7. Human Nutrition Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is a balanced diet?

A

A balanced diet consists of all of the food groups in the correct proportions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the necessary food groups?

A

Carbohydrates
Proteins
Lipids
Vitamins
Minerals
Dietary Fibre
Water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the function of carbohydrates?

A

Source of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the function of proteins?

A

growth and repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the function of lipids?

A

insulation and energy storage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of dietary fibre?

A

provides bulk (roughage) for the intestine to push food through it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the function of vitamins and minerals?

A

needed in small quantities to maintain health

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the function of water?

A

needed for chemical reactions to take place in cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are sources of carbohydrates?

A

bread, cereals, pasta, rice, potatoes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are sources of proteins?

A

meat, fish, eggs, pulses, nuts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are sources of lipids?

A

butter, oil, nuts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are sources of dietary fibre?

A

vegetables, whole grains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are sources of vitamins?

A

fruits and vegetables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are sources of minerals?

A

fruits and vegetables, meats, dairy products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are sources of water?

A

water, juice, milk, fruits and vegetables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What 4 specific vitamins and minerals do we need?

A

vitamin c
vitamin d
calcium
iron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the function of vitamin c?

A

forms and essential part of collagen protein which makes up skin, hair, gums and bones
deficiency causes scurvy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the function of vitamin d?

A

helps the body to absorb calcium and so required for strong bones and teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the function of calcium?

A

needed for strong teeth and bone and involved in the clotting of blood
deficiency can lead to rickets or osteoporosis later in life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the function of iron?

A

needed to make haemoglobin, the pigment in red blood cells that transports oxygen
deficiency leads to anaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are sources of vitamin c?

A

citrus fruit (oranges, lemons)
strawberries
green vegetables

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are sources of vitamin d?

A

oily fish, eggs, liver, dairy products, also made naturally by the body in sunlight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are sources of calcium?

A

milk, cheese, eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are sources of iron?

A

red meat, liver, leafy green vegetables like spinach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What could be the cause of a vitamin d deficiency?

A

-lack of sunlight, fish, eggs, butter in diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What could be the cause of an iron deficiency?

A

lack of leafy green vegetables, red meat, liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What does a vitamin d deficiency lead to?

A

causes RICKETS
- where bones become soft and deformed (this is because vitamin D is needed for absorption of calcium into the body which is a key component of bones and teeth)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does an iron deficiency lead to?

A

causes ANAEMIA
- where there are not enough red blood cells so tissues do not get enough oxygen delivered to them (this is because iron is a key component of haemoglobin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is malnutrition caused by?

A

Malnutrition is caused by not eating a balanced diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does the type of malnutrition depend on?

A

There are different types of malnutrition depending on the cause of the imbalance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What 4 types of malnutrition are there?

A

Starvation
Coronary heart disease
Constipation
Obesity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the cause of starvation?

A

taking in less energy than is used (over a long period)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the cause of coronary heart disease?

A

diet too high in saturated fat and cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the cause of constipation?

A

lack of fibre in the diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the cause of obesity?

A

taking in more energy than is used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the effect of starvation?

A

body starts to break down energy stores
- first fat and then muscle tissue leading to severe weight loss and eventually damage to heart and immune system, increasing the risk of many diseases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the effect of coronary heart disease?

A

fat deposits build up in arteries supplying the heart, reducing flow of blood to the heart muscle cells which do not work properly due to the lack of oxygen. Can lead to heart attacks and death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the effect of constipation?

A

Food lacks bulk for muscles to push it through the alimentary canal and so risk of diseases such as bowel cancer are increased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the effect of obesity?

A

extra energy stored as fat, weight increases and contributes to development of many diseases such as heart disease and diabetes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What can lead to mass malnutrition in certain countries?

A

In many countries in the world, droughts, natural disasters, wars and a poor economy can lead to mass malnutrition in large areas of the country

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are the two type of most common malnutrition termed in (mainly) LEDC’s?

A

Protein energy malnutrition (PEM)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are two types of PEM?

A

Kwashiorkor and Marasmus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is kwashiorkor caused by?

A

caused by a lack of protein in the diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

In whom is kwashiorkor most common?

A

most common in children under 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Why is kwashiorkor common is places of poverty?

A

Often caused by poverty as high protein foods tend to be more expensive and scarcer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What are signs that a child has kwashiorkor?

A

Children suffering from kwashiorkor are always underweight for their age but they often have a swollen abdomen as their diet may contain a lot of carbohydrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What causes marasmus?

A

a lack of both protein and energy in the diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What are signs that a person has marasmus?

A

People suffering from this have a much lower body weight than normal and look emaciated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What 4 factors affect dietary needs?

A

age
activity levels
pregnancy
breastfeeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

How does age affect dietary needs?

A

The amount of energy that young people need increases towards adulthood as this energy is needed for growth.
Children need a higher proportion of protein in their diet than adults as this is required for growth.
Energy needs of adults decrease as they age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

How do activity levels affect dietary needs?

A

The more active, the more energy required for movement as muscles are contracting more and respiring faster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

How does pregnancy affect dietary needs?

A

During pregnancy, energy requirements increase as energy is needed to support the growth of the developing foetus, as well as the larger mass that the mother needs to carry around
extra calcium and iron are also needed in the diet to help build the bones, teeth and blood of the foetus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

How does breastfeeding affect dietary needs?

A

energy requirements increase and extra calcium still needed to make high quality breast milk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What 6 stages does the food go through in the alimentary canal?

A

Ingestion
Mechanical digestion
Chemical digestion
Absorption
Assimilation
Egestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Ingestion definition

A

the taking of substances, e.g. food and drink, into the body through the mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Mechanical digestion definition

A

the breakdown of food into smaller pieces without chemical change to the food molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Chemical digestion definition

A

the breakdown of large, insoluble molecules into small, soluble molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Absorption definition

A

Absorption is the movement of digested food molecules from the digestive system into the blood (glucose and amino acids) and lymph (fatty acids and glycerol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Assimilation definition

A

the movement of digested food molecules into the cells of the body where they are used, becoming part of the cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Egestion definition

A

the passing out of food that has not been digested or absorbed, as faeces, through the anus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Function of mouth

A

the mouth is where mechanical digestion takes place - teeth chew food to break it into smaller pieces and increase it’s surface area to volume ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Function of salivary glands

A

amylase enzymes in saliva start digesting starch into maltose the food is shaped into a bolus (ball) by the tongue and lubricated in saliva so it can be swallowed easily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Function of the oesophagus

A

tube that connects the mouth to the stomach where the food bolus goes after being swallowed wave - like contractions (peristalsis) will take place to push the food bolus down without relying on gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Function of stomach

A

food is mechanically digested by churning actions while protease enzymes start to chemically digest proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What is present in the stomach and what does it help?

