Digestive System

Front 1

What does food contain?

Back 1

Substances and energy the body needs to construct all cell components.

Front 2

What does food need to be broken down into before it can be digested?

Back 2

Molecular sized pieces.

Front 3

Name the six processes of the digestive system:

Back 3

1. Ingestion

2. Motility

3. Secretion

4. Digestion

5. Absorption

6. Defecation

Front 4

Name the 2 types of digestion

Back 4

Mechanical and Chemical break down

Front 5

Describe ingestion:

Back 5

Taking food into the mouth

Front 6

Describe motility:

Back 6

The mixing and peristalsis

Front 7

What is peristalsis?

Back 7

The propulsion of food by alternating waves of contraction and relaxation of smooth muscle in the GI tract walls.

Front 8

What is secreted into the lumen of the GI tract during secretion?

Back 8

- 7L of water

- Enzymes

- Acid

- Buffers

Front 9

Describe how mechanical breakdown occurs (digestion):

Back 9

- Mouth by biting and chewing

- Stomach and small intestine by churning and mixing food.

Front 10

Describe what happens during chemical breakdown (digestion):

Back 10

Breakdown of food by enzymes into small molecules.

Front 11

Describe absorption:

Back 11

Movement of molecules into epithelial cells lining the GI tract & into blood & lymph.

Front 12

Describe defecation:

Back 12

Elimination of faeces from the body.

Front 13

Name the four layers of the digestive tract:

Back 13

1. Mucosa

2. Submucosa

3. Muscularis

4. Serosa

Front 14

Describe the mucosa:

Back 14

A moist epithelial inner layer that lines the GI tract from mouth to anus.

Front 15

What are the 3 functions of the mucosa?

Back 15

- Secrete mucus, digestive enzymes and hormones.

- Absorb products of digestion.

- Protect against disease.

Front 16

Describe the submucosa:

Back 16

Areolar connective tissue that binds mucosa to muscularis.

Front 17

What does the submucosa contain and function?

Back 17

- Blood and lymphatic vessels to receive absorbed nutrients.

- Nerves to control the GI tract.

Front 18

Describe the muscularis:

Back 18

Inner circular and outer longitudinal layer of smooth muscle.

Front 19

What is the function of the muscularis?

Back 19

The mixing and peristalsis of the contents of the lumen.

Front 20

What is a sphincter (muscularis)?

Back 20

A thickened ring of circular smooth muscle surrounding an opening, that acts as a valve.

Front 21

Describe the serosa:

Back 21

A serous membrane.

Front 22

What does the serosa secrete?

Back 22

Serous fluid.

Front 23

What is the serosa also known as?

Back 23

The visceral peritoneum.

Front 24

What is the function of the serosa?

Back 24

Allow movement of organs inside the abdominal cavity without friction.

Front 25

What is the peritoneum?

Back 25

The largest serous membrane.

Front 26

Name the sublayers of the peritoneum:

Back 26

- Parietal layer

- Peritoneal cavity

- Visceral layer

Front 27

What does the parietal layer line?

Back 27

The abdominopelvic cavity

Front 28

What does the peritoneal cavity contain?

Back 28

Serous fluid

Front 29

What does the visceral layer cover?

Back 29

The organs

Front 30

Name two disturbances of homeostasis in the peritoneum:

Back 30

- Abdominal ascites

- Peritonitis

Front 31

What is abdominal ascites:

Back 31

Increase in fluid in the peritoneal cavity causing abdominal distension.

Front 32

What is peritonitis?

Back 32

Acute, potentially life-threatening inflammation and subsequent infection of the peritoneum.

Front 33

What is peritonitis caused by?

Back 33

Usually caused by trauma, surgery or perforated organs eg. appendix.

Front 34

Name two important folds of the peritoneum:

Back 34

- Greater omentum

- Mesentery

Front 35

Function of the greater omentum:

Back 35

Drapes over the small and large intestine like a fatty apron.

Front 36

Function of the mesentery:

Back 36

Wraps around the small intestine and binds to the posterior abdominal wall.

Front 37

Name the components of the oral/buccal cavity:

Back 37

- Hard palate

- Soft Palate

- Uvula

- Cheeks

- Tongue

- Teeth

Front 38

What kind of tissue is the tongue composed of?

Back 38

Skeletal muscle covered by a mucous membrane.

Front 39

Function of the tongue?

Back 39

- Tastes

- Manipulates food for chewing

- Aids swallowing

- Articulates speech

Front 40

How many taste buds do we have and where are they found?

Back 40

10,000 found on the tongue, soft palate, pharynx and larynx

Front 41

What do taste buds detect?

Back 41

Sweet, sour, bitter, salty and savoury

Front 42

What are teeth primarily composed of?

Back 42

Dentin

Front 43

What is dentin?

Back 43

A calcified connective tissue that gives teeth their basic shape and rigidity.

Front 44

In the crown of the tooth, what is dentin covered by?

