10-3 Venous Drainage of Lower Limb Flashcards
What serves as the boundary between superficial and deep veins?
The deep fascia
- Superficial veins are in the superficial fascia and follow cutaneous nerve branches
- Deep veins cannot be palpated and follow arteries
True or false:
Only deep veins have valves.
False, both deep and superficial veins have valves– deep vein tend just tend to have more.
What type of veins link the superficial to deep venous systems?
Communicating or perforating veins.
What is the term for two or more veins that accompany an artery?
Venae comitantes
What are the relationship benefits to venae comitantes?
- countercurrent heat exchange
- arteriovenous pump
What major arteries do not have venae comitantes?
- Femoral
- Deep femoral
- Popliteal
How does the musculovenous pump aid in conveying blood from superficial to deep veins?
Think in general, not specifically the foot
Muscles contraction provides pressure on the veins (remember, due to the presence of deep fascia, there is limited room for expansion of the muscles) that with the venous valves, keep the blood from flowing backwards from the deep to the superficial system.
What are the components of the dorsal venous system of the foot?
Superficial system:
- starts with dorsal digital veins
- ends with great & small saphenous veins
Deep system:
- veins accompanying the dorsalis pedis & its branches
What are the components of the plantar venous system?
Superficial system:
- extremely superficial, intradermal/subdermal mesh
- joins the dorsal system on the medial and lateral borders of the foot
Deep system
- veins accompany the medial and lateral plantar arteries and their branches
What is unique about the venous system in the foot?
Most of the perforating veins (that connect the deep venous system to the superficial system) in the foot do not have valves.
This means that blood can flow bi-directionally on its way up the leg towards the heart.
When the valves are present in these pedal perforating veins, blood travels from deep to superficial on its way up the leg. This is the opposite in the leg and thigh, where blood flows from superficial to deep.
What is the name of the condition when incompetent venous valves cause retrograde blood flow and distended/tortuous superficial veins (generally in leg/thigh)?
Varicose veins
What is a thrombosis?
The formation of a blood clot within a vessel
What is a potentially fatal complication of a DVT (deep vein thrombosis)?
Pulmonary embolism–> when the thrombosis in the leg breaks free and travels to the lungs
