5 - Structure & Function of Blood Vessels Flashcards
Describe the structure of a blood vessel:
Lumen, Tunica Intima, Tunica Media, Tunica Adventitia/externa
Inwards —> Outwards
Features of the Tunica Intima?
- Endothelium – simple squamous epithelium
- Basal lamina (scaffold that anchors epithelial,
muscle, and nerve cells) of epithelial cells - Subendothelial connective tissue
Features of the Tunica Media?
- Smooth muscle fibres in loose connective tissue
- May contain elastic fibres
Features of the Tunica Externa?
- Connective tissue
- Merges with surrounding connective tissue
- May contain Vaso-vasorum
- Vaso Vasorum: small blood vessels comprising vascular network supplying walls of large blood vessels/// deliver nutrients & oxygen to arterial and venous walls & remove “waste”
What are the 3 types of arteries?
Elastic, Muscular, Arterioles
Function & structure of Elastic (conducting) arteries?
Function:
Withstand changes in press. during cardiac cycle (ensure continuous blood flow)
Structure:
Thick tunica media w/ many elastic fibres, few smooth muscle cells
Function & structure of Muscular (distributing) arteries?
Function:
-Distribute blood to muscles & organs
-Capable of vasodilation/vasoconstriction to control rate of blood flow, based on needs of organ
Structure:
-Smooth muscle cells in tunica media
-Distinct internal (IEL) & external (EEL) elastic laminae
-Thick tunica externa
Function & structure of Arterioles (Resistance Vessels?
Function:
-Capable of vasoconstriction/vasodilation
-Control blood flow to organs
-Involved in blood pressure control
Structure:
-1-2 layers of smooth muscle cells in tunica media
-Poorly defined tunica externa
What are the 3 types of capillaries?
Continuous, Fenestrated, Sinusodial
What are metarterioles?
Arterioles which supply the capillary bed
What is the Arteriovenous anastomosis?
- Form direct path between arteriole & venule
- When dilated, blood bypasses capillary bed &
flows directly to venous circulation