Back 44

enamel

Front 45

What is the hardest substance in the body?

Back 45

enamel

Front 46

What is a disturbance of homeostasis in the mouth?

Back 46

Tooth and gum disease

Front 47

What are dental cavities caused by?

Back 47

Plaque laid down by bacteria.

Front 48

How do bacteria cause cavities?

Back 48

Plaque accumulates forming a stone hard, calcified deposit between the gum and teeth allowing a gap for bacteria to cause infection.

Front 49

What are the implications of tooth and gum disease?

Back 49

gums become red, sore, swollen and bleed.

Front 50

How does tooth/gum disease increase risk of heart disease and stroke?

Back 50

Causes chronic inflammation.

Front 51

Treatment for plaque build-up?

Back 51

Scrape off calcified plaque.

Front 52

What should nurses do to reduce tooth and gum disease?

Back 52

Include oral assessment when examining a patient.

Front 53

What secrete saliva into the oral cavity?

Back 53

Salivary glands.

Front 54

What does saliva do?

Back 54

- Soften, moistens and dissolves food.

- Cleans mouth and teeth.

Front 55

What are the components of saliva?

Back 55

- 99.5% water

- 0.5% solutes

Front 56

What does the water in saliva do?

Back 56

Dissolves foods to begin the digestive process and stimulates taste buds.

Front 57

What does salivary amylase do?

Back 57

Digests starch to maltose.

Front 58

What does mucus do?

Back 58

Lubricates food for movement and swallowing.

Front 59

What does lysozyme do?

Back 59

Destroys bacteria.

Front 60

What pushes a bolus into the oropharynx as a voluntary movement?

Back 60

The tongue

Front 61

What is the pharynx composed of?

Back 61

Skeletal muscle lined by a mucous membrane

Front 62

What covers the larynx?

Back 62

The epiglottis

Front 63

How does food move from the oropharynx to the oesophagus?

Back 63

There is an involuntary movement of the epiglottis to cover the larynx and the food moves into the oesophagus.

Front 64

How is the bolus transported to the stomach via the oesophagus?

Back 64

The oesophagus secretes mucus and transports the bolus to the stomach by peristalsis.

Front 65

Describe the stomach:

Back 65

A 'J' shaped enlargement of the GI tract which acts as a temporary storage tank.

Front 66

How many layers of muscle in the stomach and what do they do?

Back 66

3 layers to compress, knead and mix food.

Front 67

What are rugae?

Back 67

Longitudinal folds in the mucosa

Front 68

What do rugae do?

Back 68

Allow the mucosa to stretch

Front 69

What is the name of the creamy paste food is converted to?

Back 69

Chyme

Front 70

What lines the stomach to protect it from strong stomach acid and digestive enzymes?

Back 70

A sodium-bicarbonate mucus layer.

Front 71

What does chyme leave the stomach through?

Back 71

The pyloric sphincter.

Front 72

Name a potential disturbance of homeostasis in the stomach:

Back 72

Peptic ulcer disease

Front 73

What is a peptic ulcer?

Back 73

When a crater-like erosion forms in the mucous membrane exposed to gastric acid.

Front 74

Where can peptic ulcers form?

Back 74

The stomach, oesophagus and duodenum.

Front 75

What causes ulcers in the oesophagus.

Back 75

Gastro-oesophageal reflux disorder (GORD)

Front 76

Why do ulcers form in the oesophagus?

Back 76

- If the lower oesophageal sphincter doesn't close properly there could be a reflux of gastric acid.

- The oesophagus doesn't have the same amount of a mucous barrier that the stomach does.

Front 77

What can cause ulcers in the stomach?

Back 77

Helicobacter pylori that drill through the protective mucous barrier in the stomach.

Front 78

What is gastric juice produced by?

Back 78

Gastric glands in the stomach

Front 79

What does gastric juice contain?

Back 79

- Hydrochloric acid (HCl)

- Mucus

- Gastric Enzymes

Front 80

What does hydrochloric acid do?

Back 80

- Kills microbes in food

- H+ ions are actively pumped into the lumen by proton pumps

Front 81

What does mucus do?

Back 81

Protects stomach wall from damage by HCl

Front 82

What do gastric enzymes do?

Back 82

- Pepsin begins the chemical digestion of proteins.

Front 83

If a person has a stomach disease or condition what might be impaired?

Back 83

The digestion of proteins.

Front 84

What is vomiting?

Back 84

Forceful expulsion of contents of stomach and sometimes duodenum.

Front 85

Cause of vomiting?

Back 85

Bacterial toxins, stomach distension, excess alcohol, unpleasant sights, dizziness, general anaesthetic, drugs.

Front 86

Describe the action of vomiting:

Back 86

Stomach is squeezed between abdominal muscles and diaphragm, oesophageal sphincters open.

Front 87

What can excess vomiting cause?

Back 87

Dehydration and disrupt the electrolyte and pH balance. As acid is lost the blood become alklotic.