1. Blood Vessels & Circulation
Exercise 21
Blood Vessels & Circulation
Portland Community College
BI 232

2. Blood vessels
Conduits that carry oxygen and nutrients to cells and remove wastes
Arteries transport blood away from the heart.
Deliver blood to capillary beds where gas and nutrient exchange occurs.
Veins transport blood toward the heart.

3. Martini pg. 711

4. General Circulatory Patterns
Two main circuits:
Pulmonary circulation: Blood goes from the heart to the lungs and returns to the heart. The pulmonary trunk and its branches; leave the right ventricle of the heart and contain deoxygenated blood.
Systemic Circulation: Blood goes from the heart to rest of the body. The aorta and its branches; leave the left ventricle of the heart and contain oxygenated blood.

5. Artery and Vein Histology
Walls have 3 layers:
Tunica intima
Tunica media
Tunica externa

6. Tunica Intima Is the innermost layer near the lumen Includes:
The endothelial lining
Connective tissue layer
Internal Elastic Membrane: In arteries, is a thick layer of elastic fibers in the outer margin of the tunica intima

7. Tunica Media Is the middle layer
Contains concentric sheets of smooth muscle in loose connective tissue
Binds to inner and outer layers

8. Tunica Externa (aka: Tunica Adventitia)
Is outer layer
Contains connective tissue sheath
Anchors vessel to adjacent tissues
In arteries:
Contain collagen
Elastic fibers
In veins:
Contain elastic fibers
Smooth muscle cells

9. Elastic Arteries
Also called conducting arteries, these are the largest arteries
Tunica media has many elastic fibers and few muscle cells
Elasticity evens out pulse force
Examples:
Pulmonary trunk
Aorta
Common carotid arteries
Subclavian arteries
Common iliac arteries

10. Aorta el = elastic fibers end = endothelial cells
n = smooth muscle cell
TA = tunica adventitia
TI = tunica intima TM = tunica media

11. Vasa Vasorum Aorta “Vessels of Vessels”
Small arteries and veins in the walls of large arteries and veins
Supply cells of tunica media and tunica externa
Vasa Vasorum
Aorta

12. Muscular Arteries
Also called distribution arteries, are medium-sized (most arteries)
Tunica media has many muscle cells
Examples:
External carotid arteries
Brachial arteries
Femoral arteries

13. Muscular Arteries

14. Arterioles The smallest branches of arteries Feed into capillaries
Have little or no tunica externa
Have thin or incomplete tunica media

15. Arteriole
end = endothelial cell nucleus n = smooth muscle nucleus rbc = red blood cells
end = endothelial cell nucleus n = smooth muscle nucleus rbc = red blood cells

16. Capillaries The smallest vessels
Structure: Simple squamous epithelium tube
Lumen side has a thin basal lamina
No tunica media, No tunica externa
Location of exchange between blood and interstitial fluid.
Gasses and chemicals diffuse across their walls

17. Veins
Carry blood to the heart
Are larger in diameter than arteries
Have thinner walls
Contain valves
Folds of tunica intima that prevent blood from flowing backward
Venules: The smallest veins that carry blood away from the capillaries

18. Veins Medium-sized veins: Large veins:
Thin tunica media and few smooth muscle cells
Tunica externa with longitudinal bundles of elastic fibers
Large veins:
Have all 3 tunica layers
Thick tunica externa
Thin tunica media
Example: Inferior and Superior vena cava

19. Venous Valve in Medium Vein
ad = adipose tissue TA = tunica adventitia TM = tunica media v = valve

20. Large Vein

21. Arteries Vs. Veins Arteries and veins run side-by-side
Arteries have thicker walls and higher blood pressure
Collapsed artery has small, round lumen
Vein has a large, flat lumen