A

hydrochloric acid is present to kill bacteria in food and provide the optimum ph for protease enzymes to work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What is the first section of the small intestine called and what is its function?

A

first section is called the duodenum and is where the food coming out of the stomach finishes being digested by enzymes produced here and also secreted from the pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is the pH of the small intestine

A

ph of the small intestine is slightly alkaline - around ph 8 - 9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is the second section of the small intestine called and what is its function?

A

second section is called the ileum and is where absorption of digested food molecules takes place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What are some of the adaptations of the ileum?

A

the ileum and is where absorption of digested food molecules takes place surface area over which absorption can take place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is the function of the large intestine?

A

water is absorbed from remaining material in the colon to produce faeces faeces is stored in the rectum and removed through the anus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What is the function of the pancreas?

A

produces all three types of digestive enzyme: amylase, protease and lipase secretes enzymes in an alkaline fluid into the duodenum for digestion to raise ph of fluid coming out of the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What is the function of the liver?

A

produces bile to emulsify fats (break large droplets into smaller droplets) - an example of mechanical digestion amino acids not used to make proteins broken down here (deamination) which produces urea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What is the function of the gall bladder?

A

stores bile to release into duodenum as required

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What is diarrhoea?

A

Diarrhoea is the loss of watery faeces from the anus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What can severe diarrhoea lead to?

A

If it is severe and continues for a long time, it can lead to death
Severe diarrhoea can cause the loss of significant amounts of water and ions from the body, causing the tissues and organs to stop working properly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

How can diarrhoea be effectively treated?

A

It can be effectively treated by oral rehydration therapy

This is a drink with a small amount of salt and sugar dissolved in it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is one cause of diarrhoea?

A

There are many causes of diarrhoea, one of which is infection with Vibrio cholera bacteria, which causes the disease cholera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

How does cholera lead to diarrhoea?

A

Ingested via infected water or food, if it enters the small intestine it can cause illness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What does C bacteria attach to?

What do they release?

A

Bacteria attach to the wall of the small intestine

They produce a toxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What does the toxin produced by C do?

A

The toxin stimulates the cells lining the intestine to release chloride ions from inside the cells into the lumen of the intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Why is the accumulation of chloride ions harmful?

A

The chloride ions accumulate in the lumen of the small intestine and lower the water potential there
Once the water potential is lower than that of the cells lining the intestine, water starts to move out of the cells into the intestine (by osmosis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

How are large quantities of water lost during diarrhoea?

A

Large quantities of water are lost from the body in watery faeces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

How does C affect the blood?

A

The blood contains too little chloride ions and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What are the main examples of mechanical digestion? (3)

A

It is mainly carried out by the chewing action of the teeth, the churning action of the stomach and the emulsification of fats by bile in the duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

Where are teeth held?

A

Teeth are held firmly in the bone of the jaw

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

What are teeth used for?

A

used for chewing to increase the surface area of the food so that it can be exposed to saliva and other digestive juices and broken down more quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What do the different sizes of teeth allow them to do?

A

The differing shapes and sizes of teeth enable them to perform slightly different functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

What are the 4 main types of teeth?

A

incisors
canines
premolars
molars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

Function of incisors

A

chisel-shaped for biting and cutting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

Function of canines

A

pointed for tearing, holding and biting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Function of premolars and molars

A

larger, flat surfaces with ridges at the edges for chewing and grinding up food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

What kind of problems can bacteria cause to teeth?

A

Tooth decay and gum disease are both caused by bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

When do bacteria in the mouth become a problem?

A

Many bacteria live in the mouth and most are harmless, however some form a sticky film with saliva, called plaque, which coats teeth and the areas where they attach to gums

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

When does plaque become a problem?

A

To begin with, plaque is soft and easy to remove, however if it hardens and forms tartar, it cannot be removed by brushing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

What can the accumulation of tartar cause?

A

Tartar around the edges of teeth and gums can allow bacteria to work their way into roots, causing gum disease and loss of teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

What can feed the bacteria in the mouth?

A

If sugar is left in the mouth after eating, bacteria in plaque will feed on it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

What do bacteria in the mouth use sugar for?

A

They use it in respiration and turn it into acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

Why is the acid produced by bacteria in the mouth harmful?

A

The acids gradually dissolve the enamel coating of the teeth, working its way into the dentine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

Why is it a problem when the acid (produced by bacteria in the mouth) reaches dentine?

A

Dentine is softer than enamel and so dissolves more easily and quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

What is called when the acid reaches dentine and what does this lead to?

A

This is tooth decay and if not dealt with, can cause painful infections and loss of teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

What can prevent tooth decay?

A

Reducing the amount of sugar eaten can prevent tooth decay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

How is brushing teeth regularly helpful?

A

Brushing teeth regularly removes the buildup of plaque that can cause gum disease and removes the sugars in the mouth so bacteria cannot turn them into acids and cause tooth decay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

What specific type of toothpaste should be used and how is it beneficial?

A

Teeth should be brushed with a fluoride toothpaste as this helps to strengthen enamel and reduce damage from acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

What is also useful in maintaining healthy teeth and preventing the development of tooth decay etc?

A

Regular visits to a dentist ensures that any signs of gum disease or tooth decay can be dealt with promptly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

What is the purpose of digestion?

A

The purpose of digestion is to break down large, insoluble molecules (carbohydrates, proteins and lipids) into small, soluble molecules that can be absorbed into the bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

Why is food partially digested mechanically?

A

Food is partially digested mechanically (by chewing, churning and emulsification) in order to break large pieces of food into smaller pieces of food which increases the surface area for enzymes to work on

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

In what way does digestion take place mainly? How does this work?

A

Digestion mainly takes place chemically, where bonds holding the large molecules together are broken to make smaller and smaller molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

What is chemical digestion controlled by?

A

Chemical digestion is controlled by enzymes which are produced in different areas of the digestive system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

What are the main types of digestive enzymes?

A

carbohydrases, proteases and lipases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

Where is amylase produced?

A

Amylases are produced in the mouth (salivary gland) and the pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

Where are amylases secreted into

A

The mouth and the duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

What does amylase digest?

A

digests starch to maltose (a disaccharide)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

What is maltose digested by? What is it converted to?

A

Maltose is digested by the enzyme maltase into glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

Where is maltose digested?

A

on the membranes of the epithelium lining the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

What are proteases?

A

Proteases are a group of enzymes that break down proteins into amino acids in the stomach and small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

Where does protein digestion take place?

A

Protein digestion takes place in the stomach and duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

What are the two types of proteases?

A

Pepsin and trypsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

Where is pepsin produced?

A

in the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

Where is trypsin produced and where is it secreted into?

