Human nutrition Flashcards
what are the 6 nutrients that humans need for a balanced diet
minerals, vitamins, carbohydrates, proteins, fats, water
what is one hting humans need but its not a nutrient
fibre
what does the amount of energy we use depend on
age, gender, occupation (lifestyle)…
what nutrients are startch and sugar included in
carbohydrates
what do we need fats and oils for
to make cell membranes
where do we store excess fats and oil
under the skin in adispose tissue
benefits of fats and oils
act as an insulator, can form around organs, physically protecting them
where do we get our fats and oils
oils, meat, eggs, dairy products, oily fish deu
what do we need protein for
to build new cells, for growth
what happens to proteins inside us
they are broken down into amino acids that are used to make other proteins
where do we get our proteins
meat, fish, eggs, dairy products, peas, beans, nuts
what are vitamins
organic substances
do we need LOTS of vitamins
no, only in tiny amounts
where is vitamin C found
in citrus fruits and raw vegetables
deficiency disease for vitamin C
scurvy, bleeding from gums and other places
where is vitamin D found
butter, egg yolk, sunlight
why do we need vitamin C
to make collagen, keep tissues in good repair
why do we nneed vitamin D
absorption of calcium, making bones & teeth
deficiency disease for vitamin D
rickets
what is water important for
its an important solvent in cytoplasm, metabolic reactions dont happen if the cell is dehydrated. the spaces between cells is also a watery liquid. water is also the liquid part of blod, its a solvent for enzymes and nutrients in the digestive system, gets rid of waste products
what is fibre important for
to keep the digestive system working between the mouth and the anus
what is peristalsis
rhythmic muscular contractions that move through food through the digestive system
what is ingestion
taking food and drink into the mouth, using tongue, teeth and lips
what is physical digestion
large pieces of food are broken down into smaller pieces through mechanical means. food is then able to undergo chemical digestion
what is chemical digestion
large molecules are broken down into smaller molecules by enzymes. molecules must be small enough to pass into blood
what is absorption
movement of small molecules and mineral ions through the walls of the intestine and into the blood
what is assimilation
absorption of nutrients by individual cells and used for energy or to make new substances
what is egestion
material that we cannot digest remains in our intestines and eventually is passed out as faeces
in digestion, what happens in the mouth
teeth grind food to increase the surface area, tongue mixes the food with saliva forming the bolus that can be swallowed
what enzyme digests startch
amylase
in digestion, what happens in the oesophagus
it takes food down into the stomach;
what is the hole down the center of the oesophagus called
lumen
how is the entrance to the stomach controlled?
its controlled by a sphincter muscle: opens to let food in then closes
describe the location of the oesophagus and the trachea
they are next to each other, trachea is in front, close to the lungs. oesophagus is behind, closer to the stomach
how does our body prevent food from going in out trachea
because of the epiglottis, that opens and closes so that food won’t go in the trachea
what does the stomach do
the stomach is muscular walls that contract to mix food with mucus and enzymes. goblet cells secrete mucus, cells produce enzymes that break down protein, they also produce hydrochloric acid
for how long can the stomach store food. what happens when it can no longer hold it
1-2 hours, then the sphincter opens to the duodenom
how long is the small intestine
5m long
what is the small intestine
its composed of two parts, the duodenom, that is the first part and is close to the stomach; and the ileum, that is the last part and nearest to the colon
how long is the large intestine
1.5m long
what is the large intestine
its composed of two parts. the colon, that absorbs water still left in food, and the rectum that stores undigested food as faeces
what does the pancreas do
it secretes enzymes into the intestines
what does the liver do
it creates bile, a liquid that helps to neutralise the acidic mixture from the stomach
where is bile storedd
in the gall blader
what happens when food enters the duodenom
bile flows through a bile duct and is mixed with the food
