Lecture 19

Question 1

Four regions of the stomach (in order)
1.
2.
3.
4.
5.
- areas that form the pyloric part)= ________ and ______

Answer 1

1. Cardia
2. Fundus
3. Body
4. Pyloric
   - antrum; pylorus

Question 2

The muscularis externa in the stomach has 3 layers
1.
2.
3.
- it allows the stomach to _____ (mechanical breakdown) and ____ food

Answer 2

1. oblique muscle
2. circular muscle
3. longitudinal muscle
   - churn; mix

Question 3

Stomach ______: (wrinkles in stomach ______) mucosal folds that allow for gastric __________, enabling it to accommodate varying volumes of ingested food and liquids… _______ the surface area for digestive processes

Answer 3

rugae; lining; expansion; increases

Question 4

Pyloric Sphincter
- located:
- thick ring of ______ muscle that regulates the passage of ______ into the _________

Answer 4

• at the end of the pyloric part of the stomach
• smooth; chyme; duodenum

Question 5

• ________: inner curvature of the stomach
• ________: outer curvature of the stomach
• ___________: double layered peritoneal fold that connects the lesser curvature of the stomach to the ________, it helps suspend and support the stomach

Answer 5

• lesser
• greater
• lesser omentum; liver

Question 6

• pH level within the lumen of the stomach= ______
• pH level near the epithelial cells that line the walls of the stomach= ______
  -this difference is possible due to the ______ of gastric juices (which contain __________) in the lumen. The epithelial cells have _________ mechanisms to prevent the acidic environment from affecting them directly

Answer 6

• 1.5
• 7
• secretion (hydrochloric acid); protective

Question 7

Three mechanisms that protect the stomach from the harsh acidic and enzymatic environment…
1. _____________: the bicarbonate is a ____ that ________ stomach acid
2. __________: prevent ______ _______ from seeping between them
3. ___________: every ___ to ____ days due to the presence of the _____ cells; rapid replacement

Answer 7

1. Mucous-bicarbonate barrier (mucous coat); base; neutralizes
2. Epithelial tight junctions; gastric juice
3. (Damaged) Epithelial cell replacement; 3 to 6; stem

Question 8

• in the mucous coat of the stomach, the _________ ion is abundant
• _______ cells (surface epithelial cells) of the stomach lining is the source of this ion
• this ion acts as a ______ (____ in this case) neutralizing acid

Answer 8

• bicarbonate
• mucous
• buffer; base

Question 9

Does the stomach have any secretion coming from accessory glands?

Answer 9

NO

Question 10

________: fluid secreted by the stomach glands, composed mainly of _____, _____, & _____

Answer 10

gastric juice; water; acid; pepsin

Question 11

Secretions of different cell types in gastric glands
- parietal cells:
- chief cells:
- G cells:
- Enteroendocrine cells:
- Enterochromaffin cells:

Answer 11

• gastric acid (HCl) & intrinic factor
• pepsinogen & lipase
• gastrin
• hormones
• histamine

Question 12

• _____________: glycoprotein that aids in vitamin _____ absorption by the small intestine
• produced in the gastric glands by the __________ cells

Answer 12

• intrinsic; B12
• parietal

Question 13

Pepsinogen is activated by ______ to become pepsin (active… digests ______)

Answer 13

gastric acid (HCl); proteins

Question 14

The digestion of proteins beings in the _______; which enzyme secreted in the gastric glands digests proteins? __________ which was first ___________ secreted by ________ cells then it underwent transformation with the presence of acid

Answer 14

stomach; pepsin; pepsinogen; chief

Question 15

• Gastrin is a ________ secreted by ____ cells (mostly in the _____ _______ but can also be found in the __________)
• amount other functions, it stimulates secretion of ______ by the ______ cells

Answer 15

• hormone; G (pyloric antrum; duodenum)
• HCl; parietal

Question 16

• Cells that are responsible for acid production in the stomach= ___________
• Specific name of the stomach acid= ________
• pump crucial for gastric acid production= __________
  -this pump exchanges ______ for ______ ions across the gastric parietal cell membrane
• ______ used by the proton pump comes from inside the partial cell, ________ ______ (_________) breaks down into __________ ion and ____

Answer 16

• parietal cells
• hydrochloric acid (HCl)
• H+/K+ ATPase (=proton pump)
  -H+ for K+
• H+; carbonic acid (H2CO3); bicarbonate; H+

Question 17

Parietal cells do _____ create HCL in their cytoplasm (it would _______ the cell)!
- so transporting _____ and ____ separately, allows for the cell to maintain its structural integrity

Answer 17

• NOT; destroy
• H+; Cl-

Question 18

What triggers the production of stomach acid?
- Neural: _______ secreted by the _________ nervous system through __________ type 3 receptors
- Hormonal: __________
- Paracrine: __________

