Peripheral Veins

____________ are vessels that carry blood away from the heart and toward the tissues

arteries

A transition vessel between arteries and capillaries is formed by the ____________

meta-arteriole

__________ permeate the body organs and tissues and act as the vehicles for exchange of materials between blood and cells

capillaries

_______ convey blood from the tissues and toward the heart and act as volume conduits rather than pressure vessels

veins

Which characteristic of capillaries helps them serve as the vessels through which exchange of materials between cells and blood occurs?

extreme thinness

What characteristic of capillaries ensures a slow flow of blood through vessels, permitting time for exchanges to occur?

large surface area

What are venules?

small veins that drain the capillary beds

What are the 2 layers of tissue in venule walls?

endothelium and a surrounding layer of collagenous connective tissue

What is the name of the system of blood vessels that nourish the tissue in the walls of medium and large vessels?

vasa vasorum

What happens as blood flows into smaller arteries and arterioles?

the pulsatility declines

Where does the greatest volume of blood (70-80%) reside within circulation?

venous vasculature

Because they contain the greatest volume of blood, what are veins referred to as?

capacitance vessels

Which vessel layer contains the vasa vasorum?

tunica adventitia

How are the tunica adventitia and media in veins different than it in arteries?

they are considerably thinner and less strong

How is the tunica intima in veins different than it in arteries?

there are valves present

What direction do the valves in the perforating veins direct blood to?

superficial to deep systems only

What are the small sinuses in veins?

• a dilated area just cephalad to and surrounding the valve cusps

• aids in the function of valves by facilitating their closure

Where do venous thrombi tend to form?

in the valve sinuses because blood flow at the base of the valve cusp is relatively stagnant

Which veins contain more valves?

veins below the knee

What veins have no valves?

• SVC

• brachiocephalic

• vena cava

• common iliac vein

• 75% external iliac veins

What are deep veins?

veins that lie under both the skin and fascia and are surrounded by muscle in the extremities

What are the two exceptions in name for the deep vein/arteries similarities?

• internal jugular & common carotid

• vena cava & aorta

What are the two exceptions in number for the deep vein/arteries similarities?

• one brachiocephalic artery vs two brachiocephalic veins

• one infrapopliteal artery vs two or more infrapopliteal veins

Blood returning from the digital or finger veins empties into a venous network in the hand called the ____________

palmar arch

What do the deep and superficial palmar arch unite to form the beginning of?

radial and ulnar veins of the forearm

Where do the radial and ulnar veins unite to form the brachial vein?

just below the antecubital fossa

What vein do some anatomist consider to be the first of the true deep veins of the upper extremity because it has no superficial component?

brachial vein

On the right and left sides, the subclavian vein joins the internal jugular vein to form the ______________

brachiocephalic vein

On the left side, there is a brachiocephalic vein, but no ____________

brachiocephalic artery

What do the right and left brachiocephalic veins join to form?

superior vena cava

All blood supplied by the arterial system comes from the heart by way of the _______

aorta

All blood drained by the venous system returns to the heart by way of the _______

vena cava

Which of the vena cava is larger?

superior vena cava

What parts of the body does the superior vena cava receive blood from?

head, neck, thorax, and upper extremities

Where are the first of the exclusively deep veins of the lower extremities?

the ankle

Where do the posterior tibial veins originate?

from the foot veins behind the medial malleolus

What do the posterior tibial veins drain?

the plantar venous arch and superficial venous network of the foot

What is the distal landmark of the posterior tibial veins?

the area between the medial malleolus and Achilles tendon

The peroneal and posterior tibial veins join to form the ___________

tibioperoneal trunk and popliteal vein

The anterior tibial vein is a continuation of the ______________

dorsalis pedis vein

Large spindle shaped veins called the __________ collect the venous drainage from the soleus muscle and terminate in the posterior and peroneal veins

soleal sinusoids

What are the gastrocnemius veins?

