What is the structure of cardiovascular system?

1. Heart (Central organ of the cardiovascular system)

* Four-chambered muscular organ enclosed in the mediastinum.

* Chambers: Right atrium, Left atrium, Right ventricle, Left ventricle

* Valves: Tricuspid valve, Pulmonary valve, Mitral (bicuspid) valve, Aortic valve

2. Blood Vessels:

Arteries: Carry oxygenated blood away from the heart to the body tissues. **

- Pulmonary artery: Carries deoxygenated blood from the right ventricle to the lungs for oxygenation.

- Aorta: Largest artery in the body arising from the left ventricle and branching to arteries supplying various parts of the body.

Veins: Carry deoxygenated blood back to the heart from the body tissues.

- Superior and Inferior vena cava: Return deoxygenated blood from the upper and lower body respectively into the right atrium.

- Pulmonary veins: Carry oxygenated blood from the lungs into the left atrium.

3. Capillaries:

* Microscopic blood vessels that connect arteries to veins.

* Oxygen and nutrients from arteries diffuse into the tissues through the capillaries, while waste products diffuse from the tissues into the capillaries.

4. Blood:

* Fluid that circulates within blood vessels. Composed of:

* Plasma (55%): Water, electrolytes, hormones, and proteins

* Red Blood cells (35%): Contain hemoglobin to carry oxygen

* White Blood Cells (7%): Play a role in immunity and defense

* Platelets (3%): Involved in blood clotting

5. Lymphatic System:

* Network of tissues and vessels that collect and return interstitial fluid (lymph) to the bloodstream.

- Lymph nodes are structures in the lymphatic system that contain immune cells and filter foreign particles and organisms from the lymph.