Compendium 3

Question 1

Functions of digestive system?

Answer 1

INGESTION: Introduction of food into stomach

MASTICATION: chewing, breakdown particles for chemical digestion

SECRETION: lubricate, liquefy , digest

DIGESTION: mechanical and chemical digestion of food into nutrient

ABSORPTION: movement of nutrients out of digestive tract into cells

ELIMINATION: waste products removed from body, feves

Question 2

Histology of digestive tract?

Answer 2

1. MUCOSA: innermost layer, secretes mucus
2. SUBMUCOSA: connective tissue layer, contains blood vessels, nerves, ect
3. MUSCULARIS: 2/3 muscle layers, movement and secretion
4. SEROSA/ADVENTITIA: Outermost layer, connective tissue, stability

Question 3

Types of Peritoneum?

Answer 3

Visceral: covers organs
Parietal: covers interior surfaces of body wall

Question 4

Oral cavity?

Answer 4

Hard plate: hard bone, anterior

Soft plate: soft muscle, posterior

Tongue

Teeth

Masticate food and turns it into bolus

Question 5

salivary glands

Answer 5

Protects oral cavity, moistens, lubricates and digest food

Amylase - enzyme found in saliva that breaks carbohydrates into smaller sugars

Lysozyme - antibacterial enzyme

Question 6

Pharynx and esophagus

Answer 6

Pharynx: connects oral cavity to oesophagus
Uvula (soft palate) prevents food/drink from enter nasopharynx

Oesophagus

Tube that connects pharynx to stomach
Epiglottis prevents food/drink from entering trachea

Question 7

Swallowing?

Answer 7

1. VOLUNTARY PHASE: tongue pushes bolus to back of oral cavity towards pharynx
2. PHARYNGEAL PHASE: soft plate closes off the nasopharynx. Bolus touches receptors on oropharynx and swollen int reflex moves bolus down pharynx and into Esophagus. Epiglottis cover trachea.
3. OESOPHAGEAL PHASE: bolus is moved down oesophagus towards stomach peristalisis

Question 8

What is peristalisis?

Answer 8

Process by which food moves through the gut. Waves of smooth muscle relaxation and contraction

Question 9

Stomach?

Answer 9

Food comes from the oesophagus and the stomach mixes it (churns) into chyme (think liquid)

Produces mucus, hydrochloride acid, protein digesting enzyme

Contains a thick mucus layer that lubricates and protects epithelial cells on stomach wall from acid pH 2-3

Question 10

Small intestine?

Answer 10

1. Plicae circulares - circular folds in the wall of the small intestine
2. Villi - folds of the mucosa that contain capillaries and lacteals
3. MICROVILLI: small folds into epithelial cell surface

Question 11

Large intestines?

Answer 11

-absorption of water

Question 12

Liver, gall bladder and pancreas?

Answer 12

Liver- makes bile, stores glucose, and lipid for energy. Detoxification.

gall bladder - stores concentrated bile

Pancreas - produces digestive enzyme. Produces insuline and glucagon for blood sugar homeostasis

Question 13

Carbohydrates ?e I

Answer 13

45-65 daily intake

Monosaccharides are the small building blocks

Functions:

• produces atp
• glycogen and stored in muscles
• part of DNA

Question 14

Types of fatty acids?

Answer 14

SATURATION: how many h atoms on each chain

SATURATED: Animal fats

UNSATURATED: Contains one or more double bonds in the carbon chain, so there is less H atoms

TRANS FATS: unsaturated fats that are artificially altered to be more saturated

Question 15

Use of lipids?

Answer 15

Cholesterol: component of plasma membranes, modified to form bile salts

Phospholipids: major components of plasma membranes, myelin Seth, part of bile

Eicosanoids: derived from fatty acids. Involved in inflammation, blood clotting

Question 16

Proteins

Answer 16

Amino acids are basic building blocks and are not stored in body

ESSENTIAL AMINO ACIDS; can’t be produced by body so must be obtained from diet

NON ESSENTIAL: still required by our body but synthesised from essential amino acids

FUNCTIONS;
Globular proteins - haemoglobin 
Structural muscle proteins 
Cell membrane transport
Enzyme
Hormones
Antibodies

Complete protein - meat

Incomplete protein - leafy green

Question 17

Recommended amounts?

Answer 17

Carbohydrates 45-65%

Lipids 10-25%

Proteins 10-35%

Question 18

enzymes ?

Answer 18

A protein catalyst that increases the rate at which a chemical reaction proceeds without the enzyme being permanently changed