vein (venous blood from GI, pancreas and spleen)
2. lobules or acini are the functional units
3. blood sinusoid, separates acini

Front 42

vessels of the liver

Back 42

arterial blood come from the hepatic artery, venous blood come from the portal vein. central veins carry clean blood from the sinusoid. portal vein and hepatic vein come together at the central vein.

Front 43

blood flow in the liver

Back 43

portal vein and hepatic artery -> hepatic sinusoids -> central (hepatic) vein -> leaves the liver

Front 44

Kupffer cells and hepatocytes

Back 44

kupffer cells (macrophages) and hepatocytes clean the blood, before the blood reaches the central vein.

Front 45

Classic liver lobule: what's in the center? corners are consist of what?
Portal lobule: what's in the center? the corners are consist of what?
hepatic acinus: arranged around what? what's on the corners?

Back 45

Classic liver lobule: central vein is at its center. portal triads lie at the corners of hexagonal classical liver.
Portal lobule: portal triad is at its center. centeral veins are at its 3 corners.
Hepatic acinus: with 2 portal triads and 2 central veins at its corners. branches of portal artery, vein and bile duct running btw the portal triads.

Front 46

the 3 concentric elliptical zones

Back 46

1. these cells are the 1st to receive O2, nutrients, and toxins from the sinusoidal blood and to show morphological changes; they are last to die and the first to regenerate
2. are the first to show ischemic necrosis due to limited circulation and the 1st to show fat accumulation
3. cells have functional and morphological characteristics and responses intermediate to those of zone 1 and 3.

Front 47

Functional units of livers (3 units) and its shapes

Back 47

1. classic liver lobule (hexagon)
2. portal lobule (triangle)
3. hepatic acinus (diamond)

Front 48

Can hemopoesis resume if bone marrow losses its ability to produce blood cell?

Back 48

yes to some degree

Front 49

where's RBC's located in the liver

Back 49

btw the liver parenchymal cells and the endothelium lining the vascular sinuses

Front 50

Flow of bile in the liver from cells to the duct

Back 50

bile canaliculus (intercellular space) -> bile ductule (periphery of the lobule) -> bile ducts (portal traid) -> left and right hepatic ducts -> gall bladder

Front 51

portal triads are composed of 3 structures

Back 51

branches of portal vein, hepatic artery and bile duct

Front 52

bile contains

Back 52

conjugated bile salts, cholesterol, phospholipids and bilirubin

Front 53

structure and cells of gallbladder

Back 53

1. tall, columnar, absorptive epithelial cells
2. attach to the surface of the liver
3. muscularis resembles the muscularis externa in the intestine (consists of smooth muscle bundles)
4. adventitia contains nerves and blood vessels
5. no muscularis mucosa and submucosa
6. basolateral intercellular space
7. lymphocytes
8. mucus-secreting glandFuFun

Front 54

what is Rokitansky-Aschoff sinuses, what organ does it belong to?

Back 54

They are outpouches of the epithelial lining that can extend thru the muscularis. It's found in the gallbladder and is associated with gallstones.

Front 55

Function of pancreas

Back 55

1. source of enzymes that break down fats, CHO, proteins, substance that neutralize stomach acid.
2. insulin, glucagon and somatostatin

Front 56

Structure of pancreas

Back 56

exocrine: serous secreting acinar cells. endocrine: islets of Langerhans

Front 57

islet of Langerhans

Back 57

B cells: insulin
A cells: glucagon
D cells: somatostatin

Front 58

course of enzyme secretion in pancreas

Back 58

Acini -> intercalated ducts -> intralobular ducts (simple cuboidal) > pancreatic duct