1.3 - Structure of the Heart

LO1: Understand the cardiovascular systems, malfunctions and their impact on individuals
LO1.3: Identify and describe the structure of the heart

Atria: Upper chambers of the heart that receive blood.
Ventricles: Lower chambers of the heart that pump blood out.
Vena Cava: Major veins that carry deoxygenated blood to the heart.
Pulmonary Arteries: Carry deoxygenated blood from the heart to the lungs.
Pulmonary Veins: Carry oxygenated blood from the lungs to the heart.
Aorta: The body's main artery that carries oxygenated blood from the heart to the body.
Tricuspid Valve: Valve between the right atrium and right ventricle, prevents backflow.
Bicuspid Valve (Mitral Valve): Valve between the left atrium and left ventricle, prevents backflow.
Semi-lunar Valves: Valves in the aorta and pulmonary artery that prevent backflow into the ventricles.
Coronary Arteries: Supply blood to the heart muscle.
Double Pump: Refers to the heart's dual function of pumping blood to both lungs and body.
Diastole: The phase of the heart cycle when the heart relaxes and fills with blood.
Systole: The phase of the heart cycle when the heart contracts and pumps blood.
Cardiac Cycle: The complete sequence of events in one heartbeat.

Known as the circulatory system because blood flows in a circuit around the body.
Transport system carrying substances such as nutrients, gases, hormones throughout the body.
Components: Heart, blood vessels, and blood.

Two Types of Blood:
- Oxygenated Blood: High in oxygen and low in carbon dioxide; travels from lungs to body cells.
- Deoxygenated Blood: Low in oxygen and high in carbon dioxide; travels from body cells to lungs.
The heart features a double circulatory system, meaning blood passes through the heart twice for each circulation of the body.

Aorta: Delivers oxygenated blood to body cells.
Vena Cava: Returns deoxygenated blood from the body to the right atrium.
Pulmonary Artery: Carries deoxygenated blood from right ventricle to lungs.
Pulmonary Veins: Carry oxygenated blood from lungs to left atrium.
Right Atrium: Receives deoxygenated blood from body cells.
Tricuspid Valve: Prevents backflow into the right atrium during ventricular contraction.
Right Ventricle: Pumps deoxygenated blood to the lungs.
Pulmonary Valve: Prevents backflow into the right ventricle from pulmonary artery.
Left Atrium: Receives oxygenated blood from lungs.
Bicuspid Valve: Prevents backflow into left atrium during ventricular contraction.
Aortic Valve: Prevents backflow into left ventricle from aorta.
Left Ventricle: Pumps oxygenated blood to the body.

Sino-atrial (SA) Node: Located at the top of the right atrium; initiates heartbeats.
Atrial-Ventricular (AV) Node: Slows the current allowing ventricles to fill up.
Purkinje Fibres: Spread the electrical impulse to contract the ventricles from the apex upwards.