Energy And Nutrients Flashcards
(56 cards)
What are essential nutients
One’s your body can’t produce
What is the role of essential nutrients
Energy, metabolism, promotion of growth and development, maintenance of good health
How much of your daily energy expenditure is made up from the GI tract
10-20%
What does the GI tract do
Breakdown, absorption, excretion
What happens in the oesophagus
Peristalsis begins, moving food automatically to the stomach
What is peristalsis and how does it work
Propelling food down the GI tract
- contraction of longitudinal muscles
Explain what happens in the stomach (GI tract)
Food is mixed with digestive juices forming chyme
What is chyme
A thick, semifluid substance consisting of food and gastric juices.
What happens in the small intestine (GI tract)
Digestion continues, nutrients and water are absorbed
What happens I the large intestine (GI tract)
Absorbs water, forms and moves stool to rectum
What are the elements of the alimentary canal or GI tracts
- moth
- Oesophagus
- stomach
- small intestine
- Large intestine
- anus
What are the accessory organs of the GI tract
Salivary glands
Liver
Pancreas
Gall bladder
What is the role of the salivary glands
Produce saliva to moisten food aiding easy movement to the stomach
What is the role of the pancreas
Produce enzymes that break down carbohydrates, fats and proteins
What is the role of the liver in GI tract
Produces bile which helps in the breakdown of fats
What is the role of the gallbladder in the GI tracts
Stores bile from the liver and releases it into the small intestine when needed
What is digestion and what are the two types
Breaking down food small enough to be absorbed by the body
- mechanical
- chemical
What is absorption
Transporting these digested molecules across the walls of the GI tract and into the bloodstream
What are the stages of mechanical digestion
Chewing
Peristalsis
Segmentation
What stage of digestion happens before food intake
The cephalic stage
The anticipatory physiological response to sensing or expecting food
- vagus nerve activated
Increase production of saliva
Prep for processing
20% of acid secretion before food enters stomach
Bile + enzymes
Explain what peristalsis is and where it takes place
Propelling using longitudinal muscles, wave like contractions
Oesophagus
Stomach
Small intestine
(Mainly)
Smooth muscle
Stomach rumbling
What is segmentation and where does it occur
Mixes chyme
Mainly smalintestine
Alternating movements, circular muscles
What is chemical digestion and what are the elements
Dietary components
(Macronutrients broke down into smaller molecules)
Enzymatic hydrolysis
What are enzymes and what is enzymatic hydrolysis
Protein molecules with active sites which speed up chemical reactions
• enzymes break down the chemical bonds holding food molecules together, transforming them into their constituent building blocks which can then be absorbed and utilised by he body.
