The cardio-vascular system Gillian Rowe

Learning outcome At the end of this session you will understand The function of the heart within the CV system The description of pulmonary and systematic circulation The names of the structures within the heart The functions and location of the semi-lunar and atrio-ventricular valves

function The heart is the primary muscle in the body Beats continuously Provides the tissues and cells with oxygen and nutrients Heart is divided in to four chambers

The Heart

The 4 chambers Top two chambers – atria Lower two chambers – ventricles – more muscular than atria as these are the main pumps Muscular wall in the middle – septum dividing the heart sagitally

Double pump Left side of the heart – The SYSTEMIC CIRCULATION Circulating oxygen rich blood through the body Right side of the heart – PULMONARY CIRCULATION Circulating oxygen poor blood back to the lungs

Valves Major vessels that act as entry and exit points are at the top of the heart To ensure smooth passage of blood through the heart, a number of VALVES exist Valves ensure blood only flows in one direction, and the ‘lub dub’ sound of the heart The ‘lub’ is the sound of the bicuspid and tricuspid valves (atrio-ventricular valves) closing The ‘dub’ sound is the sound of the pulmonary and aortic valves (semi-lunar valves) closing

Muscular composition of the heart Heart – Cardiac tissue Thick outside tissue – pericardium Thick muscular wall of the heart – myocardium Inner layer of single cells that line the ventricles – endocardium

overview http://www.youtube.com/watch?v=H04d3rJCLCE