• drain the gastrocnemius muscle

• empty into the popliteal veins

The popliteal artery first divides to form the anterior tibial artery and then the ____________

tibioperoneal trunk

In the arterial system, the tibioperoneal trunk divides to become the ___________

posterior tibial and peroneal arteries

The popliteal vein leaves the fossa and extends upward through _______

adductor (Hunter’s) canal

After passing through adductor (Hunter’s) canal, the popliteal vein becomes the __________

thigh femoral vein

What is another name for the internal iliac veins?

hypogastric veins

What is May Thurner syndrome?

compression of the left common iliac vein by the right common iliac artery

What are superficial veins?

veins located under the skin but above the fascia

The superficial veins that run along the lateral aspect of the arm are called the ____________

cephalic veins

The superficial veins that run along the medial aspect of the arm are called the ___________

basilic veins

The main trunk of the cephalic vein empties into the _________

subclavian vein

The main trunk of the basilic vein empties into the ________

axillary vein

The small saphenous network empties into the _________ usually at the middle portion of the popliteal fossa

popliteal vein

The great saphenous network connects with the deep venous system a few cm below the ___________

inguinal ligament

What is the longest vein in the body?

GSV

What is the superficial connection of the three ankle perforating veins that drains into the saphenous veins?

posterior arch vein

The confluence of the cephalad end of the GSV with the deep venous system is called the _________

SFJ

How do the walls of the saphenous veins differ from the walls of the deep veins?

they are stronger than those of the deep veins

What are the 4 main groups of perforator veins in the lower extremity?

• foot

• medial calf

• lateral calf

• thigh

What are the most important perforator veins?

direct medial calf perforators

What is the Hunterian perforator?

a constant perforator vein in the distal thigh that connects the femoral vein to the GSV

What is distendibility?

the ability of a blood vessel wall to expand and contract passively with changes in pressure

Veins are ______ more distensible than arteries

8x

Pulmonary arteries are _______ more distensible than systemic arteries

6x

Pressure driving blood back to the heart is about ________ mmHg

7

What is compliance of a vessel?

• opposite of its elastance

• if you keep increasing the volume of blood in the veins, their walls will become distended allowing for more blood to be accommodated

Veins which are abnormally compliant can be associated with ____________

edema

_________ are sometimes used to externally reduce compliance, and thus keep blood from pooling in the legs

pressure stockings

The pressure in the venous system is relatively _________

low

The pressure in the venules is _________ mmHg

15-20

The pressure in the right atrium is _______________ mmHg

0-6

In any position other than horizontal, ____________ plays a major role in determining the pressure within the veins

hydrostatic pressure

What is hydrostatic pressure due to?

the weight of the column of blood within the vessel

What is hydrostatic pressure equal to?

density of blood x acceleration due to gravity x height of column of blood

When supine, hydrostatic pressure is negligible and the pressure will approximate the ____________

dynamic pressure

Because veins are collapsible tubes, their shape is determined by _____________

transmural pressure

What is transmural pressure equal to?

the difference between the pressure within a vein and the tissue pressure

When is transmural pressure low?

when the patient is supine

At low transmural pressures (supine), a vein will assume a __________ shape

dumbbell

As transmural pressure within a vein increases, the shape of the vein will become ___________

elliptical

At high transmural pressures (standing), the shape of the vein will become ________

circular

Because of the proximity to the heart, which veins are pulsatile?

• internal jugular

• subclavian

• sometimes axillary

All deep veins normally exhibit ___________, even those that are somewhat pulsatile

phasicity

During inspiration, the thoracic cavity ___________ and the abdominal cavity _________

expands; contracts

During expiration, the thoracic cavity _________ and the abdominal cavity ___________

contracts; expands

What is the result of inspiration?

• collapse of the IVC

• decreased/no flow from lower extremities

What is the result of expiration?

• increased venous blood flow to the heart from lower extremities

• decreased flow from upper extremities

Edema is a consistent sign of ___________ venous pressure

increased

What is the Starling equilibrium equation?

it describes the movement of fluid across the capillary

What are the forces that act to move fluid out of the capillary?

• intracapillary pressure

• interstitial osmotic pressure

What are the forces that favor the reabsorption of fluid from the interstitium?

• interstitial pressure

• capillary osmotic pressure

In the presence of venous thrombosis, venous pressure is _________

increased

What is the calf muscle pump?

it aids in the return of blood from the legs against the force of gravity

Venous obstruction is almost always a result of ___________

venous thrombosis

What is the primary clinical concern when DVT is suspected?

pulmonary embolism

What is treatment of a DVT?

• immediate anticoagulation

• acute: heparin

• chronic: warfarin

After a DVT episode, there is an acute inflammatory response in the vein wall and in the thrombus itself leading to a dynamic process in which the thrombus regresses due to _________

recanalization

What is recanalization?

the return of blood flow to a venous segment that had previously been occluded

Recanalization often results in _____________

valve incompetence