Digestive System Flashcards

1
Q

What are the 6 basic functions of the digestive system?

A
  • Ingestion
  • Secretion
  • Propulsion & mixing (deglutition & peristalsis)
  • Digestion (mechanical & chemical)
  • Absorption
  • Defecation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 4 layers of the alimentary canal?

A

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

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

What are the main functions of the mucosa?

A

Inner layer lined with epithelial tissue

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

What does the mucosa do?

A

Lubricates the food to ease passage through the intestines

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

What is the submucosa?

A

Supports the mucosa. Made of connective tissue

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

What is the muscularis externa?

A

Provides movement

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

What is the serosa?

A

Outmost, protective layer

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

What does the mesentery and mesocolon do?

A

Binds the small intestines to the wall

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

What is the lesser omentum?

A

2 folds around stomach and duodenum suspending them from the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the greater omentum?

A

It folds itself twice and thus is 4 layered. Attaches itself along the stomach and duodenum, passes downward over the small intestines and upwards to the transverse colon.

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

What do the lips and cheeks do?

A

Help to keep food between teeth when chewing

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

What is the hard palate in the mouth?

A

Lies anterior, made of bone

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

What is the soft palate in the mouth?

A

Lies posterior, made of muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the tongue do?

A

Forms floor of the mouth, repositions and mixes food, initiates swallowing

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

What do the teeth do?

A

Tear and grind food

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

What is salivary amylase?

A

Converts starch to simple sugars

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

What is lingual lipase?

A

Starts the digestion of fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does deglutition mean?

A

Swallowing

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

What are the 3 stages of swallowing?

A
  • Voluntary stage
  • The pharyngeal stage
  • The oesophageal stage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What happens in the voluntary stage of swallowing?

A

The tongue moves the bolus up and back into the oropharynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What happens in the pharyngeal stage of swallowing?

A

The bolus stimulates the receptors in the oropharynx, messages travel via 2 cranial nerves to the medulla and lower pons in the brain stem. Then instructions from the motor branches cause the soft palate and uvula to move upwards closing the nasopharynx.

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

What happens once food passes from the oropharynx into the laryngopharynx?

A

The larynx is pulled forward and upward under the tongue which results in the epiglottis and vocal cords being moved thus sealing off the respiratory tract

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

What happens in the oesophageal stage of swallowing?

A

Movement through the oesophagus is almost instantaneous for fluids and 4-8 seconds for semi solid foods.

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

What moves food through the muscular tube?

A

Penstalsis

25
Q

Where is the stomach located?

A

Upper left quadrant directly under the diaphragm, nearly hidden by liver and diaphragm

26
Q

What are the functions of the stomach?

A
  • Reservoir for food
  • Production of intrinsic factor, pepsinogen, mucus, HCL and gastric
  • Absorption, only water, alcohol and some drugs
  • Acts as a churn due to an extra 3rd layer of muscle
  • Has the enzymes to digest protein and fat, fat takes much longer to process in the stomach
27
Q

What are the regions of the stomach?

A
  • Cardia
  • Fundus
  • Body
  • Pylorus
28
Q

What is the cardia region of the stomach?

A

Top near oesophagus surrounding the cardiac sphincter

29
Q

What is the fundus region of the stomach?

A

Dome - shaped part tucked under the diaphragm

30
Q

What is the body region of the stomach?

A

Main part

31
Q

What is the pylorus region of the stomach?

A

Funnel - shaped. Ends in the pyloric sphincter

32
Q

What is the duodenum?

A

First part of the small intestine

33
Q

What is the pancreas?

A

Lies behind the stomach. It is both endocrine (produces glucagon and insulin) and exocrine glands ( produces pancreatic juice)

34
Q

What does the pancreatic juice flow through?

A

Pancreatic ducts, hepatopancreatic duct and the sphincter of Oddi into the duodenum

35
Q

What does the pancreatic juice contain?

A

HCO3- and enzymes

36
Q

What enzymes are in the pancreatic juice?

