ANFF topic 1 part 1 Flashcards
1
Q
What are the three classifications of animals (based on diet)?
A
- herbivores
- carnivores
- omnivores
2
Q
What can herbivores be further classified into (what types of herbivores are there?)
A
- frugivores (fruit-eaters)
- granivores (seed-eaters)
- nectivores (nectar feeders)
- folivores (leaf eaters)
3
Q
What are obligate carnivores?
A
- rely entirely on animal flesh to obtain their nutrients
- e.g. lions, cheetahs
4
Q
What are facultative carnivores?
A
- eats non-animal food in addition to animal food
- e.g. dogs
5
Q
What is mastication?
A
- the chewing action of teeth
- food consumed is broken into smaller particles
6
Q
What major glands secrete saliva?
A
- parotid glands
- submandibular glands
- sublingual glands
7
Q
What does saliva contain?
A
- 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
8
Q
How is a bolus formed?
A
- the chewing and wetting action provided by the teeth and saliva prepare the food into a mass for swallowing
9
Q
What is the function of the tongue?
A
- helps in swallowing –> move bolus from the mouth into the pharynx
10
Q
What is the difference between the glottis and the epiglottis?
A
- glottis: opening located in the trachea
- epiglottis: cartilaginous flap covering the glottis
11
Q
How is food kept out of the trachea?
A
- when swallowing, the epiglottis closes the glottis and food passes into the oesophagus and not the trachea
12
Q
How does food move down the oesophagus
A
- 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
13
Q
What is the pH in the stomach?
A
- 1.5-2.5
14
Q
Describe the stomach.
A
- sac-like organ that secretes gastric digestive juices
15
Q
why does the stomach have a low pH?
A
- chemical breakdown of food and the extraction of nutrients
16
Q
How is protein digested in the stomach?
A
- 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
17
Q
What do parietal cells secrete?
A
- hydrochloric acid
18
Q
What does the hydrochloric acid do in the stomach?
A
- helps to convert the inactive pepsinogen to pepsin
- kills many microorganisms in the food
- hydrolysis of protein in the food
19
Q
what is chyme?
A
- mixture of partially digested food and gastric juice
20
Q
What digestion takes place in the small intestine?
A
- protein
- fats
- carbohydrates
21
Q
What are villi?
A
- long, tube-like organ with a highly folded surface containing finger-like projections
22
Q
What are microvilli?
A
- microscopic projections (hair-like) on the surface of each villus
23
Q
What are the functions of the villi and microvilli?
A
- 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
24
Q
Where are absorbed nutrients in the blood carried to?
A
- carried to the liver
- via the hepatic portal vein
25
What does the liver do with the absorbed nutrients?
- regulates the distribution of nutrients to the rest of the body and removes toxic substances
26
What separates the duodenum and the stomach?
- pyloric sphincter
27
What happens when chyme moves from the stomach to the duodenum?
- 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
28
Where are the digestive juices in the duodenum from?
- liver
- pancreas
- gallbladder
- gland cells of the intestinal wall
29
Where is bile produced and stored?
- produced in the liver
| - stored and concentrated in the gallbladder
30
What is the function of bile?
- contains bile salts which emulsify lipids
31
What is the second part of the small intestine called?
- jejunum
32
What is the function of the jejunum?
- hydrolysis of nutrients
| - carbohydrates and amino acids are absorbed through the intestinal lining
33
What is the last part of the small intestine called?
- ileum
34
What happens in the ileum?
- bile salts and vitamins are absorbed into the bloodstream
35
How is undigested food sent from the ileum to the colon?
- via peristaltic movements of the muscle
36
What is the function of the large intestine?
- reabsorbs the water from undigested food material and processes the waste material
37
State and describes the parts of the large intestine.
- 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
38
What is the function of the liver?
- 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
39
What is the function of the gallbladder?
- aids the liver by storing bile and concentrating bile salts
