M6: Blood Flashcards
Functions of blood
- TRANSPORT
- gases, nutrients and waste
- processed molecules (e.g. vitamin D)
- regulatory molecules (e.g. hormones)
- REGULATION OF pH
- BODY TEMPERATURE MAINTENANCE
- PROTECTION AGAINST FOREIGN SUBSTANCES
- CLOT FORMATION
total volume of blood in average adult
4-6L
(8% of total body weight)
composition of blood
PLASMA (55%)
- 7% proteins
- 91% water
- 2% other solutes (ions, nutrients, waste, gases, hormones)
FORMED ELEMENTS (45%)
- platelets
- white blood cells
- red blood cells
buffy coat
- coat between red blood cells and plasma in a blood sample
- contains platelets and white blood cells
plasma components
- COLLOID (fluid with suspended substances)
- 91% water
- 9% proteins/other solutes
Proteins
- 58% ALBUMINS (osmotic pressure, transports fatty acids, bilirubin and thyroid hormones)
- 38% GLOBULIN (antibodies, transports lipids, iron and sex hormones)
- 4% FIBRINOGEN (blood clotting)
plasma vs serum
plasma: inside body
serum: plasma in a clot
components of formed elements
95% RED BLOOD CELLS
- biconcave disks, no nucleus or mitochondria
- hemoglobin, transports O2 and C02
- converts C02 and water to carbonic acid (carbonic anhydrase)
5% WHITE BLOOD CELLS
- GRANULOCYTES (large granules, multi-lobed nuclei)
- NEUTROPHILS, EOSINOPHILS, BASOPHILS
- AGRANULOCYTES (small granules, non-lobed nuclei)
- LYMPHOCYTES and MONOCYTES
PLATELETS (thrombocytes)
- cell fragment
- form platelet plugs and release chemicals for blood clotting
process of blood cell production is called
Hematopoiesis or hemopoiesis
stem cell in red bone marrow
hemocytoblast
initial cells that create formed elements
PROERYTHROBLASTS -> RBC
MYELOBLASTS -> granulocytes (basophils, neutrophils, eosinophils)
LYMPHOBLASTS -> lymphocytes
MONOBLASTS -> monocytes
MEGAKARYOBLASTS -> platelets
components and transport functions of red blood cells
- 1/3 hemoblobin
- 2/3 lipids, ATP, carbonic anhydrase
transport functions
- O2: 98.5% bound to hemoglobin (rest is dissolved in plasma)
- C02: 23% bound to hemoglobin (70% as bicarbonate, rest is dissolved in plasma)
- H+: generated from carbonic anhydrase reaction
structure of hemoglobin
- 4 globin molecules (polypeptide chains)
- 4 heme molecules, each with 1 iron atom
Called OXYHEMOGLOBIN when transporting oxygen
Called DEOXYHEMOGLOBIN when no oxygen bound
Called CARBAMINOHEMOGLOBIN when transporting C02
formation of red blood cells called
erythropoiesis
explain erythropoisis
Formation of red blood cells
- takes about 4 days
- cells last for about 120 days in circulation
Process
- decreased oxygen in blood triggers kidneys to release ERYTHROPOIETIN
- travels to red bone marrow, stimulates proerythroblast production (takes a few days)
- RBCs formed
process of RBC recycling
- natural degeneration of RBCs
- separation of components
- globin -> amino acids
- heme -> iron removed via TRANSFERRIN, carried to liver to store in FERATIN or recycled into more heme
- iron free heme -> bilirubin, to liver and SI, creates pigment for urine and feces
WBC structure and function
- protect body against microorganisms
- remove dead cells and debris
- nucleated, no hemoglobin
Movement
- AMEBOID movement (arm-like extensions)
- DIAPEDESIS (cells become thin and move between/through endothelial cells of capillaries)
- CHEMOTAXIS (attraction to and movement towards foreign materials or damaged cells)
Nuetrophil structure/function
WBC, granulocyte
first line of defense
- 60-70% of WBCs
- nuclei lobed (2-5 lobes)
- 10/12 hours in circulation
- phagocytize foreign matter
- secrete LYSOZYME (enzyme that metabolizes bacteria)
Eosinophil structure/function
WBC, granulocyte
allergic reaction helpers, worm destroyers
- 2-4% WBCs
- usually 2-4 lobes on nuclei
- active in allergic reactions
- destroy inflammatory chemicals
- release chemicals that help destroy worm invasions! tapeworms, hookworms etc
Basophil structure/function
WBC, granulocyte
attacks the invaders by letting more WBC in!
- 0.5-1% of WBC
- inflammation and allergic response
- produces HISATIME (vasodilation and bronchial constriction)
- produces HERAPIN (inhibits blood clotting
Lymphocyte structure/function
WBC, agranular
fights bad guys: bacteria, bacteria, tumors
- 20-25% WBC
- smallest
- produced in red bone marrow, proliferates in lymphatic tissue
- produces ANTIBODIES (pr- that destroy bacteria viruses, tumors)
Monocyte structure/function
WBC, agranular
eats the bad guys
- 3-8% of WBCs
- become macrophages after 3 days
- phagocytic cells
- increases with chronic inflammation
Platelet structure/function
- aka thrombocytes
- cell fragments pinched off from megakaryocytes
- surface pr- can form PLATELET ADHESIONS and stick to other molecules (i.e. collagen on blood vessel lining)
- prevent blood loss via PLATELET PLUGS (clots)
Breakdown of Heme
- biliverdin
- bilirubin in blood
- ” in liver
- “in bile
- ” in small intestine
- urobilinogen in large intesine
to urine - urobilin
- urine
to feces - stercobilin
- feces