A

Trypsin is produced in the pancreas and secreted into the duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

Trypsin is produced in the pancreas and secreted into the duodenum

A

Lipase enzymes are produced in the pancreas and secreted into the duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
121
Q

What do lipases digest?

A

They digest lipids into fatty acids and glycerol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
122
Q

What is the gastric juice?

A

The stomach produces several fluids which together are known as gastric juice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
123
Q

How does HCl in the stomach kill bacteria?

A

The low pH kills bacteria in food that we have ingested as it denatures the enzymes in their cells, meaning they cannot carry out any cell reactions to maintain life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
124
Q

What is pepsin’s optimum ph?

A

around pH 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
125
Q

What does the HCl ensure in relation to pepsin?

A

The hydrochloric acid produced in the stomach ensures that conditions in the stomach remain within the optimum range for pepsin to work at its fastest rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
126
Q

What are the 2 main roles of bile?

A

It is alkaline to neutralise the hydrochloric acid which comes from the stomach
It breaks down large drops of fat into smaller ones. This is known as emulsification.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
127
Q

What is the difference between the enzymes in the stomach and in the small intestine?

A

The enzymes in the small intestine have a higher (more alkaline) optimum pH than those in the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
128
Q

How is emulsification beneficial?

A

The larger surface area allows lipase to chemically break down the lipid into glycerol and fatty acids faster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
129
Q

Is emulsification a chemical or physical process?

A

This is an example of MECHANICAL DIGESTION, not chemical digestion – breaking something into smaller pieces does not break bonds or change the chemical structure of the molecules which make it up, which is the definition of chemical digestion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
130
Q

Where is water absorbed?

A

Water is absorbed in both the small intestine and the colon, but most absorption of water also happens in the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
131
Q

Where does absorption take place?

A

Absorption takes place in the second section of the small intestine, the ileum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
132
Q

What adaptations does the ileum have?

A

The ileum is adapted for absorption as it is very long and has a highly folded surface with millions of villi (tiny, finger like projections)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
133
Q

How do the ileum’s adaptations help with absorption?

A

These adaptations massively increase the surface area of the ileum, allowing absorption to take place faster and more efficiently

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
134
Q

What are (briefly) the 4 adaptations that a villus has?

A

have microvilli
thin wall of villus
connected to a network of blood capillaries
has a lacteal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
135
Q

How do microvilli help the villus with its function?

A

Microvilli on the surface of the villus further increase surface area for faster absorption of nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
136
Q

How does the wall being thin help the villus with its function?

A

Wall of villus is one cell thick meaning that there is only a short distance for absorption to happen by diffusion and active transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
137
Q

How does the villus being connected to a network of blood vessels help the villus with its function?

A

Well supplied with a network of blood capillaries that transport glucose and amino acids away from the small intestine in the blood
(creates a conc. gradient)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
138
Q

How does a lacteal help the villus with its function?

A

Lacteal runs through the centre of the villus to transport fatty acids and glycerol away from the small intestine in the lymph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
139
Q

What is nutrition?

A

Nutrition is the taking in of materials for energy, growth and development.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
140
Q

What is a balanced diet?

A

A balanced diet provides all the nutrients, in the correct amounts, needed to carry out the life processes and to ensure good health and growth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
141
Q

People use different amounts of energy depending on what?

A

People use different amounts of energy depending on their age, gender, and degree of activity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
142
Q

What are the necessary food groups?

A

The necessary food groups are:

Carbohydrates (Glucose and starch).
Proteins.
Lipids.
Vitamins.
Minerals.
Dietary Fibre.
Water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
143
Q

What are 5 sources of carbohydrates?

A

Bread, cereals, pasta, rice and potatoes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
144
Q

What are sources of lipids (mention unsaturated fats and saturated fats)?

A

Plaint oils (nuts and seeds are rich in unsaturated fats).
Animal fats (dairy products are rich in saturated fats and cholesterol e.g. butter, fatty meat and oily fish).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
145
Q

What are 9 sources of proteins?

A

Meat, fish, eggs, milk, cheese, peas, beans, soya, and mycoprotein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
146
Q

What are 2 sources of vitamin c (water soluble)?

A

Citrus fruit, strawberries and green vegetables.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
147
Q

What are 5 sources of vitamin d (fat-soluble)?

A

Liver, dairy products, eggs, oily fish, and sunlight exposure on the skin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
148
Q

What are 4 sources of the mineral calcium (mineral)?

A

Milk, cheese, bread and fish.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
149
Q

What are 4 sources of the mineral iron (Fe)?

A

Red meat, liver, egg yolk, leafy vegetables e.g. spinach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
150
Q

What are 2 sources of fibre?

A

The indigestible cellulose cell wall found in all fruits and vegetables.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
151
Q

What are 4 sources of water (H₂O)?

A

Water, fruit juice, food, and respiration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
152
Q

What is the dietary importance of dietary fibre?

A

Provides bulk so muscles of the gut wall can push the faeces along by peristalsis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
153
Q

What is the dietary importance of the mineral iron?

A

For making haemoglobin, the red pigment in blood which carries oxygen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
154
Q

What is the dietary importance of calcium?

A

Strengthens bones and teeth, aids blood clotting and aids muscle contraction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
155
Q

What is the dietary importance of Vitamin D?

A

Helps calcium to be absorbed to strengthen bones and teeth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
156
Q

What is the dietary importance of Vitamin C?

A

Protects cells from aging and aids the resistance to disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
157
Q

What is the dietary importance of proteins (4)?

A

Growth and repair of muscles and cells.
Used as enzymes in reactions.
Transporting other molecules such as hemoglobin.
Used in cells to produce new proteins by protein synthesis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
158
Q

What is the dietary importance of fats/ lipids or oils (3)?

A

Storage of energy in fat.
Myelin sheath provides insulation under the skin and keeps the body warm.
Forms part of the cell membrane in seeds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
159
Q

What is the dietary importance of carbohydrates?

A

Carbohydrates are used as a source of energy in respiration in cells for active transport, muscle contraction and cell division.
Excess carbohydrates are stored as glycogen or fat.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
160
Q

What is the dietary importance of Water (3)?

A

Necessary for chemical reactions to take place in cells.
Waste removal from the body.
Temperature regulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
161
Q

What is deficiency disease due to a lack of carbohydrates and proteins?

A

Lack of carbohydrates and proteins leads to marasmus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
162
Q

What is marasmus?

A

Deficiency disease of carbohydrates and proteins which causes the wasting away of muscle leading to weight loss, diarrhea, vomiting and fatigue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
163
Q

What is a deficiency disease of proteins that is not marasmus and give the 4 signs?

A

Kwashiorkor.

Signs include swollen abdomen, thin arms and legs, red hair and irritability.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
164
Q

What is scurvy and what are the 4 signs?

A

A deficiency disease of Vitamin C.

