Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

HUBS1404 > Digestive system > Flashcards

Digestive system Flashcards

1
Q

What is the main role of the digestive system?

A

▫ Break down food
▫ Absorb nutrients
▫ Eliminate indigestible material
* The digestive system is also home to our microbiome
▫ Host bacteria that reside in our large intestine
▫ Huge area of research
▫ Contribute to health and disease states via metabolites

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

What are the macromolecule nutrients in food?

A

Proteins, Carbohydrates, Lipids, Nucleic acids.

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

What are the micronutrients in food?

A

Vitamins, minerals / trace elements.

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

What are the 6 processes of the digestive system?

A

-Ingestion
- Secretion
- Mixing and Propulsion
- Digestion
- Absorption
- Defecation

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

What is ingestion?

A

▫ Process of placing food in the mouth

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

What is secretion?

A

▫ Release of water, digestive enzymes and acids, salts and buffers into the GI tract

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

What is mixing and propulsion?

A

▫ Alternating contraction and relaxation of smooth muscle
▫ Mixes food and secretions
▫ Moves contents down G.I. tract

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

What is digestion?

A

▫ Mechanical and Chemical breakdown of food
▫ Breaks down polymers into monomers
▫ Enables passage through epithelium

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

What are the two types of digestion?

A

Mechanical and Chemical

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

What is absorption?

A

▫ Describes the passage of nutrients and water across the digestive epithelium
▫ Enters either blood or lymph

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

What is defecation?

A

▫ Removal of wastes, indigestible material, bacteria, dead cells and other unabsorbed products

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

How long is the GI tract?

A

5-7 m long

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

What are the four layers of the GI tract?

A

Mucosa, Submucosa, Muscularis and serosa.

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

What muscle does the muscularis layer contain?

A

smooth muscle in two orientations - circular and longitudinal.

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

Does the stomach contain a third muscle layer?

A

Yes, the inner oblique.

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

What is the Mucosa?

A
  • Inner most layer, lines GI tract.
  • Moist due to glandular secretions.
  • Divided into surface epithelium and lamina propria
  • Thin smooth muscle layer (muscularis mucosae)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is submucosa?

A
  • Connective tissue
  • Extensive vascularisation, nervous supply and lymphatics.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the Muscularis (externa)?

A
  • Muscle layer divided into circular and longitudinal muscle.
  • Moves food and fluid through tract by ‘peristalsis’
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is peristalsis?

A

the involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wave-like movements that push the contents of the canal forward.
/
Circular muscles contract behind bolus and relax ahead
* Longitudinal muscles ahead of
bolus contract to shorten the segment
* This sequence pushes bolus through tract

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

What is the serosa?

A
  • Outermost layer
  • Thin connective tissue surrounds tract and extends to form mesentery that anchors tract to abdominal wall.
    -Adventitia replaces serosa on oesophagus.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the four functions of the stomach?

A
  • Accommodation of ingested food.
  • Secretion of gastric juice
  • Mixing food, saliva and gastric juice using peristaltic mixing waves to form chyme.
  • Secretion of the hormone gastrin.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the four sections of the stomach?

A

Fundus, Cardia, Body, Pylorus

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

What does the lower oesophageal sphincter do?

A

Permit entry of food and fluid into stomach.

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

What does the Pyloric sphincter do?

A

Controls exit into duodenum

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

What are Rugae?

A
  • Large fold of mucosa that are evident when the stomach is empty.
  • Permits distension when food and fluid enter the stomach.
  • Surface epithelium contains gastric pits, within these lie gastric glands
26
Q

How long is the small intestine?

A

3 m long and 2.5 cm in diameter

27
Q

What are the three segments of the small intestine?

A

Duodenum, Jejunum, Ileum

28
Q

What are the three main functions?

A

▫ Mix chyme with pancreatic juice and bile
▫ Complete chemical digestion of nutrients
▫ Absorb nutrients and water (90%)

29
Q

What are the main characteristics of the duodenum?

A
  • 25cm long C-shaped tract extending from the pyloric sphincter.
  • Receives chyme together with digestive secretions from liver and pancreas.
30
Q

What are the main characteristics of the Jejunum?

