Heart Flashcards
What is ECG?
An instrument used to monitor electric activity of the heart. It records potential changed produces by the cardiac muscle fibers.
Explain what systole is
The depolarization of the cardiac muscle cells, which makes them contract.
What is systolic pressure?
The force that makes the blood flow of the body from the heart. Systolic pressure is the first number measured in bloodpressure. Normal systolic pressure is below 120.
Explain what diastole is
Happends after systole, it is the repolarization of the cardiac muscle clls, which makes them relax.
What is diastolic pressure?
“minimum” blood pressure. Relaxing.
What is arterial mean pressure?
The average blood pressure during a single cardiac cycle.
What is puls-pressure?
The difference between systolic and diastolic pressure readings. Reprecent the force the heart generates each time it contracts.
What is brainbridge reflex?
Also called atrial reflex, is an increase in heart rate due to increase in central venous pressure
What is the baroreceptor reflex?
reflex that can regulate the blood pressure.
What is the peripheral resistance?
The resistance of arteries to blood flow. As arteries constrict, the resticance increases as the dialate resistance decreases.
What is cardiac output?
The total volume of blood being pumped from the ventricle in one minute. (speed of bloodflow through the body) stroke volume * heart rate
What is heart rate?
Number of heartbeats per minute
What is stroke volume?
Volume of blood leaving the heart via the aprta. (can only be measured with ultrasound of the heart)
What is the sack the heart lays in called?
Pericardium
Explain the difference between arteries and veins
Arteries pumpes blood out of the heart
Veins pumpes the blood back into the heart
Name some of the hearts most important tasks
Transporting nutrience to the body
Transporting oxygen
Regulating heat
Transporting toxins and gases out of the body
Define Respiratory sinus arrhythmia
the way the heart rate varies in synch with respiration. The rate is faster on inspiration, and decreases on expiration.
Define Ventricular diastole
The period during which the ventricles are filling and relaxing
Define Atrial diastole
The period during which the atria are relaxing
Define Ventricular systole
Contraction of the ventricles, forcing blood into the aorta and pulmonary artery.
Define Atrial systole
Contraction of the atria by which blood is forced into the ventricles. Indicated by the fourth heart sound. (indicated electrically by the P wave)
Define blood pressure
The pressure of circulating blood on the walls of blood vessels