Signs include bleeding gums, teeth falling out, skin covered with bruises and poor healing of wounds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
165
Q

What is rickets and what is the sign?

A

A deficiency disease of Vitamin D.

Sign include bones becoming soft and deformed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
166
Q

Why do bones become soft and deformed when you lack Vitamin D in your diet?

A

This is because Vitamin D is needed for absorption of calcium into the body which is a key component of bones and teeth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
167
Q

What are the signs of a Calcium deficiency?

A

Brittle bones and teeth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
168
Q

What is the deficiency disease for Iron (Fe) and what is a sign?

A

Anaemia.
Tired is a sign of anaemia because there are not enough red blood cells so tissues do not get enough oxygen delivered to them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
169
Q

What is a sign of a deficiency in dietary fibre?

A

Constipation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
170
Q

Coronary Heart Disease is a form of overnutrition. What is this heart disease caused by?

A

Too much fat causes fatty blockages which block arteries around the heart meaning the heart does not receive enough oxygen and cannot function properly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
171
Q

What is obesity (a form of overnutrition)?

A

Obesity is having excessive fat stores in the body and is caused by eating too much and can lead to diabetes, high blood pressure and heart disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
172
Q

What is starvation (a form of undernutrition) and what does it lead to?

A

Caused by eating too little food and leads to weight loss and organ damage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
173
Q

Define malnutrition.

A

Malnutrition is a type of disease where a person’s dietary needs are not met. This can be caused by getting too much or not enough (a deficiency) of a particular food or nutrient.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
174
Q

What are the three ways a person can be malnourished?

A

They eat too much (overnutrition).
They have too little food (undernutrition).
They eat foods in the wrong proportions (unbalanced diet).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
175
Q

What caused tooth decay?

A

Too many acidic and sugary food cause tooth decay.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
176
Q

What causes high blood pressure and stroke?

A

Too much salt causes water to be drawn into the blood leading to high blood pressure and a stroke.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
177
Q

Why are the energy requirements for women lower than men?

A

lower body mass than men

physical demands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
178
Q

Why does energy requirements increase as a child grows?

A

for the growth process

the extra energy needed to maintain their body temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
179
Q

How could jobs affect energy requirement?

A

A person who does hard labour work will use more energy than a person sitting on a desk
someone who takes part in a lot of sport will need more energy than a person who doesn’t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
180
Q

Describe the energy requirements of a pregnant woman.

A

If the woman has an adequate diet there is no need for more food as the baby’s metabolism will adapt to the demands of a growing baby and the demand for energy and protein increases

If the diet is deficient, in protein, calcium, iron, vitamin D, folic acid, she will need to increase the uptake.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
181
Q

What is a protein needed for?

A

Required for making tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
182
Q

What is calcium needed for?

A

Bone development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
183
Q

What is Iron needed for?

A

haemoglobin for blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
184
Q

What is lactation?

A

Production of breast milk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
185
Q

How is lactation affected by energy requirements?

A

The production of milk rich in protein and minerals makes a large demand for the mother’s resources.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
186
Q

What is a balanced diet?

A

Contains the correct proportions of lipids, carbohydrates proteins, vitamins and minerals, water and fibre that the body needs to function properly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
187
Q

What are the sources of carbohydrates?

A

Rice potato pasta provide starch

deserts and sweet provide refined sugars

188
Q

What are the functions of carbohydrates?

A

oxidised source of energy for respiration

excess carbo stored as glycogen and fat

189
Q

What are the sources of lipids?

A

Meat and animal food rich in saturated fat and cholesterol

plant sources are rich in unsaturated fats

190
Q

What are the functions of lipids?

A

energy store
provide insulation
make steroid hormones
form part of the cell membrane

191
Q

What are the sources of proteins?

A

meat fish eggs legumes

192
Q

What can deficiency in protein cause?

A

marasmus and kwashiorkor

193
Q

What is the function of proteins?

A

To transport molecules
make enzymes
structural materials hormones and antibodies

194
Q

What are the sources of vitamin c?

A

cherries citrus fruits green vegetables

195
Q

What are the deficiency symptoms of vitamin c ?

A

Scurvy- production of fibres in the body is affected

196
Q

What are the sources of vitamin d?

A

Liver, dairy products, eggs and sunlight

197
Q

What are the deficiency symptoms of vitamin d?

A

rickets- bones are soft and may bend as vit D needed for absorption of calcium

198
Q

What are the sources of iron?

A

red meat, liver spinach

199
Q

What are the deficiency symptoms of iron?

A

Anaemia as iron is needed for the production of haemoglobin

200
Q

What are the sources of calcium?

A

milk and cheese and fish

201
Q

What are deficiency symptoms of calcium?

A

Weak bones, poor clotting of blood, uncontrolled muscle spasms, rickets

202
Q

What is fibre?

A

Indigestible part of food mainly cellulose from plant cell walls
helps to stretch muscles in the gut and push food along through peristalsis

203
Q

What is malnutrition?

A

Bad feeding includes eating too much, eating too little food or eating food in wrong proportions

204
Q

Define Starvation

A

Suffering or death that is caused by not eating enough food

205
Q

Describe the diet of kwashiorkor

A

Diet high in carbohydrates and low in protein

206
Q

What are the signs of kwashiorkor?

A

mental and physical development may be impaired
slow muscle development and swollen liver
swollen abdomen due to water from the blood left behind in the tissues

207
Q

what is marasmus?

A

general starvation. body tissues waste away, thin with wrinkled skin

208
Q

What is coronary heart disease?

A

Too much saturated fat and cholesterol will cause blockage in blood vessels

209
Q

What is constipation?

A

Infrequent bowel movements causing difficulty passing faeces

210
Q

What is obesity?

A

When the fat storage is beyond a healthy limit

211
Q

What is ingestion?

A

Taking substances through the mouth

212
Q

What is mechanical digestion?

A

The breakdown of food into small pieces without chemical change to the food molecules

213
Q

What is chemical digestion?

A

The breakdown of large insoluble molecules into small water-soluble molecules

214
Q

What is absorption?

A

The movement of small digested food molecules and ions through the wall of the intestine into the blood

215
Q

What is assimilation?

A

Movement of digested food molecules into the cells of the body where they are used becoming part of the cells.

216
Q

What is egestion?

A

Passing out of undigested food substances and dietary fibre through the anus

217
Q

What is diarrhoea?

A

It is the loss of watery faeces.

218
Q

What is diarrhoea caused?

A

It is caused by a bacterial or viral infection from food or water

219
Q

How does cholera cause diarrhoea?

A

Vibrio cholera bacteria are ingested and they multiply in the small intestine and invade its epithelial cells. As the bacteria become embedded they release toxins which irritate the intestinal lining and leads to the secretion of large amounts of water and salt. Salts decrease the osmotic potential of the gut drawing more water from surrounding tissues by osmosis. The blood contains too little chloride ions and water

220
Q

What can diarrhoea cause?

