Organisation - Lungs and Circulatory System 56-60 Flashcards
what is the thorax and how is it separated
2 points
1) the top part of your body
2) separated form your lower body by the diaphragm
explain how air travels in your body
1) the air that you breathe in goes through the trachea
2) it splits into two tubes called bronchi, one going into each lung
3) the bronchi splits into progressively smaller tubes called bronchioles
4) the bronchioles finally end at small bags called alveoli where the gas exchange takes place
draw and label the lungs and stuff
look on page 56 of biology book
where does gas exchange happen
in the alveoli
what are alveoli surrounded by
blood capillaries
explain how gas exchange works at the alveolus
3 points
1) the blood passing next to the alveolus contains lots of CO2 and very little O
2) the oxygen diffuses out of the
alveolus (high concentration) into the blood (low concentration)
3) carbon dioxide diffuses out of the blood (high concentration) into the alveolus (low concentration) to be breathed out
draw and label gas exchange at an alveolus
look on page 57 of Bio book
explain how gas exchange works at body cells
3 points
1) when the blood reaches the body cells oxygen is released from the red blood cells and diffuses into the body cells
2) at the same time, carbon dioxide diffuses out of the body cells into the blood
3) it’s then carried back to the lungs
draw and label gas exchange at body cells
look on page 57 of bio book
what is the circulatory system made up of
3 points
1) the heart
2) blood vessels
3) blood
what kind of circulatory system do human have and what is this
2 points
1) we have a double circulatory system
2) this is two circuits joined together
what happens in the first circuit of the circulatory system
2 points
1) the right ventricle pumps deoxygenated blood to the lungs to take in oxygen
2) the blood then returns to the heart
what happens in the second circuit of the circulatory system
2 points
1) the left ventricle pumps oxygenated blood around all the other organs of the body
2) the blood gives up its oxygen at the body cells and deoxygenated blood returns to the heart to be pumped out to the lungs again
what are the walls of the heart mostly made of
muscle tissue
what do the valves of the heart do
they make sure blood flows in the right direction, prevent it from flowing backwards
what are the four chambers of the heart
4 points
1) right atrium
2) left atrium
3) right ventricle
4) left ventricle
draw and label the heart and its chambers
look on page 58 if bio book
how does the heart use its four chambers to pump blood around the body
5 points
1) the blood flows into the two atria from the vena cava and the pulmonary vein
2) the atria contract, pushing the blood into the ventricles
3) the ventricles contract, forcing the blood into the pulmonary artery and the aorta, and out of the heart
4) the blood then flows to the organs through the arteries, and returns through veins
5) the atria fill again and the whole cycle starts over
what do the coronary arteries do
1) the heart also needs its own supply of oxygenated blood
2) the coronary arteries branch off the aorta and surround the heart making sure it gets all the oxygenated blood it needs
how is your resting heart rate controlled
2 points
1) by a group of cells in the right atrium wall that act as a pacemaker
2) these cells produce a small electric impulse which spreads to the surrounding muscle cells, causing the to contract
what is an artificial pacemaker
3 points
1) used to control the heartbeat if the natural pacemaker cells don’t work properly
2) it’s a little device that’s implanted under the skin and has a wire going to the heart
3) it has an electric current to keep the heart beating regularly
what are the three different types of blood vessels and what do they do
3 points
1) arteries - these carry the blood away from the heart
2) capillaries - these are involved in the exchanged of materials at the tissues
3) veins - these carry blood to the heart
describe the characteristics of arteries
3 points
1) the heart pumps blood out at high pressure so the artery walls are strong and elastic
2) the walls are thick compared to the size of the hole down the middle (the lumen)
3) they contain thick layers of muscle to make them strong ans elastic fibres to allow them to to stretch and spring back
describe the characteristics of capillaries
6 points
1) arteries branch into capillaries
2) they are really tiny, too small to see
3) they carry the blood really close to every cell in the body to exchange substances with them
4) they have permeable walls, so substances can diffuses in and out
5) they supply food and oxygen, and take away wastes like CO2
6) their walls are usually only one cell thick. this increases the rate of diffusion
describe the characteristics of veins
4 points
1) capillaries eventually join up to form veins
2) the blood is at a lower pressure in the veins so the walls don’t need to be as thick as artery walls
3) they have a bigger lumen than arteries to help the blood flow despite the lower pressure
4) they also have valves to help keep the blood flowing in the right direction
what is the job of red blood cells
they carry oxygen from the lungs to all the cells in the body
what is the shape of red blood cells and how does this help
2 points
1) biconcave disc shape
2) this gives it a large surface area for absorbing oxygen
why don’t red blood cells have a nucleus
allows more room to carry oxygen
what is the red pigment in red blood cells
haemoglobin
in the lungs and body tissues what happens to haemoglobin
2 points
1) in the lungs, haemoglobin binds to oxygen to become oxyhaemoglobin
2) in body tissues the opposite happens. the oxyhaemoglobin splits up into haemoglobin and oxygen to release oxygen to the cells
what do white blood cells do
they fight against infection
1) some can change shape to engulf unwelcome microorganisms in a process called phagocytosis
2) others produce antibodies to fight microorganisms, as well as antitoxins to neutralise any toxins produced by the microorganisms
what do platelets do
they help blood to clot at a wound, to stop blood pouring out and to stop microorganisms getting in
what are platelets
these are small fragments of cells, they have no nucleus
what can a lack of platelets cause
excessive bleeding and bruising
what is plasma
plasma is the liquid that carries everything in blood
what does the plasma carry
7 points
1) red and white blood cells and platelets
2) nutrients like glucose and amino acids
3) carbon dioxide from organs to the lungs
4) urea from the liver to the kidneys
5) hormones
6) proteins
7) antibodies and antitoxins
