Arterial Circulatory System

Question 1

What are the small vessel capilliaries in the tunica adventitia called?

Answer 1

Vasa vasorum

Question 2

What do arterioles provide and how?

Answer 2

Provide resistance to blood flow by contraction of the smooth muscle.

Question 3

What are arterioles known as in the vascular system?

Answer 3

“Stopcocks”

Question 4

What arteries are considered “small and medium”?

Answer 4

All arteries except the aorta and its major branches.

Question 5

What are small and medium arteries composed of?

Answer 5

Both smooth muscle layers as well as elastic and fibrous tissue.

Question 6

What are large arteries composed of?

Answer 6

More elastic fibres and less smooth muscle cells than arterioles/smaller arteries/

Question 7

What branches of the aorta are considered large arteries?

Answer 7

1. Brachiocephalic
2. Common carotids
3. Subclavian
4. Common iliacs

Question 8

What arteries supply the brain?

Answer 8

1. Two internal carotid arteries

2. Two vertebral arteries

Question 9

What supplies the central nervous system with blood?

Answer 9

The great vessels coming off the aortic arch (brachiocephalic, left common carotid, left subclavian).

Question 10

What is another name for the innominate artery?

Answer 10

The brachiocephalic

Question 11

How does the innominate travel/divde and what does it divide into?

Answer 11

The innominate (brachiocephalic) travels superior and posterior from the aortic arch to the right side of the neck where is divides into the RCCA and the R subclavian.

Question 12

Where does the brachiocephalic artery divide?

Answer 12

At the upper border of the right sternoclavicular junction.

Question 13

How does the left CCA travel?

Answer 13

It ascends from the aortic arch and passes beneath the left sternoclavicular joint

Question 14

Do the CCA’s have any branches?

Answer 14

No

Question 15

Where does the CCA divide into the internal and external carotid arteries?

Answer 15

Where the vessel becomes enlarged (carotid bulb) at the upper border of the thyroid cartilage.

Question 16

Where do the ICA bifurcate?

Answer 16

Once they enter the cranium

Question 17

What do the ICA’s supply?

Answer 17

The anterior circulation of the cerebrum (brain).

Question 18

Do the ICA have branches?

Answer 18

Not until they enter the cranium

Question 19

What is the first branch of the ICA?

Answer 19

The ophthalmic artery

Question 20

What are the segments of the ICA from proximal to distal?

Answer 20

1. Cervical
2. Petrous (through bone)
3. Cavernous
4. Supraclinoid

Question 21

Where does the ophthalmic artery branch from the ICA?

Answer 21

At the carotid siphon

Question 22

What is the carotid siphon?

Answer 22

The cavernous and supraclinoid segments of the ICA

Question 23

What does the ICA bifurcate into?

Answer 23

In the cranium the ICA bifurcates into the middle cerebral artery and the anterior cerebral artery

Question 24

If the ICA becomes occluded how is collateral flow created?

Answer 24

The ophthalmic artery anastomoses with the 3 branches of the ECA.

Question 25

What 3 branches of the ECA can help with collateral flow in the event the ICA is occluded?

Answer 25

1. Supraorbital (over eye) 2. Frontal Artery (inner eye) 3. Nasal artery (medial bridge of nose)

Question 26

What does the nasal artery terminate as?

Answer 26

The angluar artery

Question 27

What other artery also terminates near the nasal/angular artery?

Answer 27

Facial artery

Question 28

What is the first branch of the ECA?

Answer 28

Superior thyroid

Question 29

When does the ECA provide flow to the brain?

Answer 29

In the event of an occlusion

Question 30

What ECA branches are most vital to collateral circulation?

Answer 30

1. Ophthalmic artery | 2. Arteries that interconnect between the muscular branches of the occipital and vertebral arteries

Question 31

What is the atlanto-occipital interspace?

Answer 31

Where C1 meet the skull and the vertebral arteries course into the subarachnoid space.

Question 32

Where do the vertebral arteries join and what do they form?

Answer 32

At the pontomedullary level to form the basilar artery

Question 33

What does the basilar artery contain?

Answer 33

4 branches that feed the pons and anterior ad posterior cerebellum

Question 34

What arteries join to form the circle of willis?

Answer 34

The cerebral branches of the internal carotid arteries and the vertebral arteries at the base of the brain

Question 35

What is the most important collateral circulation intercranially?

Answer 35

The circle of willis because it connects the anterior and posterior circulation

Question 36

What branch artery supplies most of the blood to the brain?

