The Circulatory System

The Circulatory System transports oxygen and nutrients throughout the entire body and carries away carbon dioxide and waste materials. © iTutor All Rights Reserved

Parts:  Heart  Blood  Blood Vessels - Arteries - Veins -Capillaries Heart Blood Arteries Veins © iTutor All Rights Reserved

 The heart can pump blood because it is made of muscle. Muscle tissue works by contracting (squeezing) as the heart pumps blood and relaxing as the heart reloads blood.  One complete sequence of contraction and relaxation is called a heartbeat.  Occurs approximately every second © iTutor All Rights Reserved

 The circulatory system carries two types of blood Oxygen-rich blood c Oxygen-poor blood Contains oxygen picked up from the LUNGS Pumped FROM the heart through ARTERIES Contains carbon dioxide picked up from the body Travelling back TO the heart through VEINS © iTutor All Rights Reserved

The Human Heart  Atrium -The upper chambers (receives blood)  Ventricle -The lower chambers (pumps blood)

O x y g e n ri c h b lo o d Oxygen- rich blood Oxygen-poor blood Lungs Body

1. Blood containing wastes & CO 2 flows from the body through the Vena Cava to the right atrium. 2. Blood moves into the right ventricle and gets pumped to the lungs 3. In the lungs, the blood picks up oxygen and removes carbon dioxide.

4.Blood containing oxygen flows from the lungs back to the heart through the left atrium. 5. Blood moves into the left ventricle and gets pumped through the Aorta back to the body.

 valves between the atrium and ventricles keep blood flowing in one direction Open valve Closed valve

Pathway of Circulation YouTube video-Bill Nye Circulation right atrium right ventricle left atrium left ventricle

Blood moves through the circulatory system in three types of blood vessels:  Arteries: Large vessels that carry oxygen rich blood away from the heart.  The largest artery is the Aorta © iTutor All Rights Reserved

 Veins: Carry oxygen- poor blood from the body towards the heart  The largest vein is the Vena Cava

 Capillaries: smallest vessels that branch off the main vessels and link the arteries to veins.

Blood – Humans have 5 liters of blood in their body Composed of:  Red blood cells  White blood cells  Platelets  Plasma

© iTutor All Rights Reserved Red Blood Cells  most numerous blood cells  Red/Disk shaped  Made in bone marrow  Transport oxygen  Give blood it’s color

White Blood Cells  Larger than red blood cells  Guard against infection and attack bacteria  Number of WBC’s increases when body is fighting infections

Platelets  Pieces of blood cells that float in blood  Clump together to form sticky clots to repair blood vessels

Plasma  Liquid part of blood  mostly water  some gases, salts, nutrients, wastes, and proteins.

 There are four different blood types: A, B, AB, and O  A certain protein known as an antigen on the outside of the red blood cell determine a person’s blood type Blood Types

antigen A antigen B

 When blood is donated from one individual to another this is known as a transfusion.  Blood transfusions are done to replace blood lost during surgery, serious injury, or if a person’s body can't make blood properly because of an illness.  Mixing blood of certain types can cause problems to occur in the blood. This could result in clumping and death.

You must be at least 17 to donate blood or 16 with parent permission

 People with TYPE O blood are called Universal Donors, because they can give blood to any blood type.  People with TYPE AB blood are called Universal Recipients, because they can receive any blood type.

 The force of blood on the wall of the arteries  Blood pressure decreases as the heart relaxes, but the rest of the circulatory system is still under pressure. © iTutor All Rights Reserved

 When blood pressure is taken, the cuff is wrapped around the upper portion of the arm and pumped with air until blood flow in the artery is blocked.

As the pressure in the cuff is relaxed, 2 numbers are recorded. Systolic pressure - 1 st number The force felt in the arteries when the ventricles contract. Diastolic pressure- 2 nd number The force of the blood on the arteries when the ventricles relax.

Heart Attack  When blood can't get to your heart, your heart muscle doesn't get the oxygen it needs And cells can be damaged or die.

This can be caused by cholesterol and a fatty material called plaque can build up on the walls inside blood vessels that take blood to your heart.

Stroke  blood flow to an area of the brain is cut off, brain cells are deprived of oxygen and begin to die.  abilities controlled by that area of the brain such as memory and muscle control are lost.  How a person is affected by their stroke depends on where it occurs in the brain and how much the brain is damaged.

Leukemia  An abnormal rise in the number of white blood cells.  They crowd out red blood cells and platelets.  Despite their vast numbers, these leukemia cells are unable to fight infection the way normal white blood cells do.

Videos  Bill Nye Blood and Circulation  What is Blood? AmericanBlood.org 2:23  How your Heart Works Kids Health  How the Heart Works 3D Video.flv 2:56  Types of Blood Vessels eMedTV 1:09  Schoolhouse Rock: Do the Circulation  The Heart Mr. Parr 2:40  Circulatory Song Mr. Parr 3:19