The Circulatory System

1. Functions of the supplies blood for pulmonary circulation right side of the receives blood from vena carva heart pumps blood into pulmonary artery 2. Functions of the supplies systemic circulation- circulation around rest of left side of the body heart receives blood from pulmonary vein 3. why do multicel- bigger diffusion distance lular organisms increasing size, metabolic waste cannot rely on simple need a circulato- diffusion ry system 4. CVS has three components Blood vessels heart 5. Blood-plasma 90% is water 8% of proteins- albumin, enzymes, hormones etc. Plasma proteins help with oncotic pressure nitrogenous substances- urea, creatinine nutrients electrolytes-maintain normal pH 6. Blood: Leukocytes Granulocytes Neutrophils Eosinophils Basophils Agranulocytes Leukocytes- Help defend against diseases Granulocytes- type of leukocyte. Cytoplasmic granules can be easily stained Neutrophils- type of granulocyte. contain granules of peroxidase and hydrolytic enzymes. sites of inflammation and engulf invading cells Eosinophils-attack parasitic worms. Basophils-contain histamine- when released dilates arterioles, attracting leukocytes to the area Agranulocytes- lymphocytes(t-lymphocytes-viral infective cells and b-lymphocytes: plasma cell for antibodies) 7. Blood- platelets for clotting- actiavted to form a plug to reduce bleeding granules of 5HT causing vasoconstriction- reducing blood flow 1/5 made from fragments of cell-tiny, no nucleus release molecules that activate other platelets 8. systemic and systemic- blood supplied to all parts of the body except for pulmonary circu- the lungs lation pulmonary- supplied to the heart- oxygenated 9. vessels- arteries carry blood under high pressure thick walls-tunica media and adventitia control wall diameter- elastic and smooth muscle 10. vessels- elastic and muscle artery elastic- largest diameter, closest to heart, thick elastic layer and is able to recoil muscle-between elastic artery and capillary, smooth muscle allows to contract and relax 11. vessels-arterioles arteries branch off to arterioles and finally divide to form capillaries walls that can withstand blood pressure sympathetic nervous system allows contraction and dilation of arterioles-important for blood flow 12. vessels-capillar- once cell thick ies narrow lumen gas exchange 13. vessels-venules drains blood from capillaries post capillary veins- two/more capillaries join mostly consist of endothelial cells fluid and leukocytes easily pass through walls 14. vessels-veins carry blood under low pressure larger lumens, thicker walls capacitance vessels- have big impact on the blood volume returned to the heart 15. venous return flow of blood back to heart because venous pressure is low, factors that help: respiratory pump-when muscles contract and relax during inspiration and exhalation pressure changes occur in the 2/5 thoracic and abdominal cavity muscle pump-skeletal muscle compress veins for increase of blood back into the heart 16. lymphatic system osmotic and hydrostatic pressure force out of caplillaries and reabsorbed at venous end lymphatic vessels contain extra fluid and is returned to vessels 17. lymphatic vessels form one way drainage system- lymph flows back to heart 18. right and left lym- right- drains head, neck, right thorax and arm phatic duct left-drains rest of body 19. blood pressure blood will flow from area of low pressure to high arteries- 80-120 mmHg capillaries-16-35 mmHg veins- 4-7 mmHg 20. blood pressure normally refers to systemic arterial blood pressure expressed in two numbers e.g: 120/80 mmHg first number- systolic pressure-contracts second number - diastolic pressure-relax 21. blood pressure equations to know(3) blood pressure= blood flow x vessel resistance cardiac output= heart rate x stroke volume blood pressure= heart rate x stroke vol x vessel resistance 22. control of blood hypertension(hgih BP 14/90 mmHg) and hypotension( low pressure blood pressure) cardiovacular centre receives info from baroreceptors 23. atrial natriuretic released to due high BP peptide atria stretches peptide antagonizes aldosterone- kidneys reabsorb less sodium and water vasodilation 24. 3/5 Anti-diuretic hor- BP dangerously low mone (ADH) kidneys reabsorb more water vasoconstriction 25. angiotensin II increases BP- stimulates aldosterone 26. endothelin increases blood flow- released as response to low blood BP 27. nitric oxide released from endothelium in response to high BP- decreases BP 28. where is the heart located? mediastinum- between lungs posterior to sternum slightly left to midline anterior to spine 29. where is the apex at bottom left heart orientated? apex between 5th and 6th rib 30. atrium/atria first chamber-receives blood from great vein diastole- blood flows through atria systole-pumps blood into ventricles little pressure-thin walls 31. ventricles pumps blood into artery high pressure-thick walls 32. coronary arteries of the heart 33. muscle tissue skeletal: voluntary control attavhed to bone, long and parallel to its neighbour cardiac muscle: involuntary. branched fibres, end is connected to another end for quick conduction of action potentials smooth muscle: non striated middle is thickest. 34. SAN located on right side, beats a little more than rest of heart- to cause the whole heart to beat 4/5 electrical conductivity of the heart 35. components of ECG trace rhythm influenced by nervous system SAN- AN- Bundle of His- Purkyne fibres- right and left ventricle stimulated p wave-atrial depolarization. qrs wave- ventricular depolarization. impulse spreads from bundle of His. t wave- ventricular repolarisation 36. the cardiac cycle vena cava-right atrium-tricuspid valve-right ventricle-pulmonary/semilunar valve-pulmonary artery-pulmonary circulation- pulmonary vein- left atrium-biscuspid valve/mitral- left ventricle-aortic/semilunar valve-aorta 37. heart sounds lub and dub lub-closing tricuspid and bicuspid valve at the beginning of systole(contracting). first sound dub- second sound. end of systole, closing of semilunar valves 38. diastole vs systole diastole-heart is relaxed. blood enters atria then ventricles. arterial blood pressure is at lowest systole- heart contracts. atria pumps blood into ventricles. arterial blood pressure is at highest 5/5