Answer 36

Anterior cerebral artery

Question 37

What is the most common congenital variation of the circle of willis out of how many?

Answer 37

Out of Nine Absence or hypoplasia of one of the communicating arteries is the most common

Question 38

How may an obstuction of an artery affect flow in collateral pathways?

Answer 38

1. Increase volume 2. Increase velocity 3. Reverse flow 4. Varying pulsatility

Question 39

What muscle does the subclavian artery pass posterior to?

Answer 39

The scalenus anterior muscle

Question 40

Where does the subclavian artery become the axillary?

Answer 40

As it passes the lateral border of the first rib

Question 41

What does the axillary artery become and where?

Answer 41

The axillary artery becomes the brachial artery at the lower border of the teres major muscle in the axilla

Question 42

What branch comes off the brachial artery?

Answer 42

The profunda brachii artery

Question 43

What does the brachial artery bifurcate into and where?

Answer 43

The radial and ulnar arteries at the antecubital fossa

Question 44

What is the most common variant of the upper extremity arteries?

Answer 44

Common origin of the brachiocephalic (innom) and the left common carotid

Question 45

What are other variants of the UE?

Answer 45

- High origin of the radial artery | - Duplicated brachial artery

Question 46

What are the rare but more common locations of stenosis in the UE?(5)

Answer 46

- Prox subclav - Innom - Distal subclav - Axillary - Brachial or branches

Question 47

Where do the External iliacs become the common iliacs?

Answer 47

Inguinal ligament

Question 48

What does the Common femoral bifurcate into and where?

Answer 48

Superficial femoral artery and the deep femoral (profunda) 4cm distal to the inguinal ligament

Question 49

What is another name for the adductors canal and where is it?

Answer 49

Hunters canal (distal thigh)

Question 50

What are the small branches off of the popliteal artery?

Answer 50

1. Gastocnemius 2. Medial and lateral superior genicular 3. Medual and lateral inferior genicular 4. Middle genicular

Question 51

What does the popliteal bifurcate into?

Answer 51

The tibioperoneal trunk and the anterior tibial artery

Question 52

How does the anterior tibial artery course?

Answer 52

Anterior and lateral between the tibia and fibula

Question 53

What does the anterior tibial artery become?

Answer 53

The dorsalis pedis artery when it travels across the dorsal side of the foot

Question 54

What does the dorsalis pedis artery bifurcate into?

Answer 54

The metetarsal arteries

Question 55

What does the tibioperoneal trunk bifurcate into?

Answer 55

Posterior tibial artery and the peroneal artery

Question 56

How does the posterior tibia travel?

Answer 56

Posterior to the medial malleolus

Question 57

How does the peroneal artery travel?

Answer 57

Down the middle of the calf

Question 58

What does the posterior tibial artery bifurcate into?

Answer 58

The medial plantar and lateral plantar arteries of the foot.

Question 59

What is the most common anatomic variant of the LE?

Answer 59

Hypoplasia/aplasia of the anterior tibial artery

Question 60

What is the most common collateral route of a unilateral CIA obstruction?

Answer 60

The contralateral iliac/femoral provides flow through the pelvic arteries (hypogastric/internal iliac = most common)

Question 61

What makes up the tunica intima?

Answer 61

Endothelial lining with connective tissue behind.

Question 62

What makes up the tunica media?

Answer 62

Smooth muscle cells arranged circularly around the vessel (thickest layer).

Question 63

What makes up the tunica adventitia?

Answer 63

Connective tissue, nerve fibres and vasa vasorum.

Question 64

What are the most common collateral routes for a distal AO or bilateral CIA obstruction? (3)

Answer 64

- Thoracic and abd wall arteries - Mesenteric arteries - Lumbar arteries

Question 65

What is the most common collateral route for an external iliac and CFA obstruction?

Answer 65

Ipsilateral pelvis and femoral artery branches

Question 66

What are the most common collateral routes for a deep femoral (profunda) obstruction? (3)

Answer 66

- Prox ipsilateral pelvic and femoral arteries - Distal SFA - Popliteal

Question 67

What are the most common collateral routes for a SFA or Pop obstruction? (2)

Answer 67

- Deep femoral branches | - Pop to trifurcation

Question 68

What are the most common collateral routes for a trifurcation (calf) obstruction? (2)

Answer 68

- Prox calf branches | - Distal peoneal branches to ATA and PTA