Blood Components Flashcards
Constituents of blood
Men have 4-6 litres, women have 4-5 litres
Plasma 55% and formed elements is 45%
Plasma= 70-80% water , 7% plasma proteins , 1% other solutes
Proteins maintain osmotic pressures, tissue repair and clotting
1% solutes would mean dissolved gases, Na+, K+ and ca++
Formed elements= 95.6% oxygen, 0.1% WBC , 4% platelets
Plasma
Straw coloured fluid , like interstitial fluid
92% water
Small amount electrolytes (sodium. Potassium and calcium ions)
6-8% plasma proteins = Fibrinogen, albumin and globulins
Waste products
Nutrients, vitamins and hormones
Gases like O2, CO2 and nitrogen
Plasma + interstitial fluid maintain osmotic pressures + hydrostatic pressures
Oedema
Erythrocytes
95.6% Red bone marrow Biconcave discs- thin in middle and thick at edges No nuclei so can’t reproduce No mitochondria- rely on energy from anaerobic glycolysis Carry 02 but to other cells Lack ribosomes RBC programmed for 120 days = apoptosis Constantly produced in bone marrow
Haemoglobin = 4 polypeptide chains and haem + iron
Leucocytes
0.1% formed elements
Lymphatic system
Connective tissue
Granulocytes = Neutrophils, basophils + eosinophils, nucleus appears under stain
Agranulocytes= Lymphocytes and monocytes, nucleus does not appear under stain
WBC appear in inflammation and infection
Only specific cells are lymphocytes
Roles of different WBC
Neutrophils - Phagocytosis of bacteria+ pus
Eosinophils- allergic reactions, defend against parasites , control inflammation
Basophils- allergic reactions + inflammation
Lymphocytes = T and B cell, immunity
Monocytes= phagocytosis of large particles, attracts immune system cells
Platelets
Thrombocytes
Red bone marrow
Small , no colour and disc shaped fragment
No nucleus
Large numbers in blood
Release clotting chemicals
Patch damaged vessel walls + contract tissue after clot formation
Sizes = RBC largest, then WBC then platelets
Blood functions
Transportation
Regulation
Protection
Transportation
60,000 blood vessels
To tissue: Oxygen Nutrients Electrolytes (Na+ and k+ for nerves and ca++ for muscles) Vitamins and hormone
Carries these things away: CO2 H20 Electrolytes Urea in urine via kidney
Regulation
Regulate acidity of fluids using buffers
Eg PH of 7.35-7.45
Enzymes activity optimal
Blood control ph by controlling levels of bicarbonate and co2
Regulates volume of fluid in tissues by proteins - osmosis
Thermoregulation - redistribute blood and excess heat
Protection
Defend against disease - carry WBC, factors for inflammation and antibodies
Haemostasis - prevent major blood loss
Haemostasis
Very pretty cake
VASCULAR
PLATELET
COAGULATION
Vascular phase
Immediate vasospasm
Basement membrane of vessels exposed
Endothelial cells release chemical factors and hormones for more muscle contraction. ADP + tissue factor = smooth muscle contraction.
Also cell division of endothelial cells, smooth muscle cells and fibrocytes
Endothelial cells sticky
Platelet phase
PLATELET ADHESION - 15 secs after injury. Platelets stick to the sticky endothelium, basal laimnae and exposer collagen fibres
PLATELET AGGREGATION - platelets accumulate and stick together.
Release substances for more platelet
More sticky so more can stick
Platelet plug formed
Coagulation phase
Involves series of steps, converting circulating fibrinogen to insoluble fibrin
Chain reaction of enzymes and pro enzymes
EXTRINSIC= blood vessel damaged from outside eg, kicked INTRINSIC= inside damage
COMMON PATHWAY- Both get to here, and made clotting factor 10 + prothrombinase
Common pathway
Prothrombinase with CF10 changes prothrombin into thrombin
Thrombin converts fibrinogen into fibrin
Fibrin, with calcium and stabilising factor, becomes fibrin threads
Fibrin threads = Mesh with blood cells and plasma
Fibrin mesh covers platelet plug , traps blood cells and seals off area
