You are thrown from a bicycle while riding at speed on a gravelroad. Immediately you start bleeding from several places where thegravel cut through your epidermis into your dermis and brokenumerous blood vessels.

Your body's first response to this injury is to beginthe process known as [a]. This process has threesteps.

1. [b]: the [e] in the tunicamedia of your damaged blood vessels begins to contract,[f] blood flow to this portion of vessel, in anattempt to limit blood loss. Also, the [f1] ofyour tunica interna become \"sticky\" in an effort to help kick offthe next step...
2. [c]: [g] circulating in yourblood are attracted to exposed [h] and to the[f2] that became \"sticky\" at the end of step one.They begin to form a [i] and also begin toactivate more cells of the same type to join them.
3. [d]: [q] factor (factor[1]) is released by damaged extravascular tissue.Together with the mineral [j], this factoractivates factor [2], completing the[k] pathway. This factor activates factor[3], beginning the [l] pathway.Next, factor [4] is activated, then factor[5], known as [m]. This lastfactor initiates a [n] feedback cycle, activatingmore of itself as well as activating factor [6],known as [o1], a meshwork of which begins to formthe actual [p1]. Finally, factor[7] is activated to strengthen the clot and beginits retraction. Blood cells of various sorts get caught in the[o2] mesh and help to solidify the[p2], stopping blood loss until the endothelialcells and rebuild the vessel lining.

WORD BANK:

• clot

• positive

• endothelial cells

• intrinsic

• platelet activation

• collagen fibers

• fibrin

• inflammation

• reducing

• extrinsic

• hemostasis

• coagulation

• tissue

• smooth muscle

• leukocytes

• vascular spasm

• calcium

• hemopoiesis

• thrombin

• common

• increasing

• magnesium

• thrombocytes

• negative

• plug

• I

• II

• III

• IV

• V

• VII

• IX

• X

• XI

• XIII