What is the circulatory system’s main function?
To get food and oxygen to every cell and to collect all the waste products like CO2 and urea so they can be removed from the body
What type of circulatory system do humans have?
A double one where two circuits are joined together.
What does the first (right side) circuit do?
What then happens to the blood?
Pumps deoxygenated blood to the lugs to take in more O2. The blood then returns to the heart
What does the second (left side) circuit do?
What then happens to the blood?
Pumps oxygenated blood around all the other organs of the body.
It gives up all of its oxygen to the body cells and the deoxygenated blood returns to the lungs
How does the blood get pumped around the body?
What are the walls of the heart mostly made of?
The heart is a pumping organ, contracting to pump the blood around the body.
Muscle tissue
What do the heart valves do?
Make sure the blood flows in the right direction, preventing it going backwards.
How does the heart pump the blood around? Describe the process…
- Blood in
- Down
- Up and out
- Around and in
- Into
- Blood flows into the atria, the right from the vena cava and the left from the pulmonary vein
- The atria contract, pushing the blood into the ventricles, right and left.
- The ventricles contract forcing the blood out into the pulmonary artery on the right, and the aorta on the left, out of the heart.
- The blood then flows through the organs through the arteries, and returns through the veins, right vena cava, and left pulmonary vein.
- The atria fill and the process repeats
Describe the flow diagram of the blood’s journey around the circulatory system…
- Start with the vena cava…
- Don’t describe what happens, just where it goes…
- Up and out… where to?
- Into ? from where ?
- Into
- Down into?
- What now where to?
- And back to…. after being….
- The deoxygenated blood flows into the the right atrium through the vena cava (from the head, and the rest of the body).
- The blood is pumped down into the right ventricle
- Then it’s pumped up the PULMONARY artery, to go to the lungs to oxygenate
- The blood comes back into the PULMONARY vein (P artery to the P vein) from the lungs
- The blood fills the left atrium
- Then is pumped into the left ventricle
- Then is pumped out to the rest of the body, (towards the left) through the aorta
- When deoxygenated it returns to the vena cava.
What do doctors hear when they use a stethoscope?
The valves closing
What is the function of the arteries -
to carry the blood away from the heart at high pressure
What is the function of the capillaries -
these are involved in the exchange of materials at the tissues
What is the function of the veins -
to carry the blood to the heart
- Arteries carry the blood under….
- The hearth pumps the blood out at high…. so the walls of the arteries are…
- The …. are thick compared to the size of the …. down the middle, the …..
- They contain … layers of … to make them ….
- They contain ……. to allow them to …. and ….. back
- high pressure
- pressure, strong and elastic
- walls, hole, the lumen
- thick, muscle, strong
- elastic fibers, stretch, spring
- Arteries branch into ….. which are really ….
- These carry the blood ……. to …. cell in the body to ….. with them
- They have … walls so …. can … out
- They supply … and …, and remove…..
- They usually have ….-….. thick walls increasing the rate of … as it …. the distance over which it occurs
- It has a very small….
- capillaries, small
- really close… every… to exchange substances with them
- They have permeable walls so substances can diffuse out
- Food and oxygen, waste (CO2)
- One cell thick, diffusion, decreases
- Lumen
What do veins do?
- The …. eventually join up to form …
- The blood is at ….. so the walls don’t need to be as .. as the … walls
- They have bigger … than … to help the … flow despite the …….. …… .
- They also have …. to prevent … flowing in the … direction.
Take blood back to the heart
- Capillaries, veins
- Lower pressure, thick, artery
- Lumen than arteries, blood, lower pressure
- Valves, the blood, wrong
Blood is a type of …
It is part of a huge….
Red blood cells carry…
tissue
transport system
oxygen
What is the RBCell's job? Why are they biconcave? What don't they have and why not? What do they carry? What does haemoglobin do in the lungs? What does haemoglobin do in the body tissues?
To carry oxygen from the lungs to all the cells in the body
To give them a larger surface area for absorbing O2
A nucleus, so that there’s more room to carry O2
A red pigment called haemoglobin
Combines with O2 to become oxyhaemoglobin
It splits up into haemoglobin and O2 to release O2 into the cells
What do WBCells do?
How do they protect you against microorganisms?
What do they do to fight microorganisms?
What do they have that RBC don’t?
Defend against disease
They can change shape and engulf foreign microo’
They produce antibodies to fight them, and antitoxins to neutralise any toxins the microorganisms produce.
A nucleus
What do platelets do?
To stop what?
What are they?
What happens if you have a lack of platelets?
Help blood to clot at a wound
To stop you bleeding and microorganisms getting in
Fragments cells, they have no nucleus
You can get excessive bleeding and bruising
What is plasma? What does it carry? 1. blood stuff 2. food stuff 3. Breath stuff 4. Apres digestion stuff 5. Stress 6. Fighting
It is the liquid that carries everything in blood, it is straw coloured.
- Red and White blood cells and platelets
- Nutrients like glucose and the amino acids, the products of soluble digestion absorbed from the gut and taken to cells of the body
- CO2 from the organs to the lungs
- Urea from the kidneys
- Hormones
- Antibodies and antitoxins produced by WBC
What can keep you alive in an emergency?
Artificial blood
What happens when someone loses a lot of blood?
Their heart can still pump the remaining red blood cells around their body as long as the volume of blood is topped up.
What is artificial blood?
Is it safe?
Can it keep people alive?
What will happen if patients lose too many RBC?
A blood substitute, e.g a salt solution saline, used to replace the lost volume of blood.
It’s safe if no air bubbles get into the blood
It can keep them alive even if they lose 2/3 of their red blood cells. This may give the patient enough time to produce new RBC
They will need a blood transfusion
What would an artificial blood product ideally replace?
When will these be available?
The function of the RBC so no transfusion is needed
They are currently being developed but have problmeatic side effects
