7. Human Nutrition Flashcards
What is a balanced diet
A balanced diet is a diet that contains the correct proportions of nutrients that the body needs to function correctly
Which general group of people require the most calories in their diet
Adolescent males with active lifestyles
Why do pregnant women need a larger caloric intake
They need more energy to support the development of the child
The diet needs to be balanced as well to provide the correct nutrients
What is constipation caused by
A lack of dietary fiber
What is starvation
Suffering or death that is caused by not eating enough food
What is constipation
Infrequent bowel movements causing difficulty passing faeces
What is scurvy caused by
A lack of vitamin C
Give 3 sources of carbohydrates in the diet
Pasta
Bread
Potato
Give 3 sources of fat in the diet
Oily fish
Nuts
Full fat dairy
Give 3 sources of protein in the diet
Meat
Fish
Nuts
Give 2 sources of vitamin c in the diet
Fruit vegetables
Give 2 sources of vitamin d in the diet
Oily fish
Eggs
Give 2 sources of iron in the diet
Brown rice
Meat
Give 2 sources of calcium in the diet
Milk
Cheese
What are the 2 main groups of dietary fiber
Soluble fiber
Insoluble fiber
Give 2 sources of soluble fiber
Oats
Fruit
Give 2 sources of insoluble fiber
Whole meal bread
Nuts
What are the causes of vitamin d deficiency
Not enough sunlight
Not enough oily fish, egg yolks or fortified milk
What are the effects of vitamin d deficiency
Vitamin d deficiency can cause rickets in children which leads to weak bones which can cause deformities
What are the causes of iron deficiency
A diet lacking iron
Blood loss
Pregnancy
What are the effects of iron deficiency
Fatigue
Dizziness
Headache
Chest pain
What is ingestion
The intake of substances into the body through the mouth
What is mechanical digestion
The process of breaking down food without altering it chemically
What is chemical digestion
Breaking insoluble large molecules into smaller soluble ones
What is chemical digestion
Breaking insoluble large molecules into smaller soluble ones
What is absorption
The process where ions and broken down food molecules move into the blood through the wall of the intestine
What is assimilation
The movement of digested food molecules into the cells of the body where they are used
What is egestion
The removal of undirected food as waste from the anus
What is diarrhea
Passing watery faeces
How can diarrhea be treated
Using oral rehydration therapy which involves taking a sugar/salt solution orally
What is cholera
A disease caused by a bacterium that causes severe dehydration and diarrhea
What is an ion channel
They are proteins that span cell membranes that allow charged molecules to pass through the membrane
How does the cholera bacterium cause dehydration and diarrhea
- the cholera bacterium produces a protein toxin
- the toxin causes chloride ion channels in the small intestine membranes to open
- chloride ions move into the gut
- water then also moves into the gut down its concentration gradient
- faeces becomes watery
Identify the structures of the digestive system labeled in the diagram
What is the difference between the alimentary canal and the digestive system
The alimentary canal involves the tubes that the food passes through whereas the digestive system also includes digestive glands
Describe the passage of food through the alimentary canal
Mouth
Esophagus
Stomach
Small intestine
Large intestine
Rectum
What is the function of the mouth
To chew and break down food
To secrete digestive enzymes
What is the esophagus
The tube that carries food from the mouth to the stomach
What does the stomach do
The stomach is a muscular sac containing acid that pummels the food and breaks it down further
What role does the pancreas play in digestion
The pancreas secretes digestive enzymes into the small intestine
Where are the salivary glands located
In the mouth
Name the 2 parts of the small intestine
Duodenum and ileum
What is the function of the duodenum
The duodenum receives food directly from the stomach and uses enzymes and chemical digestion to break the food down
What is the function of the ileum
Most nutrients are absorbed from the food in the ileum into the blood
How is the ileum adapted for absorption
The ileum is lined with villi and micro I’ll which provide a large surface area for absorption
How are villi adapted for absorption
Thin walls
Large surface area
Good blood supply close to the surface
What is the function of the large intestine
Water is reabsorbed into the blood in the large intestine
What is the function of the rectum
The rectum stores faeces before egestion
Name the types of teeth in each of the 4 coloured sections
Red - incisors
Yellow - canines
Blue - premolars
Green - molars
Label this diagram of a tooth
What is the function of incisors in mechanical digestion
Biting and breaking sections of food off a larger piece
What is the function of canines in mechanical digestion
Ripping and shredding food
What is the function of premolars and molars in mechanical digestion
Chewing and grinding food
What causes dental decay
Bacteria found in the mouth use sugars from foods to respire which produces acid that breaks down the enamel on teeth
How can dental decay be prevented
Brush teeth regularly
Control diet and limit the consumption of sugary food and drinks
What is the purpose of chemical digestion
Breaking larger insoluble molecules into smaller soluble molecules that can be absorbed
What does amylase do
Amylase is a digestive enzyme that breaks starch down into simple sugars
Describe the digestion fo starch in the alimentary canal
Amylase is secreted and breaks starch down into maltose in the alimentary canal
Maltese breaks maltose down on the membranes of the small intestine
What does protease do
Protease is a digestive enzyme that breaks proteins down into amino acids
What does lipase do
Lipase is a digestive enzyme that breaks lipids down into fatty acids and glycerol
Give 2 places in the alimentary canal that amylase is secreted
The pancreas
The salivary glands in the mouth
Give 2 places in the alimentary canal that protease is secreted
The pancreas
The stomach
Where in the alimentary canal is lipase secreted
The pancreas
Give 2 examples of protease enzymes
Pepsin and trypsin
Where is trypsin secreted from
The small intestine
Where is pepsin secreted from
The stomach
What are the functions of the hydrochloride acid in gastric juice
Killing bacteria
Gives the appropriate pH for enzymes to work
Explain the functions of hydrochloric acid in gastric juice
Low pH kills bacteria by denaturing the enzymes inside them
Low pH is the optimum pH for pepsin
What does bile do
Bile neutralizes the stomach acid and provides alkaline conditions for the digestive enzymes in the small intestine
Bile also emulsifies fats which increases their surface area for chemical digestion
In which part of the alimentary canal is digested food absorbed
The small intestine
What is the purpose of villi in the small intestine
Villi increases the surface area for absorption
Describe the structure of a villus
Central láctea used for transporting acids and glycerol in the lymph fluid
Lots of capillaries to absorb nutrients into the blood
Thin wall to minimise the diffusion distance
State 2 parts of the alimentary canal where water is absorbed
The small intestine
The colon
