Lecture 6 Arteries & Veins Flashcards
The pathway of supply arteries (6 diaphragm to sole of foot)
Common Iliac Artery
External Iliac Artery
Femoral Artery
Popliteal Artery
Posterior Tibial Artery
Plantar Arch
Drainage channel to heart
The pathway of drainage veins (6 foot to diaphragm)
alt pathway
Plantar venous arch
Posterior tibial vein
Popliteal vein
(Great saphenous vein)
Femoral vein
External Iliac vein
Common Iliac vein
Inferior vena cava
Great saphenous vein
longest vein in body, harvest for coronary artery bypass graft
Runs along superficial compartment
As it comes towards the trunk it joins up to the femoral vein
Blood vessels have a three layered wall
Tunica (layer) Intima
Tunica (layer) Media
Tunica (layer) Adventitia (Externa)
Tunica Intima consists of
Endothelium - A simple squamous epithelium which lines the lumen of all vessels.
Sub-endothelium - A sparse pad of loose FCT cushioning the endothelium.
Internal Elastic Lamina (IEL)- a condensed sheet of elastic tissue. The IEL is well developed in arteries and less developed in veins.
Endothelium
A simple squamous epithelium which lines the lumen of all vessels.
eg heart chambers, valves, capillary, artery, veins.
Really thin non stick surface prevents clots.
part of tunica intima.
Sub-endothelium
A sparse pad of loose FCT cushioning the endothelium.
part of tunica intima
Internal Elastic Lamina (IEL)-
a condensed sheet of elastic tissue. The IEL is well developed in arteries and less developed in veins.
part of tunica intima
Tunica Media consists of
Smooth muscle (involuntary, non striated, in blood vessels)
connective tissue fibres - Elastin and collagen.
Thickness proportional to both vessel diameter and blood pressure.
Thicker (artery) higher pressure
Thinner (vein) lower pressure
Tunica Adventitia (Externa)
Loose FCT - high content of collagen and variable amount of elastin.
In larger vessels, has vasa vasorum (smaller vessels).
Lymphatics and autonomic nerves.
Thoracic Aorta (known as, consists of)
elastic artery
Elastic throughout Tunica media
IEL
Rubbery elastic pipe
Femoral artery (known as, consists of)
Muscular artery
Dominated by smooth muscle not a lot of elastic in tunica media
IEL
Arteriole
small arteries,
Resistance vessels of circulation determine blood pressure.
Capillaries
Site of exchange between blood and tissues.
Venules
start of the drainage system (collects)
Veins Functions
Low pressure, large volume transport system
One-way (unidirectional) flow
Capacitance vessels
Veins Histological Structure
Irregular, flattened shape with large lumen & thin wall.
Veins 3 layers
Intima
Media -Much thinner than arteries - a few layers of smooth muscle (often in two distinct layers).
Adventitia -Often the thickest layer of a vein.
Tunica intima made up of
Endothelium
Sub endothelium
Internal elastic lamina (IEL)
Endothelium
- makes up Tunica Intima
- A simple squamous epithelium which lines the lumen of all vessels. Eg heart chambers, heart valves, capillary, artery, veins.
- Really thin, non stick surface prevents clots
Sub-endothelium
- makes up Tunica Intima
- A sparse pad of loose FCT. cushioning the endothelium.
Internal Elastic Lamina (IEL)
- makes up Tunica Intima
- a condensed sheet of elastic tissue.
- well developed in arteries and less in veins.
Capacitance vessels
Have spare capacity
can take up extra blood volume
neurovascular bundle
artery
veins
nerves
Vascular bundle
Artery
vein
what happens to veins when skeletal muscle contracts?
Skeletal muscles squeezes on veins and pushed blood to the heart only as valves are pushed open. Unable to go back to feet because leaflets close to prevent backflow.
Calf muscle pump
upright posture
what veins are between skeletal muscles?
Deep vein
Varicose veins
- distend, wider, more dilated
- valve leaflets don’t get longer
- Leaflets unable to come back together to form a seal and blood will fall back down due to gravity.
