Peripheral Vasculature of the Limbs

Question 1

How much of the blood volume is in the arterial and venous systems?

Answer 1

o 20% in arteries

o 80% in veins (large diameter and ability to expand)

Question 2

What forms the start of the upper limb vasculature?

Answer 2

Aortic arch

Question 3

What is the axillary artery?

Answer 3

• Continuation of subclavian arteries
  o Starts at lateral border of 1st rib
  o Ends at lateral border of teres major (muscle)
  o Runs through axilla (armpit)
• Branches to chest wall, and shoulder girdle
  o Humeral circumflex

Question 4

What is the brachial artery?

Answer 4

• Continuation of the axillary artery
  o Ends roughly 1cm below elbow
• One major branch:
  o Profunda brachii (deep artery of the arm) runs down posterior side supplies triceps
  o Brachial a. runs superficial on anterior side

Question 5

How is the brachial pulse taken?

Answer 5

• Medial to distal tendon of biceps brachii
• Place two fingers over the bend in the elbow on the medial side pushing gently laterally (cubital fossa) and feel the pulse under your fingers.

Question 6

Where are the ulnar and radial arteries?

Answer 6

• Ulnar a. runs down medial aspect of forearm supplies medial muscles of forearm
• One branch:
  o Common interosseous supplies deep flexors and extensors of forearm
• Radial runs down lateral aspect of the forearm
• Supplies the lateral muscles of forearm

Question 7

What are the palmar arches?

Answer 7

• Superficial and deep palmar arches
  o branches of both radial and ulnar arteries
• Superficial arch mainly from ulnar artery
• Deep arch mainly from radial artery
• Metacarpal and digital arteries arise from arches and supply the fingers

Question 8

Where are the radial and ulnar pulses found?

Answer 8

-	Radial
o	Lateral to tendon of FCR
-	Ulnar
o	Lateral to tendon of FCU
o	More difficult to palpate because it runs deeper and lies under the pisiform and the palmar fascia

Question 9

What is the Allen test and what is it used for?

Answer 9

• 42% of people may have a non arch palmar supply of some type
• Determines patency of radial and ulnar arteries.
• Step 1 the hand is exsanguinated by making a fist and digital pressure on both radial and ulnar arteries at the distal end of forearm
• Step 2 patient opens hand (hand should be pale) pressure released of either radial or ulnar arteries individually and capillary refill of entire hand indicates patent artery and palmar arches
• Normal filling time <5 seconds

Question 10

What happens in venous return in the upper limb?

Answer 10

• Deep and superficial venous drainage
• Deep veins take the same name as the arteries
• 2 superficial veins start from dorsal venous network
  o Basilic vein
  o Cephalic vein
• Median cubital v. across cubital fossa most common vein for venipuncture
• Basilic and cephalic plus deep veins drain into axillary vein
• Axillary vein becomes subclavian vein
• Subclavian veins drain into brachiocephalic veins then into superior vena cava to heart
• Basilic = towards the base
• Cephalic = towards the head
• Median cubital = joins cephalic and basilic

Question 11

How can doppler ultrasound show phasic variations in amplitufe in the vessels?

Answer 11

• Doppler shows phasic variations in amplitude
  o Right atria reflects back into vessels
   Cardiac pulsatility
  o Respiratory pump
   Increased flow with inspiration and decreased flow with expiration
• Upper extremity shows larger pulsatility because of closeness to the heart

Question 12

Which vessels are between the descending aorta and the femoral artery?

Answer 12

• Abdominal aorta ends at L4, dividing into common iliac arteries
• At level of sacroiliac joints common iliac arteries divide into 2 branches
  o S1
• Internal iliac artery
  o Supplies pelvic walls and pelvic viscera
  o Gluteal region
• External iliac artery
  o Supplies lower limbs

Question 13

What is the internal iliac artery?

Answer 13

• Superior and inferior gluteal arteries supply the gluteal muscles
• Obturator artery
• Posterior and anterior divisions
  o Posterior = superior gluteal artery (largest branch of internal iliac)
  o Anterior = obturator and inferior gluteal arteries

Question 14

What is the obturator artery?

Answer 14

• Obturator artery passes through obturator foramen

o Acetabular branch supplies the hip joint.

Question 15

What is the femoral artery?

Answer 15

• Continuation of external iliac artery as it passes under the inguinal ligament.
• Passes down anteromedial thigh giving off several branches

Question 16

Where can the femoral pulse be found?