A

The loss of body fluids and salt leads to dehydration and kidney failure.

221
Q

What is treatment for cholera?

A

Oral hydration therapy

drinking plenty of fluids sipping small amounts of water at a time to rehydrate the body

222
Q

What are the incisors meant to do?

A

for cutting and biting

223
Q

What are the canines meant to do?

A

For holding and tearing

224
Q

What are the premolars supposed to do?

A

For chewing and crushing

225
Q

What are the molars supposed to do?

A

For chewing and crushing

226
Q

What does the pulp cavity contain?

A

Tooth producing cells
blood vessels
nerve endings which can detect pain

227
Q

What is dentine?

A

Harder than bone and made of calcium salts deposited on collagen fibres and has canals

228
Q

What is enamel?

A

Hardest tissue in the body
produced by tooth forming cells and made of calcium salt
once formed enamel cannot be renewed or extended

229
Q

What is the cement?

A

No canals and anchors tooth to jaw

230
Q

What is gum?

A

Covers the junction between enamel and cement.

231
Q

What is a periodontal membrane?

A

Bundles of collagen fibres anchoring the cement covering of the tooth to the jawbone
Many nerve endings which detect pressures

232
Q

What is a cavity?

A

Small holes that appear in the enamel

233
Q

What are cavities caused by?

A

By bacteria feeding on the sugars deposited on the teeth, respiring and producing acid which dissolves the calcium salts in the tooth enamel.

234
Q

Describe dental decay

A

The enamel is dissolved away exposing the dentine to the acids. Dentine is softer than the enamel and dissolves more quickly so cavities form. The acids produced by the bacteria nitrate the nerve endings and cause toothache.

235
Q

List 6 ways to prevent dental decay

A

Eating food with a low sugar content
brushing of teeth twice a day
Eating crisp vegetables
dental floss or interdental cleaners
visit the dentist
fluoride treatment

236
Q

What is chemical digestion?

A

Chemical digestion is breaking down large insoluble molecules into small soluble ones.

237
Q

What is the ideal environment for chemical digestion?

A

Enzymes work at 37C at a suitable pH

238
Q

Where does chemical digestion happen?

A

mouth
stomach
small intestine

239
Q

Which enzyme is found in the mouth and what does it break down?

A

Maltase breaks down starch into soluble simpler sugar maltose.

240
Q

What does saliva contain?

A

Sodium hydrogen carbonate which provides ideal pH conditions for amylase

241
Q

What does the pyloric sphincter do?

A

Lets the liquid products of the digestion pass a little at a time into the first part of the small intestine called the duodenum.

242
Q

What does the small intestine consist of?

A

Duodenum and ileum

243
Q

What enters the duodenum?

A

Digestive juices from the liver (bile) and pancreas (enzymes)

244
Q

What do the digestive juices contain that enter the duodenum?

A

Trypsin
amylase
lipase
bile

245
Q

What is bile?

A

Bile is a green fluid delivered to the duodenum by the bile duct. It emulsifies the fats, breaking them up into small droplets with a larger surface area so it can be digested by lipase more efficiently. It neutralises the acidic mixture of food and gastric juices entering the duodenum from the stomach.

246
Q

Where does the absorption of digested food take place?

A

In the ileum along with most of the water

247
Q

Why is the ileum efficient in absorption?

A

The long and large absorbing surface area
Microvilli on the surface of the villus further increase surface area for faster absorption of nutrients
Wall of villus is one cell thick meaning that there is only a short distance for absorption to happen by diffusion and active transport
Well supplied with a network of blood capillaries that transport glucose and amino acids away from the small intestine in the blood
Lacteal runs through the centre of the villus to transport fatty acids and glycerol away from the small intestine in the lymph

248
Q

How does glucose and amino acids get absorbed?

A

they pass into the cells and through the wall of the capillaries in the villus and into the bloodstream

249
Q

How do fatty acids and glycerol get absorbed?

A

they pass into the cells and are absorbed by the lacteal which connects to the lymphatic system

250
Q

What is the lymphatic system?

A

Transport lymph, a fluid containing infection-fighting white blood cells throughout the body

251
Q

What is the lacteal?

A

Absorbs fatty acids and glycerol

252
Q

What is the thin epithelium?

A

One cell thick to increase the diffusion rate.

253
Q

What is the blood capillary?

A

Absorbs glucose and amino acids

254
Q

Where does the blood from the intestines travel to?

A

The liver

255
Q

What are the functions of the liver?

A

Manufacture bile
store glucose as glycogen
transamination
deamination
detoxification

256
Q

What is transamination?

A

converting amino acids into others that the body requires

257
Q

What is deamination?

A

Removing nitrogen-containing part of amino acids to form urea followed by the release of energy from the remainder of the amino acid

258
Q

What is detoxification?

A

Break down of alcohol and toxins

259
Q

Why is the liver important?

A

It provides the ideal concentration of food molecules for the body tissues

260
Q

What does the large intestine consist of?

A

colon and rectum

261
Q

What does the material that passes into the large intestine consist of?

A

Consists of water with the undigested matter, largely cellulose, vegetable fibres, mucus and dead cells

262
Q

What does the colon do?

A

Absorbs much of the water

263
Q

What are faeces?

A

A semi-solid waste which is passed to the rectum where it is stored.

264
Q

What do the salivary glands do?

A

Produce saliva and pour it into the mouth through the salivary ducts

265
Q

What do the oesophagus?

A

a muscular tube which helps food move to the stomach by peristalsis

266
Q

What is the stomach?

A

A muscular bag which stores food for a short time and mixes food with acidic digestive juices to form chyme

267
Q

What is the gall bladder?

A

Stores bile before pouring it into the duodenum through the bile duct

268
Q

What is the duodenum?

A

The first part of the small intestine where semi-liquid food is mixed with pancreatic juice and bile

269
Q

What is the pancreas?

A

Produces pancreatic juices which are poured into the small intestine through the pancreatic duct

270
Q

What is the ileum?

A

The longest part of the small intestine where digested food is absorbed into the blood and lymphatic system

271
Q

What is the rectum?

A

Stores faeces before expelling them at a convenient time

272
Q

What is the anus?

A

Exit for faeces

273
Q

What is the large intestine?

A

The colon is part of the large intestine. It reabsorbs water from the gut contents which also absorbs some vitamins and minerals

274
Q

What is peristalsis?

A

Waves of muscular contraction and relaxing in the oesophagus

275
Q

What is the mouth?

A

Food is chewed by teeth and mixed with saliva

tongue rolls the food into a bolus

276
Q

What is the epiglottis?

A

A flap of skin that prevents food from entering the bronchus.

