Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
Know
remaining cards
Save
0:01
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
Retries:
restart all cards
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Thrombocytes

202 - Lec 3: Thrombocytes

QuestionAnswer
Thrombopoiesis -Originate in the bone marrow -Endomitosis or Endoreduplication – nuclear division without cytoplasmic division (stays as once cell and it just keeps getting larger; goes through about 2-5 divisions; multinucleated)
Where is thrombopoietin produced? In the liver and kidney
Megakaryocyte Development Stages • Progenitor Cell • Megakaryoblasts • Promegakaryocyte • Mature Megakaryocyte • Productive Megakaryocyte
Thrombocyte Life Cycle • Individual platelets are fragmented and released into circulation • Remaining nucleus is destroyed by macrophages • Remain in circulation for 7-10 days • Platelets become less functional as they age
Where are platelets found in the body? -2/3rds of all platelets in the body are in circulation and the rest remain in the red pulp of the spleen - when animal is excited they release adrenalin which then contracts the spleen and the platelets are released into the blood stream
Platelet Morphology • Shape: Discoid, oval, slightly elongated • Size: Variable • Romanowsky Stains : Central cluster of azurophilic granules; Pale blue background
What is the main function of platelets? Hemostasis
What are other functions of platelets? o Inflammation: May initiate or contribute to the inflammatory response; Thrombospondin – causes bacteria to adhere to platelet during inflammation and infection o Wound repair: Release vasoactive substances o Tissue repair
Hemostasis Process Platelets are attracted & undergo shape change Platelet adhesion mediated by vWF TXA2 (thromboxane – released from damaged tissue) in combo with ADP recruit more platelets- form plug PF-3 activates the intrinsic coagulation system
Platelet Quantity • Dog or cat – 200-400,000 per microliter of blood • ~10-20 platelets/oil immersion (1,000x) filed • Spontaneous bleeding may occur at <20,000 platelets per microliter
What is Thrombocytosis? • Increased platelet count
What are the mechanisms for Thrombocytosis? o Essential thrombocythemia – overproduction of platelets o Secondary (reactive) thrombocytosis – the body is reacting to something – platelets are being made for a reason o Physiological thrombocytosis – caused by a physiological response
What is Thrombocytopenia? • Decreased platelet count (<100,000 per microliters of blood)
What are the mechanisms of Thrombocytopenia? o Decreased production o Accelerated removal – body/disease is using them faster than the body is producing them o Abnormal distribution – many diseases can cause this o Combination of above
What is Thrombocytopathia? • Decreased platelet function, not number
What are the mechanisms for Thrombocytopathia? o Acquired – happened during the animal’s life that interfered with the platelets function o Congenital – animal born with disease that interferes with platelet function
What are the clinical Signs of Thrombocytopenia and Thrombocytopathia? Bleeding from mucosal surfaces Melena (digested blood upper GI– black)/Hematochezia (fresh/frank blood lower GI) – blood in the stool Hematuria – blood in urine Epistaxis – nose bleed Cutaneous Ecchymoses – bruising Prolonged/excessive bleeding
Created by: jenn.messier11