Answer 18

• Acetylcholine; parasympathetic; muscarinic
• gastrin
• histamine

Question 19

Factors that stimulate the release of gastrin produced by the _______ cells
- the presence of _____ and _____ in the stomach (increase pH)

Direct effects of gastrin on acid gastric secretion
- it stimulates the ______ cells to release _____ upon binding to a surface receptor

Indirect effects of gastrin on acid gastric secretion
- induces _______ release from ___________ cells, which in turn acts as a _________ signal to further stimulate acid secretion by _______ cells in the gastric mucosa

Answer 19

G
- AAs; peptides
- parietal; HCl
- histamine; enterochromaffin-like (ECL); paracrine; parietal

Question 20

Term for the partially digested, semi-fluid mixture of food and digestive fluids in the stomach

Answer 20

chyme

Question 21

Three phases of gastric acid secretion
1. _________:
2. ________:
3. ________:
- in which gastric acid secretion phase does the enterogastric reflex occur= ________

Answer 21

1. Cephalic phase:
2. Gastric phase
3. Intestinal phase
   - intestinal phase

Question 22

• What stimulates gastric acid secretion during the cephalic phase? ________________
• cephalic phase effects are mediated by the ____________ NS by the ______ nerve
• gastric juice is secreted in response to _____ stimulation

Answer 22

• the sight, taste, smell, or thought of food
• parasympathetic; vagus
• vagal

Question 23

• What triggers the gastric phase of gastric acid production? _____________
• Three factors that induce gastric acid secretion in the gastric phase
  1. ___________ pH of stomach contents
  2. ____________ of the stomach wall
  3. release of _______ triggered by the presence of ________

Answer 23

• the entry of food into the stomach
  1. increase
  2. distension (stretching)
  3. gastrin; peptides

Question 24

When food enters the stomach, it _______ stomach walls, activating two reflexes:
1. _______ reflex: involves ______ stimulation and the release of __________, contributing to acid secretion
2. ______ reflex: coordinated by ________ nerve plexus, influencing muscular _________ and local responses

Answer 24

stretches
1. long; vagal; acetylcholine
2. short; myenteric; contractions

Question 25

- What triggers the intestinal phase of gastric acid production? the arrival of ______ into the _______ which produces its ________ - In this phase, what is the purpose of the duodenum sending inhibitory signals to the stomach? to _____ secretion and ______

Answer 25

- chyme; duodenum; distension - SLOW; motility

Question 26

_____________ reflex: stretching of the wall of the ___________ results in the ___________ of gastric motility (including peristalsis) and reduced stomach _________ rate

Answer 26

Enterogastric; duodenum; inhibition; emptying

Question 27

Hormones that the duodenum releases during the intestinal phase 1. 2. 3.

Answer 27

1. Secretin 2. Gastric Inhibitory Peptide (GIP) 3. Cholecystokinin (CCK)

Question 28

- What triggers the release of secretin by the intestinal cells? __________ - Primary influence of secretin on gastric function is to _________ gastric acid secretion

Answer 28

- decreased pH - DECREASE

Question 29

- GIP= ____________ - CCK= ___________ -major nutritents that stimulate CCK release in duodenum are the arrival of ________ and _______

Answer 29

- Gastric Inhibitory Peptide - Cholecystokinin -lipids (fatty acids); proteins (amino acids)

Question 30

During which of the three phases of gastric acid production is gastric acid secreted in greater proportion? During the ________ phase

Answer 30

GASTRIC

Question 31

- liver ___________: the structural and function units of the liver - ___________ shape in cross section - consists of a ___________ surrounded by __________; they also contain ________ (small blood vessels between rows of ___________)

Answer 31

- lobules - hexagonal - central vein; hepatocytes; sinusoids; hepatocytes

Question 32

- __________ are liver cells, and they are found in the _________ of the liver, contributing to the structural and functional units of the liver tissue

Answer 32

- hepatocytes; lobules

Question 33

Portal triad refers to a specific anatomical arrangement in the _______, and it is found at each ______ of the hepatic lobules. The portal triad consist of THREE structures... - a branch of the hepatic _________ - a branch of the hepatic _______ - a _______ ______

Answer 33

liver; vertex - portal vein - artery - bile duct

Question 34

- ___________: the epithelial cells of the _______ duct - primary function involves the __________ and _________ of _____

Answer 34

- cholangiocyte; bile - modification; transportation; BILE

Question 35

- _________ cells are in the __________( small blood vessels between hepatocytes) - they function as specialized ___________, involved in phagocytosis and immune functions within the _______

Answer 35

- Kupffer; sinusoids - macrophages; liver

Question 36

- ___________ cells: are in the perisinusoidal space (space been the hepatocytes and the sinusoidal endothelial cells) - they are the major storage site for ___________ - upon liver damage: ______________ (scar creation) and _______________

