Nutrition Flashcards
1
Q
Nutrition
A
the way in which living things obtain and use their food
2
Q
Autotrophs
A
make their own food
3
Q
what do autotrophs make their own food from?
A
simple molecules
4
Q
1 example of an autotroph
A
green plants make food during photosynthesis
5
Q
heterotrophs
A
cannot make their own food and must get it from their environment
6
Q
3 types of heterotrophs
A
carnivores
herbivores
omnivores
7
Q
herbivores
A
animals that only eat plants
8
Q
2 examples of herbivores
A
cows
horses
9
Q
carnivores
A
animals that eat other animals (flesh eaters
10
Q
2 examples of carnivores
A
fox
cat
11
Q
omnivores
A
animals that eat plants and animals
12
Q
2 examples of omnivores
A
badger
bear
13
Q
4 stages of human nutrition
A
ingestion
digestion
absorption
egestion
14
Q
other stage of human nutrition
A
assimilation
15
Q
ingestion
A
taking in of food (into the mouth)
16
Q
digestion
A
breakdown of food into small soluble molecules so that they can be absorbed and transported
17
Q
absorption
A
soluble products of digestion pass through the cells in the gut lining into the blood and lymph systems
18
Q
egestion
A
unabsorbed, undigested material eg.fibre is removed through the anus
19
Q
assimilation
A
the absorbed food is used to make new molecules or for the release of energy
20
Q
2 names for the human digestion system
A
alimentary canal
gut
21
Q
2 types of digestion in the gut
A
chemical and mechanical
22
Q
3 times mechanical digestion can be seen in the alimentary canal
A
teeth
gut muscles
bile salts
23
Q
explain how the teeth preform mechanical digestion
A
teeth cut and chew food
24
Q
explain how the gut muscles preform mechanical digestion
A
they contractions of the gut muscles churn and mix food with gut secretions
25
explain how the bile salts preform mechanical digestion
they emulsify lipids
26
what is the function of mechanical or physical digestion
food is made into smaller pieces for a larger surface area for the chemical digestion
27
explain chemical digestion
food is made into smaller pieces by enzymes
28
explain chemical digestion
cells in the lining of the gut and glands associated with the gut, secrete juices containing mucus and digestive enzymes onto food as it moves along
29
the buccal cavity
oral cavity//mouth//area under nose
30
pH of the buccal cavity
pH 7
31
what mainly occurs in the buccal cavity
food is mechanically broken down by the teeth
32
3/4 types of teeth
incisors
canines
pre-molars and molars
33
function of incisors
front teeth, flat sharp edges for cutting
34
function of canines
eye teeth. pointed crowns for tearing
35
function of pre-molars and molars
side and back teeth with projections or cusps for chewing and grinding
36
first set of teeth a human has
milk teeth
37
how many permanent teeth is normal for a human adult
32
38
how many incisors
8
39
how many canines
4
40
how many premolars
8
41
how many molars
12
42
what is the dental formula (just understand)
the number and position of each type of tooth in the upper and lower jaws in ONE side of the mouth
43
human dental formula
I22 C11 P22 M33
44
what is the correlation between dentition and diet
the number and type of teeth present differs from one mammal to another according to the diet of the mammal
45
teeth of carnivores
long, sharply-pointed canines for tearing flesh
46
teeth of herbivores
broad ridged premolars and molars for grinding tough plant material
47
teeth of omnivores
a full set of teeth without any one type being modified
48
Chemical digestion in the mouth
food is mixed with saliva secreted by the salivary glanda
49
saliva consists of (3)
water
mucus
salivary amylase
50
function of water and mucus in saliva
to lubricate the food
51
function of salivary amylase in saliva
enzyme that breaks down starch to maltose
52
what happens to food before it is swallowed
the food is shaped into a ball or 'bolus' by the tongue
53
what does it mean to swallow
it is passed through the pharynx into the oesophagus
54
what does the epiglottis do during swallowing
it closes over the entrance to the trachea and prevents food from going the 'wrong way'
55
what is the oesophagus
a narrow muscular tube that carries food from the pharynx to the stomach
56
how is food moved in the oesophagus
food is moved by waves of muscular contraction called peristalsis
57
what is the stomach?
a j-shaped muscular bag in the abdominal cavity
58
mechanical digestion in the stomach
food is churned into a semi-liquid state called chyme by the contraction of the thick muscle wall
59
chemical digestion in the stomach
food is acted on by gastric juice secreted by the gastric glands in the stomach lining
60
3 components of gastric juice
Mucus
HCl
Enzyme (pepsin)
61
function of mucus in the stomach
protects from self - digestion and lubricates (moistens) the food
62
function of HCl in the stomach 3
provides the optimal pH for pepsin
it sterilised the food
it hydrolyses (splits) starch
63
pH of stomach
2
64
function of enzyme in the stomach
pepsin converts protein to peptides
65
3 other things that occur in the stomach
food is heated to suitable temp for enzyme
absorption of water, glucose, salts and alcohol
food stored temporarily
66
how does food pass from the stomach to the duodenum
through the relaxed pyloric sphincter
67
2 parts of the small intestine
duodenum and ileum
68
pH of small intestine
7-9
69
3 things that occur in the small intestine
food is:moved along
digested
absorbed
70
what is the duodenum
the first part of the small intestine and the main area of digestion
71
3 places from which the duodenum receives secretions
liver
pancreas
lining of small intestine
72
what does the liver produce
bile
73
what is bile
a yellow green alkaline fluid
74
where is bile stored
the gall bladder
75
what does bile consist of
bile salts (alkaline) and bile pigments
76
2 functions of bile
to emulsify fats
| to neutralise the acid food coming from the stomach
77
what does it mean to emulsify fats
to break them down into small droplets to increase their surface area
78
what does the pancreas produce?
