Human Nutrition Flashcards
What is a diet
Food consumed by organism
Name all six types of required nutrients
Proteins, Carbohydrates, Fats, Water, Minerals, Vitamins
What is a balanced diet
A diet consumed by organisms where nutrients are taken in through suitable proportions and required energy needs are met.
What are carbohydrates needed for
To create energy
Excess - stored as fats
Name 4 uses of fats and oils
-> Creates cell membrane
-> Insulation
-> Mechanical protection
->Provides energy
Name four functions of proteins
-> Creates cells
-> Provides insulin
-> Provides Haemoglobin
-> Creates antibodies
Why is vitamin C needed
To produce collagen
What is the deficiency for vitamin D + symptoms
Rickets - Soft bones
What is Vitamin D needed for
Strong, hard bones
What is the deficiency for vitamin C + symptoms
Scurvy - Joint pain
What is calcium needed for
Strong bones, Blood clotting
What is the deficiency of calcium
Poor blood clotting
What is Iron needed for
Production of haemoglobin
Deficiency disease of Iron + symptoms
Anemia - Lack of oxygen in the body
Whart is peristalisis
Rythmic muscular contractions in the alimentary canal that allow for food to be passed through
Why is fibre needed in the alimentary canal
To stimulate the muscles and allow for peristalsis to occur
5 functions of water
- Removal of toxic wastes
- Metabolic reactions
- Prevents cells from drying out
- Makes up plasma
- Present in between cells
What is the digestive system
System of organs that perform the digestion of food
What is ingestion
Taking in of nutrients as food
What is physical digestion
Breaking down small pieces of food into smaller pieces
What is chemical digestion
Breaking down small molecules into smaller molecules
What is absorption
Nutrients passing from the villi of the small intestine into the blood
What is assimilation
The usage of the nutrients in the blood for energy and for production of new substances
What is egestion
The removal of excess undigested food + fibres
What are sphincter muscles
Muscles that separate the organs in the alimentary canal which stops food from going from one part to another
Ehat is the alimentary canal lubricated with
Mucus
Where are goblet cells found and what do they secrete
Line the alimentary canal and secrete mucus
What makes up saliva and what do they do ?
-> Water - dissolves the food
-> Mucus - Lubricates the food/makes it into a ball
-> Amylase - Breaks down Starch into maltose
What is a lumen
A hole or smn
How does the stomach mix foods with mucus and enzymes
through contractions
What is the pH of hydrochloric acid in the stomach and why is it that way?
pH - 2
Since it is optimum for the enzymes, and kills microorganisms
How long does the stomach hold food for
2 hours
How long is the small intestine
5 metres
What are the first and last parts of the small intestine called, respectively
First - Duodenum
Second - Ileum
Function of the duodenum
Uses pancreatic juice + bile to break down food (digestion)
Function of the ileum
Absorbs nutrients found in food and a little bit of water
What is the large intestine made up of
Colon, Rectum
Function of the colon
Absorbs water from digested food
Function of the rectum
Stores undigested food + fibres until it is egested through the anus
Function of the pancreas
Produces pancreatic juice which is made up of enzymes. These enzymes digest food in the duodenum
Function of the liver
Produces a green alkaline solution called bile which emulsifies fat and neutralizes the stomach acid
Which organs conduct physical digestion
Teeth, Churning of the stomach
How does mechanical digestion occur
The teeth and stomach break down the larger pieces of food into smaller ones
How do teeth help with digestion
They increase the surface area of the food so that the enzymes can react faster
What is the enamel
Hardest substance that covers the surface of the teeth
What is the dentine
Stores living cytoplasm
What is the pulp
Produces cytoplasm, has network of arteries
What is the cement
COnnects the teeth to the gum
What do incisors and canines perform
Biting, Tearing
What do premolars and molars perform
Chewing, grinding
How many of each teeth are present in the jaws
Incissors - 8
Canines - 4
Premolars - 8
Molars - 12
Where does starch break down
In the mouth
Where does maltose break down
In the duodenum (maltase is secreted by the epithelium)
What is the final form of starch
Glucose
What is the protease secreted by the stomach called
Pepsin
What is the protease secreted by the pancreas
Trypsin
Explain emulsification - bile
Emulsification is when the bile dissolves the fats and lipid droplets into smaller drops. This increases their surface area and makes them soluble in water
Is emulsification physical or chemical digestion
Physical Digestion
What are villi
Projections on the small intestine
What are microvilli
Folds on top of the villi
WHere do these substances that are absored go
Through the hepatic portal vein that carries them to the liver
Lipids - carried through the lacteals(eventually reaches the blood)
How do the villi and microvilli increase the rate of absorption
They increase the surface area of the aborption process
