Components of the Cardiovascular System Generating & Measuring heart impulses

 To transport oxygen and carbon dioxide around the body  To distribute nutrients and transport waste  To maintain body temperature  To circulate hormones With its massive infrastructure within our body, the cardiovascular system is our very own transportation system. As such, it has four (4) main functions:

“Closed” system“Open” system Our circulatory system is a “closed” system

complete, single Oxygenated blood incomplete, double De-oxygenatedblood complete, double Mixed blood Our circulatory system is a “complete, double” system

STRUCTURE and FUNCTION The circulatory system is made up of 3 components: a) The heart (a pump) – that pushes blood through the vessels b) Blood vessels c) A fluid in which materials are transported (i.e. blood) heart blood vessels blood

heart blood vessels blood

Two (2) main circuits: a) The Pulmonary circuit – blood vessels that carry blood to the lungs where it picks up oxygen and then back to the heart. b) The Systemic circuit – blood vessels that carry oxygen rich blood to the body tissues and deoxygenated blood back to the heart. A third minor circuit: c) The Coronary circuit – blood vessels surround the heart to provide it with oxygen site of gas exchange pulmonary systemic site of gas exchange

septum right lung neck and head trunk and legs 1. The heart is really a double pump separated in the middle by a wall called a septum. 2. The heart consists of 4 chambers. two (2) top chambers = atriums, two (2) bottom = ventricles. left lung 3. The left side of the heart receives oxygen-rich blood from the lungs & pumps it to the body. 4. The right side of the heart receives deoxygenated blood back from the body and pumps it to the lungs to pick up more oxygen. Vena cava

Vein Artery Arteriole Venule Capillary blood exchange in the capillaries Blood from heart O 2 blood going to heart CO 2

a) Arteries: blood vessels that carry blood away from the heart.  thick walls of muscular layers  largest is the aorta that carry oxygenated blood to the body b) Veins: blood vessels that carry blood towards the heart.  veins have thinner walls than arteries and contain valves to prevent back flow of blood (i.e. so blood can be pumped against gravity).  major veins are the vena cavas that carry deoxygenated blood to the right side of the heart. c) Capillaries: very small blood vessels, red blood cells must travel single-file, gases exchange across the walls of capillaries and into the surrounding tissues. When tending wound, apply ice or cold solution to constrict blood flow!

Blood component DiagramFunction PlasmaAllowcellstoeasilytravelthroughvessels Redbloodcells (erythrocytes) CarryO 2 tothecells,andcarryCO 2 from thecellstothelungstobeexhaled Whitebloodcells (leukocytes) Actasyourimmunesystem,circulate throughthebodyengulfingharmful particles PlateletsPlatelets+redbloodcellsjoinandform clots  The average adult has about 5L of blood.  Blood is 55% liquid, called plasma and 45% cells (red blood cells, white blood cells and platelets)

aorta left pulmonary vein left pulmonary artery left atrium left ventricle superior vena cava right pulmonary vein right pulmonary artery right atrium Coronary circuit right ventricle inferior vena cava

Sinoatrial (S.A.) Node:  the pace maker of the heart.  beats are regulated at about 72 beats/min.  its activity is triggered by the swelling of the atrial walls.  once activated, it triggers the A.V. node. Atriaventricle (A.V.) Node:  is another pace maker  it prepares the fibres in the septum to contract the Right and Left Ventricles.

Valves: there are two (2) types of valves 1. Atrioventricular valves:  located between the atria and ventricles.  has three or two flaps  these valves open when the atria contract,  once the ventricles have filled, the AV valves snap shut to prevents the backflow of blood to the atria. 2. Semi-lunar valves:  has three (2) flaps  these open when the ventricles contract.  on the right, blood is pumped to the pulmonary artery, and simultaneously on the left, blood is pumped into the aorta)  once completed, these valves snap shut to prevents the backflow of blood into the ventricles.

Electrocardiography: Time (s) ECG shows three (3) recognizable waves: P wave – small wave immediately before atria contraction QRS complex – complicated wave before ventricle contraction T wave – when the ventricle relaxes and preparing for the next contraction event

“ Lubb-dubb”: Heart sound ‘lubb dubb’ is the Two (2) types of blood pressure: a) Systolic pressure: when blood is pumped out of the left ventricle b) Diastolic pressure: the pressure in the artery walls in a relaxation state Q. What is happening in the heart during Diastolic Pressure? The atria + ventriclesare filling with blood. d shutting of the two sets of valves respectively. Blood pressure: your pulse (feel as a surge of blood passes through your arteries.)

 Blood pressure is measured in mm of Hg,  Blood pressure is written as: systolic pressure diastolic pressure  Normal blood pressure is 120/80. Sphygmomanometer