22. Vein
Artery

23. Aortic Arch
Left Coronary A.
Ascending Aorta
Right Coronary A.

24. Aortic Arch Internal Carotid External carotid Common Carotid
R. Vertebral
R. Axillary a.
R.Subclavian a.
L.Subclavian a.
Brachiocephalic Trunk

25. Brachiocephalic Trunk Left Common Carotid
Right Common Carotid
R.Subclavian
Vertebral
L..Subclavian
Brachiocephalic Trunk
Left Common Carotid

26. Descending aorta Thoracic aorta: above the diaphragm
Includes the intercostal arteries which run between the ribs
Abdominal aorta: below the diaphragm

27. Axillary Artery
R. Axillary a.
Brachial a.
Radial a.
Ulnar a.

28. Circle of Willis
Internal Carotid
Vertebral
External carotid

29. Arteries of the head and neck

30. Circle of Willis Anterior communicating Anterior cerebral
Internal Carotid (cut)
Middle cerebral
Posterior communicating
Posterior cerebral
Basilar
L. Vertebral
R. Vertebral

31. Anterior cerebral
Internal Carotid
Middle cerebral
Posterior cerebral

33. Abdominal Aorta Celiac Trunk Superior Mesenteric Renal A. Gonadal
Inferior Mesenteric
Common Iliac
External Iliac
Internal Iliac

34. Abdominal Aorta Celiac Trunk Common Hepatic Left Gastric Splenic
Superior Mesenteric
Inferior Mesenteric

35. Spleen
Splenic a.
Renal a.

37. Thigh
Anterior
Posterior
External Iliac
Femoral
Deep Femoral

38. Lower Leg Femoral Popliteal Fibular Anterior tibial Fibular
Posterior tibial
Dorsalis Pedis

40. Axillary vein
Cephalic vein
Brachial vein
Basilic vein
Cephalic vein
Median Cubital vein
Radial vein
Basilic vein
Ulnar vein

41. Right Left Subclavian vein Axillary vein Cephalic vein Brachial vein
Brachiocephalic
Right Left
Subclavian vein
Axillary vein
Cephalic vein
Brachial vein
Basilic vein
Hemiazygos
Azygos

42. Superior Sagittal sinus
Petrosal sinus
Cavernous sinus
Superior Sagittal sinus
Straight sinus
Transverse sinus
Internal Jugular
Sigmoid sinus
Brachiocephalic
Right
Left
Vertebral Vein
External Jugular
Superior Vena Cava
Subclavian vein

44. Femoral
Popliteal
Small Saphenous
Great Saphenous
Anterior Tibial
Small Saphenous
Anterior Tibial
Fibular
Posterior Tibial

45. Deep Femoral
Femoral
Great Saphenous
Popliteal
Small Saphenous
Anterior Tibial
Small Saphenous
Posterior Tibial
Fibular

47. Hepatic veins
Inferior Vena Cava
Renal vein
Common iliac vein
Internal iliac vein
External iliac vein

48. Inferior Vena Cava
Hepatic veins
Hepatic Portal vein
Splenic vein
Superior Mesenteric
Inferior Mesenteric

50. Hepatic Portal Circulation
Veins that flow into the liver before returning to the heart
Blood from digestive organs and spleen travel to capillaries of the liver.
The liver processes the blood before sending it through the hepatic vein.
Blood then travels to the inferior Vena Cava

51. Thoracic Veins Intercostal veins which drain the intercostal muscles
Azygos and hemiazygos veins which drain blood from the thoracic region

52. Fetal Circulation Lungs of fetus are non functional.
Oxygen and nutrients move from the maternal side of the placenta to the fetal bloodstream and CO2 and wastes moves from the fetal blood to the placenta

53. Fetal Circulation Blood flow
From the umbilical cord blood travels through the ductus venosus which shunts the blood to the inferior vena cava
From the VC blood travels to the right atrium of the heart

54. Fetal Circulation
Blood can then move either to the right ventricle or through a hole in the right atrium called the foramen ovale (bypass route)
Blood in the right ventricle moves into the pulmonary trunk where another shunt vessel, the ductus arteriosus carries blood to the aortic arch, bypassing the lungs.
Closing to the foramen ovale leaves the fossa ovalis which we learned about in the heart lab.

