BLOOD TESTS, CLOTTING AND DISORDERS: http://people.eku.edu/ritchisong/301notes4.htm Acidosis : below pH 7 alkalosis : above pH 7 Respiratory system and kidneys restore pH via negative feedback : ADH, Rennin and Angiotensisn Homeostasis = hemostasis= clotting 3 phases = vascular spasm -àplatelet plug -à coagulation Cascade Coagulation video : http://www.youtube.com/watch?v=co6ar6vVp70&feature=related

Hemostasis - prevention of blood loss from broken vessel (check this Hemostasis animation):

1 - Vascular spasm - vasoconstriction of injured vessel due to contraction of smooth muscle in the wall of the vessel. This 'spasm' may reduce blood flow & blood loss but will not stop blood loss.

Serotonin causes the vascular spasm ex. Positive feedback (short term an dlocalized)

2 - Formation of a platelet plug –

3 - Blood coagulation (clotting):

The result of all of this is a clot - formed primarily of fibrin threads (or polymers), but also including blood cells & platelets.

Clot retraction:

• "tightening"  of  clot  • contraction  of  platelets  trapped  

within  clot  shrinks  fibrin  meshwork,  pulling  edges  of  damaged  vessel  closer  together  

 

Over time (with the amount of time depending on the amount of damage), the clot is dissolved and replaced with normal tissue.

Fibrinolysis:

• dissolution  of  clot  • mechanism  =  ____________________  (a  plasma  protein)  is  activated  by  many  factors  &  

becomes  ___________________.  Plasmin  then  breaks  down  fibrin  meshwork  &  phagocytic  WBCs  remove  products  of  clot  dissolution  

Blue arrows = stimulation; red arrows = inhibition. tPA is released by damaged endothelium (Source: en.wikipedia.org/wiki/Fibrinolysis)

Blood clotting SUMMARY Serotonin = vascular spasm + tissue thromboplastin + prothrombin/Ca++ =thrombin + fibrinogen = fibrin = clot

Disorders of hemostasis or Inappropriate  clotting:  

_______________________  -­‐  clot  formed  in  an  intact  vessel,  possibly  due  to:  

o roughened  vessel  walls  (atherosclerosis;  see  normal  &  occluded  coronary  arteries  below)  

o slow-­‐moving  blood  (e.g.,  in  varicose  veins)  =  small  quantities  of  fibrin  form  &  accumulate  

o check  this  animation  about  deep  vein  thrombosis  

 

______________________  -­‐  'moving'  clot  

• Source:  http://www.ors.od.nih.gov/medart/portfolio/Donny/embolus.html  • Thrombus  and  embolus  :  video:  http://people.eku.edu/ritchisong/301notes4.htm  

Clotting:  normal  is  2-­‐6  min  decreases  with  Ca  dropping  and  aspirin  increasing    

Anticoagulants  ____________________________  which  is  made  by  mast  cells  and  basophils  inhibits  prothrombin  from  converting  into  thrombin  

Warafrin:  Vit  K  antagonist  so  4  CF  cannot  be  made  

Excessive bleeding:

• ________________________________  o genetic  'defect'  o inability  to  produce  certain  clotting  factors  

• ________________________________  o abnormally  low  platelet  count  o most  persons  have  idiopathic  thrombocytopenia  (=  unknown  cause)  while  in  

others  it's  an  autoimmune  disease  o potentially  leading  to  mild  to  serious  bleeding  o  bleeding  can  happen  inside  the  body  (internal  bleeding)  or  on  the  skin.    o A  normal  platelet  count  is  150,000  to  450,000  platelets  per  microliter  of  blood.    o serious  bleeding  at  very  low—less  than  10,000  or  20,000  platelets  per  microliter.    

Several  factors  can  cause  a  low  platelet  count,  such  as:    

• The  bone  marrow  doesn't  make  enough  platelets.  

• The  bone  marrow  makes  enough  platelets,  but  the  body  destroys  them  (autoimmunity)  or  uses  them  up.  

• The  spleen  holds  onto  too  many  platelets.  Or  a  combo  of  these  (Source:  NHLBI).  

Blood tests: know how to perform these, read then and interpret 1. Blood typing 2. Talliquist: preliminary quantitative % Hb. Used as an indicator for anemia 3. Erythrocyte Sedimentation rate: http://medical-dictionary.thefreedictionary.com/Blood+sedimentation

Normal results

A  normal  value  does  not  rule  out  disease.  Normal  values  for  the  Westergren  method  are:  Men  0  mm/hour-­‐15  mm/hour;  women  0  mm/hour-­‐20  mm/hour;  and  children  0  mm/hour-­‐10  mm/hour.  

Abnormal results

Lower rate : RBC abnormalities such as sickle cell

Higher Rate: Menses, pregnant, anemic

Very high rate; infection or condition of tissue destruction, cancer, rheumatoid arthritis 4. Hematocrit: % of RBC per unit volume Too high = polycythemia

- bone marrow cancer - slide: immature,

nucleated RBC o

Anemia: http://www.unm.edu/~mpachman/Blood/anemias.htm How to diagnose? http://www.youtube.com/watch?v=pGTu2aDbLpg Anemia from RBC loss: http://www.youtube.com/watch?v=1ueLaBS9_dM&feature=channel

Types of Anemias a. decrease in RBC number

b. inadequate Hb in RBC

c. Abnormal Hb in RBC

Liver and jaundice: due to a buildup of bilirubin Macrophage phagocytizes RBC in spleen, liver and bone marrow.

1. heme is separated from globin 2. Fe is removed from heme by transferrin 3. Biliverdin is green inside the macrophage and converted into bilirubin in the blood 4. Bilirubin in the blood goes to liver 5. Liver secretes bilirubin into bile 6. Bile goes to LI where bacteria convert bile into urobilinogen

a. Goes back to blood as urobilin (yellow pigment) and is reoved by kidneys b. sterobilin (brown pigment feces)

Ex. Neonatal due to immature liver, blue wavelengths of light breaks it up Ex. Hepatitis: liver infected Ex. Alcohol: liver destruction Cord Blood: http://www.youtube.com/user/cordbloodregistry?v=96DItviGvKI