Answer 16

• Below inguinal ligament and mid-inguinal point

o Half-way between pubic symphysis and anterior superior iliac spine

Question 17

What is the deep inguinal ring?

Answer 17

• Deep inguinal ring is a hole in transversalis fascia lying 3cm superior to mid point of inguinal ligament, indirect hernias are loops of intestines that push through the deep ring down the inguinal canal and out into the scrotum via the superficial ring.
• In life the vas deferens passes through this structure
• Direct hernias are medial to this point.

Question 18

What is the profunda femoris?

Answer 18

• Profunda femoris
  o Deep artery of the thigh
  o Main arterial supply to the thigh muscles (quadriceps, hamstrings and adductors)
• From profunda femoris arise the lateral and medial circumflex arteries
  o The circumflex arteries supply the neck and head of the femur
• Lateral circumflex
  o Heads laterally and passes anteriorly around neck of femur
• Medial circumflex
  o Initially goes medially then passes posteriorly around neck of femur
• They anastomose (join)

Question 19

What is the popliteal artery?

Answer 19

• Close to knee the femoral artery passes through a gap in the tendon of adductor magnus
  o Adductor hiatus
• Enters the popliteal fossa (back of the knee)
• Changes its name to popliteal artery
• A continuation of the femoral artery
• Contributes to the anastomosis that supplies the knee region
• It will split into
  o Anterior tibial artery
  o Posterior tibial artery

Question 20

How can you find the popliteal pulse?

Answer 20

• Difficult to find as deep in popliteal fossa
  o Person supine with knee flexed to relax the popliteal fascia and hamstrings
  o Pulsations are best felt in the inferior part of the fossa where the popliteal artery is closer to the tibia

Question 21

What is the anterior tibial artery?

Answer 21

• Runs through anterior compartment of the leg

- Supplies the dorsiflexors and extensors of the ankle and foot

Question 22

What is the dorsalis pedis artery?

Answer 22

• Continuation of anterior tibial artery distal to inferior extensor retinaculum
• Supplies dorsum of foot giving off branches to the arcuate artery from which the metatarsal arteries arise

Question 23

What is the posterior tibial artery?

Answer 23

• Larger of the two arteries from popliteal artery
• Passes down the posteromedial side of the leg.
• Fibular or peroneal artery is deeper branch from posterior tibial artery
• Both supply the posterior (plantarflexors) and lateral muscles of the leg

Question 24

How do you find the two distal pulses of the leg/foot?

Answer 24

• Dorsalis pedis
  o Lateral to tendon of extensor hallucis longus
• Posterior tibial
  o Half-way between medial malleolus and calcaneal tendon

Question 25

What are the lateral and medial plantar arteries?

Answer 25

• Posterior tibial a. divides at the ankle:
  o Lateral plantar
  o Medial plantar
• Supply the plantar surface of the foot (sole)
• Lateral plantar forms lateral end of plantar arch from which the digital arteries arise

Question 26

What happens in venous return in the lower limb?

Answer 26

• Deep and superficial veins
• Deep veins run within the fascia and take the name of the artery they run with e.g. popliteal, femoral etc.
• Superficial veins run outside of fascia 2 main veins
  o Small saphenous
  o Great saphenous
• Small saphenous drains into popliteal v. at the knee
• Great saphenous longest vein in body
• Drains into femoral vein just distal to the inguinal ligament
• Superficial veins have numerous perforating veins that connect with the deep veins
• Valves only allow blood to flow from superficial to deep

Question 27

How is venous return in the lower limb controlled against gravity?

Answer 27

-	Control of Venous Return:
o	Movement from superficial to deep veins
o	Respiratory pump
o	Muscular pump
o	Smooth muscle (venoconstriction)
o	Valves

Question 28

What happens in venous stasis and varicose veins?

Answer 28

-	Chronic venous insufficiency (CVI)
o	Strains walls of veins
	Varicose veins
	Itching
	Hyperpigmentation
	Chronic swelling (oedema)
	Varicose eczema (stasis dermatitis)
	Venous ulceration
o	Improved by treatment of the superficial venous system

Question 29

What is peripheral vascular (arterial) disease and what is its pathology?

Answer 29

• Occlusive disease of the arteries of the lower extremities
• Most common cause
  o Atherosclerosis, arteritis, aneurysm and embolism
• Pathophysiology
  o Arterial narrowing = decreased blood flow = pain
  o Pain results from an imbalance between supply and demand

Question 30

How may thrombosis (clots) show up on angiograms?

Answer 30

Dark space in part of blood vessel