Double circulatory system The Heart Double circulatory system Review video https://www.youtube.com/watch?v=9fxm85Fy4sQ System of double circulation

Pulmonary circulation Blood flowing to and from the lungs

Systemic circulation Blood flowing to and from all other organs in the body. Including, heart muscles.

The Heart Circulation of Blood through the Body Capillaries of head and arms The Heart Superior vena cava Pulmonary artery Aorta Circulation of Blood through the Body Pulmonary vein Capillaries of right lungs Capillaries of left lung The circulatory system is divided into two pathways. Pulmonary circulation carries blood between the heart and the lungs. Systemic circulation carries blood between the heart and the rest of the body.  Inferior vena cava Capillaries of abdominal organs and legs

Structure of the heart Draw and label a diagram of the heart. Include the following labels: Aorta Semi lunar (aortic) valve Left ventricle Atrioventricular (mitral) valve Left atrium Pulmonary vein Vena cava Right atrium Atrioventricular (tricuspid) valve Right ventricle Semi lunar (pulmonary) valve Pulmonary artery Septum PAGE 295 new book. Or google structure of the heart and image search an appropriate diagram

The Heart The Heart The heart is a double pump: The right side of the heart pumps blood to the lungs The left side of the heart pumps blood to the rest of the body.

The Heart The Heart The walls of the heart are composed of cardiac muscle. Contraction of cardiac muscle is myogenic. Myogenic means that it can contract on its own it does not need to be stimulated by a nerve.

The Heart The Heart The heart is enclosed in a protective sac of tissue. In the walls of the heart, two layers of tissue form around a thick layer of muscle. Contractions of the layer of muscle pump blood.

The Heart – Coronary arteries There are many capillaries in the muscular wall of the heart. These are called the coronary arteries.

The Heart – Coronary arteries The function of the coronary arteries are listed below: Bring nutrients to heart muscle Bring oxygen for aerobic cell respiration, which provides heart tissue with energy necessary for heart contraction. Remove waste products (CO2) from heart muscle

Flow of blood tutorial : http://www. kscience. co Flow of blood tutorial : http://www.kscience.co.uk/animations/blood_system.swf Virtual Heart Dissection: http://www.gwc.maricopa.edu/class/bio202/cyberheart/anthrt.htm

atherosclerosis Causes and consequences of occlusion (blockage) of the coronary artery. Development of fatty tissue (aka atheroma) in the artery wall next to the endothelium. Risk factors include: High concentration of low density lipoproteins in the blood, consumption of trans fats (damage endothelium, chronic high blood pressure due to smoking/stress Chronic high blood glucose concentration (diabetes, poor diet), infection of the artery wall (Chlamydia pneumoniae), Atheroma is naturally occurring, commonly seen in young children and adults. Only problematic once vessel becomes blocked to the extent that normal blood flow is impaired. Angina = pain caused when heart muscles do not receive enough oxygen, therefore heart muscle not contracting properly. More details on pg. 297.

Control of heart rate Cardiac muscle contracts and relaxes spontaneously – myogenic muscle contraction Sinoatrial node (SA) in the right atrium. Natural pacemaker, ‘sends out’ electrical signals every 0.8 sec. Contracts both atria. Atrioventricular node (AV) also in the right atrium. Receives signal, sends a second signal 0.1 sec. later. Contracts ventricles. The medulla area in the brainstem, sends signals to the SA, via the cranial nerve to alter the heart rate depending on body conditions. E.g. exercise. Diagram showing location of the nodes, pg. 298 Nodes are controlled by the medulla of the brain (cardiovascular centre) Nerves regulate heart beat in response to pH level (CO2 concentration), oxygen conc.

TOK point Intent and consequences… Ethical decisions often faced by doctors who are asked by a patients family to withdraw treatment to ‘ease a patients suffering’, this can result in the death of the patient. Euthanasia is illegal in many countries, but should we always prolong life if we can… these are important questions which cannot always be answered easily. More information pg. 299.

The cardiac cycle http://highered.mheducation.com/sites/0072495855/student_view0/chapter22/animation__the_cardiac_cycle__quiz_2_.html http://library.med.utah.edu/kw/pharm/hyper_heart1.html http://www.austincc.edu/apreview/NursingAnimations/cardiac_cycle.swf On the second one, use the tutorial sections in the drop down menu to work through and understand the cardiac cycle.

Epinephrine Aka adrenaline Hormone, produced by the adrenal glands. Causes an increase in the heart rate – fight or flight hormone.