M7 Deck - Digestion and Nutrition Flashcards
(29 cards)
What happens to a bolus of food as it passes along the oesophagus.
Peristalsis moves the bolus of food using muscle contractions and the epiglottis prevents food from entering the trachea as you swallow.
The 3 functions of the ileum.
- the second part of the small intestine
- absorbs broken down food into the alimentary canal
- 6 meters long and has a large surface area
The 3 functions of the villi in the small intestines.
- finger like projections on the inner walls
- have microvilli to increase surface area for absorption
- contain a lacteal that absorbs fatty acids from fat digestion
What is the length of the small intestine?
The length of the small intestine is 7 metres long.
What are epithelial cells
Have a large number of mitochondria that give energy for transport of nutrients from ileum to the blood.
Functions of the stomach
- the walls contract and relax to churn food
- mixes food with chyme and gastric juice
3 Functions of the liver
- filters toxins and waste products from blood
- produces bile that breaks down fats through emulsification.
- stores vitamins and minerals
What is chyme?
Food mixed with enzymes, mucus and hydrochloric acid
Gastric juices
contain mucus, HCL and pepsin that are secreted from the gastric juice glands into the stomach to break down proteins.
What does the pancreas do?
produces enzymes for digestion and hormones for blood sugar regulation such as lipase, amylase, protease and insulin
What is the function of lipase, where is it produced and where is it secreted?
The function of lipase is to break down lipids into fatty acids and glycerol it is found in the pancreas and secreted through the pancreas.
What are Iodine tests on foods used for and what color is shown when starch is present and absent?
- used to test for starch
- deep blue when iodine is present (positive)
- brown when iodine is absent (negative)
The 7 main characteristics of enzymes.
- Enzymes are proteins
- all specific to the chemical reaction it speeds up
- required in small amounts
- prevented from working by poisons
- work best at a particular temperature
- destroyed by high temperature
- work best at optimum pH.
What is amylase and what does it break down?
Amylase is an enzyme that breaks down polysaccharides into disaccharides and monosaccharides.
What is protease and what does it break down?
Protease is an enzyme that breaks down protein into amino acids.
What is lipase and what does it break down?
Lipase is an enzyme that breaks down lipids into fatty acids and glycerol.
What are the effects of temperature on the activity of digestive enzymes?
Higher temperatures destroy enzymes.
Vitamin deficiency diseases caused by Vitamin C
Vitamin deficiencies caused by vitamin c is scurvy. Symptoms of scurvy are gums bleeding, wounds take longer to heal, and heart failure.
Vitamin deficiency diseases caused by Vitamin D
Vitamin deficiencies caused by vitamin D is rickets. Symptoms of rickets are growing bones do not calcify, results in bowlegs in younger children or knock knee in older children.
Disease caused by a deficiency in iron.
The disease caused by a deficiency in iron is called anaemia. Symptoms of anaemia include tiredness, lack of energy due to a reduction in red blood cells, since iron is in charge of making haemoglobin.
What happens to the unusable materials (materials that are not absorbed) during the digestive process.
Unusable materials are expelled through excretion/egestion.
What substances are absorbed into the lacteal of the villus?
Also known as the lymph capillary the lacteal absorbs fatty acids from the digestion of fat.
Two substances that are absorbed into the blood capillaries
Two substances that are absorbed into blood capillaries are simple sugars and amino acids.
One way the body uses glucose that is absorbed by the villus.
used in respiration