A
  • Pancreatic amylase (for carbohydrates)
  • Trypsinogen, Chymotrypsinogen, Procarboxypeptidase, Proelastase (for proteins)
  • Pancreatic lipase (for fats)
  • Ribonuclease, Deoxyribonuclease (for nucleic acid)
37
Q

What is the gall bladder?

A

It is a muscular sac lined with a mucus membrane and is located behind the liver. When empty the lining folds to form rugae. It has a fundus, body and neck

38
Q

What are the 2 major functions of the gall bladder?

A
  • Storage of bile

- Bile is concentrated and mucus is added to protect the gall bladder lining

39
Q

What is bile?

A
  • It is made by hepatocytes and mainly contains waste materials from excretion e.g. bilirubin
  • Bile is an alkaline and is mad continuously but at varying rates according to need
  • It is highly coloured due to the presence of bilirubin, biliverdin and various salts
40
Q

What are bile salts?

A

They are important in the small intestine for the emulsification and absorption of dietary fats

41
Q

What is the liver covered by?

A

It is covered by by though fibrous capsule and visceral peritoneum and is held in place by ligaments

42
Q

What are the 4 lobes of the liver?

A
  • Left
  • Right
  • Caudate
  • Quadrate
43
Q

What are lobules of the liver?

A

Each lobe contains many ‘hexagonal, lobules. Lobules are the functional units of the liver, they contain millions of hepatocytes

44
Q

What 2 large blood vessels supply the liver?

A

Hepatic artery and hepatic portal veins

45
Q

What are kupffer cells?

A

They are fixed phagocytes found in the sinusoids to destroy damaged blood cells and pathogens

46
Q

What are the functions of the liver?

A
  • Carbohydrate, protein and lipid metabolism
  • Nutrient inter - conversion
  • Detoxification of drugs and hormones
  • Recycling of erythrocytes and excretion of bilirubin
  • Storage of vitamins and some minerals
  • Activation of vitamin D
  • Produces bile
  • Produces cholesterol
47
Q

What are the stages of the small intestine?

A

Commences with the duodenum, then the jejunum, and finally the ileum

48
Q

What is mechanical digestion?

A

Occurs due to segmentation in which localised areas alternately contract to mix chyme with alkaline digestive juices and to present it to the mucosa.

49
Q

What are the methods of transport from the small intestine into the bloodstream?

A
  • Secondary active transport
  • Facilitated diffusion
  • Simple diffusion
50
Q

What are the main functions of the large intestine?

A
  • Completion of absorption for remaining water, electrolytes and vitamins
  • Production of vitamins, faeces and defecation
  • Secretion of mucus
  • Storage of indigestible food until elimination
51
Q

What is the internal sphincter?

A

Involuntary

52
Q

What is the external sphincter?

A

Voluntary

53
Q

What is haustral churning?

A

Occurs by filling of a haustrum to its maximum, followed by a haustral contraction followed by filling of a succeeding haustrum. chyme moves forwards and backwards whilst water, ions and vitamins are absorbed

54
Q

What is mass production?

A

Forcible peristaltic movements of short duration, occurring only 3 or 4 times a day, which moves the contents from the mid colon towards the anus. It is mediated by parasympathetic autonomic motor impulses; it is often stimulated by gastric filing

55
Q

What are the 3 phases of digestion?

A
  • The cephalic phase
  • The gastric phase
  • The intestinal phase
56
Q

What is the cephalic phase of digestion?

A

Where thought, sight and smell of food stimulates production of saliva and gastric juice is prepared for eating

57
Q

What is the gastric phase of digestion?

A

Begin as food enters the stomach. Gastric juice is secreted, cardiac sphincter then closes, pyloric sphincter opens slowly after gastric churning

58
Q

What is the intestinal phase?

A

Begins as chyme enters the duodenum slowly (to prevent overloading duodenum) prolonging stomach emptying time this is controlled by nerves and hormone, GIP.