Circualtion Of Heart Flashcards
What does the atria do
Receives blood returning to the heart
What does the vena cava do?
Returns DEOXYGENATED blood to the rift atrium
What does the pulmonary vein do?
Gives OXYGENATED blood to the left atrium
What does the right ventricle do?
Pumps DEOXYGENATED blood through pulmonary artery to the lungs
What does left ventricle do?
Pumps OXYGENATED blood through aorta
What does the septum do?
Separates two sides
How to calculate cardiac output
Heart rate X stroke volume
What happens during diastole ? ( 3)
- Muscles relax
- High pressure closes SL valves
- Atria fills with blood from vena cava and pulmonary vein & some flow to ventricles
What happens in systole?
- Atria contract
- remainder of blood transfer through AV valves into ventricles
- ventricular systole closes AV valves to allow blood to transfer through aorta and pulmonary artery
What is the average length of a cardiac cycle?
0.8 seconds
What are heart murmurs and what causes them?
Caused by abnormal patterns I.e valves fail to open or close properly
When is there high and low pressure ?
Diastole - low pressure
Systole - high pressure
What does the SAN do?
Sets the rate at which cardiac muscles contract
Describe route of electrical impulses
- from SAN (top of atria) pass to AVN (bottom)
- AVN go through septum to muscles in ventricles
- results in muscle contractions
What is an electrocardiogram (3)
- shows electrical pulses from heart beat
- can identify problems with the heart I.e MI
- place electrodes on surface of body
What is the P wave?
Impulses spread over the atria from SAN
What is the QRS complex?
Impulses through the ventricles
What is the T wave
Electrical recovery of ventricles at the end of systole
What is the role of medulla?
Regulates the rate of SAN through Automatic nervous system (ANS)
What do sympathetic nerves do?
Accelerate heart and strength of contractions
Release nor- adrenaline which can be activated through strength and fear
What do parasympathetic nerves do?
Slow the heart and release acetylcholine which activates during rest
How can you measure blood and what are stages
Sphygmomanometer attaches to arm
Systolic
Diastolic
What is the normal reading for a round adult
120/170mmhg
What is hypertension and what can it cause
High blood pressure
Cause coronary heart disease and stroke
