Digestion

Question 1

What are the Digestive Functions?

Answer 1

1) Ingestion
2) Mechanical Processing
3) Digestion (Chemical Processing)
4) Secretion
5) Absorption
6) Excretion

Question 2

What does the Oral Cavity do?

Answer 2

1) Analyses Material (Gustation)
2) Mechanical Processing (Mastication)
3) Lubricates (mucus & saliva)
4) Begins Digestion (Carbs & Fats)

Question 3

What is the purpose of the Tongue?

Answer 3

1) Aids in Mechanical processing
2) Manipulates to assist chewing by teeth
3) Sensory analysis (touch, temp., taste)
4) Lingual lipase starts lipid digestion immediately

Question 4

What is the purpose & function of Salivary Glands?

Answer 4

1) Produce Saliva [Lubricates, Buffers, Digests]
a) Parotid - Salivary Amylase [Starches]
b) Sublingual - Buffer and Lubricant
c) Submandibular - Salivary Lipase [Lipids]

Question 5

What are the different teeth types and what do they do?

Answer 5

1) Incisor [4xT/B]
a) Blade shaped for clipping/cutting
2) Cuspid [2xT/B]
a) Cone shaped for tearing/slashing
3) Premolar [4xT/B]
a) Flattened with ridges for grinding and crushing
4) Molar [6xT/B]
a) Flattened with ridges for grinding and crushing
b) The most posterior are the wisdom teeth

Question 6

What is the Pharynx and what purpose does it serve?

Answer 6

1) Common pathway fir food, liquid, and air
2) Naso/Oro/Laryngo
3) Pharyngeal muscles assist in swallowing

Question 7

What is the Oesophagus? What purpose does it serve?

Answer 7

1) Muscular tube connecting the oral cavity to the stomach
2) Sealed on both ends by sphincter muscles
a) Upper Oesophageal/Pharyngoesophageal and Lower Oesophageal Sphincter
3) Upper portion contains skeletal muscle for voluntary swallowing
4) Lower majority portion contains smooth muscle for peristalsis
5) GORD

Question 8

What is the Stomach? What is its purpose?

Answer 8

1) Temporary storage of ingested foods
2) Mechanical breakdown of foods
3) Chemical breakdown via acid and enzymes
4) Production of Intrinsic Factor (B12)
5) Food [Chyme] leaves the stomach via the Pyloric sphincter

Question 9

What is the Small Intestine [DJI]?

Answer 9

1) Completes digestion of all food groups
2) Segmentation moves and breaks up food
3) Site of absorption of nutrients
4) Contains villi which increase surface area and are the site of absorption
5) Flow of material from the Small Intestine to Colon is controlled by the Ileocaecal Valve

Question 10

What occurs in the Colon?

Answer 10

1) Reabsorbs water and compacts faeces
2) Absorbs vitamins freed by Intestinal Bacteria
3) Stores Faeces prior to defecation [Rectum]

Question 11

What is the purpose/occurs in the Liver?

Answer 11

1) Makes & releases Bile
2) Maintains normal blood glucose, amino acid, and fatty acid concentrations
3) Nutrient storage [inc. Vitamin, Iron, Glycogen, and more]
4) Inactivates Toxins
a) Converts Ammonia to Urea
b) Inactivates drugs [inc. alcohol]
c) Absorb and store environmental toxins like DDT

Question 12

What is the purpose of the Cholecyst?

Answer 12

1) Stores and modifies Bile
2) Bile is used to emulsify fats preparing them for digestion
3) Bile travels to the Duodenum via the Common Bile Duct and is released when the Hepatopancreatic Sphincter relaxes

Question 13

What is the purpose of the Exocrine Pancreas?

Answer 13

Produces enzymes used to complete digestion in the Small Intestine

Question 14

What is the purpose of the Endocrine Pancreas?

Answer 14

Releases Insulin and Glucagon

Question 15

How are Pancreatic Enzymes released?

Answer 15

Enzymes released into the Duodenum via the Pancreatic Duct [& Accessory Pancreatic Duct] through the Hepatopancreatic Sphincter

Question 16

How does Nutrient Absorption occur?

Answer 16

1) Occurs through Intestinal Villi and Lacteal
2) Nutrients travel via the Hepatic Portal Vein to the Liver except larger fatty acids
3) Fatty acids enter the blood stream through the Thoracic Duct