The Circulatory System Essential Question: What is the function of the circulatory system? What is the pathway of blood through the heart? What’s the difference between pulmonary and systemic circulation? How are the three types of blood vessels different?

Functions of the circulatory system:  Brings oxygen, nutrients, and hormones to cells  Fights infection  Regulates body temperature

The Heart <3  Serves as a pump to make sure blood gets to all parts of the body  4 chambers  The right side receives blood from the body, and pumps it to the lungs  The left side receives blood from the lungs, and pumps it to the body

Deoxyenated- blood carrying no oxygen Deoxyenated- blood carrying no oxygen –Already gave it away to the body Oxygenated- blood carrying oxygen Oxygenated- blood carrying oxygen –Hasn’t given it to the body yet

Circulation through the body  1. Pulmonary circulation Blood from the body (no oxygen)  R side of the heart  lungs  Blood trades gases with the lungs  CO 2 goes from blood to lungs, O 2 is absorbed from lungs  Blood returns to the L side of the heart

 Systemic circulation Lungs  L side of the heart  body  Takes O 2 to the body, picks up CO 2 and returns to the R side of the heart  Goes back to pulmonary circulation

Now it’s our turn!  You will have the chance to demonstrate systemic circulation.  We will represent blood cells in this exercise.  Come to the front of the room and pick up a blue ball.

Blood flow through the heart Blood flow through the heart Blood flow through the heart Blood flow through the heart How the heart works How the heart works How the heart works How the heart works

Blood Vessels As blood moves through circulatory system, it moves through three types of blood vessels As blood moves through circulatory system, it moves through three types of blood vessels 3 types: 3 types: –Arteries- Large; carry blood away from the heart  carry oxygenated blood  have thick walls to withstand high pressure from heart contractions

–2. Capillaries: smallest blood vessels  Walls are one cell thick  Connect veins and arteries  Gas exchange: Brings nutrients and oxygen to tissues….and absorbs CO 2 and other waste products

–Veins: Carry blood back toward the heart  Low pressure  Largest veins have one-way valves, keep blood flowing toward the heart

The Circulatory System

Blood Pressure Measures the force of the blood on the vessels’ walls Measures the force of the blood on the vessels’ walls –Required to move blood, but ↓ when the heart relaxes

Disorders of the Circulatory System Atherosclerosis: Fatty deposits (plaque) build up on the walls of vessels, blocking blood flow. Atherosclerosis: Fatty deposits (plaque) build up on the walls of vessels, blocking blood flow. –↑ blood pressure –Blood clots can form High Blood Pressure High Blood Pressure –Makes the heart work harder

Prevention of Circulatory System Disorders Exercise- strengthens heart & makes the respiratory system more efficient, helps with weight Exercise- strengthens heart & makes the respiratory system more efficient, helps with weight Weight control Weight control Sensible diet- low in saturated fat Sensible diet- low in saturated fat Not smoking Not smoking

1’s- explain to 2’s how the blood vessels are different 2’s- explain to 1’s where gas exchange happens, and what is exchanged.