Digestive System Flashcards

1
Q

Digestive system order (from food intake to excretion)

A

Oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, rectum

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2
Q

Enteric nervous system

A

collection of 100 million neurons that govern function of gastrointestinal system. Triggers peristalsis.

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3
Q

Hormones that drive thirst, hunger, and satiety

A
  1. Thirst: ADH, Aldosterone
  2. Hunger: Glucagon, Ghrelin
  3. Satiety: Leptin, Cholecystokinin
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4
Q

Ptyalin

A

Salivary amylase. Breaks sugar into smaller sugars (maltose and dextrins)

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5
Q

Esophagus: what muscles comprise it

A
  1. Top: somatic (voluntary) control, mostly skeletal

2. Bottom: autonomic (involuntary) control, mostly smooth

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6
Q

Swallowing: where initiated and where end

A
  1. Initiated at upperesophageal sphincter (at oropharynx)

2. End with lower esophageal sphincter (cardiac sphincter)

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7
Q

Emesis

A

Vomiting

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8
Q

Gastric gland: 3 cells and their roles

A
  1. Mucous cells: secrete mucus, bicarbonate. Protect muscular wall from acidic conditions
  2. Chief cells: produce pepsinogen. Pepsin digests peptides near aromatic amino acids
  3. Parietal cells: produce H+ that cleave pepsinogen to pepsin, produce intrinsic factor. Intrinsic factor helps absorb vitamin B12
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9
Q

Gastric gland

A

Gland in fundus and body of stomach that respond to signals from vagus nerve (parasympathetic)

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10
Q

Pylori glands

A

contain G-cells that secrete gastrin

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11
Q

Gastrin

A

Induce parietal cells to secrete more HCl, signal stomach to mix contents

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12
Q

Small intestine order

A

Duodenum, Jejunum, Ileum

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13
Q

Enzymes and hormones in duodenum

A

Enzymes: brush-border enzymes, enteropeptidase
Hormones: secretin, Cholecystokinin

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14
Q

Brush-border enzymes

A

In luminal surface.

  1. Disaccharidases (maltase, isomaltase, lactase, sucrase)
  2. Aminopeptidase: removes N-terminal AA. Di- and tripeptides can be absorbed back into the intestinal wall
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15
Q

Enteropeptidase

A

Activation of other digestive enzymes from accessory organs.

  1. Secretes hormones (secretin, CCK)
  2. Critical for trypsinogen activation
  3. Can activates procarboxypeptidases A and B
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16
Q

Secretin

A

peptide hormone, causes pancreatic enzymes to be released into duodenum

  1. Regulates pH of digestive tract by reducing HCl production (by parietal cells)
  2. Increases bicarbonate secretion from pancreas

Enterogastrone - hormone that slows motility through digestive tract

17
Q

Cholecystokinin (CCK)

A

Stimulates bile & pancreatic juice secretion. Secreted with entry of chyme

18
Q

Bile

A

Fluid of bile salts, cholesterol, and pigments.

19
Q

Bile salts

A

Cholesterol derivatives that make lipids form micelles, easier for pancreatic lipase for digestion

20
Q

Pancreatic juice

A

complex mixture of several enzymes in bicarbonate-rich alkaline solution. Neutralizes acidic chyme, provides good environment that digests nutrients.

21
Q

Accessory organs of digestion

A
  1. Pancreas
  2. Liver
  3. Gallbladder
22
Q

Pancreas role in digestion

A
  1. Release insulin, glucagon, somatostatin
  2. Made of acinar cells, producing pancreatic juices
  3. Secrete products into ducts that enter duodenum
23
Q

Liver functions

A
  1. Processing nutrients (glycogenesis and glycogenolysis)
  2. Production of urea from ammonia
  3. Detoxification of chemicals
  4. Production of bile
  5. Synthesis of albumin and clotting factors
24
Q

Albumin

A

Protein that maintains plasma oncotic pressure, carrier for drugs, and hormones

25
Bile ducts
Connect liver w/ gallbladder and small intestine. 1. Bile produced in liver, stored in gallbladder 2. Bile pigment: bilirubin (byproduct of Hg breakdown). Bilirubin travels to liver - conjugated then secreted into bile for excretion 3. Jaundice when liver malfunctions
26
Gallbladder role in digestion
Stores & concentrates bile. 1. Contracts and pushes bile out to biliary tree upon CCK 2. Common site of cholesterol or bilirubin stone formation
27
Lacteal
lymphatic channel that takes up fats for transport into lymphatic system
28
What is absorbed via 2ndary active transport and facilitated diffusion
Simple sugars (glucose, fructose, galactose), amino acids. Small fatty acids.
29
Packaging larger fatty acids
Reformed into triglycerides, then packaged into chylomicrons. Enter circulation via lacteals.