9 - Cutaneous Vasculature Flashcards
Blood vascular system is lined by a once-cell-thick layer of epithelium-like mesenchymal cells
Endothelium
The endothelium is supported by various mural cells, typically _____ in microvessels and _____ in larger caliber vessels
Pericytes
Smooth muscle cells
Superficial vascular plexus located
Just beneath the epidermal surface
Deep vascular plexus located
Above the boundary between the reticular dermis and the underlying subcutis
Layers of arterioles and venules
Intima
Media
Adventitia
Layers of capillaries and postcapillary venules
Monolayer of fenestrated endothelial cells sitting on a simple basement membrane
Fenestrae of dermal capillary endothelial cells are formed primarily by a protein called ______; used as a marker of microvascular endothelial cells
Plasmalemmal vesicle protein-1 (PV-1)
Y/N: Pericyte cells outnumber endothelial cells in skin microvessels.
No - endothelial cells outnumber pericyte cells
Principal cell responsible for maintaining blood fluidity, and may be altered when needed to actively promote clot formation
Endothelial cell
Key inhibitors of coagulation basally expresses by endothelial cells
Tissue factor pathway inhibitor
Thrombomodulin
Anticoagulant heparan sulfates
Prevents the dramatic increases of the enzymatic activity of factor VIIa on factors IX and X that is catalyzed by tissue factor
Tissue factor inhibitor
Redirects thrombin from cleaving and thereby converting fibrinogen to fibrin to target and activate protein C instead
Thrombomodulin
Activate antithrombin III to function as an inhibitor of thrombin and factor Xa
Anticoagulant heparan sulfates
Most transit takes place across this portion of the superficial vascular plexus
Capillaries
Tight junction are expressed in the
Arterioles and capillaries
The ______ lack tight junctions and express adherens junctions
Postcapillary venules
Vasodilators produced by endothelial cells
Nitric oxide
Prostacyclin
Vasoconstrictors produced by endothelial cells
Endothelin
Angiotensin-converting enzyme
(Vasodilation/Vasoconstriction) is normally dominant
Vasodilation
Skin blood flow
250-300 mL/min
(Nonglabrous/glabrous) skin is subject to reflex thermoregulation by the sympathetic nervous system
Nonglabrous