4. Human Nutrition Flashcards
Balanced diet
A diet that contains all the right nutrients in the correct amounts and proportions to maintain good health.
Malnutrition
Lack of proper nutrition, caused by not having enough to eat, not eating enough of the right things(unbalanced diet), or unable to use the food that one does eat.
Kwashiorkor
A form of malnutrition that most often affects children in developing regions of the world where there is famine or a limited food supply. It is due to a lack of protein.
Marasmus
A type of malnutrition caused by a lack of calories.
Diarrhoea
The loss of watery faeces and is usually treated using oral rehydration therapy.
Facilitated diffusion
Larger molecules move through carrier proteins from high concentration to a low concentration.
Mechanical digestion
The breakdown of food into smaller pieces without chemical change to the food molecules.
Chemical digestion
The breakdown of large,insoluble molecules unto small, soluble molecules usually by the action of enzymes.
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.
The stomach releases gastric juice, which contains hydrochloric acid. This helps by;
Denaturing enzymes in harmful micro-organisms in food (killing them)
Providing an acid(optimum) pH for enzyme (pepsin) activity.
Villi
Finger-like projections found lining the small intestine. The epithelial cells that make them up are also found to have little hairs on the called microvilli.
What are the adaptations of the villi?
Many microvilli
Good blood supply
Thin walls
Role of the lacteal in the villi?
It takes the insoluble products of fat digestion, fatty acids and glycerol, into lymphatic system and through lacteal instaed of dissolving straight into blood.
