Circulatory system Flashcards
cardiovascular system composed of
heart (cardio) + blood vessels (vascular)
blood vessles are divided into:
Arteries:
Thick walled. Main trunk routes for carrying oxygentated blood from heart to body tissues
Veins:
Thin walled. drain deoxygenated blood from tissue and return it to the heart. There are twice as many veins than arteries which means veins hold more blood and can be used for reserve.
Arterioles:
smaller branches of arteries. They contract and enlarge to control the supply of blood to organs
capillaries
Capillaries are very small blood vessels that connect the arteries at one end to veins at the other, and they form networks in the bodily tissues
smalles type of blood vessor responsible for gas and nutrient exchange between cells and blood
Blood is carried into the capillaries from the arteries, travels through the capillaries, which allow transfer of nutrients from the blood to the tissues and waste from the tissues to the blood, and out of the capillaries into veins.
Venules
To drain deoxygentated blood and waste products into the veins and carry them back to the heart , the capillaries connect up with venules
composition of blood
Plasma - fluid composed of:
Red blood cells for O2 transport
White blood cells to fight infection
Platelts that help blood vessels heal after injury
blood cells can live for?
140 days
get made in bone marrow
Oxygenation of blood
oxygen diffuses from alveoli and enter blood plasma
Red blood cells carry oxygen via haemoglobin (1 molecule carries 4 moldecules of O2)
Oxygenated blood is heavy on O2 and is bright red
deoxygenated blood
colour is dark purple/blue
also ‘cyanosis’ during hypoxia
what is anemea
blood that is low in red cells, or low in hemaglobin or both
hemaglobin is iron rich
blood low in hemaglobin lacks iron -> insufficient oxygen supply
can result in chronic loss of blood
it can be caused by pregnancy or peptic ulcers or blood loss
why is time imposed between blood donation and flying
because whilst blood plasma restores quickly after blood loss, the level of oxygen carrying red cells take longer to restore.
what is sickle cell aneamea
abnormality in hemaglobin that distorts shape of the red blood cell causing blocked capilaries
Carbon Monoxide poisining
binds to haemoglobin 200 x more than O2
harder to shift it off.
may not show signs of cyanosis and face can still be fushed/red.
ex: smoking + internal combustion in engines
**Pulmonary circulation
**
A circuit that supplied deoxygentated blood from right side of the heart to the lungs via pulmonary artery, where carbon dioxide is excreted
the oxygentated blood leaving the lungs flow back to the heart (left) by pulmonary veins
**this is the only time the arteries and veins follow opposte rule
the heart
muscular structure split in halves (left and right)
Each half is split into chambers - ventrical (lower chamber) and atrium (upper chamber)
chambers are connected by blood vessels and 1 way valves
**The rate and force at which the heart muscle contracts **controls **how much and how quickly blood is delivered **to the organs and tissues of the body.
function of cardiovascular system
transport hormones
regulate body temperature
fight diseases and connecting organs to immune system
transport oxygen and nutrients to the body
allow the removal of waste from the body and excrete it
**Systemic circulation
**
Oxygenated blood travels from lower left chamber through the aorta & arteries to body tissues & organs via capilaries
via the capilaries, O2 is exchanged with waste/carbon dioxide
the waste, goes through the veins to the top chamber of the right side of the heart
as blood travels around the systemic circulation, it receives nutrients that are absorbed from the gut and carries waaste to liver and kidnesys
Pulmonory circulation
blood travels from lower Right chamber to the lungs where the waste carbon idioxxide is removed and oxygen is replensihed.
then oxygenated blood travels to top chamber of left side of the heart and into the bottom chamber.
then systemic circulation begins
