Definition
Heart is the pumping organ of blood. It has four different chambers to separate oxygenated and de-oxygenated blood. Why? For efficient transportation.
Chambers in Heart
- 2 chambers - Mixing of blood (inefficient); present in aquatic organisms, fishes, etc.
- 3 chambers - Partial mixing; present in amphibians, reptiles
- 4 chambers - no mixing (most efficient, yet); present in mammals, birds, crocodile (exception from reptiles)
Atria
The heart has two atria: Left and Right.
- Deoxygenated blood comes from body to the Right Atrium then goes to Right Ventricle.
- Oxygenated blood comes from lungs to the Left Atrium then goes to Left Ventricle.
Ventricles
- Deoxygenated blood is passed though the Pulmonary Artery to the Lungs by the Right Ventricle.
- Oxygenated blood is passed through the Aorta to the body by the Right Ventricle.
- The walls of the ventricles are stronger, thicker than of the atria. Why? Because it needs uses more force to push the blood out.
Valves
- Valves ensure that the blood doesn’t flow backward.
The Process
Deoxygenated blood from body → Vena Cava (superior and inferior) → Right Atrium → Right Ventricle → Pulmonary Artery → Lungs → Pulmonary Vein → Left Atrium → Left Ventricle → Aorta → Body
Double Circulation
The blood passes twice through the heart (once from body, once from lungs) in a single heartbeat.
Cardiac Cycle
Sequence of events in a single heartbeat.
Blood Pressure
Pressure of the blood in the arteries after pumping.
- Measured by sphygmomanometer.
- Normal blood pressure:
- Systolic Pressure: Pressure in artery during contraction
- Diastolic Pressure: Pressure in artery during relaxation
Backlinks
Flashcards
Why are the walls of the ventricles are stronger, thicker than of the atria?;;Because the ventricles use more force push blood.
What is the process of circulation in heart? ? Deoxygenated blood from body → Vena Cava (superior and inferior) → Right Atrium → Right Ventricle → Pulmonary Artery → Lungs → Pulmonary Vein → Left Atrium → Left Ventricle → Aorta → Body
Why does the heart have four different chambers?;;To differentiate between oxygenated and deoxygenated blood
What is the use of valves in the heart?;;So that the blood doesn’t flow backward.
What is double circulation?;;The blood passes twice through the heart (once from body, once from lungs) in a single heartbeat.
What is cardiac cycle
?
Sequence of events in a single heartbeat.
What is blood pressure? ? Pressure of the blood in the arteries after pumping.
- Measured by sphygmomanometer.
- Normal blood pressure:
- Systolic Pressure: Pressure in artery during contraction.
- Diastolic Pressure: Pressure in artery during relaxation.
How is blood pressure measured? ? Sphygmomanometer