Chapter 7 Flashcards
State what is meant by the term balanced diet for humans
an adequate intake of the biological molecules and energy needed to sustain the body and ensure good health and growth.
Explain how age, gender and activity affect the dietary needs of humans including during pregnancy and whilst breast-feeding
Age:
Children need more energy because they have BMR. A child may weigh less but they need energy for growing. The opposite for older people.
Gender:
woman have a higher fat content than men in their bodies. fat tissue has a lower metabolic rate than muscle, so women have a lower energy requirement than men.
Activity:
People who are in more rigorous sports and physical jobs require higher energy and protein diets.
Pregnancy:
Woman need extra nutrients during pregnancy for their child and breast-feeding.
Describe the effects of malnutrition in relation to starvation, constipation, coronary heart disease, obesity and scurvy
If individuals do not eat enough food from malnutrition, this can lead to starvation.
If an individual eats too much food with saturated fats and high energy contents, they can become obese.
If a person does not eat enough fibres, they can go through constipation (when the movement of food is too slow in the alimentary canal)
If an individual lacks enough vitamin C, they would get scurvy. This can cause bleeding in part of the body like the gums.
If an individual produces too much cholesterol, it can line the lining of the coronary artery; making it smaller and increasing the blood pressure.
List the principal sources of, and describe the dietary importance of carbohydrates
Sources:
Pasta, bread, potatoes
Importance:
They provide us a ready source of energy that is easily respired.
List the principal sources of, and describe the dietary importance of fats
Sources:
butter, cheese, nuts
Importance:
They are a long-term energy store and it is stored under the skin and around the heart and kidneys to protect our organs and work as thermal insulators.
List the principal sources of, and describe the dietary importance of proteins
Sources:
meat, milk, nuts, eggs
Importance:
Cell membranes and cytoplasm need to be made out of protein and it is needed to replace old damaged cells. Overall, it is important for growth and repair in organisms
List the principal sources of, and describe the dietary importance of vitamins
Sources:
VC - oranges, lemons, citrus fruits
VD - fish oil, milk, butter, also made by the skin from the sun
Importance:
VC - helps with tissue repair and resistance to disease
VD - Strengthens bones and teeth
List the principal sources of, and describe the dietary importance of mineral salts (calcium and iron)
Sources:
Iron - liver, meat, cocoa, eggs
Calcium - milk, fish, green vegetables
Importance:
Iron - used in the formation of haemoglobin in the blood
Calcium - strengthens bones and teeth
List the principal sources of, and describe the dietary importance of fibre (roughage)
Sources:
cabbage, sweetcorn, celery
Importance:
it helps to pass food down the gut from the mouth to the anus.
List the principal sources of, and describe the dietary importance of water
Source:
freshwater lakes, seas
Importance:
Water is needed for chemical reactions to take place in solution. Blood transports substances dissolved in water, urea leaves with water as urine
Explain the causes and effects of vitamin D and iron deficiencies
VD deficiency from lacking of eating citrus fruits causes soft bones and rickets and iron deficiency from lack of iron rich food causes tiredness and anaemia.
Explain the causes and effects of protein-energy malnutrition, e.g. kwashiorkor and marasmus
marasmus is caused by undernutrition and kwashiorkor is caused by undernutrition of proteins, PEM (protein energy malnutrition), causing the cells of the pancreas and intestine to die. So fewer digestive enzymes are released and the surface area for absorption is reduced. Therefore the body uses protein as an energy source. For kwashiorkor, it causes oedema, sparse, dry hair, flaky skin and fat accumulation in the live. For marasmus, it causes low body mass, thin arms and legs, little muscle or fat, wizened old looking face.
ingestion
the taking of substances, e.g. food and drink, into the body through the mouth
mechanical digestion
the breakdown of food into smaller pieces without chemical change to the food molecules
chemical digestion
the breakdown of large, insoluble molecules into small, soluble molecules
absorption
the movement of small food molecules and ions through the wall of the intestine into the blood
assimilation
the movement of digested food molecules into the cells of the body where they are used, becoming part of the cells
egestion
the passing out of food that has not been digested or absorbed, as faeces, through the anus
Describe diarrhoea
the loss of watery faeces
Outline the treatment of diarrhoea using oral
rehydration therapy
Diarrhoea causes the lose of salts and minerals and if you eat it will simply pass through. Therefore you need oral rehydration therapy in order to gain the minerals and salts you need to survive. Therefore, water containing salts and minerals is fed for the person so it can be taken in by diffusion, without passing through without absorption.
Describe cholera
a disease caused by a bacterium which produces a toxin that causes secretion of chloride ions into the small intestine, causing osmotic movement of water into the gut, causing diarrhoea, dehydration and loss of salts from blood
Identify the main regions of the alimentary canal and associated organs
mouth –> salivary glands –> oesophagus –> stomach –> bile duct (liver, gallbladder, pancreas) –> small intestine (duodenum and ileum) –> large intestine –> colon, rectum, anus
Describe the functions of the regions of the alimentary canal listed above, in relation to ingestion, digestion, absorption, assimilation and egestion of food
Supplement
Ingestion - taking of substances into the body through the mouth.
Digestion - breaking down of large insoluble molecules into small soluble molecules so they can pass through the gut wall into the blood
Absorption - the movement of small food molecules and ions through the wall of the intestine into the blood
Assimilation - the movement of digestive food molecules into the cells of the body where they are used becoming part of the cells
Egestion - the passing out of food that has not been digested or absorbed, as faeces through the anus
Identify the types of human teeth
incisors (chisel), canines (fangs), premolars (cusps) and molars (large cusps)