A
  • 1 m long.
  • Site of most chemical digestion and nutrient absorption.
31
Q

What are the main characteristics of the Ileum?

A
  • longest segment - 2m long.
  • Absorbs bile salts, Vit B12 and any remaining nutrients.
  • Ends with ileocecal valve - sphincter muscle controlling flow into large intestine.
32
Q

How does the structure of the jejunum and ileum facilitate absorption of nutrients?

A
  • Folds on the internal lining called plicae
  • Intestinal villi cover mucosa.
  • Each villus is covered with epithelial cells with their own microvilli.
  • known as brush border.
  • Increases surface area from 3300 cm^2 to 2 million cm^2 (600x)
  • Massively facilitates the absorption of nutrients.
33
Q

What is the function of plicae?

A
34
Q

What is the function of intestinal villi?

A
35
Q

How long is the large intestine?

A

~ 1.5 m long.

36
Q

What are the four regions of the large intestine?

A

Caecum, Colon, Rectum, Anus

36
Q

What is the colon divided into?

A

Ascending, Transverse, Descending and Sigmoid

37
Q

What is wider? The large intestine or the small intestine?

A

The large intestine at 6.5 diameter.

38
Q

How does the large intestine attach to the posterior abdominal wall?

A

via mesocolon

39
Q

What does mucosa contain in the large intestine?

A

Absorptive cells primarily for water absorption
- Goblet cells produce mucus for lubrication.

40
Q

What is the last section of the GI tract?

A

The anus

41
Q

What are the two sphincter muscles of the Anus?

A

-Involuntary and voluntary

42
Q

What are the three major pairs of major salivary glands?

A
  • Parotoid
  • Sublingual
  • Submandibular
43
Q

What are the components of saliva?

A
  • Water (99.5%)
  • Amylase
  • Lipase
  • IgA
  • Lysozyme
  • ions (sodium, potassium, chloride, bicarbonate, phosphate)
  • Urea and uric acid
  • Antioxidants
44
Q

What is amylase?

A

Carbohydrate-digesting enzyme.

45
Q

What is lipase?

A

Lipid-digesting enzyme

46
Q

What is IgA?

A

Immunoglobulin - Immune function

47
Q

What is lysozyme?

A

Antibacterial enzyme

48
Q

What is urea and uric acid?

A

Nitrogenous waste products.

49
Q

What lie in the gastric glands?

A

Parietal cells, chief cells and G cells.

50
Q

What do parietal cells secrete?

A

Hydrochloric acid (HCl) and intrinsic factor.

51
Q

What do chief cells secrete?

A

Pepsinogen and gastric lipase.

52
Q

What do G cells secrete?

A

produce and release gastrin.

53
Q

What does HCl do in gastric juice?

A

-Kills most microorganisms
- Denatures proteins and breaks down plant cell walls.
- Activates pepsinogen to form pepsin
- promotes the flow of bile and pancreatic juice.

54
Q

What is in the oral cavity?

A

Upper lip, lower lop, gums, superior labial frenulum, hard palate, soft palate, Uvula, Palatine tonsil, oropharynx, teeth, tongue and inferior labial frenulum, epiglottis, larynx and oesophagus.

55
Q

What is the voluntary phase of swallowing?

A

The tongue pushes the bolus posteriorly towards the oropharynx.

56
Q

What is the Pharyngeal phase of swallowing?

A

The bolus enters the oropharynx; the soft palate and epiglottis seal off the nasopharynx and larynx, respectively.

57
Q

What is the oesophageal phase?

A

Peristaltic waves move the bolus down the oesophagus to the stomach.

58
Q

What is the churning mechanism in the stomach?

A
  1. the stomach’s smooth muscle contracts and propels a small amount of chyme through the pyloric sphincter. The rest is propelled backward.
  2. The stomach’s peristaltic waves churn the remaining chyme.
  3. The remaining chyme is again propelled toward the pyloric sphincter. More chyme is forced through as the process repeats.
59
Q
A

HUBS1404 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions