Heart Flashcards
Function of the heart
To pump blood around the body
Through which side of the heart does oxygenated blood enter? what is its color? Where does it go?
Left side, bright red, rest of the body
Through which side of the heart does deoxygenated blood enter? what is its color? Where does it go?
Right side, bluish red, lungs
What type of circulatory system do we have?
Double circulatory system because the blood travels twice through the heart on one complete journey around the body
What type of muscle is the heart made of? Why’s it special?
Cardiac muscle, it doesn’t get tired
Size, weight and capacity of an average adult man’s heart
clenched fist, 300g, 250cm3
How many times a minute does the heart beat?
70 times a minute
What supplies the cardiac muscle with O2 and nutrients
Coronary arteries
What removes the cardiac muscle’s waste products?
Coronary veins
What makes the heart beat?
Tiny pulses of electricity which are sent out from the sinoatrial node (SA node) or pacemaker
What senses CO2 levels?
The medulla, if CO2 levels increase then the brain sends nerve impulses to the pacemaker to make the heart beat faster
What do you see when a heart is cut open?
You will find that it is hollow with 4 separate chambers
What are the chambers in the heart called?
2 upper chambers-atria, 2 lower chamber-ventricles
What separates the left and right sides of the heart
A septum
What happens during cardiac diastole?
-Whole heart relaxes
-Blood flows into the heart from the pulmonary vein and vena cava
-Bicuspid and tricuspid valves open
-Pulmonary and aortic valves closed
What happens during atrial systole, ventricular diastole?
-Valves in vena cava and pulmonary vein are closed
-muscles of atria contract
-Bicuspid and tricuspid valves open
-Blood forced from atria to ventricles
-Pulmonary and aortic valves closed
-Aorta recoils
What happens during atrial diastole, ventricular systole?
-muscles of atria relax
-Bicuspid and tricuspid valves closed
-muscles of ventricles contract
-Pulmonary and aortic valves open
-Blood forced out of ventricles into arteries
-Aorta wall expands with blood
Job of atria
Receive blood from lungs or body and supply to nearby ventricles
Job of ventricles
Pump blood out of heart
What has thicker walls?
The ventricles because they have to pump blood out of the heart
Which ventricle has a thicker wall?
The left because it pumps blood to the rest of the body and the right pumps to the lungs which are close by
What is the pulse?
The stretching and recoiling of the artery wall causing a ripple effect in the blood
How many flaps are the bicuspid and tricuspid valves
2, 3
Function of heart tendons
To maintain the valves closed when the ventricles contract and make sure that the valves do not open backwards inside out
