Cardio System Flashcards
What does the cardiovascular system transport throughout the body?
oxygen to cells nutrients to cells hormones to cells waste products from cells heat around the body
How much blood is in an adult male?
6 litres
how much blood is in an adult female?
5 litres
How much blood is in an 8 year old?
2 litres
How much blood is in an average full term baby?
300mls
How much blood is in an average 30 week pre term baby?
100mls
Describes the structure of the heart?
4 hollow chambers
2 on the right and 2 on the left
2 pumps separated by the septum
The right side of the heart deals with deoxygenated blood
The left side of the heart deals with oxygenated blood
What are the 3 layers that the walls of the heart are made from?
Pericardium
Myocardium
Endocardium
Describe pulmonary circulation.
The right ventricle pumps deoxygenated blood into the pulmonary arteries. These arteries carry the blood to the lungs where it passes through a capillary network close to air filled alveoli. This enables the release of carbon dioxide and the uptake of oxygen from the air. The now oxygenated blood returns to the left atrium in the pulmonary veins.
Describe Systemic circulation.
Oxygenated blood that flows into the left atrium, then flows into the left ventricle. the left ventricle then pumps the blood through the aorta, the major artery which supplies blood to the body.
Describe the Sa node.
Small mass of specialised cells. Near to the opening of the superior vena cava. Electrically unstable means discharge 60-80 times per minute. Followed by recovery. Triggers arterial contraction.
What is the AV node?
transmits electrical signals from the atria into the ventricles
What is the AV bundle?
Divides into left and right branches. Branches then break up into fibres. Transmits electrical impulses from the AV node to the apex of the myocardium.
What controls the heart rate?
Regulated by the autonomic nervous System. Vasomotor centre found in the medulla Oblongata in the brain sends nerve impulses to the sino-atrial system. Influenced by hormones particularly adrenaline.
Describe arteries.
Their major role is to carry away from the heart delivering oxygen rich blood to capillaries. 3 layers: outer, middle muscular and inner smooth epithelial. they expand and contract.
Describe veins.
Their main role is to carry blood to the heart, carrying oxygen depleted blood and carbon dioxide from the capillaries. 3 layers: outer, middle muscular and inner smooth epithelial. They expand and contract.
Describe the capillaries.
Their main role is the exchange of oxygen and carbon dioxide, involved in the release of heat. They are thin and fragile, one epithelial cell in depth.
What way do the arteries flow blood?
away from the heart