Cardiovascular System

Heart, Blood and Blood vessels

Cardiovascular System

• Heart---- which is the driving force which propels the blood

• Blood----Which is the fluid in which materials are carried to and from the tissue

• The Blood Vessels---- the routes by which the blood travels to and through the tissues and back to the heart.

Cardiovascular System

• Heart

Left

RightRight Atrium

Left Atrium（心房）

Right Ventricle

Left Ventricle（心室）

Components of Blood

(1) blood plasma--a watery liquid(2) formed elements, which are cells and cell

fragments.

Cardiovascular System

The Blood Vessels

Arteries —Carry blood away from the heart

Veins – Bring blood back toward the heart

Arterioles-- smaller arteries

Capillaries--numerous tiny vessels in tissue

Venules--small veins

Heart

• The heart pumps blood through blood vessels to all body tissues.

Four Chambers

• On either side of the heart are two chambers, one a receiving chamber (atrium) and the other a pumping chamber (ventricle):

Four Chambers• 1. The right atrium is a thin-walled chamber that

receives the blood retuning from the body tissues. This blood, which is low in oxygen.

• 2. The right ventricle pumps the venous blood received from the right atrium and sends it to the lungs.

• 3. The left atrium receives blood high in oxygen content as it returns from the lungs.

• 4. The left ventricle, which has the thickest walls of all, pumps, oxygenated blood to all parts of the body. This blood goes through the arteries, the vessels that take blood from the heart to the tissues.

• HeartLeft

Right

Right Atrium

Left Atrium（心室）

Right Ventricle

Left Ventricle（心房）

Four Valves

• Since the ventricles are the pumping chambers, the valves, which are all one way, are located at the entrance and the exit of each ventricle.

• Tricuspid valve• Mitral (Bicuspid) valve• Pulmonary valve• Aortic valve

The Conduction System of the Heart

• Sinoatrial (SA) node ---- pacemaker• Atrioventricular (AV) node• Atrioventricular bundle• Bundle branches• Purkinje fibers

Blood Supply to the Myocardium

• Right coronary arteries• Left coronary arteries

• Capillaries• cardiac veins• Coronary sinus

Blood vessels

• The five main types of blood vessels are : – Arteries: carry blood away from the heart to other organs.

– Arterioles: smaller arteries – Capillaries: numerous tiny vessels in tissue– Venules: small veins– Veins: convey blood from the tissues back to the heart.

– Vena cava: large veins carry blood into right atrium

Lymphatic System

• Lymph Organs: – Lymph nodes– Tonsils– Thymus– Spleen

• lymph-vessel– Lymphatic capillary– Lymphatic vessel– Lymphatic trunk– Lymphatic duct– Thoracic duct or Right Lymphatic Duct

The Thymus Gland

• The thymus gland lies in the upper part of the chest above the heart.

• The production of a hormone called thymosin, it helps in the development of certain white blood cells, called Tlymphocytes that help protect the body against foreign organisms.

• The gland is most active before birth and early in life, it is large during childhood but gradually shrinks in size as one reach adulthood.

Lymph vessels

• Lymphatic capillaries• Lymphatic vessels like vein also have valves.• Lymphatic trucks• Right lymphatic duct (drains upper right part

of the body in to right subclavian vein)• Thoracic duct (drains remainder part of the

body into left subclavian vein)