Blood Vessels

1. Human Anatomy
Blood Vessels
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2. Direction of Flow
Heart to aorta to arteries to
arterioles to capillaries.
Capillaries to venules to veins to
vena cava to heart.

3. Arteries
Veins

5. • Capillaries form Microcirculation
• Microscopic vessels that connect arterioles to venules
• Found near every cell in the body but more extensive in
highly active tissue (muscles, liver, kidneys & brain)
•entire capillary bed fills with blood when tissue is active
•lacking in epithelia, cornea and lens of eye & cartilage
• Function is exchange of nutrients & wastes between
blood and tissue fluid
• Structure is single layer of simple squamous epithelium
and its basement membrane

6. Capillaries:
1. Continuous
2. Fenestrated
3. Sinusoid

7. Venous valves

8. Blood Distribution
 12% pulmonary vessels
 8 % = heart
 15% = systemic arteries and arterioles
 5% = capillaries
 60% = systemic veins and venules

10. Venous flow occurs by:
1. muscle contraction
2. respiratory pump
3. valve assistance
4. Ventricular
relaxation

11. Varicose Veins
 Twisted, dilated superficial veins
 caused by leaky venous valves
 congenital or mechanically stressed from prolonged standing
or pregnancy
 allow backflow and pooling of blood
 extra pressure forces fluids into surrounding tissues
 nearby tissue is inflamed and tender
 Deeper veins not susceptible because of support of
surrounding muscles

12. Anastomoses
 Union of 2 or more arteries supplying the same body
region
 blockage of only one pathway has no effect
 circle of willis underneath brain
 coronary circulation of heart
 Alternate route of blood flow through an anastomosis is
known as collateral circulation
 can occur in veins and venules as well
 Alternate routes to a region can also be supplied by
nonanastomosing vessels

14. Pulse Pressure
 Pulse pressure = systole - diastole
 MAP = diastolic pressure + pulse pressure/3
 MAP = mean arterial pressure
 MAPB = diastole + 1/3 (systole – diastole)
 MAPB = mean arterial blood pressure

17. Blood Pressure
Influenced by:
 Peripheral resistance
 Heart efficiency
 Blood viscosity
 Total blood vessel length
 Arteriole elasticity
 Blood volume

20. Hormones that affect BP
 Renin angiotensin
 Epinephrine and norepinephrine
 Antidiuretic hormone
 Atrial natriuretic peptide

22. Autoregulation of BP
 Physical changes
 Vasodilating and constricting chemicals

27. Major Branches of the Aorta
 Coronary arteries
 Brachiocephalic
 Left common carotid
 Left subclavian
 Celiac
 Superior mesenteric artery
 Renals
 Ovarian / testicular
 Inferior mesenteric

28. Minor Branches of the Aorta
 Pericardial Thoracic
 Bronchial Lumbar
 Esophageal Suprarenal
 Mediastinal
 Intercostal
 Phrenic

33. Celiac circulation

34. Abdominal arteries

44. Arterial supply and venous
drainage of the liver

51. Hypertension
 Systole > 140
 Diastole > 90
 Causes: diet high in fat and sodium, obesity, older age,
race, heredity, stress, and smoking.

52. Words to Learn
 Aneurysm Shock
 Angiogram Sphygmomanometer
 Diuretic Korotkoff sounds
 Phlebitis Angiogenesis
 Phlebotomy Hypotension
 Thrombophlebitis Occlusion
 Syncope White Coat
Hypertension
 Tachycardia Edema