277
Q

Describe the movement of the muscles when a bolus enters the oesophagus.

A

When the bolus enters the oesophagus the v=cricular muscles behind its contract and the longitudinal muscles relax.

278
Q

What is the enzyme that breaks down carbohydrates?

A

Carbohydrase

279
Q

What is the enzyme that breaks down proteins?

A

Protease

280
Q

What is the enzyme that breaks down lipids?

A

lipase

281
Q

What is pepsin?

A

A protease enzyme which breaks down large protein molecules into small soluble amino acids

282
Q

What is the mucus?

A

Protects the wall of the stomach

283
Q

What do glands in the lining of the stomach contain?

A

Pepsin
Hydrochloric acid
mucus

284
Q

What does the ileum absorb?

A

Fats
glucose
amino acids

285
Q

Where is amylase made?

A

Pancreas/Mouth

286
Q

Where is protease made?

A

Pancreas/stomach

287
Q

Where is lipase made?

A

Pancreas

288
Q

Why is the hydrochloric acid in the stomach useful?

A

Kill bacteria in the food and denatures enzymes in harmful microorganisms in food
Provides optimum pH for pepsin.

289
Q

What contributes to differentiating energy requirement

A

Activity levels
Age
Pregnancy
Lifestyle
Climate
Metabolic rate
Health/medical conditions

290
Q

From the mouth the food passes through the pharynx (back of throat) and then where?

A

Dow on the oesophagus

291
Q

What is peristalsis?

A

Waves of muscular contraction followed by relaxation that pushes food down the oesophagus and down into the stomach. It occurs along the entire length of the digestive system

292
Q

How is the oesophagus adapted to suit its function as a passage way?

A

Muscular

Mucus is produced from goblet cells to reduce friction

293
Q

Describe three main events that take place in the stomach

A

HCL is produced. This gives the correct ph for the enzyme pepsin to work. Acid also kills any ingested bacteria
Mechanical digestion by peristaltic movements
Chemical digestion. Pepsin realised from stomach lining and breaks large protein molecules down to amino acids

294
Q

Where is bile produced and stored

A

Produced by liver, stored by gall bladder

295
Q

Why do we need bile

A

Neutralises stomach acid and emulsifies lipids

296
Q

From the stomach the food enters a region of the small intestine called the

A

Duodenum

297
Q

What is the alimentary canal?

A

The whole digestive system.

298
Q

What happens in the duodenum

A

Pancreatic juices from the pancreas neutralises stomach acid and more enzymes are added.

299
Q

What is the other part of the small intestine called?

A

The ileum

300
Q

What happens in the ileum

A

Small molecules (final products of digestion) e.g glucose, amino acids, fatty acids and glycerol, vitamins and minerals are absorbed.

301
Q

How is the ileum adapted to its absorption role?

A

The whole surface is folded and covered with villi

302
Q

What passes into the large intestine?

A

Digestion is finished by this point and the waste material consists of fibre and water and some dead or living bacteria

303
Q

What is the first part of the large intestine called?

A

Colon

304
Q

What does the colon do?

A

Reabsorbs most of the water from the contents leaving faeces

305
Q

What happens if the water is not absorbed?

A

Too much water is lost (dehydration)

The faeces is too liquid (diarrhoea)

306
Q

Why is there so much water to be absorbed?

A

Lots of water has been added from the bile, pancreatic juices, saliva, music, gastric juices.

307
Q

How does the structure of the large intestine compare to the small intestine?

A

Large also has some internal folds but no villi
Also muscular to move material by peristalsis
Wider diameters that the ileum but much shorter in length

308
Q

What is the final region of the large intestine called?

A

The rectum where the faeces is stored temporarily

309
Q

How does villi help absorption in the small intestine?

A

Big surface area
Contain blood capillaries to carry away absorbed nutrients
The villi have a rich blood supply. The blood supply has a lower concentration of food molecules and so diffusion occurs quickly.

310
Q

Balanced diet

A

A balanced diet is a diet containing nutrients such as carbohydrates, proteins, fats,
vitamins, and minerals along with water in the appropriate proportions and ensures good health and
growth.

311
Q

Functions of the balanced diets nutrients

A

● Provision of energy
● To allow growth and repair
● To regulate the body’s metabolism

312
Q

carbs source

A

Rice

313
Q

carbs use

A

simple sugars provide quick energy
Starch releases much more energy after digestion

314
Q

carbs Deficiency disease

A

Kwashiorkor

315
Q

proteins source

A

Meat

316
Q

proteins source

A

Meat

317
Q

proteins use

A

Broken down to amino acids, before being changed to
various proteins for growth and repair

318
Q

proteins Deficiency disease

A

protein energy malnutrition (PEM)

319
Q

fats source

A

Butter

320
Q

fats use

A

Long term energy and insulation under heart and skin

321
Q

water use

A

Most of body mass/ metabolism / blood / excretion

322
Q

Vitamin C source

A

Citrus

323
Q

Vitamin C uses

A

Tissue repair/disease resistance/muscles and bones

324
Q

Vitamin C Deficiency disease

A

Scurvy

325
Q

Vitamin D source

A

Milk

326
Q

Vitamin D use

A

Strengthens bones and teeth

327
Q

Vitamin D Deficiency disease

A

Rickets

328
Q

Iron source

A

Liver

329
Q

Iron uses

A

Formation of hemoglobin in RBCs

330
Q

iron deficiency

A

Anemia

331
Q

Calcium source

A

Milk

332
Q

Calcium uses

A

Strengthens bones and teeth

333
Q

Calcium deficiency disease

A

Rickets

334
Q

Fiber source

A

Cereal

335
Q

Fiber uses

A

Prevents constipation / lowers blood cholesterol

336
Q

fiber Deficiency disease

A

Coronary heart disease/ bowel cancer

337
Q

VItamin A source

A

Carrots

338
Q

Vitamin A uses

A

Vision, healthy skin, immunity

339
Q

Vitamin A Deficiency disease

A

Night blindness

340
Q

Factors that affect nutritional requirements

A

age
pregnancy
gender
breast feeding woman

341
Q

how does age affect nutritional requirements

A

● More calcium for youngsters and elderly for
strengthening of bones
● More energy for children - more active

342
Q

how does pregnancy affect nutritional requirements

A

● Greater supply of all nutrients
● More iron is required for the formation of
hemoglobin in the fetus’ blood

343
Q

how does gender affect nutritional requirements

A

● Boys - more active - more energy
● Girls require more iron than boys

344
Q

how do breast feeding woman affect nutritional requirements

A

● Greater supply of calcium, vitamins, and
minerals required to produce breast milk

345
Q

Why can fat be bad for us?

