The Heart Flashcards
The heart is protected by…..
1) The rib cage
2) The pericardium
Purpose of the fluid in the pericardium
Reduces friction when the heart beats
Where is the heart located?
In the thoracic cavity (or thorax), behind the breastbone (sternum), between the lungs - slightly to the left.
What is the heart made of?
It is made of CARDIAC MUSCLE – an involuntary (meaning not consciously controlled by the brain) muscle that does not fatigue (never gets tired).
Why is the wall of the left ventricle much thicker than the wall of the right ventricle?
The wall of the left ventricle is thicker than the wall of the right ventricle because the left ventricle has to pump blood a greater distance (all around the body). (The right ventricle only has to pump blood to the lungs.)
What are the atria and ventricles separated by?
Atria and ventricles are separated by CUSPID VALVES (BICUSPID and TRICUSPID) which prevent blood flowing back to the atria from the ventricles.
What does the left side of the heart do?
Collects oxygenated blood from the lungs (via pulmonary veins) and pumps oxygenated blood to the body (via the aorta)
What does the right side of the heart do?
Collects deoxygenated blood from the body (via vena cava) and pumps deoxygenated blood to the lungs (via pulmonary artery)
Where is the pacemaker (SA NODE) locates?
At the top of the right atrium, near the opening of the superior vena cava.
Function of the pacemaker
Causes the atria to contract
Where is the av node located?
At the bottom of the right atrium, near the septum
Function of the AV node
Causes the ventricles to contract
What blood vessels deliver blood to the heart muscle cells?
The coronary arteries
Where do the coronary arteries originate?
In the aorta, just above the semilunar valve
What blood vessels collect deoxygenated blood from the capillaries in the heart wall?
Coronary Veins
Definition on the cardiac cycle
The cardiac cycle is a series of events that occur during one heartbeat
Definition of Systole
Is when the muscular walls of the heart contract and empty of blood
Definition of Diastole
Is when muscular walls of the heart relax and fill with blood
Definition of a pulse
A pulse is an expansion and contraction of the wall of an artery
Where can a pulse be easily detected?
Where an artery is close to the surface of the skin and passing over a bone
eg. The wrist, temple and neck
Average heart rate of a healthy adult
70-75 beats per minute
Definition of blood pressure
The force of blood against the wall of an artery
Factors that effect the circulatory system
Smoking
Diet
Exercise
