Learn: The Heart and Blood Vessels

Welcome!Today, we’re learning about the heart and blood vessels. This is an important topic to understand how blood is pumped and transported around the body. Let’s get started!

What is the cardiovascular system?The cardiovascular system consists of the heart, blood, and blood vessels. It is responsible for transporting oxygen, nutrients, hormones, and waste products around the body. It plays a vital role in maintaining homeostasis.

The HeartThe heart is a muscular organ that pumps blood through the body. It has four chambers: two atria (upper chambers) and two ventricles (lower chambers). The heart ensures oxygenated and deoxygenated blood do not mix.

Blood VesselsThere are three main types of blood vessels: arteries, veins, and capillaries. Arteries carry blood away from the heart, veins return blood to the heart, and capillaries are tiny vessels where gas exchange occurs.

The Cardiac CycleThe cardiac cycle is the sequence of events that occur as the heart contracts and relaxes. It includes systole (contraction) and diastole (relaxation). This ensures blood is pumped effectively to the body and lungs.

Valves in the HeartValves ensure blood flows in the correct direction and prevent backflow. Examples include the tricuspid valve, bicuspid (mitral) valve, and the semilunar valves.

Blood PressureBlood pressure is the force exerted by blood against the walls of blood vessels. It is measured in millimetres of mercury (mmHg) and consists of two values: systolic (pressure during contraction) and diastolic (pressure during relaxation).

Oxygenated vs Deoxygenated BloodOxygenated blood is rich in oxygen and travels from the lungs to the body via arteries. Deoxygenated blood has less oxygen and returns to the lungs through veins.

Review Time!Great work! You've learned about the heart, blood vessels, the cardiac cycle, and more. Let’s test your understanding now.