The Circulatory System (cardiovascular) Flashcards
what makes up the circulatory system?
-the heart
-the blood
-the blood vessels
functions of the circulatory system
-pushes blood around the body, carrying oxygen to all the muscles and cells
-removes carbon dioxide and waste products
-provents infection and fights disease
systolic pressure
this is pressure in the arteries as the left ventricle contracts. it is a maximum reading
diastolic pressure
this is pressure in the arteries as the left ventricle relaxes. it is a minimum reading
where should blood pressure range from?
from 100/60 to 140/90 , an average is 120/80
the structure of blood vessels in arteries:
the lumen - is small in relation to the diameter of the artery
-the wall of an artery is thick, with a lot of muscle and elastic fibre
-a capillary is very small, walls only one cell thick
-the lumen of a capillary is big enough for a red blood cell to squeeze through
the structure of a blood vessel in veins:
-the wall of a vein is relatively thin with just little muscle and elastic fibre
-the lumen is relatively large in comparison to the diameter of the vein
aspects of arteries
-take blood away from the heart
-thick walls
-more elastic
-carries blood at a higher pressure
-carries oxygenated blood away from the heart
-has no valves
-has smaller lumen
aspects of veins
-take blood to the heart
-thin walls
-less elastic
-carries blood at a lower pressure
-carries deoxygenated blood to the heart
-has valves
-wide lumen
heart beat
one contraction of the heart
heart rate
the number of times the heart beats per minute
stroke volume
the amount of blood pumped out in one beat
cardiac output
the amount of blood pumped out in one minute
systole
the faze of the heart beat when the heart muscle contracts and pumps blood from the atriums into the ventricles
diastole
the faze of the heart beat when the heart muscle relaxes and lets the chambers fill with blood
what happens to the cv system during exercise?
-increase heart rate:
(the average heart rate is between 60-80 bpm), the fitter you are, the stronger your heart is, which means your resting heart rate will be lower
-increase blood pressure:
as more blood is pumped around the body the pressure on the walls of the blood vessel increases
capillaries
-one cell thick
-blood pressure very low
-links arteries and veins
at one end they have oxygenated blood which transfers oxygen and nutrients to the muscle
-on the other end there is deoxygenated blood which picks up carbon dioxide and gets rid of it
-gaseous exchange also take place here, when oxygen goes into the tissues and carbon dioxide goes out
-they are important in sport because they are the point where oxygen is delivered to the muscle and then deoxygenated blood is taken away
red blood cells
-shaped like discs also called erythrocytes
-haemoglobin gives them there red colour and attracts oxygen
-high cell count
-low cell count (anaemia) symptoms are: breathlessness and lack of energy due to lack of oxygen. losing blood or lack of iron can also cause this.
how do red blood cells help to perform better in sport?
-people at high outitude often have more red blood cells as the air is thinner, so their bodies help out by creating more red blood cells.
-atheletes will train at high outitude before big competitions to naturally increase there red blood cell count.
-when they return to sea level the cells remain for a period of time which help them perform better. endurance athletes will benefit form this.
white blood cells
-these are transparent cells also called (leukocytes)
-they fight infection
blood platelets
-formed in the red bone marrow
-cause your blood to clot
plasma
-this is the fluid part of the blood
-it is yellow
-its job is to circulate between cells
-contains: salt, sugar, antibodies, waste products and plasma proteins
-made up of 90% water
vascular shunting
-as your exercise, your body will divert blood to the areas that need it the most
-this is achieved through vasodilation and vasoconstriction
vasodilation
-as the muscles work harder, oxygen levels drop. lactic acid and CO2 build up
-blood vessels will now dilate (get bigger) so oxygen can get to them easier as the blood flows easier
-it also helps get rid of the build up of heat
vasoconstriction
-when your start exercising the blood vessels will contract (get smaller)
-blood goes to the muscles sot he blood pressure rises
-reflexes get faster and muscles tense which enables blood to get to the muscle faster
effects of regular exercise on the CV system
-increased stoke volume
-increased cardiac output (CO=SV x HR)
-size of heart increases
-decrease resting heart rate
-increase heart recovery rate
-lower blood pressure
-healthy veins and arteries
