Digestive Flashcards

1
Q

GI tract consists of

A

1) Mouth
2) Pharynx
3) Oesophagus
4) Stomach
5) Small intestine
6) Large intestine
7) Anus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Accessory structure consists of

A

1) Tongue
2) Salivary glands
3) Spleen
4) Pancreas
5) Liver
6) Gallbladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Small intestine subdivisions are

A

1) Duodenum
2) Jejunum
3) Iluem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Large intestine subdivisions are

A

1) Cecum
2) Ascending
3) Transverse
4) Descending
5) Sigmoid
6) Rectum
7) Anal canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Process of ingestion

A

Selective intake of food and drink

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Process of secretion

A

Secretion of water, HCL, salts, buffers, digestive enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Process of propulsion

A

Moving food along the digestive tract form one part to the next

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Digestion: Mechanical

A

Physical breakdown of food into smaller pieces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Digestion: Chemical

A
Breakdown of food by digestive enzymes 
– Carbohydrates → Sugars
– Proteins → Amino acids 
– Fats → Fatty acids
– Nucleic acids → Nucleotides and acids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Process of absorption

A

Uptake nutrients into digestive cells, blood and lymph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Process of defacation

A

Elimination of undigested material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Basic structure of alimentary canal (from inside to out)

A

1) Mucosa
2) Submucosa
3) Muscularis
4) Serosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Mucosa functions

A
  • Secrete mucus/digestive enzymes/hormones
  • Absorb the end products of digestion to blood
  • Protect against infectious disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Submucosa functions

A

Regulates the movement of stomach/intestine/blood vessels vasoconstriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Muscularis functions

A

Contraction moves food along the digestive tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Serosa functions

A

Secretes serous fluid (Reduces friction as it moves over other organs in the abdominal cavity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Peristalsis is

A
  • Propulsion of food along GI tract by circular muscle layers
  • Strongest in oesophagus & stomach
  • Weakest in small intestine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Segmentation is

A

Alternating ring-like, evenly spaced / localised contractions in the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Mass peristalsis is

A
  • Progressive, strong & vigorous peristaltic waves

* Starts in the transverse colon propel colon contents into rectum/anus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Mouth

A
  • Ingestion (food in)
  • Chewing (mastication)
  • Saliva (mucous, amylase, lysozyme)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Pharynx

A

Swallowing (deglutition)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Oesophagus

A

Peristalsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Stomach

A

1) Churning (mixing of food with gastric juices)
2) Secretions
• Hydrochloric Acid
• Pepsinogen
• Lipase
• Rennin
• Intrinsic Factor
• Mucus
• Hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Liver functions

A

Produces and secretes bile
Excretion: Bilirubin
Processing: The liver detoxifies certain substances and excretes drugs into bile
Metabolises: Carbohydrates, proteins and fats
Stores: Carbohydrates, fats, vitamins and minerals
Phagocytosis: The Kupffer cells of the liver phagocytise aged red & white blood cells and some bacteria
Activation of vitamin D: Synthesises the active form of vitamin D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Gallbladder

A

Stores and concentrates bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Pancreas types of glands

A

Endocrine glands

Exocrine glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Pancreas: Endocrine

A

Release of hormones into bloodstream

28
Q

Pancreas: Exocrine

A

Digestive enzymes through duct

29
Q

Hydrochloric acid

A

Activates pepsin and lipase, kills bacteria

30
Q

Pepsinogen

A

Inactive form of pepsin, breakdown protein

31
Q

Lipase

A

Breakdown fat

32
Q

Rennin

A

Curdles milk

33
Q

Intrinsic Factor

A

Absorption of B12 by small intestine

34
Q

Mucus

A

Protects stomach lining

35
Q

Hormones

A

Regulates HCl secretion and gastric mobility

36
Q

Pancreatic juice consists of

A
  • H2O
  • Sodium bicarbonate –Neutralises stomach’s acidic chyme
  • Lipase –Breakdown lipids into fatty acids & glycerol
  • Amylase - CHO (polysaccharides, disaccharide maltose)
  • Trypsin, chymotrypsin & carboxypeptidase  Proteins (polypeptides) broken down into short chain amino acids
  • RNA & DNA digestive enzymes  Nucleases
37
Q

Small intestine functions

A

Goblet secretes mucous
Enteroendocrine cells secrete hormones
Paneth’s cells secrete lysozymes
Peyer’s patches are aggregated lymphoid follicles at end of small intestine

38
Q

Small intestine structural modifications for absorption

A

1) Circular folds
2) Villi
3) Microvilli

39
Q

Circular folds

A

Permanent folds (~1 cm deep) that force chyme to slowly spiral through lumen, allowing more time for nutrient absorption

40
Q

Villi

A

Fingerlike projections of mucosa (~1 mm high) with a core that contains dense capillary bed and lymphatic capillary called a lacteal for absorption

