chap 7- Human nutrition Flashcards
(74 cards)
1
Q
What is a balanced diet?
A
- Provides all the nutrients in correct amounts needed to carry out life processes
2
Q
How does age affect dietary needs?
A
Children need less total dietary energy (kJ) than adults
3
Q
How does gender affect dietary needs?
A
- Men need more total energy (kJ) than women
4
Q
How do activity levels affect dietary needs?
A
- Increased activity levels need more total energy (kJ)
5
Q
How does pregnancy affect dietary needs?
A
- Pregnant women need more total energy (kJ) than non-pregnant women
6
Q
What is the energy requirement in pregnant and breastfeeding mothers?
A
- Pregnancy needs less energy than breastfeeding
7
Q
protein dietary importance
A
Growth and repair of muscles,
enzymes, hormones, antibodies
8
Q
protein source
A
Meat, fish, eggs,
legumes, mycoprotein
9
Q
protein deficiency disease
A
Kwashiorkor
10
Q
carbohydrates dietary importance
A
Energy store
11
Q
carbohydrates source
A
Rice, Potatoes, wheat,
cereals
12
Q
Fat dietary importance
A
Insulation and concentrated
energy store
13
Q
Fat source
A
Meat, eggs, milk, cheese
14
Q
water dietary importance
A
70% of body. Tissue fluid,
cytoplasm, blood.
15
Q
water Deficiency Disease
A
dehydration
16
Q
Fibre (roughage) dietary importance
A
prevents constipation, encourages peristalsis
17
Q
Fibre (roughage) deficiency disease
A
Constipation
18
Q
Calcium dietary importance
A
Strong teeth and bones
19
Q
calcium source
A
Milk, cheese, and fish
20
Q
Calcium deficiency disease
A
weak bones, poor clotting,
spasms, rickets
21
Q
Iron dietary importance
A
Healthy blood
22
Q
iron source
A
Red meat, liver, leafy
greens
23
Q
Iron deficiency disease
A
Anaemia
24
Q
vitamin C dietary importance
A
Sticks together cells lining the
mouth
25
vitamin C source
Citrus fruits, leafy greens
26
Vitamin C deficiency disease
Scurvy - bleeding gums
27
Vitamin D dietary importance
Strong bones
28
Vitamin D source
Liver, dairy products,
eggs
29
Vitamin D deficiency
Rickets
30
ingestion
taking substances (food and drink) into the body through the mouth
31
Mechanical digestion
-breakdown of food into smaller pieces without chemical change in food molecules.
* E.g. chewing, stomach muscles churning food
32
Chemical digestion
-breakdown of large, insoluble molecules into small soluble molecules.
E.g. amylase in saliva breaks down starch into simple sugars
33
Absorption-
movement of small molecules and ions through the wall of the intestine into the blood
34
Assimilation
movement of digested food molecules into the cells of the body where they are used, becoming part of the body
35
Egestion
passing out of food that has not been digested or absorbed as faces through the anus
36
What is diarrhoea?
* Loss of watery faeces
37
How is diarrhoea treated?
* Oral rehydration therapy - mixture of water and mineral salts
* Prevents dehydration
38
What is cholera?
* Bacterial disease
* Bacteria produces toxin
* Toxin increases loss of chloride ions in small intestine
* Leads to osmotic loss of water into gut
* Causes diarrhoea, dehydration, loss of salts from blood
39
Mouth
Food converted to bolus by teeth during mastication (chewing)
40
Salivary Glands
Produce saliva, transport to mouth by salivary ducts
41
Oesophagus
Food moves to stomach by peristalsis (contraction of circular muscles)
42
Stomach
The food mixes with hydrochloric acid - forms chyme
43
Small Intestine (Duodenum And Ileum)
Covered in villi to to increase absorption of digested food
44
Duodenum
Semi liquid food mixes with pancreatic juice
45
Ileum
Digested food absorbed in to blood
46
Liver
Produces bile - neutralizes acid and emulsifies fat in the small intestine
47
Pancreas
Produces pancreatic juice, transported into small intestine by pancreatic duct
48
Gall Bladder
Stores bile - transported into duodenum by bile duct
49
Large Intestine - Colon
Reabsorbs water
50
Rectum
Stores faeces
51
Anus
Exit for faeces- two sphincter muscles
52
What is the function of the teeth?
* Mechanical digestion
* Incisors cut/bite
* Canines hold/cut
* Premolars crush and chew
* Molars grind and chew
53
ROOT function
Embedded in the gum to anchor the tooth in the mouth
54
Enamel function
Hardest substances made by animals. Covers the tooth and provides a tough
surface for biting and chewing
55
Dentine function
Bone-like structure under the enamel. Contains cytoplasm and tubes running
from the pulp cavity outwards which are filled with blood vessels and nerves
56
Pulp Cavity
Hollow middle of the tooth. Contains nerves and blood vessels which supply the
cytoplasm with food and oxygen
57
Cement
Covers the root of the tooth
58
Fibres
Grow out of the cement and attach the tooth to the jawbone
59
Nerves
Allow teeth to sense pressure and pain
60
What is the role of chemical digestion?
* Producing soluble small molecules that can be absorbed and assimilated
61
What is role of amylase?
* Secreted into alimentary canal
* To break down starch into simpler sugars (maltose)
62
Describe the action of maltase
* Breaks down maltose in to glucose
* Occurs on the membranes of small intestine epithelium
63
Where is amylase secreted?
* Mouth and small intestine (salivary and pancreatic)
64
Where is protease secreted?
* Stomach
* Small intestine
65
Where is lipase secreted?
* In bile in to small intestine
66
What is the role of lipase?
* To digest fats into fatty acids and glycerol
67
What is the role of protease?
* To digest proteins into amino acids
68
What are pepsin and trypsin?
* Protease enzymes
* Pepsin - works in the stomach
* Trypsin - works in the small intestine
69
Describe the functions of hydrochloric acid in the stomach
* Killing bacteria in food
* Low pH denatures enzymes in harmful microorganisms
* Provides acidic pH for enzymes
* Optimum pH for pepsin activity
70
What is the role of bile?
* Neutralises acidic food mixture from stomach
* Provides suitable pH for enzymes in small intestine
* Emulsifies fats to increase surface area for chemical digestion
71
Where is digested food absorbed?
* Small intestine
72
What is the purpose of villi and microviili?
* Increases surface area for absorption
73
Describe the structure of a microvillus
-* Epithelium one cell thick - short diffusion pathway
-Goblet cell produces mucus to protect lining of small intestine
* Good blood supply from capillaries to transport glucose to rest of body
* Lacteal transports fatty acids and glycerol
74
Where is water absorbed?
* Small intestine (mostly) and colon
