Blood - Blood Basics Flashcards
Homeostasis
“The various physiological arrangements that serve to restore the normal state of the internal environment once it has been disturbed” - W.B. Cannon (1928)
Bloods contribution to homeostasis
Serves as the vehicle for transporting materials to and from the cells, buffering changes in pH, carrying excess heat to the body surface for elimination, playing a major role in the body’s defence system, and minimising blood loss when a blood vessel is damaged.
How is homeostasis essential for survival for cells
Cells need constant supply of O2 delivered to them to support their energy-generating chemical reactions, which produce CO2 that must be removed continuously. Cells can survive and function only within a narrow pH and temperature range, and furthermore, cells must be protected against disease-causing microorganisms
Total body fluids volume
42L
Plasma volume
3L
Extracellular volume
14L
Red blood cell volume
2.5L
Intracellular volume
28L
Circulation
Serves the needs of the tissues:
Transports nutrients to tissues
Transports waste products away from tissues
Carries hormones from one part of the body to another
Maintains an appropriate environment in all the tissue fluids for optimal survival and function of the cells
Haematocrit
Sample of fresh blood with anti-coagulant spun in a centrifuge for ca. 10 minutes at 2000 rpm
The normal haematocrit is approximately 45% of the whole blood volume
42-52% male
37-47% females
Anaemia
40% of world suffer
Dietary Iron Deficiency
Diagnose by low Hb, low serum ferritin, response to iron supplementation
Polycythaemia
Symptoms:
A ruddy complexion
Headache
Blurred vision
Confusion
Stroke or Coma
Treatment:
Venesection
Water description and importance
Makes up 90% of plasma volume: provides dissolving and suspending medium for solutes and formed elements
Proteins description and importance
Accounts for 8% of plasma (by weight) most are synthesised by liver
Albumin description and importance
60% of plasma proteins largely responsible for plasma osmotic pressure
Globulin’s description and importance
36% of plasma proteins include clotting proteins, antibodies secreted by certain leukocytes during the immune response, and proteins that bind to lipids, fat soluble hormones and metal ions to transport these substances in the blood
Fibrinogen description and importance
Important in the formation of blood clots
Proteins Name Source Function
Albumins: Liver: Major contributors to osmotic pressure of plasma, carriers for various substances
Globulins: Liver and Lymphoid tissue: Clotting factors, enzymes, antibodies, carriers for various substances.
Fibrinogen: Liver: Forms fibrin threads essential for blood clotting
Transferrin: Liver and other tissues: Iron transport
Components of plasma: Nitrogenous waste products description and importance
By products of metabolism, such as urea acid and creatine
Organic nutrients description and importance
Materials absorbed from the intestines and used by cells throughout the body: includes glucose and other simple sugars, amino acids, fatty acids, glycerol, triglycerides, cholesterol and vitamins
Cations description and importance
Sodium, potassium, calcium, magnesium (important in neuromuscular signalling), and trace metals (important in normal enzyme activity)
Anions description and importance
Chloride (important in neuromuscular signalling), bicarbonate, and phosphate (important in maintenance of normal plasma pH)
Respiratory gasses description and importance
Oxygen and carbon dioxide: most oxygen and some carbon dioxide is bound to haemoglobin in erythrocytes, a significant fraction of carbon dioxide is found in the plasma in the form of bicarbonate
