Blood vessels Flashcards
(115 cards)
Define Arteries:
Conduct blood from heart to body organs.
Define Arterioles:
Medium calibre arteries branching into smaller ones.
Define Capillaries:
Small calibre vessels connecting arteries with veins at the tissue level.
Define Venules:
Several capillaries come together into small and medium venules.
Define Veins:
Larger vessels that conduct blood from body organs to the heart.
State the different functional classification of blood vessels: (5)
- conduction
- distribution
- Resistance
- Interchange
- Volume and return
What`s Conduction?
Larger vessels that conduct blood from body organs to the heart.
What`s distribution? (3)
- Medium calibre arteries.
- Smooth muscle tissue predominates in their wall.
- Regulation of regional distribution of blood flow.
What’s resistance regarding functional classification? (4)
- Smaller arteries or arterioles.
- Smooth muscle tissue predominates in their wall.
- Regulation of local circulation.
- Peripheral resistance depends on them.
Whats`s Interchange?
- Capillaries
* Exchange of substances between tissues and blood.
What’s volume and return?
- Veins
* Return blood to the heart.
When do we speak about Macrocirculation? What diameter and which vessels are included?
Vessels with a diameter >0.1 mm
- Large arterioles
- Muscular and elastic arteries
- Muscular veins
When do we speak about Microcirculation and what Vessels are included?
- Arterioles
- Capillaries
- Postcapillary venules
State the different layers of a blood vessel: (important)
- tunica interna (intima)
- tunica media
- tunica externa or adventitia
What does the tunica internal (intima) contain? What Histology features? (important)
- inner lining of vessels
- Composed of:
- Endothelium (weich) (squamous epithelium) faces the lumen
- Basement membrane: collagen fibres (zum Schutz, zum kräftigen)
- Subendothelium (um mit dem Rest zu connected) (connective tissue, few muscle fibres).
Function of internal elastic lamina, where present and what fibres are present? (4)
(important)
➢ Separates tunica intima and media.
➢ With fibres of elastin (single or few layer). Perforated (for the diffusion of molecules).
➢ Present in arteries and arterioles.
What layer is responsible for vasoconstriction and dilation?
Tunica Media
What does the tunica media contain? (important)
➢ It is the most variable of all layers.
➢ Composed of:
• Smooth muscle fibres circularly arranged (ANS control)
• Connective tissue in variable proportion: elastic, reticular
fibres, proteoglycans, and glycoproteins.
Which layer is the most variable?
Tunica media
What contains the external elastic lamina? (3)
➢ Separates tunica media and adventitia.
➢ With fibres of elastin (variable number of rows)
➢ Present only in muscular and elastic arteries.
What layer separates tunica media and adventitia?
External elastic lamina
Which vessel present the external elastic lamina?
only in muscular and elastic arteries
What tissue does the tunica external contain?
dense irregular connective tissue, longitudinally orientaded
What does the tunica externa compose? (4)
Composed of: • Collagen fibres (type I). • Elastic fibres. • Nerves (nervi vascularis). • Vasa vasorum (vessels supplying blood to vessel walls)