A

1) obesity
2) constipation

346
Q

The main causes of obesity include

A

● High intake of fatty food and refined foods containing excess added sugar
● Little exercise
● Social and emotional stress - leads to “comfort” eating

347
Q

Obesity could cause multiple problems such as

A

CHD, high BP, and diabetes

348
Q

cause of constipation

A

● Fiber adds bulk to food and allows the food to move smoothly down the alimentary canal.
● If there is too little or no fiber in the diet, food moves slowly causing constipation

349
Q

Starvation

A

period when there is no or not enough nutrient intake into the body

350
Q

The most common form of malnutrition is

A

protein-energy malnutrition (PEM)
Its worst forms are kwashiorkor and marasmus.

351
Q

Ingestion

A

taking substances (food and drink) into the body through the mouth

352
Q

Mechanical digestion

A

breakdown of food into smaller pieces without chemical change in food molecules.

353
Q

Chemical digestion

A

breakdown of large, insoluble molecules into small soluble molecules.

354
Q

Absorption

A

movement of small molecules and ions through the wall of the intestine into the blood

355
Q

Assimilation

A

movement of digested food molecules into the cells of the body where they are used, becoming part of the body

356
Q

Egestion

A

passing out of food that has not been digested or absorbed as faces through the anus

357
Q

how cholera leads to diarrhea

A

Cholera is a waterborne disease caused by the bacterium Vibrio cholerae. Some of the pathogens survive
and make it to the small intestine where they burrow in the wall of the small intestine and start to
produce a toxin, which enters the epithelial cells and disrupts the functioning of their membranes,
releasing chloride ions into the lumen of the small intestine. This creates a water potential gradient.
Through osmotic movement, water moves from a region of its higher water potential in the epithelial
cells to a region of its lower potential in the intestine. This causes diarrhea, which is the loss of watery
feces . The loss of water and ions causes dehydration.

358
Q

Oral rehydration therapy (ORT)

A

People suffering from cholera need to be given a dose of ORT solution to replenish the lost water and
salts.

359
Q

An ORT contains:

A

● Water to rehydrate blood and other tissues
● Sodium ions to replace the ions lost from the blood and tissue fluid
● Glucose to provide energy for the active uptake of sodium ions from the intestine
● Ions of potassium and chloride to replace ions lost in diarrhea

360
Q

Parts of the alimentary canal

A

1) mouth
2) salivary glands
3) esophagus
4) stomach
4) duodenum
5) ileum
6) pancreas
7) liver
8) gall bladder
9) colon
10) rectum
11) anus

361
Q

mouth function

A

To ingest food
To mix food with saliva to form bolus

362
Q

salivary gland function

A

Produces and secretes saliva to the mouth. Saliva contains water, mucus, and
salivary amylase

363
Q

esophagus function

A

Peristalsis
Behind the bolus, Circular muscles around the esophagus contract and
longitudinal muscles relax to push the food down
In front of the bolus, the circular muscles relax and the longitudinal muscles
contract to widen the esophagus to move the bolus down

364
Q

stomach function

A

Muscle bag that mixes food with HCl and pepsin to form chyme
Acid has 2 roles = optimum pH for pepsin, and kills pathogens

365
Q

duodenum function

A

Chyme passes through the pyloric sphincter into the first part of the small
intestine - the duodenum, a little bit at a time
Pancreatic juice from the pancreas and bile from the liver is added here

366
Q

ileum function

A

Most of the chemical digestion and absorption happens here
Maltase enzymes on the wall digest maltose to glucose

367
Q

pancreas function

A

Produces pancreatic juice which contains amylase, trypsin (a protease), and
lipase and transports it to the duodenum via the pancreatic duct

368
Q

gall bladder function

A

Stores bile and transports it to the small intestine via the bile duct

369
Q

colon function

A

Absorbs any excess water from undigested and unabsorbed food

370
Q

rectum function

A

Absorbs any excess water from undigested and unabsorbed food

371
Q

anus function

A

Muscular sphincter to hold the feces in the rectum

372
Q

mechanical digestion uses

A

teeth

373
Q

There are four types of teeth in humans

A

incisors, canines, premolars, and molars

374
Q

incisor shape

A

chisel

375
Q

canine shape

A

pointed

376
Q

premolar shape

A

uneven cusps

377
Q

molar shape

A

uneven cusps like premolars

378
Q

molar shape

A

uneven cusps like premolars

379
Q

incisor number in humans

A

8

380
Q

canine number in humans

A

4

381
Q

premolar number in humans

A

8

382
Q

molar number in humans

A

12

383
Q

incisor position

A

Centrally located

384
Q

canine position

A

After incisors

385
Q

premolar position

A

After canines

386
Q

molar position

A

At the back

387
Q

incisor Description

A

1 ROOT

388
Q

canine description

A

1 sharp root

389
Q

premolar description

A

1 root

390
Q

molar description

A

2 roots

391
Q

incisor function

A

Biting

392
Q

canine function

A

Tearing

393
Q

premolar function

A

grinding

394
Q

molar function

A

chewing

395
Q

why is chemical digestion important

A

to break down large insoluble molecules into small, soluble ones.

396
Q

amylase is found in

A

Mouth and the Duodenum

397
Q

Amylase in the Mouth and the Duodenum breaks down

A

Starch to Maltose

398
Q

maltase is attached to the

A

Ileum wall

399
Q

Maltase attached to the Ileum wall breaks down

A

Maltose to Glucose

400
Q

Pepsin in the

A

stomach

401
Q

Pepsin in the Stomach breaks down

A

Protein to Polypeptides

402
Q

Trypsin in the

A

Duodenum

403
Q

Trypsin in the Duodenum breaks down

A

Polypeptides to Amino acids

404
Q

Lipase in the

A

Duodenum

405
Q

Lipase in the Duodenum breaks down

A

Fats to Fatty acids and Glycerol

406
Q

Amylase, Lipase, and Trypsin are made in the

A

Pancreas and move to the intestine in the pancreatic duct

407
Q

The function of Hydrochloric Acid in the Stomach

A

● Denature enzymes in bacteria in food
● Give optimum pH for pepsin activity

408
Q

Bile function

A

●Neutralizes the acidic mixture entering the duodenum to provide optimum pH for enzymes
● Emulsifies fat to increase the surface area for the chemical digestion of fat by lipase

409
Q

Digested food is absorbed in the

A

small intestine

410
Q

Most water is absorbed in the

A

small intestine

411
Q

Any excess is absorbed in the

A

large intestine

412
Q

villi

A

The inner wall of the small intestine form folds that are called

413
Q

Behind these villi are

A

blood capillaries and the lacteal (part of the lymphatic system)

414
Q

adaptation of villi

A

● A large number of villi and microvilli increase the
surface area for absorption
● One-cell thin wall speeds up diffusion
● Blood capillaries are very close to the wall of the
villi to speed up diffusion
● Lacteals branches of the lymph system that
absorb and transport digested fat
○ Gut movements empty the lacteal and lymph
moves slowly through lymphatic vessels and
enter the blood near the heart.

