Topic 2- Blood And Circulation Flashcards
What was Harvey’s approach?
>Dissection of humans and other animals >Observation of living hearts in fish >Mathematical models >A detailed study of the structure of the heart >Experiments on human circulation
What did Harvey find and how?
He found valves in veins. He proved that they only allowed blood to circulate in one way.
He did this by wrapping a tight band around his arm. He could only push the bloody towards the heart.
What didn’t Harvey discover and why?
He didn’t discover how arteries and veins are connected because the microscope wasn’t accessible to him.
What connects arteries and veins?
Capillaries that are blood vessels.
They allow glucose and oxygen to diffuse into cells and waste out.
They are one cell thick and they have a large surface area.
What is the human circulatory system?
A double circulatory system. The blood must pass through the heart twice before completing one whole circuit of the body.
What are the two circulatory systems and explain them
Pulmonary system- blood pumped from the heart to the lungs and back to the heart. (Deoxygenated blood)
Systemic circulation- blood pumped from the heart to the body and then back to the heart. (Oxygenated blood)
Where does oxygen enter the body?
The lungs
Who, what and when was the circulatory system suggested?
Early 1600’s by William Harvey
He suggested that blood circulation around the body, flowing from the heart through arteries and returning through veins.
What is blood made up of?
Red blood cells- carry oxygen
White blood cells-defend body against pathogens
Platelets- clots the blood
Plasma- carries dissolved substances
What do red blood cells look like?
Flat
Biconcave
Disc shaped
Why are red blood cells red in colour?
The pigment haemoglobin
What is haemoglobin?
Joins with oxygen to transport it around the body
What is needed to produce haemoglobin and what happens if there is a shortage of it?
Iron. If there is a shortage, the person won’t have enough red blood cells. This is called anemia
What happens if your body has an infectn?
The number of white blood cells increase
Why are white blood cells colourless?
They have no pigment
What are the two types of white blood cells?
Phagocytes- ingest and digest ‘foreign’ cells
Lymphocytes- produce antibodies and antitoxins
What are the 3 differences between red and white blood cells?
Red blood cells:
Have no nucleus
Are regular disc shaped
Smaller
White blood cells:
Have a nucleus
Have an irregular shape
Larger
What is the purpose of platelets?
They clot the blood, forming a thick jelly. This hardens to form a scab
What are the 3 functions of platelets?
Prevent blood loss
Keeps the wound clean as the new skin grows
Prevents pathogens from entering the body
What is plasma?
Carry dissolved substances
It’s the liquid part of the blood- pale yellow, 90% water
What do plasma carry?
Small soluble food molecules Waste chemicals formed from the body Hormones carried from the endocrine glands to their target organ Antibodies produced by lymphocytes Mineral salts
What is the heart made out of?
Cardiac muscle
What are the blood vessels on the exterior of the heart called and what do they supply?
Coronary arteries
Oxygen and glucose to the heart
What happens during a heart attack?
There is a blood clot in the coronary arteries which prevent oxygenated blood reaching the heart
Why are tendons attached to valves?
So they don’t get pushed inside out
Which side of the heart pumps to which part of the body?
Right pumps to lungs.
Left pumps around the body.
Out of the atria and ventricles, which has thicker walls and why?
The ventricles have thicker walls because when they contract, they have to pump bloody around the body. Where as the atria only have to pump blood to the ventricles.
Which ventricle has a thicker wall and why?
The left ventricle is thicker because it has to pump blood around the body. Not just to the lungs.
Name the 10 labels of the heart
Pulmonary artery Pulmonary vein Aorta Vena cava Semi lunar valves Atrio ventricular valves Left and right ventricle Left and right atrium
What is the function of the pulmonary artery?
Carries deoxygenated blood from the lungs to the heart
What is the function of the semi- lunar valves?
Prevents back flow of blood when ventricles relax
What is the function of the aorta?
Artery carrying the blood to the body
What is the function of the pulmonary vein?
Carries oxygenated blood from the lungs to the heart
What is the function of the atrio ventricular valves?
Prevents back flow when the ventricle contracts
What is the function of the vena cava?
The vein that carries blood from the body back to the heart
Describe the flow of blood through the heart
- VENA CAVA carries blood from the organs to the RIGHT ATRIUM
- Blood passes through an ATRIO VENTRICULAR VALVE to the RIGHT VENTRICLE
- RIGHT VENTRICLE contracts, pumping blood trough the SEMI LUNAR VALVE into the PULMONARY ARTERY
- PULMONARY ARTERY carries blood to the LUNGS where is it oxygenated.
- PULMONARY VEIN carries blood back from the LUNGS to the LEFT ATRIUM
- Blood passes through the ATRIO VENTRICULAR VALVE Into the LEFT VENTRICLE
- LEFT VENTRICLE contracts, pumping blood through the SEMI LUNAR VALVE into the AORTA
- AORTA carries blood from the heart to the organs of the body
What are the four labels needed when labelling a blood capillary?
Vein
Venule
Arteriole
Artery
What are arteries?
Have thick walls because they carry blood under pressure away from the heart
What are veins?
Have thin walls because they carry blood under a low pressure back to the heart
What are capillaries?
Smallest blood vessels that carry blood through the organs
What are the two functions of capillaries?
They form an extensive network so that no cell is far away from a capillary.
Their walls are thin to allow easy diffusion to occur between blood and body cells
