Blood Vessels & Circulation

Vessel Walls

• Tunica intima: made up of simple squamous and areolar

• Tunica media: made up of smooth muscle cells, change diameter of vessel through vasoconstriction/vasodilation

• Tunica externa: areolar tissue

Capillary

• Smallest blood vessels where gases, nutrients occur between blood & body tissue

• Made of only single endothelial cell surrounded by thine basement membrane

Types of Capillaries

• Continuous capillaries

• Fenestrated capillaries

• Sinusoids capillaries

Pulmonary vs Systemic Circulation

Pulmonary arteries have less elastic tissue, wider lumens, shorter arteries (blood pressure is lower)

Arteries Exiting The Heart

• Right/left coronary arteries

• Aortic arch

  • Brachiocephalic

  • Left common carotid

  • Left subclavian

Arteries of Head & Neck

Supply to the head from

• Common carotid arteries then branched into

• Internal carotid: supply the brain & orbits

• External carotid: supply neck and superficial head

Arteries of Upper Extremity

• Subclavian artery: supplies upper limb

• Subclavian → axillary artery → brachial artery → radial (lateral) & ulnar (medial)→ palmar → digital

Celiac Trunk

• Left gastric artery: stomach & portion of esophagus (unpaired)

• Splenic artery: spleen, stomach pancreas (unpaired)

• Common hepatic artery: liver (unpaired)

Abdominal Arteries (Superior → Inferior)

• Adrenal (suprarenal) arteries: supply the adrenal glands (paired)

• Superior mesenteric artery: supplies small intestines (unpaired)

• Renal arteries: supply kidneys (paired)

• Gonadal: testes or ovaries (paired)

• Inferior mesenteric artery: supplies large intestines (unpaired)

Pelvic Arteries

• Left/right common iliac arteries

  • Internal iliac artery: supplies pelvis & perineum

  • External iliac artery: supplies lower extremity

External Iliac Artery

Supply to the legs, becomes

• Femoral artery (near head of femur)

• Popliteal artery (knee joint region),

• Anterior/posterior tibial arteries

• Fibular

Veins Entering the Heart

Blood returned to the right atrium through

• Left/right brachiocephalic veins merge to form superior vena cava

• Veins inferior to diaphragm merge to form inferior vena cava

Thoracic Region Veins

Azygous vein: drains the abdominal and thoracic walls

Veins of the Lower Extremity

• Fibular/tibial veins → merge to form popliteal vein → femoral vein → external iliac vein → common iliac vein

Hepatic Portal System

Direct substances from gastrointestinal tract to the liver where it filter, process, detoxify substances

Veins of Head & Neck

• Superior vena cava

• External jugular

• Internal

Veins of Upper Extremity (Deep)

• Digital veins → palmar veins → radial/ulnar veins → brachial → axillary → subclavian vein

Veins of Upper Extremity (Superficial)

• Cephalic vein (ceiling): joins the axillary/subclavian vein

• Basilic vein (basement): joins the axillary vein

Abdominal Veins

• Azygos

• Inferior vena cava

• Hepatic

• Phrenic: diaphragm

• Adrenal

• Renal

• Gonadal

Lower Extremity Veins

• Femoral vein

• Great saphenous: medial side empties into femoral

• Popliteal

• Small saphenous: lateral side empties into popliteal

• Anterior/posterior tibial

• Fibular

Pulse Pressure

PP = systolic pressure - diastolic pressure

Mean Arterial Pressure (MAP)

MAP = diastolic pressure + 1/3(PP)

Resistance

• Proportional to pressure

Based on

• Viscosity

• Blood vessels length

• Blood vessels diameter