Biology Flashcards
three major purposes of food and energy:
- Supply the energy for all activities
- Build new tissue (growth)
- Repair worn and damaged tissue
Three facts about the mouth:
- Chemical and mechanical breakdown
- Chew’s food up into easy-to-swallow balls
- Salivary glands produce Amylase ro start break down
Four facts about the oesophagus:
- Partly digested food is swallowed
- Pass down the muscular tube called the oesophagus
- It contracts rhythmically to puch food towards the stomach = peristalsis
- Force of gravity also helps
Four facts about the stomach:
- Pummels the food with muscular walls
- Produces pepsin and rennin enzymes
- Pepsin breaks down protein
- Renin coagulates casein, the soluble protein of milk = forming an insoluble curd which is then attacked my pepsin.
Why does the stomach produce hydrochloric acid? (4)
- to kill bacteria
- correct pH for the protease enzyme to work
- pH2 = acidic
About the small intestine (5):
Main place where digestion happens. The agents of digestion came from 3 sources, including the liver, pancreas and wall of the small intestine. The small intestine is where “food” is absorbed into the blood. It is long and folded to increase surface area. The villi are tiny finger-like things which cover the inner surface to increase surface area.
About the pancreas: (3)
The pancreas produces pancreatic amylase which breaks down starch to maltose, trypsin to break down protein and pancreatic lipase to break down fats into fatty acids and glycerol.
About the liver: (11)
The liver is the largest organ in the body. Its functions are to act as the chemical factory, stores food and central heating system. Liver stores glucose as glycogen. When the body needs glucose, it turns the glycogen back into glucose. Stores vitamin A, B and D as well as minerals like copper, potassium and iron. They change left overs into waste (urea) and takes poison from blood (germs, alcohol, drugs).The liver makes fibrogen. Produces heat and blood carries it around your body. Bile is produced in the liver but is stored in the gallbladder.
About the gall bladder:
Bile is stored in the Gall Bladder, before it is injected into the small intestine.
Large intestine:
Where excess water is absorbed from blood.
Anus
Where faeces (mostly indigestible food) goes out of the body.
What is gas exchange? (2)
- The exchange of oxygen and carbon dioxide.
- And always takes place by diffusion across moist cell membranes.
What features do an efficient respiratory surface need? (3)
- The surface area should be as large as possible
- The respiratory surface should be as thin as possible
- The respiratory surface should be moist to allow the gases to dissolve.
3 factors of the mammalian respiratory system:
- Air is drawn through the nose and passes into the PHARYNX > LARYNX > TRACHEA > BRONCHI > BRONCHIOLES > ALVEOLI
- The trachea and bronchi are lined with ciliated cells and secreted mucus.
- Particles of dust or bacteria are trapped by this mucus and swept by the cilia back up to the pharynx and swallowed.
About the alveoli:
It looks like bunches of grapes.
The heart:
A muscular pump with two types of pumping chambers
Veins and Arteries:
Form a network of muscular channels carrying blood to and from the heart respectively
Pulmonary vessels
Carry blood to and from the lungs
Systemic vessels:
Carry blood to and from all other parts of the body
Capillaries:
Numerous, very fine channels with thin walls, which provide a very large surface area across which gas exchange of substance can take place.
Blood
The circulating fluid consisting of plasma and sells which is highly specialized for transport and defense.
What is your muscular pump?
Heart
Right atrium:
Receive deoxygenated blood returning from the systemic circuit (body) via the VENA CAVA (vein)
Define these words to do with the heart:
- vein
- arteries
- pulmonary
Veins: Into the heart
Arteries: Out of the heart (no valves)
Pulmonary: to do with the lungs
