Veins

What is the function of venous circulation?

return deoxygenated blood back to the heart (with the exception of pulmonary veins)

How do veins differ from arteries?

veins are weaker and contain valves

Explain the difference between superficial and deep veins

superficial

• close to the skin

• 10% of blood

• drains blood to deep veins

• smaller

deep

• within muscle

• 90% of blood

• returns blood back to heart

• larger and lay along arteries

Branches are to arteries as ___ are to veins

tributaries

Explain the differences between branches and tributaries

branches: in arteries, a stream that branches off from and flows away from the main source

tributaries: in veins, stream that empties into a main source

What are the 3 systems in venous circulation?

• systemic venous circulation

  • drains systemic circulation

• pulmonary venous circulation

  • pulmonary veins

• hepatic portal circulation

  • drains the GI system

Explain the venous sinuses

• venous vessels found between the layers of the brain (receives blood from deep and superficial veins)

• superficial veins from scalp, face and neck drain into deep veins

• deep veins drain blood from the brain tissues

Explain the superior sagittal/longitudinal sinus

• along the sagittal suture

• largest sinus

• drains majority of blood from anterior and lateral aspects of the brain

• empties into the internal jugular

List and explain the 2 jugular veins

internal jugular

• drains brain

• paired

• large

external jugular

• drains exterior cranium and face

• paired

• smaller

Both jugular veins terminate at the ___

subclavian vein

Subclavian veins unite with the internal jugular veins to form the ___

right and left brachiocephalic (innominate) veins

Which brachiocephalic vein is shorter?

right

Explain the superior vena cava (drains, formed by, type of blood)

• drains head and upper extremity

• drains into right atrium

• formed by brachiocephalic veins

• deoxygenated blood

List the deep veins of the upper extremity

• deep palmar arches (veins of the hand)

• ulnar and radial veins

• brachial vein (medial side of upper arm)

• axillary

• subclavian

List the superficial veins of the upper extremity

• cephalic vein

  • located on the lateral aspect of the arm

  • unites with axillary (deep) vein

• basilic vein

  • ascends along medial side of arm

  • joins the brachial (deep) vein to form the axillary veins

• median cubital vein

  • formed by anastomosis of the cephalic and basilic veins

  • frequent site of venipuncture

List the deep veins of the lower extremity

• metatarsal veins

• posterior tibial (drains deep posterior leg)

• anterior tibial (drains anterior leg and foot)

• popliteal

• femoral

• external iliac

  • continuation of femoral vein (drains lower extremity)

• internal iliac (drains pelvic cavity)

• common iliac

  • junction of internal and external iliac veins

  • unite to form the inferior vena cava

List the superficial veins of the lower extremity

• dorsal digital veins

• lesser (short) saphenous

  • posterior

  • joins the popliteal vein

• greater (long) saphenous

  • medial

  • joins the femoral vein

Explain the inferior vena cava

• formed by the right and left common iliac veins

• parallels on the right side of the aorta

• moves anterior at renal arteries/veins area

• goes through the diaphragm at the vena cava hiatus

• returns blood from the lower extremities and abdomen to the right atrium

Are paired or unpaired veins of the abdomen direct tributaries to the IVC?

paired

List the paired veins of the abdomen

• inferior phrenic

• gonadal

• suprarenal

• renal

• hepatic

• lumbar

List the unpaired veins of the abdomen

• superior mesenteric

• splenic vein

• gastric vein

Explain the portal vein

• vein that moves deoxygenated blood from the GI tract to the liver (possible toxins are processed by liver before being released back into systemic circulation)

• splits into superior mesenteric (SB and proximal colon) and splenic (inf mesenteric) veins

• pancreatic, gallbladder, and gastric also drain into the portal vein

What organs are drained into the portal vein?

• spleen

• stomach

• gallbladder

• intestines

• pancreas

Why is the portal vein not considered a true vein?

it returns “clean” blood to the liver instead of to the heart

What is the longest vessel in the body?

great saphenous

Explain hepatic veins

• blood vessels which transport “clean” blood from the liver to the IVC (deoxygenated blood that has been filtered by the capillaries of the liver - sinusoids)

• hepatocytes - filter and detoxify blood