Vascular Tree Flashcards
What provides most of the size change in artery wall thickness?
Large tunica media
Contains a lot of elastin
What Innermost layer?
Factory produces proteins and receptors that serve as vascular processes and help the vessel respond to stimuli
What is the Vasa Vasorum?
Vessels that supplies the tunica of large vessels with nutrients and blood.
What is an anastamoses?
Where arteries communicate with each other
What is collateral circulation?
Expansion of anastomoses resulting in extensive network
Important, as one artery may become blocked, and this will allow for alternate circulation (although likely lower volumes)
What are the major vessels/veins within the groin, moving medial to lateral?
Lymph most medial Femoral Vein medial Femoral artery more lateral Femoral nerve more laterally (NAVL)
How does the femoral artery change as it moves distally?
Femoral -> moves posteriorly through adductor hiatus of adductus magnus forming the popliteal artery -> popliteal carries through popliteal fossa then bifurcates into the anterior tibial artery and the common trunk of the posterior tibial and peroneal arteries
What are the divisions of the femoral artery?
Popliteal Artery (divides into AT and PT)
Anterior Tibial Artery
Posterior Tibial Artery
Peroneal Artery (aka fibular)
How does the posterior tibial artery move throughout the foot?
Posterior tibial artery comes to medial angle and feeds plantar arch running along base (underneath) of metatarsals.
Gives rise to calcaneal, and medial/lateral plantar branches.
What does the pulse represent?
Palpable arterial pressure after each heartbeat
What are the main pulses we examine?
Carotid, brachial, radio/ulnar, femoral, posterior tibial (medial aspect of ankle), popliteal (above posterior knee), dorsal pedis
What are the upper limb pulses we can examine on ourselves?
Axillary (inferiorly on lateral wall of axilla)
Brachial (medial aspect of arm near elbow)
Radial
Ulnar
Carotid pulse
What is the ABPI
Ankle Brachial Pressure Index- checking for Peripheral Artery Disease
Comparison of blood pressure of upper and lower limbs.
Arms tend to be spared from impacts of atherosclerosis, which gives us a normal reference point for comparison
Normal >1
mild PAD 0.7-0.9
moderate 0.5- 0.7
severe PAD 0.3-0.5
Limb threat <0.3
What are exceptions to the Ankle Brachial Pressure Index test?
Calcified vessels don’t compress and can give false ABPI when looking to diagnose peripheral artery disease
What is Buerger’s test?
Differences in colour of limbs
Red feet can result due to loss of vasoconstrictive abilities because of ischemia. Vessels are in chronic vasodilated state, giving red appearance.
This should disappear when removing gravity (i.e. lift foot in Buerger’s test)
What pulse can be visualized on the abdomen?
Aorta
Palpated just above the belly button
If aneurism is present, swelling is typically observable- can palpate on either side to estimate size
Where is the iliac artery pulse typically found?
Iliac pulses are only typically felt if patient is very thin or if they are aneurismal
Found medial to ASIS
During palpation, where is the femoral artery typically found?
Femoral easily found in groin
Hard in obese patient, or weak patients. May need to use bony landmarks (pubic tubercle, and iliac spine help find ligament where vessel is just medial too)
How is the popliteal artery typically found?
Locate popliteal fossa, have patient relaxed with few degrees of flexion, apply pressure until pulsation is felt.
Can apply pressure using thumb at anterior knee to help
What signs are observed in patients with chronic lower limb ischemia
Skin is thin/shiny/scaly
May be dark red in colour, lack of hair, skin necrosis/gangrene, slow growing nails with ridges/weakness
Check for ulceration between toes and on heels
Colour changes (use Buerger’s test- should produce pallor if patient is ischemic- for patients of colour, look for swelling as colour change may not be notable)
Temp is not reliable
Is the brachial pulse present in all patients?
Brachial pulse is absent of 40% of people
What is atherosclerosis?
Calcification and plaque formation of vessel wall
Most common arterial disease
Elasticity loss
Increase in foam cells (macrophage) and fatty streaks
What are the major components of plaque?
Cells- macrophage foam cells,
ECM- collagen, elastin
How does atherosclerotic plaque form?
Begins in teenage years, fatty streak development ->
Stable angina, claudication, and PAD -> MI/unstable angina, stroke, critical limb
Steps:
1) endothelial dysfunction
2) formation of lipid layer or fatty streak within the intima
3) migration of leukocytes and smooth muscle cells into the vessel wall
4) foam cell formation
5) degradation of extracellular matrix
What is intermittent claudication?
Leg angina
Exertional leg pain, typically in calf, relieved by rest
Better outcomes in legs as opposed to systemic outcomes
What is endarterectomy?
Opening an artery to remove plaque/disease
What is an embolism?
Blockage of a blood vessel by solid, liquid, or gas that has moved to a distant location from its origin
