Human Nutrition Flashcards
(99 cards)
What are the three branches in heterotrophs?
Herbivores, Carnivores and Omnivores
What are herbivores?
Animals that feed exclusively on plants eg, cattle, sheep
What are carnivores?
Animals that feed on other animals eg, seals
What are omnivores?
Animals that feed on plants and animals eg, humans, bears
What is digestion?
It’s the breakdown of food into particles that are small enough to pass into body cells
What does digestion allow?
Allows materials needed to process the food to be localised in a single place eg, teeth in mouth
Prevents each cell having to contain a full range of digestive enzymes
What is ingestion?
It’s the taking in of food into the alimentary canal eg, putting food in your mouth
What is digestion?
It’s the mechanical or chemical breaking down of food into particles that are small enough to pass into body cells
Why is digestion essential for absorption?
If food isn’t broken down, chemicals in food would not pass from digestive system into body tissues
What is absorption?
Soluble food is passed from cells into bloodstream
What is egestion?
It’s the removal of unabsorbed and undigested material from the digestive system through anus
What sort of digestion occurs in the mouth?
Mechanical digestion, chewing action of teeth
Function of incisors
Cutting, slicing
Function of Canines
Tearing
Function of Premolars and molars
Chew, crush
What is the human dental formula?
Shows the arrangement of the different types of teeth
2(2/2 I, C 1/1, PM 2/2, M 3/3)
Upper numbers = upper jaw of one side of mouth, Lower numbers = lower jaw of one side of mouth
Digestion in the mouth
Mechanical digestion - teeth = break down food into smaller particles so it is easier to swallow and have a greater surface area for enzyme to action
Chemical digestion - due to the enzyme amylase in saliva. Saliva is produced by 3 parts of salivary glands located under the tongue, back of the jaw and cheeks. It helps soften and dissolve food so we can swallow it
What does saliva consist of?
Water, Salts, Mucous [mucin] and enzymes amylase and lysozyme
What does amylase do?
It digests starch into maltose
Ideal ph is 7/8 and temperature is 37 degrees
What is the function of the epiglottis?
It closes over the trachea and ensures it passes down the oesophagus
What is the function of the oesophagus?
It carries food to the stomach by peristalsis
What is peristalsis?
It’s an involuntary wave of muscular contraction
When food enters the oesophagus, what assists the movement?
Mucous found in saliva and by mucous produced by inner lining of oesophagus
What is the function of peristalsis?
It moves food though the alimentary canal
In stomach - it helps breakdown food mechanically
Iit mixes food with the secretions of the stomach and then forces into the small intestine
Small intestine - forces food forwards and backwards, which helps food to be absorbed
Large intestine - Strong wave of peristalsis forces waste into the rectum