415
Q

A balanced diet

A

contains the correct amount and proportion of carbohydrates, proteins, fats, vitamins, minerals, water, fiber (roughage).

416
Q

Principal and dietary sources are:

A

carbohydrates
fats and oils
proteins
vitamin C and D
mineral ions
iron
fibre ( roughage)
water

417
Q

carbohydrates

A

Needed for: energy.
Sources: Potatoes, wheat(often made into bread or pasta), rice and maize.

418
Q

fats and oils

A

Needed for: energy, to make cell membrane. Stored under skin in adipose tissue to reduce heat loss from body to air. Provide mechanical protections for organs like kidney by forming a layer around them. Sources: cooking oil, meat, dairy product and oily fish.

419
Q

proteins

A

Needed for: to build new cells for growth, to make hemoglobin, insulin, and antibodies.
Sources: meat, fish, eggs, dairy products, peas, beans, nuts, and seeds.

420
Q

Vitamin C:

A

Needed for: to make the stretchy protein collagen found in skin and other tissues. Help tissue in good repair.
Source: citrus fruit, such as oranges, lime and raw vegetables.

421
Q

Vitamin D:

A

Needed for: helps calcium to be absorbed for making bones and teeth.
Sources: oily fish, liver, red meat, egg yolk, sun

422
Q

Calcium:

A

Needed for: bones and teeth and blood clotting.
Source: Milk and other daily products, bread.

423
Q

iron:

A

Needed for: making hemoglobin the red pigment in blood, which carries oxygen.
Source. liver, red meat, egg yolk, dark green vegetables.

424
Q

fibre (roughage)

A

Needed for: Absorb and remove, toxins, prevent constipation.
Source: all plant food such as fruits and vegetables.

425
Q

water

A

Needed for: An important solvent. Metabolic reaction can only take place in
a solution. Plasma is mostly water. Cytoplasm is mostly water. To dissolve
enzymes and nutrients in alimentary canal.
Source: By drinking fluid and some fruits.

426
Q

Vitamin C deficiency causes scurvy

A

which causes pain in joints and muscles and
bleeding from gums and other places. This used to be a common disease for sailors who had no fresh vegetables during long voyages.

427
Q

Vitamin D deficiency causes

A

rickets, in which the bones become soft and deformed;
this disease was common in young children in industrial areas, who rarely got out
into the sunshine.

428
Q

Calcium deficiency results in

A

brittle bones and teeth; poor blood clotting.

429
Q

Iron defficiency causes

A

anaemia, in which there are not enough red blood cells so the
tissues do not get enough oxygen delivered to them.

430
Q

Ingestion

A

taking of substances, e.g. food and drink, into the body. Occurs in mouth.

431
Q

digestion

A

the breakdown of food

432
Q

absorption

A

the movement of nutrients from the intestines into the blood

433
Q

assimilation

A

uptake and use of nutrients by cells

434
Q

egestion

A

the removal of undigested food from the body as faeces.

435
Q

Oesophagus

A

Food travels down the oesophagus into the stomach.

436
Q

Stomach

A

Contains strong muscular walls. Muscles relax and contract to mix food enzyme and mucus.
Goblet cells in the walls secret mucus.
Digest protein.
Produce hydrochloric acid. Hydrochloric acid lowers the pH to about 2, which is the optimum pH for protease in the stomach. After the Stomach, the food moves into the duodenum.

437
Q

Small intestine:

A

Duodenum:
Mix food with bile and pancreatic juice.
Absorption of minerals, and other nutrients begins in the duodenum.
Ileum:
Absorb digested nutrients into blood.
Absorb water.

438
Q

Large intestine

A

Colon:
absorb remaining water
Rectum:
Store faeces.

439
Q

Salivary gland secrete

A

saliva in mouth, which contains the enzyme amylase, that
starts the digestion of a starch.

440
Q

Pancreas secretes

A

digestive juices, which helps in digestion of fat

441
Q

Liver produces bile

A

It is stored in gallbladder. Bile increase the pH of acidic food
from the stomach. And emulsifies fat.

442
Q

More water is absorbed in small intestine than

A

large intestine.

443
Q

Physical digestion

A

breakdown of food into smaller pieces without chemical
change to the food molecules.

444
Q

Physical digestion increases the

A

surface area of food for the action of enzymes in
chemical digestion.

445
Q

The tooth is embedded in the

A

gum

446
Q

Incisors

A

chisel shaped for biting off pieces of food.

447
Q

Canines

A

very similar to incisors in humans.

448
Q

Premolars

A

have wide surfaces for grinding food.

449
Q

Molars, like premolars, are used for

A

grinding

450
Q

Muscular walls of the stomach, mix the

A

food, enzyme and mucus together in the process of churning.

451
Q

Chemical digestion

A

break down of large insoluble molecules into small soluble
molecules

452
Q

The role of chemical digestion

A

producing small soluble molecules that can be
absorbed.

453
Q

Amylase breaks down

A

starch to maltose. It is secreted by salivary glands in mouth
and by pancreas in duodenum

454
Q

Maltase breaks down

A

maltose to glucose. Maltase is secreted by the cells in the
lining of the small intestine on the membranes of the epithelium lining of the small intestine.

455
Q

Pepsin breaks down

A

protein in acidic conditions and is secreted by the walls of the
stomach

456
Q

Trypsin breaks down

A

rotein in alkaline conditions and is secreted by the pancreas
in the duodenum.

457
Q

Lipase breaks down

A

fats and oils to fatty acids and glycerol. It is secreted by the
pancreas in the duodenum.

458
Q

The function of hydrochloric acid in gastric juice is to

A

kill harmful microorganisms in food and provide an acidic pH for optimum enzyme activity

459
Q

Bile

A

an alkaline mixture that neutralizes the acidic mixture of food and gastric juices entering the duodenum from the stomach, to provide a suitable pH for enzyme action

460
Q

Small intestine is the

A

region where nutrients are absorbed.

461
Q

Most water is absorbed from the small intestine but some is also absorbed from the

A

colon

462
Q

Villi and microvilli increase the

A

internal surface area of the small intestine and help in
faster absorption of dissolved nutrients.

463
Q

Villi

A

are tiny projections on the internal wall of the small intestine. The cell membrane on the surface of each villus is folded to form many tiny microvilli. Villi contains lacteal and blood capillaries.

464
Q

Capillaries in villi

A

absorb glucose, amino acids, fatty acids, glycerol, vitamins, mineral ions and water. These blood capillaries join to form hepatic portal vein, which takes all of these substances to the liver.

465
Q

The fatty acids and glycerol pass

A

A
into the lacteals. The contents of the lacteals are eventually emptids into the blood.