4.4 Circulation Flashcards
What are the 4 chambers of the heart?
- Left + right ventricles.
- Left + right atria.
What are the 4 main blood vessels?
- Pulmonary vein (lungs to left atrium).
- Aorta (left ventricle to body).
- Vena cava (body to right atrium).
- Pulmonary artery (right ventricle to lungs).
What are the atrioventricular valves and what do they do?
- Mitral or tricuspid/bicuspid.
- Prevent backflow form ventricles to atria.
What are the semilunar valves and what do they do?
- Pulmonary/aortic.
- Separate arteries from ventricles.
What do valve tendons do?
- Prevent atrioventricular valves from turning inside out due to the pressure when heart contracts.
What is the septum made of and what does it do?
- Muscle + connective tissues.
- Prevents oxygenated + deoxygenated blood from mixing.
What did the coronary arteries do?
- Wrapped around heart to supply cardiac muscle w/ blood.
Which side of the card is muscle is thicker?
- LHS because needed to withstand high pressure to pump blood to all tissues in body.
What are the 3 types of circulatory system?
- Closed.
- Open single.
- Open double.
What are 4 advantages of a double circulatory system?
- Conc. gradient maintained.
- Blood pressure to body tissues is higher.
- Blood pressure to lungs is lower (preventing damage).
- Organisms can develop larger bodies.
The heart is referred to as myogenic what does this mean?
- It can stimulate its own contractions wo/ nervous stimulation.
What are the 5 stages of myogenic contractions that occur in the heart?
- Depolarisation originates in sinoatrial node.
- Depolarisation spreads through atria causing atrial systole.
- Stimulates atriaventricular node.
- Delay for *batrial diastole** AVN spread depolarisation to bundle of His.
- Bundle of His splits into 2 branches - Purkinje Fibres - causes ventricular systole.
What are the 3 stages of the cardiac cycle?
- Atrial systole.
- Ventricular systole.
- Cardiac diastole.
What happens in atrial systole?
- Atria contract.
- Forces AV valves open + blood flows into ventricles.
What happens in ventricular systole?
- Contraction of ventricles cause AV valves to close + semilunar valves to open.
- Blood leaves LV through aorta + RV through pulmonary artery.
What happens in cardiac diastole?
- Atria + ventricles relax.
- Pressure inside heart chambers decreases.
- Caucasus semilunar valves to close to prevent back flow of blood.
What are 3 functions of blood?
- Transport.
- Defence against pathogens.
- Formation of lymph + fluid tissue.
What are 5 things that are transported in plasma?
- Digested food products (glucose, amino acids, etc.).
- Nutrient molecules.
- Hormones.
- Excretory products (CO2, urea, etc.).
- Heat.
What is another name for red blood cells?
- Erythrocytes.
What is another name for white blood cells?
- Leukocytes.
What do erythrocytes transport?
- O2 and some CO2.
How are erythrocytes specialised?
- Biconcave shape.
- No nucleus.
- Contain haemoglobin.
What are 2 categories of leukocytes?
- Granulocytes.
- Agranulocytes.
What are 3 examples of granulocytes?
- Neutrophils.
- Basophils.
- Eosinophils.