Circulatory System

- Made up of the heart and a network of blood vessels 3 kinds of blood vessels 1. Arteries 2. Capillaries 3. Veins

IT'S TRUE! The heart beats around 3 billion times in the average person’s life

- Have thick, elastic walls - smallest arteries called arterioles Arteries- carry blood away from the heart toward the organs and tissues of the body - Have thick, elastic walls - smallest arteries called arterioles * Ends in “oles”, gets smaller by branching off

IT'S TRUE! About 8 million cells die in the human body every second, and the same number are born each second.

Capillaries- connect arterioles and venules - thin walls allow the exchange of nutrients, waste, oxygen between the blood and body cells

IT'S TRUE! Within a tiny droplet of blood, there are some 5 million red blood cells

Veins- return blood to heart from organs and body tissues - smallest veins called venules - thin walls, not as elastic - contain valves to prevent backflow

The Heart - acts as a double pump -made up of cardiac muscle Has 4 chambers: 2 atria- upper, thin walled chambers 2 ventricles- lower, thick walled chambers valves in heart control direction of blood flow

IT'S TRUE! Red blood cells may live for about 4 months circulating throughout the body, feeding the 60 trillion other body cells.

Heartbeat- made up of two periods Systole- period of contraction - valves closed Diastole- period of relaxation - valves open “lub-dup” sound is opening and closing of the valves S-A node(sinoatrial node)- pacemaker - sends electrical impulse which triggers contraction of the heart

Blood Pressure- measured by sphygmomanometer Systolic = 120 in normal Diastolic 80 resting adult

Pathways of Human Circulation

Pulmonary Circulation- carries blood between the heart and lungs - adds oxygen and removes CO2 from the blood

Pulmonary Artery- takes blood to lungs

IT'S TRUE! Red blood cells make approximately 250,000 round trips of the body before returning to the bone marrow, where they were born, to die.

Aorta- takes blood to all other body tissues - largest artery of the body

Systemic Circulation- carries blood between the heart and the rest of the body

Consists of 3 branches: 1. Coronary Circulation- branch of the systemic circulation that supplies blood to the heart

2. Hepatic-Portal Circulation- branch of the systemic circulation that carries blood from the digestive tract to the liver

3. Renal Circulation- branch of the systemic circulation that carries blood to and from the kidneys

IT'S TRUE! It takes about 20 seconds for a red blood cell to circle the whole body.

Circulation of the Lymph

- all cells of the body are bathed in this colorless, watery fluid Intercellular Fluid- helps move materials between the capillaries and the body cells - all cells of the body are bathed in this colorless, watery fluid

Lymphatic System- collects excess fluid and proteins from intercellular spaces in the body and returns them to the blood

- they filter foreign matter from the lymph such as bacteria Lymph- what intercellular fluid is called once inside the lymphatic system Lymph Nodes- (lymph glands) - play important role in the body’s defense against disease - they filter foreign matter from the lymph such as bacteria

NODES IN YOUR NECK

Circulatory Disorders PROBLEM DESCRIPTION Heart Attack Coronary Thrombosis Angina Pectoris Hypertension Atherosclerosis

Hypertension- high blood pressure