Anatomy stomach/Intestins 2 Flashcards Preview

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Flashcards in Anatomy stomach/Intestins 2 Deck (25)
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1
Q

What are the primary functions of the stomach?

A

Storage of ingested food
Mechanical disruption
Enzymatic breakdown
Production of “intrinsic factor”

2
Q

What substances do the following secrete?

  1. Stomach epithelium mucous cells
A

Epithelium = simple columnar with mucous cells that produce an alkaline mucous.

3
Q

pH of the stomach is around what?

Acidic pH will not digest what?

A

1.5-2.0

Chyme

4
Q

What are the functions of stomach pH?

A

Kills any microorganisms
Denatures proteins and inactivates enzymes
Breaks down plant cell walls and connective tissues in meat
Pepsin only functions at low pH

5
Q

What controls gastric activity?

A

CNS
Reflexes of the enteric nervous system in the wall of the stomach
Hormones of the digestive tract

6
Q

Amylase and lipase in saliva continue to work until stomach pH drops below pH___
Pepsin activity kicks in around pH___

A

Amylase and lipase in saliva continue to work until stomach pH drops below pH4.5
Pepsin activity kicks in around pH2.0

(if pH isn’t good at digesting food it
Kills microbes or bacteria in food

7
Q

What is most important to digestion(stomach, large intestine or small intestine)?

What percent of absorption happens there?

A

Most important digestion and 90% of absorption occurs in the small intestine

8
Q

What is the major gross feature of the intestinal lining?

A

Transverse folds also called circular folds or plicae circulares

9
Q

What are the absorptive cells of the small intestine?

Secretory cells?

A

Enterocytes

Secretory cells:
Goblet cells
Paneth cells
Enteroendocrine cells

10
Q

What is secreted by goblet cells?

A

secrete mucins

11
Q

What is secreted by paneth cells

A

secrete antimicrobial compounds

12
Q

What is secreted by Enteroendocrine cells

A

cells found in epithelium produce hormones like gastrin, cholecystokinin and secretin

13
Q

What is secreted by Enterocytes?

A

(peptidases and carbohydrases), produced by these cells, finalize the digestive process right at the absorption site.

14
Q

What stimulates Myenteric reflexes?

A

Myenteric reflexes stimulated by entry of chyme to duodenum stimulate the weak peristalsis that delivers it to the jejunum

15
Q

What stimulates parasympathetic reflexes?

A

Parasympathetic stimulation promotes a more active peristalsis and segmentation

16
Q

What stimulates stretch receptors?

A

Stretch receptors and hormones may stimulate neuronal control of peristalsis and sphincter relaxation

17
Q

What is the function of the pancreas?

What does it produce?

A

Primarily and exocrine organ producing digestive enzymes and buffers, the pancreatic duct delivers secretions to duodenum.

Also an endocrine organ, Islets of Langerhans cells (1% of pancreas) produce a number of hormones including insulin and glucagon

18
Q

Acinar and epithelial cells secrete what?

A

Acinar and epithelial cells secrete pancreatic juices (about 1000 ml) (enzymes, water and ions) into the small intestine

19
Q

What are the pancreatic enzymes?

What do they each break down.

A

Alpha-amylase – breaks down starches
Lipase – breaks down lipids
Nucleases – break down RNA, DNA
Proteolytic enzymes – break down large proteins
Peptidases break down small peptides into AA

20
Q

What substances do the following secrete?

  1. Gastric glands
A

Gastric glands produce 1.5 L of gastric secretion each day:

21
Q

What substances do the following secrete?

  1. Parietal cells
A

Parietal cells secrete intrinsic factor and HCl

22
Q

What substances do the following secrete?

  1. Chief cells
A

Chief cells secrete pepsinogen which becomes active pepsin, to digest proteins

23
Q

What substances do the following secrete?

  1. Pyloric Glands
A

Pyloric Glands secrete mucous and hormones like gastrin, that stimulates parietal and chief cell secretion

24
Q
  1. What are the mucosal folds or ridges in the stomach lining called?
A

reggae

25
Q
  1. Name the two sphincters that control the stomach entrance and exit
A

Cardiac sphincter-Entrance

Illoric splinter- Exit