ANFF topic 1 part 1

Question 1

What are the three classifications of animals (based on diet)?

Answer 1

• herbivores
• carnivores
• omnivores

Question 2

What can herbivores be further classified into (what types of herbivores are there?)

Answer 2

• frugivores (fruit-eaters)
• granivores (seed-eaters)
• nectivores (nectar feeders)
• folivores (leaf eaters)

Question 3

What are obligate carnivores?

Answer 3

• rely entirely on animal flesh to obtain their nutrients

- e.g. lions, cheetahs

Question 4

What are facultative carnivores?

Answer 4

• eats non-animal food in addition to animal food

- e.g. dogs

Question 5

What is mastication?

Answer 5

• the chewing action of teeth

- food consumed is broken into smaller particles

Question 6

What major glands secrete saliva?

Answer 6

• parotid glands
• submandibular glands
• sublingual glands

Question 7

What does saliva contain?

Answer 7

• mucus –> moistens food & buffers the pH of food
• immunoglobulins and lysozyme –> antibacterial action to reduce tooth decay by inhibiting growth of some bacteria
• salivary amylase –> convert starch in the food into maltose
• lipase –> class of enzymes that break down triglycerides

Question 8

How is a bolus formed?

Answer 8

• the chewing and wetting action provided by the teeth and saliva prepare the food into a mass for swallowing

Question 9

What is the function of the tongue?

Answer 9

• helps in swallowing –> move bolus from the mouth into the pharynx

Question 10

What is the difference between the glottis and the epiglottis?

Answer 10

• glottis: opening located in the trachea

- epiglottis: cartilaginous flap covering the glottis

Question 11

How is food kept out of the trachea?

Answer 11

• when swallowing, the epiglottis closes the glottis and food passes into the oesophagus and not the trachea

Question 12

How does food move down the oesophagus

Answer 12

• peristalsis –> the smooth muscles of the oesophagus undergo a series of wave-like movements that push the food toward the stomach
• unidirectional –> moves food from mouth to stomach (reverse movement not possible)
• an involuntary reflex

Question 13

What is the pH in the stomach?

Answer 13

• 1.5-2.5

Question 14

Describe the stomach.

Answer 14

• sac-like organ that secretes gastric digestive juices

Question 15

why does the stomach have a low pH?

Answer 15

• chemical breakdown of food and the extraction of nutrients

Question 16

How is protein digested in the stomach?

Answer 16

• by pepsin
• pepsin is secreted by the chief cells in the stomach in an inactive form called pepsinogen
• breaks peptide bonds and cleaves proteins into smaller polypeptides
• starts a positive feedback mechanism that generates more pepsin

Question 17

What do parietal cells secrete?

Answer 17

• hydrochloric acid

Question 18

What does the hydrochloric acid do in the stomach?

Answer 18

• helps to convert the inactive pepsinogen to pepsin
• kills many microorganisms in the food
• hydrolysis of protein in the food

Question 19

what is chyme?

Answer 19

• mixture of partially digested food and gastric juice

Question 20

What digestion takes place in the small intestine?

Answer 20

• protein
• fats
• carbohydrates

Question 21

What are villi?

Answer 21

• long, tube-like organ with a highly folded surface containing finger-like projections

Question 22

What are microvilli?

Answer 22

• microscopic projections (hair-like) on the surface of each villus

Question 23

What are the functions of the villi and microvilli?

Answer 23

• allows nutrients to be absorbed from the digested food and into the blood stream on the other side
• the villi and microvilli (many folds) increases surface area and increases absorption efficiency of the nutrients

Question 24

Where are absorbed nutrients in the blood carried to?

Answer 24

• carried to the liver

- via the hepatic portal vein

Question 25

What does the liver do with the absorbed nutrients?

Answer 25

• regulates the distribution of nutrients to the rest of the body and removes toxic substances

Question 26

What separates the duodenum and the stomach?

Answer 26

• pyloric sphincter

Question 27

What happens when chyme moves from the stomach to the duodenum?

Answer 27

• chyme is mixed with pancreatic juices in an alkaline solution rich in bicarbonate
• neutralizes the acidity of chyme and acts as a buffer
• the pancreatic juices also contain several digestive enzymes

Question 28

Where are the digestive juices in the duodenum from?

Answer 28

• liver
• pancreas
• gallbladder
• gland cells of the intestinal wall

Question 29

Where is bile produced and stored?

Answer 29

• produced in the liver

- stored and concentrated in the gallbladder

Question 30

What is the function of bile?

Answer 30

• contains bile salts which emulsify lipids

Question 31

What is the second part of the small intestine called?

Answer 31

• jejunum

Question 32

What is the function of the jejunum?

Answer 32

• hydrolysis of nutrients

- carbohydrates and amino acids are absorbed through the intestinal lining

Question 33

What is the last part of the small intestine called?

Answer 33

• ileum

Question 34

What happens in the ileum?

Answer 34

• bile salts and vitamins are absorbed into the bloodstream

Question 35

How is undigested food sent from the ileum to the colon?

Answer 35

• via peristaltic movements of the muscle

Question 36

What is the function of the large intestine?

Answer 36

• reabsorbs the water from undigested food material and processes the waste material

Question 37

State and describes the parts of the large intestine.

Answer 37

• Cecum: joins the ileum to the colon and is the receiving pouch for the waste matter
• Colon: presence of many “intestinal flora” that aid in the digestive processes
• Rectum: extract water and mineral salts from undigested food + store waste material

Question 38

What is the function of the liver?

Answer 38

• digestion of fats and detoxifying blood
• produces bile –> breakdown of fatty components of the food in the duodenum
• processes vitamins and fats
• synthesizes plasma proteins

Question 39

What is the function of the gallbladder?

Answer 39

• aids the liver by storing bile and concentrating bile salts