pancreatic juice
79
where does the pancreatic juice enter the doudenum?
via the pancreatic duct
80
3 things that pancreatic juice consists of
water, alkaline salts and enzymes
81
function of alkaline salts in pancreatic juice
neutralise acid coming from the stomach
82
function of enzymes salts in pancreatic juice
amylase changes starch to maltose
| lipase changes lipids into fatty acids and glycerol
83
what does the lining of the small intestine produce?
intestinal juices
84
4 things that intestinal juice consists of
water mucus salts and enzymes
85
which enzymes are in intestinal juice
maltase and lipase
86
what does maltase do?
converts maltose to glucose
87
how is food kept moving in the small intestine
through peristalsis ( waves of muscle contraction )
88
chyle
a watery emulsion that the food is converted into in the small intestine
89
end products of digestion
glucose, amino acids, fatty acids, glycerol
90
explain aborption of digested food
the end products of digestion and vitamins and minerals pass through membranes in the ileum into the blood and lymph systems by diffusion
91
3 ways in which the ileum is adapted for absorption
it is a very long tube with finger-like villi to give a larger surface area
the villus wall is very thin to allow rapid movement of food through it into blood and lymph vessels
it has a large supply of blood and lymph vessels (lacteals) to absorb and carry away the products of digestion
92
2 ways in which food can be absorbed
into the blood capillaries and go into the hepatic portal vein
absorbed into lymph lacteals
93
which foods are absorbed into the blood capillaries and go into the hepatic portal vein
```
glucose
amino acids
vitamins
minerals
water
```
94
which foods are absorbed into lymph lacteals
fatty acids
| glycerol
95
where do the foods go from the hepatic portal vein
to the liver
96
where do the foods go from the lymph lacteals
to the lymph system and then to the blood system
97
the large intestine consists of (4)
caecum
appendix
colon
rectum
98
function of colon and appendix
no known function in man
| in herbivores they house cellulose-digesting bacteria (symbiosis)
99
3 functions of the colon
reabsorbs water (osmosis)
absorbs minerals and vitamins (diffusion and AT)
forms faeces
100
faeces
semi-solid waste
101
where is symbiotic bacteria found?
in the large intestine
102
function of the bacteria in the gut 3
produce vitamins B and K, defend against pathogenic bacteria and digest some food
103
5 components of faeces
undigested food, bile pigments, salts, bacteria, dead cells
104
symbiosis
relationship between 2 different species that involves benefit
105
function of the rectum
faeces is stored here before being egested via the anus
106
egestion
removal of undigested or unabsorbed material
107
largest internal organ of the body
the liver
108
where does the liver lie?
below the diaphragm on the right side of the stomacj
109
cells of liver
have a large number of mitochondria
110
3 blood vessels moving to and from the liver
hepatic artery
hepatic vein
hepatic portal vein
111
hepatic artery
brings blood (+O2) from the aorta to the liver
112
hepatic vein
takes blood from the liver to the inferior vena cava
113
hepatic portal vein
brings blood (+digested food) from the gut to the liver
114
main function of the liver
regulates the nutrients in blood
115
2 ways in which the liver regulates the nutrients in blood
it removes excess glucose and stores it as glycogen
| it removes excess amino acids and breaks them down forming urea (deamination)
116
some other functions of the liver
```
breakdown of red blood cells
makes bile
stores iron
stores vitamins ADEK
makes plasma proteins
makes cholesterol
produces heat
detoxification of blood
```
117
1 medical disorder of the digestive system
appendicitis
118
symptoms of appendicitis
severe pain in the lower right part of the abdomen
nausea and vomiting
high temperature
119
cause of appendicitis
bacteria cause inflammation. the appendix becomes swollen and may burst
120
prevention of appendicitis
unknown
121
balanced diet
a diet with the correct amount of each type of food
122
6 components of a balanced diet
lipids, protein, carbohydrates, vitamins, minerals and water
123
amount of food needed is affected by
age sex and activity
124
fibre in the diet
roughage
125
where does fibre come from
in the form of cellulose found in the cell walls of plants
126
can humans digest cellulose?
no
127
what happens to cellulose in the gut?
it absorbs and holds water
128
what is the advantage of of the cellulose holding the water in the gut?
it increases the volume of waste matter in the large intestine
129
larger volume of waste matter=
stimulates peristalsis and speeds up movement of waste matter in the intestine which can prevent constipation
130
good sources of fibre
fruit
vegetables
wholemeal bread
cereals
131
advantage of having a digestive system
all food is broken down in specialised parts of the body so it can be absorbed into the blood and lymph to go to all cells of the body
132
what does it mean for our cells that we have one big digestive system?
that all other cells in the body don't need to have a range of digestive enzymes
