Blood Circulaton (not Including Heart) Flashcards
What are veins
Veins carry blood towards the heart under low pressure and velocity
The arteries that branch out into smaller vessels are called …
arterioles
The veins that branch out into smaller vessels are called …
venules
What are capillaries
Capillaries are very small vessels linking to the arterioles and the venules. They branch out many times and lie in the tissues of the body, amongst the cells. They have a very small diameter but the walls are thin.
It is here that diffusion of substance occurs between blood and the fluid which surrounds the cells.
What colour is oxygenated blood usually represented as ?
Red.
It is actually dark red
What colour is deoxygenated blood usually represented as?
Blue.
It is actually a light red
What are the lymphatic vessels for?
The fluid that inevitably leaks out of thin walled capillaries is collected by the lymphatic vessels and eventually drains back into the bloodstream
What are arteries
Arteries carry blood away from the heart under high pressure and velocity
Pulmonary is to do with …
Lungs
Hepatic is to do with ..
Liver
Renal is to do with ..
Kidneys
What is the lumen
The space inside a blood vessel
What is the structure of an artery
Round shape Thick outer wall Thick layer of muscle + elastic fibres (so that it can recoil and doesn't burst) Smooth lining Small lumen
What is the structure of a vein
Misshapen Fairly thin outer wall Thin layer of muscle & elastic fibres Smooth lining Large lumen
What is the structure of a capillary (all cells are very close to a capillary)
Very small lumen
Wall made of a single layer of cells (so that diffusion happens quickly and easily)
Why do we need a circulatory system
To ensure all cells have fresh nutrients and that waste products are removed
What are the 3 main components of the circulatory system
Heart
Blood
Blood vessels
All mammals have a double circulatory system. What does this mean?
For every complete circuit of the body, the blood passes through the heart twice
Coronary is to do with …
The heart
What are the two types of white blood cells?
Lymphocytes and phagocytes
Describe a phagocyte (appearance)
Weirdly shaped,
Lobed nucleus
Grainy cytoplasm (sacks of enzymes that digest materials/pathogens taken into the cell)
How do lymphocytes work?
Lymphocytes produce specific antibodies to fight particular pathogens. The antibody slots into the pathogen in a lock and key way. Lymphocytes remember which antibodies to produce so if the pathogen returns it can be fought off quickly as the lymphocyte will produce them quickly
How do phagocytes work?
Phagocytes ingest pathogens and then digest them
What does blood contain?
Red blood cells, white blood cells, platelets and plasma
Why do larger organisms have respiratory systems e.t.c but unicellular organisms don’t
Larger organism need help with diffusion because their volume to surface area ration is smaller
What are the three main components of the circulatory system?
Heart, blood and blood vessels
Hepatic vein and artery are connected to what?
The liver
What does the hepatic portal vein connect?
The ileum to the liver
What do the renal vein and artery connect to?
The kidneys
What are the two vena cavas?
Vena cava from head
Vena cava from body
Why is the circulatory system called a double circulatory system?
It passed through the heart twice.
What does plasma do?
Plasma is a straw-coloured liquid. It transports dissolved substances around the body, including:
hormones
nutrients, such as water, glucose, amino acids, minerals and vitamins
waste substances, such as carbon dioxide and urea
Red blood cells
Adaptions of red blood cells
Flexible membrane
Dip in middle gives a high surface area to volume ratio so lots of exchange sites
No nucleus so can keep more haemoglobin which carries oxygen
How do vaccinations work?
A damaged or dead virus is injected into the body. It results in the manufacturing of memory cells which enables future antibody production to the pathogen to occur sooner, faster and in greater quality
Platelets are involved in blood clotting. Why do we need blood clots?
Prevents blood loss and entry of microorganisms into the body
Process of blood clotting?
Damage platelets which starts a series of reactions, fibrinogen (made in liver, present in plasma. Large protein) goes to fibrin (insoluble thread which form clots)
FIBRINOGEN TO FIBRIN
General points in arteries
Arteries carry blood away from the heart
Carry oxygenated blood (except pulmonary artery)
Arteries tend to be deeper in the body for protection (blood loss from a would in an artery would be fatal as there is high pressured blood)
General points about veins
Veins carry blood towards the heart
Carry deoxygenated blood (except pulmonary vein)
Veins near the surface of the skin. Appear blue but the blood they carry is actually dark red