41
Q

Microvilli

A

Cytoplasmic extensions of mucosal cell that give fuzzy appearance called the brush border that contains membrane-bound enzymes brush border enzymes, used for final carbohydrate and protein digestion

42
Q

Small intestine digestion: Carbohydrates (conversion into simple sugars)

A

Disaccharide + Enzyme = Monosaccharides

1) Maltose + Maltase = Glucose + Glucose
2) Sucrose + Sucrase = Glucose + Fructose
3) Lactose + Lactase = Galactose + Glucose

43
Q

Small intestine digestion : Protein peptides

A

Pancreatic protease becomes single amino acids

44
Q

Small intestine digestion: Fat

A

Secretions from pancreas and liver

45
Q

Salivary amylase

A
  • Turns starch into oligosaccharides

* Stops working is pH less then 4.5

46
Q

Important brush border enzymes

A
  • Dextrinase & Glucoamylase - act upon oligosaccharides with more than 3 simple sugars
  • Maltase, Sucrase & Lactase
47
Q

Small intestine absorption: Carbohydrates

A

Because glucose are too large to enter transportation into plasma membrane of a cells occurs through
• Facilitated Diffusion
• Sodium-Glucose Co-transporter (SGLT-1)
Sodium flow down their gradient into the cell, providing the energy to transport glucose into the cell against its gradient

48
Q

Small intestine absorption: Proteins

A

Facilitated diffusion
Glucose hitches a ride with sodium
Sodium allows absorption of carbohydrates

49
Q

Bile salts used for

A

Emulsification and absorption of lipids, cholesterol, phospholipids and lipoproteins in the small intestine

50
Q

Large intestine functions

A
  • Reabsorb H2O & electrolytes from indigestible food materials
  • Absorbs Vitamin K & B from enteric bacteria (relating to intestine)
  • Eliminate undigested residues
51
Q

Mesentery of small intestine

A

Holds many blood vessels

52
Q

Mesocolon

A

Anchors the colon to the back body wall

53
Q

Defecation

A

1) Mass peristaltic waves push faecal material from the sigmoid colon into the rectum
2) Rectum involuntary contractions push the faeces downward
3) Filling of the rectum stimulates stretch receptors
4) Involuntary internal sphincter
5) Voluntary external sphincter

54
Q

Liver consists of

A

Four lobes with thousands of lobules (functional unit)

55
Q

Liver blood supply

A
  • Oxygenated via hepatic artery

* Venous via hepatic portal vein

56
Q

Sinusoids are

A

Vascular channels allowing exchange between blood & hepatocytes

57
Q

Blood exits each lobule

A

By small veins which combine to carry blood AWAY from the liver via the hepatic vein

58
Q

Bile leaves liver

A

1) Produced in hepatocytes then drains into canaliculi
2) Exits the lobules via bile ducts
3) Exits the liver via the hepatic duct
4) Enters the duodenum via the common bile duct

59
Q

Glucose ingestion in liver causes

A

Stimulating insulin causing glycogenesis (synthesis of glycogen)

60
Q

Low glucose levels causes

A

Glycogenolysis in the liver (conversion from glycogen to glucose)

61
Q

Low glycogen stores

A
  • Body uses fats and proteins for energy

* Gluconeogenesis occurs (glucose made from triglycerides, lactic acid & certain amino acids)

62
Q

Liver metabolism: Fat

A
  • Triglycerides broken down into fatty acids and glycerol for energy (lipolysis)
  • If not need recombined into triglycerides through lipogenesis
63
Q

Liver metabolism: Protein

A
  • Proteins broken down into amino acids
  • Amino acids made of two groups: carbon and amine
  • Transamination is transfer of amine group to transfer amino acid
  • 20 amino acids with 10 are essential and the other 10 can be formed from the essential ones
64
Q

Digestion and absorption: Carbohydrates

A
Starch and disaccharides 
Mouth: Salivary amylase 
Small intestine: Pancreatic amylase
--> Oligosaccharides and disaccharides
Small intestine: Brush border enzymes 
1) Maltose + Maltase = Glucose + Glucose
2) Sucrose + Sucrase = Glucose + Fructose
3) Lactose + Lactase = Galactose + Glucose
65
Q

Digestion and absorption: Proteins

A
Proteins
Stomach: Pepsin in HCL
--> Large polypeptides 
Small intestine: Pancreatic enzymes 
--> Small polypeptides, small peptides
Small intestine: Brush border enzymes
--> Amino acids
66
Q

Digestion and absorption: Fats

A
Unemulsified triglycerides
Mouth: Lingual lipase
Stomach: Gastric lipase
Small intestine: Emulsification by bile
Small intestine: Pancreatic lipase
--> Monoglycerides and fatty acids
67
Q

Digestion and absorption: Nucleic acids

A

Nucleic acids
Small intestine: Pancreatic ribonuclease and deoxyribonuclease
Small intestine: Brush border enzymes
–> Pentose sugars, N-containing bases, phosphates ions