perforators & central veins | venous hemodynamics

What is another term for perforating veins?

Perforators

Perforating veins are vessels that (1)________ or go through the (2)________ that covers the (3)________.

1. Perforate

2. Fascia

3. Muscle

Perforating veins form connections between the ___________ and ___________ systems.

• Superficial

• Deep

Perforating veins accompany what vessels?

Perforating arteries

Name an example of a perforating vein and what it helps connect.

Connects GSV to deep system

1. Communicating veins are vessels that connect veins within the _____ system.

2. For example, ______-______ or _____________-____________ venous systems.

1. Same

2. Deep-deep, superficial-superficial

1. What vein connects the GSV and SSV?

2. Would this vein be a perforating or communicating vein?

1. Vein of Giacomini

2. Communicating veins

What is the typical diameter of a normal and competent communicating vein?

Less than 2 mm

1. Are communicating veins seen routinely during an US?

2. If not, why is that?

1. No

2. Because of their small size

The calf muscle pump mechanism helps to promote (1)_______ return during (2)_________ or __________.

1. Venous

2. Walking or running

The calf muscle pump is a way for blood to get back to the…

Heart

1. Peripheral veins can be found in what areas?

2. These veins have valves that direct flow (towards/away) from the limbs and (towards/away) from the heart.

1. Arms and legs

2. Away, towards

Valves maintain _____________ flow.

Unidirectional

1. Veins located in large muscle groups, ex. calves, undergo compression whenever the muscles…

2. They will undergo decompression when the muscles…

1. Contract

2. Relax

The calf muscle pump is essentially normal cycles of ___________ and ___________ of the vein.

• Compression

• Decompression

Perforators help to maintain an (1)_______ movement of blood with assistance of the (2)_________________ mechanism.

1. Efficient

2. Muscle pump

Venous drainage of the lower leg occurs as blood travels from the (1)__________ veins through the (2)__________, into the (3)___________ veins.

1. Superficial

2. Perforators

3. Deep

1. In normal circumstances, what system drains the subcutaneous tissues?

2. This system will periodically empty into which system?

3. This is done through what vessels?

1. Superficial

2. Deep

3. Perforating

Label the crossed-out parts of this image.

1. Superficial system

2. Perforating veins

3. Deep system

Each lower extremity can contain as many as __-__ perforators.

80 - 140

What is another term for posterior arch vein?

Posterior accessory great saphenous vein

The posterior accessory great saphenous vein is important because it represents a (1)__________ connection of the three (2)______ perforating veins.

1. Superficial

2. Ankle

Which vein plays a major role in the development of venous stasis ulcers?

Posterior arch vein

The posterior accessory great saphenous vein extends superior from the (1)______ to the (2)______________ vein.

1. Ankle

2. Great saphenous vein

The posterior arch vein receives blood from the ________________ perforators.

Posterior tibial

Label the parts of this perforator anatomy image.

1. Perforator of femoral canal (Hunter’s)

2. Perforator of femoral canal (Dodd’s)

3. Para tibial perforator (Boyd’s)

4. Posterior accessory GSV (Posterior arch vein)

5. Upper posterior tibial perforator (Cockett III)

6. Middle posterior tibial perforator (Cockett II)

7. Lower posterior tibial perforator (Cockett I)

What are the two other terms for the perforator of femoral canal?

• Hunter’s

• Dodd’s

What is the name of the medial thigh perforator?

Perforator of femoral canal (Hunter’s and Dodd’s)

The perforator of femoral canal drains blood from the (1)_____ and (2)______ thigh, and goes into the distal (3)__________ vein.

1. GSV

2. Distal

3. Femoral

What is another term for Para tibial perforator?

Boyd’s

List the 3 posterior tibial perforators.

• Upper

• Mid

• Lower

What is another term for upper posterior tibial perforator?

Cockett III

What is another term for mid posterior tibial perforator?

Cockett II

What is another term for lower posterior tibial perforator?

Cockett I

The three posterior tibial perforators connect the (1)_____ and the posterior (2)______ veins.

1. GSV

2. Tibial

In the lower extremities, the venous sinuses are dilated ________ located in the calf muscles.

Channels

Venous sinuses allow venous blood to accumulate and then drain into the (2)_________________ and (3)_________ veins.

1. Posterior tibial

2. Peroneal

These large (1)________ saccular muscle veins of the (2)________ and (3)____________ muscles act as a major part of the calf muscle pump.

1. Sinusoid

2. Soleal

3. Gastrocnemius

What is the main venous sinus?

Gastrocnemius vein

A thrombus is considered bad when found in the (superficial/deep) system.

Deep

Label the veins on this image.

1. Great saphenous vein

2. Perforating veins

3. Popliteal vein

4. Soleal veins

5. Peroneal veins

6. Posterior tibial veins

What is another term for venous sinuses?

Soleal veins

Label the parts of this vessel image.

1. Small saphenous vein

2. Lateral gastrocnemius

3. Medial gastrocnemius

4. Popliteal vein

5. Popliteal artery

Blood in the head and upper extremities empty into the…

Innominate veins

The innominate veins form the…

Superior vena cava

The superior vena cava empties into the ______ atrium of the heart.

