What is the difference between the pulmonary circulation and the systemic circulation?
- Pulmonary circulation only occurs between the heart and the lungs.
- The pulmonary circulation is the portion of the circulatory system which carries deoxygenated blood away from the right ventricle of the heart, to the lungs, and returns oxygenated blood to the left atrium and ventricle of the heart.
- Systemic circulation refers to the circulation of blood in which oxygenated blood is pumped from the heart to the body and deoxygenated blood is returned back to the heart.
- Systemic circulation occurs between the heart and the entire body.
- SYSTEMIC CIRCULATION carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart.
A pacemaker is an electrically-charged medical device. surgeon implants it under your skin to help manage irregular heartbeats called arrhythmias.
Pacemakers generally treat two types of arrhythmias:
- Tachycardia, a heartbeat that’s too fast
- Bradycardia, a heartbeat that’s too slow.
Valves of heart:
- Closes off the upper right chamber (or atrium) that holds blood coming in from the body.
- Opens to allow blood to flow from the top right chamber to the lower right chamber (or from right atrium to right ventricle).
- Prevents the back flow of blood from the ventricle to the atrium when blood is pumped out of the ventricle.
(or Pulmonic Valve)
- Closes off the lower right chamber (or right ventricle).
- Opens to allow blood to be pumped from the heart to the lungs (through the pulmonary artery) where it will receive oxygen.
- Closes off the upper left chamber (or left atrium) collecting the oxygen-rich blood coming in from the lungs.
- Opens to allow blood to pass from the upper left side to the lower left side (or from the left atrium to the left ventricle).
- Closes off the lower left chamber that holds the oxygen-rich blood before it is pumped out to the body.
- Opens to allow blood to leave the heart (from the left ventricle to the aorta and on to the body).
Phases of cardiac cycle:
- The period of time that begins with contraction of the atria and ends with ventricular relaxation is known as the cardiac cycle.
- The period of contraction that the heart undergoes while it pumps blood into circulation is called systole.
- The period of relaxation that occurs as the chambers fill with blood is called diastole.
- Phases of the Cardiac Cycle:
- Atrial contraction (First Phase)
- Isovolumetric Contraction (Second Phase)
- Rapid Ventricular Ejection (Third Phase)
- Slow Ventricular Ejection (Fourth Phase)
- Isovolumetric Relaxation (Fifth Phase)
- Rapid Passive Ventricular Filling (Sixth Phase)
- ·Slow Passive Ventricular Filling (Seventh Phase).
- Atrial contraction (mitral valve closes)
- Ventricular isovolumetric contraction—occurs when both valves are closed (aortic valve opens)
- Rapid ventricular ejection
- Slow ventricular ejection (aortic valve closes)
- Ventricular isovolumetric relaxation occurs when both valves are closed (mitral valve opens)
- Ventricular filling
- S1 Heart Sound: In the beginning of ventricular systole, mitral and tricuspid valves closure produce a sound. This is called first heart sound.
- S2 Heart Sound :Closure of aortic and pulmonary valve at the end of ventricular systole, produce a sound. This is called second heart sound.
- S3 Heart Sound: In the last moments of rapid passive ventricular filling phase, heart may produce a sound. This is called third heart sound.
- S4 Heart Sound: In the last moments of rapid passive ventricular filling phase, heart may produce a sound. This is called fourth heart sound.
- S1 is the sound created by the closing of the atrioventricular valves during ventricular contraction and is normally described as a “lub,” or first heart sound.
- The second heart sound, S2, is the sound of the closing of the semilunar valves during ventricular diastole and is described as a “dub”
- The rate at which the heart beats. The number of heartbeats per unit of time, usually per minute.
- The heart rate is based on the number of contractions of the ventricles (the lower chambers of the heart).
- The heart rate may be too fast (tachycardia) or too slow (bradycardia).
- Normal heart rate:72 / min.
- The volume of blood ejected from the left side of the heart in one minute.
- Cardiac output is the product of two variables, stroke volume and heart rate. The first variable, stroke volume, is a measure of the volume of blood that is pushed out of the ventricles (the large muscular chambers of the heart) with every beat.
- It’s the amount of blood pushed out every time the heart beats.
- The other variable, heart rate, is simply the number of times your heart beats each minute.
- CARDIAC OUTPUT= STROKE VOLUME * HEART RATE
- The pressure of the blood against the walls of the blood vessels, especially the arteries.
- The systolic pressure, which is the pressure when the left ventricle of the hear-t contracts to push the blood through the body.
- The diastolic pressure, which is the pressure when the ventricle relaxes and fills with blood.
- Normal Blood pressure : 120/80
- A condition present when blood flows through the blood vessels with a force greater than normal. Also called high blood pressure.
- Hypertension can strain the heart, damage blood vessels, and increase the risk of heart attack, stroke, kidney problems, and death.
- Normal blood pressure is 120 over 80 mm of mercury (mmHg), but hypertension is higher than 130 over 80 mmHg.
CATHERINE SHALINI RAJA
CARDIO RESPIRATORY PHYSICAL THERAPIST
FITNESS & SPORTS REHABILITATION SPECIALIST.