1.1 - What is CVD? Flashcards
done
Why do animals need a circulatory system?
- for the blood to flow around the body / allow diffusion for molecules/ions
What is a single circulatory system?
Where the blood travels from the heart to the rest of the body in one single loop
What is a double circulatory system and its advantages?
- Blood passes x2 through the heart to make one complete circuit of the body
- maintains higher blood pressure, greater flow of blood to tissues, allows seperation of oxygenated and deoxygenated.
What is a open circulatory system?
A system where blood is not contained in blood vessels but circulates in large open spaces
What is a closed circulatory system?
System where blood is fully enclosed within blood vessels
Cardiac cycle - Atrial systole
- Atrium contracts
- Blood flows from atria into ventricles
- Backflow is prevented by close of valves
Cardiac cycle - Ventricular systole
- ventricles contract
- semi lunar valves close
- pulmonary artery pushed open
- blood flows into arteries
Cardiac cycle - Diastole
- Atria and ventricles relax
- semi lunar and pulmonary artery are pushed shut
- blood flows into ventricles
What is plasma?
It takes nutrients , hormones,amino acids and glucose to the body
Liquid part of the blood
What are red blood cells?
They contain haemoglobin which transports oxygen around the body
What are white blood cells?
They help fight diseases and infections in the body
What are platlets?
Tiny cells which form clots and stop blood clotting
Blood clotting cascade
- Damage to blood vessels
- Platlets bind to exposed collagen
- Thromboplastin is activated
- Thromboplastin catalysis the conversion of prothrombin to thrombin (calcium ions and vitamin k present)
- Thrombin catalyses fibrinogen to fibrin
- Fibrin creates mesh fibres
- Platlets are trapped by mesh
- Clot is formed
Atherosclerosis
- Artery wall damaged
- Inflammatory response
- Large white blood cells enter wall
- Cholestrol accumulates
- Atheroma forms
- Calcium salts and fibrous tissue
- Hard plaque forms
- Elasticity reduced in walls
- Artery narrows
- Blood pressure rises
- Atherosclerosis
What is the order of the cardiac cycle?
vena cava -> right atrium -> tricuspid valve -> right ventricle -> pulmpnary artery -> lungs -> pulmonary vein -> left atrium -> bicuspid valve -> left ventricle -> aorta
