2.2 The cardiovascular system Flashcards
What is the function of the cardiovascular system?
Transport:
Oxygen vs Carbon Dioxide, Nutrient delivery from digestive tract, Waste removal, Hormones.
Protection:
Inflammation, WBC destroy microorganisms and cancer cells, Antibodies, Platelets and blood clotting
Regulation:
Body temperature, stabilise pH and fluid distribution.
Where is blood produced?
Red bone marrow site of production of erythrocytes & leucocytes
State the composition of blood
2.1
4 components:
erythrocytes 45%
plasma 55%
leucocytes & platelets <1%
blood transports electrolytes, proteins, gases, nutrients, waste products, hormones
Distinguish between the functions of erythrocytes, leucocytes and platelets.
2.2
Erythrocytes (RBC):
hemoglobin protein binds to oxygen -> oxyhemoglobin.
Leucocytes (WBC):
part of immune system, protects body against infection & foreign invaders. Fight pathogens such as bacteria, viruses, or parasites.
Platelets:
Form blood clots to prevent the loss of blood.
Outline the role of hemoglobin in oxygen transport
RBD site of transport:
Oxygen transported in blood as oxyhemoglobin. Hemoglobin has 4 binding sites for individual O molecules to bind to.
Describe the anatomy of the heart with reference to the heart chambers, valves and major blood vessels.
2.3
Chambers:
Right & Left: Atrium & Ventricle
Valves:
Pulmonary, aortic, tricuspid, bicuspid
Blood vessels:
Aorta, pulmonary vein, pulmonary artery, vena cava
Define pulmonary & systemic circulation
pulmonary circulation- Delivers deoxygenated blood from right side of the heart to the lungs to be oxygenated. Then carried back to left side of heart.
systemic circulation- Delivers oxygenated blood from left side of the heart to the body & capillaries. Then carried back to right side of heart.
Outline the relationship between the pulmonary and systemic circulation.
2.5
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What are arteries?
thick muscular walls; O2 rich (except pulmonary artery); transport blood away from the heart
What are capillaries?
narrow vessels with thin walls; site of exchange between blood & tissue
What are veins?
deoxygenated blood (except pulmonary veins); less muscular; valves to prevent back flow; to heart
What are valves?
Veins contain valves to stop the blood from flowing backwards due to gravity. This is because the blood inside is at low pressure.
Define:
Cardiac Output (CO) (l/min)
Stroke volume (SV) (l)
Heart Rate (HR) (bpm)
2.6
Cardiac Output (CO) (l/min) - The amount of blood ejected by the heart (ventricles) in 1 minute
-> takes approx 1 min for blood to return & pass through the heart OR. in other wordsAny RBC leaving the left ventricle will be back in approx 1 min
Stroke volume (SV) (l) - The amount of blood being pumped from the heart during each contraction
Heart Rate (HR) (bpm) - How quickly the heart is beating (per minute)
Whats the relationship btw. HR & SV? Why?
2.6
CO = HR x SV
People with higher resting SV have lower resting HR.
-> The more blood you can pump per ventricular contraction, the less your heart needs to beat to pump the blood around your body.
Analyse cardiac output, stroke volume and heart rate data between gender
2.7
-women have lower stroke volume-> smaller heart & smaller left ventricle
-women have smaller blood volume
-women have higher resting & sub-maximal heart rate -> maintain cardiac output
-max heart rate same