Right

The lower half of the body empties into the…

Common iliac veins

The common iliac veins join together to form the…

IVC

The inferior vena cava empties into the _____ atrium of the heart.

Right

Label the structures the blood goes through from the upper extremities to the right atrium.

1. Innominate veins

2. SVC

Label the structures the blood goes through from the lower extremities to the right atrium.

1. Common iliac veins

2. IVC

The main portal vein is formed from the ____________ vein and ____________ vein.

• Superior mesenteric vein

• Splenic vein

Which vein supplies 70-80% of blood to the liver?

Main portal vein

Which vein supplies 20-30% of blood to the liver?

Hepatic artery

Which blood flow is normal: hepatopedal or hepatofugal?

Hepatopedal

Hepatopedal flow is (1)________ the (2)______.

1. Towards

2. Liver

What diameter measurement is considered normal for the main portal vein?

Less than 13 mm

Hepatic veins carry blood from the (1)_____ into the (2)___.

1. Liver

2. IVC

Hepatic vein flow is characterized as ____________ flow.

Hepatofugal

Hepatofugal flow is (1)________ the (2)______.

1. Away from

2. Liver

What two factors are demonstrated in the waveform of hepatic veins?

• Cardiac pulsatility

• Respiratory phasicity

Respiratory phasicity refers to varied _________.

Breathing

The renal veins drain blood from the (1)_________ and carry it to the (2)____.

1. Kidneys

2. IVC

Which two other vessels have similar waveforms to that of the renal vein?

• Hepatic veins

• IVC

The renal vein, hepatic vein, and IVC have what waveform in common?

“Flying W”

1. Which vessel is being dopplored here?

2. What is the name for this vessel pattern?

3. What is being demonstrated here?

1. Hepatic vein

2. Flying W

3. Cardiac pulsatility

A fully distended cross-sectional area of a vein is __-__ times that of the corresponding artery.

3 - 4

Is a vein typically larger or smaller than its corresponding artery?

Larger

The vein can carry more blood without an increase in…

Pressure

What is the primary function of the venous system?

To return blood to the heart

Which veins carry about 2/3 of the blood in the body?

Extrapulmonary veins

Label the vessels seen here.

1. Artery

2. Vein

List the 3 pressure/volume relationships.

• Intraluminal pressure

• Interstitial pressure

• Transmural pressure

Intraluminal pressure is pressure exerted on the venous walls from _________ the veins.

Within

Interstitial pressure is pressure exerted on the venous walls from _________ the veins.

Outside

What is transmural pressure?

The pressure within the vein versus the pressure outside of the vein.

Transmural pressure is related to the _______ or _______ of blood in the vein.

• Amount

• Volume

Transmural pressure will determine the ______________ shape of the vein.

Cross-sectional

Label which shapes are a certain transmural pressure.

1. High transmural pressure

2. Low transmural pressure

1. High transmural pressure will have a _____ amount of blood.

2. __________ shaped vein.

1. High

2. Circular

1. Low transmural pressure will have a _____ amount of blood.

2. __________ shaped vein.

1. Low

2. Dumb-bell

Unlike arteries, veins are highly…

Compliant

A vein is highly compliant, meaning it will ________ easily.

Compress

A vein will expand into a circular cross-sectional shape as intraluminal pressure __________.

Increases

A vein will expand into a dumb-bell cross-sectional shape as intraluminal pressure __________.

Decreases

Because veins are seldom completely full of blood, as with arteries, their flattened (more elliptical) shape offers ____ resistance.

More

When veins are full distended, their more circular shape offers much _____ resistance to flow.

Less

A dumb-bell shape = _____ resistance

More

A circular shape = _____ resistance

Less

Hydrostatic pressure is equivalent to the weight of a (1)________ of blood extending from the (2)______ to the level where the (3)________ is being measured.

1. Column

2. Heart

3. Pressure

A higher column of blood = _____ hydrostatic pressure

More

Hydrostatic pressure can be determined by which two factors?

• Blood density

• Acceleration of gravity

What is the lengthened formula for calculating hydrostatic pressure in this lecture?

Specific Gravity of Blood (p) x Acceleration Due to Gravity (g) and Distance From The Heart (h)

What is the short formula for calculating hydrostatic pressure in this lecture?

HP= pgh

What is the hydrostatic pressure in a supine patient?

0 mmHg

1. What is the hydrostatic pressure at the ankles when a patient is standing?

2. Will it be the same for everyone?

1. 100 mmHg

2. No, depends on the height

What affects hydrostatic pressure the most?

Height

Since hydrostatic pressure is related to (1)______ and distance from the (2)_____, the pressure will decrease if the extremity is (3)__________ the level of the heart. It will be (4)___ mmHg.

1. Gravity

2. Heart

3. Raised above

4. -50

Label the hydrostatic pressures at each blank level:

1. Raised arm=

2. Heart level=

3. Ankle=

1. -50 mmHg

2. 0 mmHg

3. 100 mmHg

At rest, what do the veins act as?

Reservoirs for blood collection