Human Nutrition (Digestive System) Flashcards
Differentiate between herbivores, carnivores and omnivores
Herbivores: Eat plants e.g rabbits, cattle, sheep
Carnivores: Eat other organisms e.g fox’s cats dogs
Omnivores: Eat plant and animals e.g humans bears hedgehogs
What is the need for the digestive system?
To allow for the breaking down of bigger foods for easier absorption into the blood
What is digestion?
The physical and chemical breakdown of food
What is the order of thr main events in human nutrition
- Ingestion (taking in food)
- Digestion (breaking down of food)
- Absorption (intestines)
- Egestion (removal of waste)
Give examples of where both physical and chemical digestion occurs
Physical: the mouth
Chemical: the stomach
What is the dental formula
2(i2/2 C1/1 P2/2 M3/3)
What enzyme is secreted by the salivary glands and what does it break down
Amylase, starch into maltose
What separates the trachea and oesophagus
Epiglottis
What process moves food down the oesophagus
Peristalsis
What form of fibre stimulates peristalsis
Cellulose
Define peristalsis
A wave of muscular action in the walls of the alimentary canal that moves contents along
What is the acid in the stomach called
Hydrochloric acid
What enzyme breaks down protein
Pepsin, turns into peptides
Give another role of stomach acid other than digestion
Kill bacteria
What organ secretes lipase and amylase
The pancreas
What are some of the roles of the liver
- Break down red blood cells
- Make bile
- Detox the body
- Break down amino acids to urea
- Produce heat
What is the function of bile
Neutralise the stomach acid (chyme) that enters from the stomach into the duodenum
What are the 2 parts of the small intestine
The duodenum and ileum
What is the role of the duodenum
Digestion and secretion of intestinal juice
What are the lining of the intestines called
Villi
What is the role of the villi
Absorption of food through diffusion
What are some adaptations of the villi for absorption
- Large surface area
- Cell walls are one cell thick
- Rich blood supply
What is found inside the villi other than blood capillaries
Lacteals that hold lymph
What are adaptations of the small intestine for absorption
- Very long
- Has numerous villi
- Each villi has a lymph supply that carries fat away
What liquid absorbs fat into the bloodstream.
Lymph
What is the role of the large intestine
Absorb any left over nutrients in the form of liquids
What vitamins do the symbiotic bacteria in the colon produce
Vit B and vit K
Name a Digestive enzyme for carbs, proteins and lipids
Carbs: amylase
Proteins: protease
Lipids: lipase
