Vascular biology II Flashcards
What are the three types of capillaries?
- Continuous2. Fenestrated3. Sinusoidal
What type of junctional complexes do continuous capillaries have?
Tight junctions (complete or incomplete)
What are the main characteristics of continuous capillaries?
- Tight junctions2. Lack pores or fenestrae3. Numerous pinocytotic vesicles4. Well-developed basal lamina
Where are continuous capillaries found?
- Brain2. Muscle3. Connective tissue4. Exocrine glands
What are the characteristics of fenestrated capillaries?
- Fenestrae / pores2. Pores closed by thin diaphragm3. Continuous basal lamina
Where are fenestrated capillaries found?
Areas of rapid exchange:1. Kidney, nonglomerular2. Endocrine glands3. Intestines4. Kidney, glomerulus - diaphragms absent
What are the characteristics of sinusoidal capillaries?
- Discontinuous endothelial lining - large openings2. Discontinuous or absent basal lamina3. Macrophages present
Where are sinusoidal capillaries found?
Areas of rapid exchange where cells can be exchanged: 1. Red bone marrow2. Liver3. Spleen4. Adrenal cortex
Which veins possess longitudinal bundles of smooth muscle in the adventitia?
IVC, SVC, brachiocephalic, renal, iliac
Vasculogenesis: definition
De novo vessel formation
De novo vessel formation
Vasculogenesis
Angiogenesis: definition
Growth from pre-existing EC-derived channels
Growth from pre-existing EC-derived channels
Angiogenesis
Arteriogenesis: definition
Formation of arteries, arterioles and collateral vessel remodeling
Formation of arteries, arterioles and collateral vessel remodeling
Arteriogenesis
Neovascularization: definition
Overarching term to include vasculogenesis, angiogenesis, and arteriogenesis
Overarching term to include vasculogenesis, angiogenesis, and arteriogenesis
Neovascularization
Vascular remodeling: definition
Vascular response to alterations in the environment
Vascular response to alterations in the environment
Vascular remodeling
What are the two mechanisms of blood vessel formation?
- From endothelial precursor cells2. From pre-existing vessels
Where do EPCs reside?
Red bone marrow of adults and non-bone marrow niches
What are the functions of the EPC mechanism for vessel formation?
- Replace lost endothelial cells2. Re-endothelialization of vascular implants3. Neovascularization of ischemic organs, wounds, and tumors
What are the steps for vessel formation from pre-existing vessels?
- Vasodilation (via NO) and increased permeability (via VEGF)2. Proteolytic degradation of basal lamina (via MMPs)3. Loss of intercellular junctions (via plasminogen activator)4. Migration and proliferation of endothelial cells (via VEGF, ANG-2)5. Endothelial cells mature into endothelial capillary tube6. Elaboration of basal lamina (via FGF) and recruitment of periendothelial cells
What protein do tumor endothelial cells express?
Tumor endothelial marker 8 (TEM8)
