• Tunica Intima: Endothelium(simple squamous epithelial) and Subendothelial Connective Tissue.
• Tunica Media: Vascular Smooth Muscle
• Tunica Adventitia or Cerosa: Fibroelastic Connective Tissue.

Advetitia: Dense connective tissue grading to loose. Anchors it.

Cerosa: Covered by a single layer of simple mesothelium. Helps two different surfaces glide over each other.

Endothelial cells rolled into a tube and surrounded by basal lamina.

Attched by junctional complexes.

• Convert Angiotensin I to Angiotensin II: Mainly in lungs. Enhances arterial smooth muscle contraction. Reduce diameter of blood vessel. Increases blood pressure.
• Inactivate bioactive compounds to modulate blood flow. (Bradykinin, Serotonin, Prostaglandins, Norepinephrine, Thrombin.)
• Lypolysis: mobilize cholesterol & triglycerides for other cell functions.
• Prevent thrombosis formation by not letting endothelium get damaged.
• Capillary transport: exchange of nutrients, oxygen, & wastes between blood and tissue.

also called Adventitial Cells

• Cling to outer surface of capillary endothelium (scattered around)
• Enclosed in endothelial basal lamina
• Contract to reduce blood flow
• Attenuate(shrink processes) to enhance permeability between tissue and lumen.
• Functions as mesenchymal stem cells.

• Continuous
• Fenestrated
• Discontinuous/Sinusiods

• most common; (esp Nerve, Muscle)
• Complete basil lamina(outside)
• Continuous endothelial lining (inside)
• Micropinocytotic vessels within endothelial lining regulate movement

• complete basal lamina (outside)
• fenestrated endothelial lining (inside)
• The pores may be open or covered by thin Diaphrams that limit the size of macromolecules.

• Incomplete basil lamina (outside)
• Fenestrated endothelia lining (inside)
• Sometimes lets cells through
• Large openings
• Liver, Bone Marrow, Endocrine glands, Spleen.

• Micropinocytosis(vesicles)
• Diffusion: through fenestrae or whole in edothelium
• Diapedesis: leukocytes pass from blood into tissue. Can happen through wholes in endothelium or intercellular junctions.

New blood cell growing from a pre-existing one.

• Tissue Hypoxia: Not enough Oxygen so the vessels expand to try and increase surface area.
• Vascular Endothelial Growth Factor (VEGF)
• Fibroblasts Growth Factor (FGF's)
• Interleikin-8 (IL-8)

Potential approaches to stopping vascularation of tumors.

• Thrombospondin
• Tumor Necrosis Factor (TNF)
• Tissue Inhibitors of Metalloproteinases (TIMPs)

What are the different Artery sizes?

• Large Elastic Arteries
• Muscular(medium) Arteries
• Arterioles
• Metarterioles

• Located at the Aorta
• Very thick Media that is filled with elastin.
• Responsible for Diastolic blood pressure. Must remain at a certain level or there will be problems.

• The Tunica Media has a layer of internal and external Elactic Lamina. This cause it to look ruffled.

• Tunica Intima has some endothelial cells on it.
• Tunica Media(smooth muscle area) is 1-5 layers thick.

• Located at the base of the capillary where it meets the shunt.
• Some endothelial cells on the inside.
• Has discontinuous layer of smooth muscle around it.
• Regulates blood flow through capillary beds.

• Large
• Medium/Small
• Venules

How does blood move through veins?

Skeletal muscle helps move it.

Valves stop it from going backwards.

Vasa vasorum: "vessels of the vessels". Vascular supply to vessel walls.

Vasomotor(sympathetic) fiber: Unmyelinated. Lead to smooth muscle contractions.

Sensory: can sense how much their being stretched. Myelinated in Adventitia.  Can lose myelin and penetrate Media and Intima as "free nerve endings".

• Blind-ending
• Sinosoidal/Discontinuous

Collected at capillary beds.

Droped off at right lyphatic duct and thoracic duct.

Elephantiasis

• Blockage of lymph flow by Lymphatic Filariasis
• Filaria parasitic infection.