Hemostasis Pathology Study Guide

Hemostasis

The body’s natural response to an injury that stops the bleeding and fixes the damage is known as hemostasis.

Blood must be able to flow freely through blood vessels in order to reach tissues.

Hemostasis, which involves the creation of a thrombus (clot) at the site of vascular injury, repairs damage to the wall.

There are two phases of hemostasis:

Hemostasis. Aggregation of thrombocytes (platelets). Platelet-rich human blood plasma (left vial) is a turbid liquid. Upon addition of ADP, platelets are activated and start to aggregate, forming white flakes (right). Dietzel65, Steffen Dietzel. Not altered. CC BY-SA 3.0

Primary hemostasis forms a platelet plug.

Primary hemostasis is caused by interactions between:

The clot in the esophagus at the site of the primary hemostasis. Combined use of clips and nylon snare ("tulip-bundle") as a rescue endoscopic bleeding control in a mallory-weiss syndrome. Ivekovic H, Radulovic B, Jankovic S, Markos P, Rustemovic N - Case reports in gastrointestinal medicine (2014). Not Altered. CC.
Primary Hemostasis. The classical blood coagulation pathway. Dr Graham Beards. Not altered. CC BY-SA 3.0
Primary Hemostasis. Modern coagulation pathway. Hand-drawn composite from similar drawings presented by Professor Dzung Le, MD, PhD, at UCSD Clinical Chemistry conferences on 14 and 21 October 2014. Original schema from Introduction to Hematology by Samuel I. Rapaport. 2nd edition;Lippencott:1987. Dr Le added the factor XI portion based on a paper from about year 2000. Dr. Le's similar drawings presented the development of this cascade over 6 frames, like a comic. Niels Olson . Not altered. CC BY-SA 4.0
Primary Hemostasis. Blood coagulation pathways in vivo. Dr Graham Beards. Not altered.CC BY-SA 3.0

Secondary hemostasis stabilizes the platelet plug.

Secondary hemostasis is mediated by the coagulation cascade.

Secondary Hemostasis. Not altered. CC
Secondary Hemostasis. Coagulation with arrows for negative and positive feedback. Joe D. Not altered. CC BY-SA 3.0
Platelet interactions in hemostasis and corresponding platelet-inspired design of PLN technology. Schematic showing normal hemostatic interactions that inspire PLN design. Platelet-like nanoparticles: mimicking shape, flexibility, and surface biology of platelets to target vascular injuries. Anselmo AC, Modery-Pawlowski CL, Menegatti S, Kumar S, Vogus DR, Tian LL, Chen M, Squires TM, Sen Gupta A, Mitragotri S - ACS nano (2014). Not Altered. CC.