Answer 36

- stellate - vitamin A - fibrogensis; regeneration

Question 37

- fibrogensis: the development of _________ tissue - fibrosis: refers to the ____________ accumulation of fibrous connective tissue, mainly composed of _______, in an organ or tissue - this process occurs in response to ______, inflammation, or chronic damage and can lead to the ________ and stiffening of the affected tissue - cells in the hepatic lobule that contribute to this process= _____________

Answer 37

- fibrous - excessive; collagen - injury; scarring - stellate cells

Question 38

Can hepatocytes undergo replacement, meaning does the liver regenerate after experiencing damage? _______ because of ______ cells

Answer 38

YES; stem

Question 39

- Bile contains ________ (_______) and they play a major role in _____ digestion - Bile is produced by __________ in the _____ and secreted into _______ _______ (channels)

Answer 39

- bile acid (bile salts); fat - hepatocytes; liver; bile canaliculi

Question 40

The "tubular structure" that connects the bilecanaliculi to the bile duct (or biliary) is the _____________

Answer 40

bile ductule (canal of hering)

Question 41

In the Bile duct (biliary).. - bile is modified by ____________ lining the ducts

Answer 41

cholangiocytes

Question 42

_________ is a hormone that STIMULATES the cholangiocytes to secrete ________ and _______ into the bile within the bile duct

Answer 42

Secretin; bicarbonate; water

Question 43

- The __________ duct and ________ duct form the ________ duct - the ________ duct and _______ duct form the common bile duct

Answer 43

- right hepatic; left hepatic; common hepatic - common hepatic; cystic

Question 44

- the common hepatic duct: collects ____ from the _____ _______ (bile flows out of ____) - the common bile duct: transports the combined bile from the common hepatic duct and the ______ duct (from the _________) to the ________ for digestion

Answer 44

- bile; liver lobules (liver) - cystic (gallbladder); duodenum

Question 45

- the _________ of ________ is located at the confluence of the __________ duct and the __________ duct - its the spot where _____ and ______ gets released into the _________

Answer 45

- ampulla of vater; common bile; pancreatic - bile; pancreatic; duodenum

Question 46

Which spinster regulates the release of pancreatic juice and bile into the duodenum through the ampulla of water?

Answer 46

Sphincter of Oddi (aka hepatopancreatic ampulla)

Question 47

- In the gallbladder, CCK induces ___________ - CCK facilitates the _________ of stored bile into the _______ duct

Answer 47

- contraction - secretion; cystic

Question 48

CCK causes __________ in the Spincter of Oddi - this facilitates the secretion of bile and pancreatic juice into the ________

Answer 48

relaxation - duodenum

Question 49

- pancreatic juice is a ___________ rich fluid containing ________ that digest all categories of foods - the ________ portion of the pancreas produces pancreatic juice - pancreatic juice is transported from the ________ to the ________ though the ________ duct that will join the common bile duct and finally at the ______________

Answer 49

- bicarbonate; enzymes - exocrine - pancreas; duodenum; pancreatic; ampulla of vater

Question 50

Two cell types that constitute the exocrine pancreas 1. _________: present in the pancreatic ducts 2. _________: located in the acini or clusters

Answer 50

1. duct cells (ductal cells) 2. acinar cells

Question 51

Pancreas - Acinar cells secrete the ________- rich component - _______ is the hormone that induces this secretion

Answer 51

- enzyme - CCK

Question 52

Name of granules found in the acinar cells= ___________ - they contain _______ _______ (_________ or ________)

Answer 52

zymogen granules - inactive enzymes (proenzymes or zymogens)

Question 53

Certain enzymes present in pancreatic juice are in the form of zymogens for ________ measure - prevents __________ activation and potential damage to __________ tissue by these powerful digestive enzymes - activation typically occurs in __________, ensuring safe and controlled digestion

Answer 53

- protective - premature; pancreatic - duodenum

Question 54

Pancreatic duct cells secrete a ________ secretion, rich in _________ ions - the hormone _________ stimulates this secretion

Answer 54

- watery; bicarbonate - secretin

Question 55

Three zymogens that are released by the pancreas to facilitate PROTEIN digestion and names of their corresponding active enzymes 1. 2. 3.

Answer 55

1. trypsinogen--> trypsin 2. chymotrypsinogen --> chymotrypsin 3. procarboxypeptidase --> carboxypeptidase

Question 56

- in which location is pancreatin trypsinogen converted into the active form? ___________ - trypsinogen is converted into the active form through the action of __________ (enzyme), which is present in the ______ ________ of the _______ mucosa - _____________ cleaves trypsinogen to form the active enzyme ________ - the activation process for the remaining pancreatic zymogens is through _______

Answer 56

- duodenum - enteropeptidase; brush border; duodenal - enteropeptidase; trypsin - trypsin

Question 57

Four other enzymes found in pancreatic juice 1. 2. 3. 4.

Answer 57

1. pancreatic amylase 2. pancreatic lipase 3. ribonuclease 4. deoxyribonuclease