1. Double circulatory system
The Heart
Double circulatory system
Review video
System of double circulation

2. Pulmonary circulation
Blood flowing to and from the lungs

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

4. 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

5. 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

6. 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.

7. 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.

8. 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.

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

10. 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

11. Flow of blood tutorial : http://www. kscience. co
Flow of blood tutorial : Virtual Heart Dissection:

12. 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.

15. 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.

16. 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.

17. The cardiac cycle
On the second one, use the tutorial sections in the drop down menu to work through and understand the cardiac cycle.

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