Microvascular Physiology Flashcards
What is vascular morphogenesis?
Vascular remodeling
Does vascular remodeling occur physiologically throughout a person’s life?
Yeah
Can vascular morphogenesis be pathologic?
Yeah
What is the difference between angiogenesis and vasculogenesis?
Angiogenesis is the formation/budding of new blood vessels from preexisting vasculature, whereas vasculogenesis is de novo blood vessel formation from angioblastic precursor cells.
During vasculogenesis, a _______ microvessel is first formed, after which _______ cells are recruited, forming a stable vessel.
unstable microvessel forms first, then mural cells are recruited, forming a stable vessel.
Are endothelial cells heterogeneic?
Yeah!
Name the ten steps in microvascular maturation/remodeling.
- GF (VEGF) production/release by vascular and non-vascular associating cells.
- Endothelial cell activation.
- Changes in microvascular permeability.
- ECM remodeling.
- Pericyte recruitment.
- Endothelial cell migration.
- Cell proliferation/division.
- Lumen formation.
- Initiation of blood flow.
- Sprouting/angiogenesis.
How does lumen formation occur?
Dunno!
Does blood flow only once a lumen is formed?
Yeah
Research has shown that primary tumors _____ the growth of secondary metastases.
inhibit
What is a cryptic angiogenesis inhibitor? Name two examples.
The angiogenic inhibitors released by primary tumors. Examples are angiostatin (a cleavage product of plasminogen), and endostatin (a cleavage product of collagen 18).
How do tumor cells make angiostatin and endostatin?
They release a protease that cleaves plasminogen and collagen 18 to give rise to the angiogenesis inhibitors.
What are mural cells?
Supporting cells like pericytes and smooth muscle cells.
What three things can pericytes control?
Vascular permeability, growth, and contractility.
Amongst different vessel types, the pericyte : endothelial cell ratio is highly ______.
variable
Recruitment of ______ cells is largely responsible in stabilizing a newly formed microvessel.
mural
What does ischemia/hypoxic insult do to endothelial cells?
It triggers VEGF gene transcription, leading to VEGF protein production –> angiogenic response by endothelial cells.
Do most of us have unknown, dormant microscopic avascular lesions (avascular micrometastatic lesions) in our bodies?
Yeah
Mechanical deformation of an endothelial cell by a pericyte can push the endothelial cell out of quiescence and into the _______ cycle.
growth
In diabetic retinopathy there is increased _________ in the retina.
angiogenesis
Plantar ulcers in diabetics are largely due to _______ angiogenesis.
impaired
The ________ switch aids greatly in the generation of an invasive cancer from a microscopic, avascular tumor.
angiogenic
What is the difference between angiogenesis in diabetic retinopathy and age-related macular degeneration?
In diabetic retinopathy angiogenesis occurs in the retina, which hemorrhage, causing bind spots in the patient’s field of vision. In AMD, angiogenesis occurs in the choroid plexus behind the eye: endothelial cells invade though the sclera, through Bruch’s membrane, and disturb the macula –> loss of central field of vision.
