Blood system Flashcards
What are the function of blood?
- Respiration (transport O2 and CO2)
- Nutrition (transport of nutrients - glucose, fats)
- Excretion (transport of metabolic waste for removal)
- Acid-base balance.
- Water balance
- Regulation of body heat
- Defense against infection.
- Cellular communication (hormones, cytokines
What is the normal red blood cell (erythrocytes) count?
4.0 - 6.5 x 10^12 /-1
What is the normal white blood cell (leukocytes) count?
4 - 11 x 10^9 /-1
What is the normal platelets (thrombocytes) count?
1.5 - 4.5 x 10^11 /-1
What are the subdivision of leukocytes (WBC)?
- Granulocyte
- monocyte
- lymphocytes
What are the subdivision of granulocyte?
- neutrophils
- basophils
- eosinophils
What are the subdivision of eosinophils?
- B-cells
- T-cells
- natural killer cells
What are the structure and function of red blood cells (erythrocytes)?
Function:
- Specially adapted cells for transporting O2
Structure:
- No nucleus
- No mitochondria
- Simple cytoplasm, packed with Hb, few organelles.
- No or limited capacity for protein synthesis.
- Flexible membrane
- Short life-span (~120 days)
What are the function and structure of white blood cell (neutrophils)?
- 40 - 75% of all WBC
- Highly motile phagocytes, first line of defence against microbes.
- Multi-lobed nucleus with fine blue-pink granules.
- Stored in BM and released to fight acute infection.
- Short-lived, circulate for ~ 6 - 8 hrs.
Attach to endothelium by adhesion molecules and migrate into tissues at sites of inflammation.
What is the function and structure of eosinophils?
- 1 - 5% of all WBC
- Bi-lobed nucleus, coarse, pink-staining granules.
- Granules contain basic proteins which disrupt cell membranes and generate ROS.
Counts are raised in parasitic infection and allergy.
What is the function and structure of basophils?
- 0.2 - 1.0% of all WBC
- Bi - or - tri - lobed nucleus, abundant large dark granules.
- Granules contain histamine and heparin.
- Degranulation results in acute inflammation vasodilation and increased vascular permeability.
What is the function and structure of monocytes?
- 5 - 10% of all WBC
- Circulate for ~ 2-3 days.
- Migrate into tissues and become tissue macrophages.
- Histocytes, Kupffer cells, reticuloendothelial cells.
- May remain resident in tissues for months.
Phagocytose dead cells, infected cells.
What is the function and structure of lymphocytes?
- 20 - 40% of all WBC.
- T -cells form in BM and mature in thymus.
- T helper cells activate B- and T cytotoxic cells.
- T cytotoxic cells destroy infected and cancerous cells
- T suppressor cells regulate immune responses
- B - cells present antigens to T-cells and when activated mature into antibody-secreting plasma cells.
- Large granular lymphocytes (NK cells) directly attack non-self-cells.
What is the function and structure of platelets?
- Cell-like fragments of megakaryocyte cytoplasm.
- Circulate for about 10 days.
- Stick to collagen in damaged blood vessels.
- Release granule contents on activation.
- Aggregate at wound sites to form a haemostatic plug.
What type of electrolytes can be found in the plasma?
- Na+ = 150 mM
- K+ = 4.5 mM
- Ca++ = 2.5 Mm
- Mg++ = 0.8 mM
- Cl- = 110 mM
- HCO-3 = 26 mM
- Phosphates = 3.5 mM
- Proteins = 1mM
