Cardiovascular anatomy Flashcards
Why do physiotherapists need to know about the cardiovascular system? (5)
Cardiovascular conditions (eg. myocardial infarction, heart failure, peripheral vascular disease)
To understand links with the respiratory system and respiratory conditions
For health promotion
To understand physiological signs such as heart rate, pulse and blood pressure.
To understand exercise physiology and exercise testing
superior vena cava function
The superior vena cava carries deoxygenated blood from the body (and head) to the right atrium in the right side of the heart.
right pulmonary artery function
carries deoxygenated blood from the right ventricle and pulmonary trunk to the lungs for respiratory gas exchange in the pulmonary capillaries.
right pulmonary vein function
receive oxygenated blood from the lungs and deliver it to the left atrium of the heart.
inferior vena cava function
carries deoxygenated venous blood from the body to the right atrium in the right side of the heart.
right ventricle function
pumps deoxygenated blood through the pulmonary semilunar valve into the pulmonary trunk towards the lungs for gaseous exchange in pulmonary capillaries
left ventricle function
pumps oxygenated blood into the aorta via the aortic semilunar valve.
why are there differences in the thickness of the muscle in the left and right ventricles
The muscular wall of the left ventricle is the thicker than the right ventricle because it is the main pumping chamber in the heart and has to eject blood to the systemic (body) circulation.
The right ventricle needs less muscle as it pumps blood into the pulmonary (lung) circulation which has much lower blood pressure and resistance in its blood vessels.
left pulmonary vein function
receive oxygenated blood from the lungs and deliver it to the left atrium in the left side of the heart.
left pulmonary artery function
carries deoxygenated blood from the right ventricle and pulmonary trunk to the lungs for gas exchange in the pulmonary capillaries
right atrium function
receives deoxygenated venous blood from the inferior and superior vena cava
tricuspid / atrioventricular valve location
right side of heart
tricuspid / atrioventricular valve function
has 3 cusps which open to allow deoxygenated blood to pass in a forward direction from right atrium to right ventricle. The cusps then close preventing backward movement of blood from ventricle to atrium, known as regurgitation.
how can heart valves become damaged and what effects can this have?
Heart valves can be malformed due to congenital heart disease or become damaged due to ageing or disease. This can cause the valve cusps to either fail to completely close or to prolapse into the right atrium during ventricular contraction.
Papillary muscle + chordae tendineae function
The papillary muscle extends from parts of the ventricle wall and connects to the chordae tendineae above. These in turn attach to the valve cusps. Both structures help to secure the atrioventricular valve cusps, preventing them from everting into the atrium during ventricular contraction (no backward flow)
intraventricular septum function
separates the right and left ventricles to prevent deoxygenated and oxygenated blood from mixing. It also has a part of the heart’s electrical conduction pathway which runs down its length.
how can the intraventricular septum become damaged and what effects can this have?
The septum can be breached due to congenital heart disease or following a myocardial infarction (heart attack) which allows mixing of deoxygenated and oxygenated blood or disruption of electrical conduction in the heart
Mitral / atrioventricular valve function
a valve with 2 cusps which opens to allow oxygenated blood to pass in a forward direction from the left atrium to the left ventricle
left atrium function
receives oxygenated blood from the lungs via the pulmonary veins
What are the 3 main functions of the cardiovascular system?
transport, protection & regulation
describe transport as a function of the cardiovascular system
Transport of oxygen, nutrients and hormones to all body tissues/cells and removal of carbon dioxide and waste materials, such as lactic acid, from all body tissues and cells. These are transported by the red blood cells and plasma.
describe protection as a function of the cardiovascular system
Protection of the body via white blood cells as part of the immune system. Prevention of excessive blood loss via blood platelets which clot the blood
describe regulation as a function of the cardiovascular system
Regulation of body temperature, pH and fluid balance as part of homeostasis
describe the blood flow through the heart
deoxygenated blood from sup & inf. vena cava and coronary veins » right atrium » right ventricle » pulmonary arteries » lungs (oxygenated) » pulmonary veins » left atrium » left ventricle » aorta systemic arteries » capillary bed » restart cycle
name the 3 layers of the heart
epicardium, myocardium, endocardium
describe the epicardium layer of the heart
the outer layer composed of a thin layer of connective tissue and adipose tissue
describe the myocardium layer of the heart
the middle layer composed of myocardial muscle cells (myocytes). This is the thickest layer forming the bulk of the heart.
describe the endocardium layer of the heart
the inner layer composed of endothelial cells which line the chambers of the heart, the heart valves and great vessels.
The pericardium is a membrane surrounding the heart and consists of several layers. The outermost is the tough fibrous pericardium composed of dense irregular connective tissue.
What are its functions?
- Protection of the heart from overfilling and over distension with blood.
- Protection of the heart from surrounding structures.
- Anchoring of the heart in its position in the mediastinum during movement.
The outer fibrous pericardium is formed from connective tissue and creates a sac around the heart attaching at the central tendon of the diaphragm below and tunica externa of the great vessels above.
Serous pericardium
The serous pericardium lies beneath the outer fibrous pericardium (the outermost sac covering the heart). Can you describe the structure and function of this part of the heart wall?
The delicate serous pericardium lies between the outer fibrous pericardium and the middle layer of the heart wall - the myocardium.
The serous pericardium itself consists of a double membrane with a cavity between:
- The outer parietal pericardium which fuses with the fibrous pericardium
- The pericardial cavity - a narrow gap containing a few mls of serous pericardial fluid which helps lubrication between heart layers giving friction-free movement during beating of the heart. The serous pericardial cells secrete this fluid.
- The inner visceral pericardium (also known as the epicardium) which fuses with the myocardial layer.