55. Blood Pressure
Maintenance of bp is important for the health of the heart and proper functioning of various organs
The force exerted by blood on the walls of blood vessels.
A function of the pumping action of the heart and the resistance to flow as blood moves through the blood vessels.

56. Blood Pressure
In large elastic arteries, the BP fluctuates between a max. and min. value
Systolic pressure is the maximum pressure exerted on bv walls.
Diastolic pressure is the minimum level

57. Blood Pressure Measured in units called millimeters of mercury (mmHg)
If the pressure in a bv is 95mm Hg, it means that the force exerted by the blood will cause a column of mercury to rise 95mm

58. Blood Pressure Cuffs BP cuffs come in different sizes.
Be sure to choose the one that is appropriate for the patient
Large Adult
Infant

59. Measuring Blood Pressure
Most cuffs are marked with an O or an arrow. This should be placed near the artery.

60. Measuring Blood Pressure
Place the BP cuff snugly on the patient's arm.
Check to make sure you have found the artery.
Line the mark on the cuff up with the artery

61. Measuring Blood Pressure
Stethoscope: Note how the ear pieces slant slightly in one direction.
Make sure the ear pieces on the stethoscope are point away from you when you put them on.
Place stethoscope on the artery, tucked slightly under the cuff

62. Measuring Blood Pressure
WRONG TECHNIQUE
Measuring Blood Pressure
The cuff should be placed at the level of the heart.
The patients arm (or leg) should be completely relaxed.
Resting on the table or in their lab is helpful
CORRECT TECHNIQUE

63. Inflate the Cuff
A Grasp the bulb so that your thumb can easily access the valve.
Turn the valve to the right to tighten it and pump up the cuff, turn it to the left to loosen it and deflate the cuff.

64. Measuring Blood Pressure
Pump up the cuff until the sphygmomanometer reads 180 to 200.
Loosen the valve to let a little of the air out.
Listen for the first heartbeat, that is the top number (systolic BP)
Continue to listen until there are no more heartbeats. The last beat you hear is the bottom number (diastolic BP)
Let the air all the way out and remove the cuff.

65. Video Demonstration for Measuring Blood Pressure

66. Normal Blood Pressure For adults 18 and older who:
Reference:
August 2004, National Heart Lung and Blood Institute – Diseases and Conditions Index
For adults 18 and older who:
Are not on medicine for high blood pressure
Are not having a short-term serious illness
Do not have other conditions such as diabetes and kidney disease
Systolic BP: Less than 120
Diastolic BP: Less than 80

67. Pre-Hypertension Systolic BP: between 120-139
Diastolic BP: between 80-89
Examples: 118/82, 128/89, or 130/86
If your blood pressure is in the pre-hypertension range, it is more likely that you will end up with high blood pressure unless you take action to prevent it.
Note: When systolic and diastolic blood pressures fall into different categories, the higher category should be used to classify blood pressure level.

68. Hypertension Stage 1 Systolic BP: between 140-159
Diastolic BP: between 90-99
Stage 2
Systolic BP: 160 or higher
Diastolic BP: 100 or higher

69. Hypotension Hypotension is a subnormal arterial pressure.
There is not enough pressure to adequately perfuse the tissues.
There is usually a mean arterial pressure (MAP) below 60 mmHg.
MAP= diastolic + 1/3(systolic-diastolic)
Example: BP= 120/70
MAP= /3(120-70)= 86.6
People who are chronically hypertensive may feel symptoms of hypotension if their mean arterial pressure drops by 40 mmHg, even if the absolute value is still over 60.

70. Pulse
The rhythmic expansion and recoil of the arteries is known as the pulse.
Can be found in various locations
Diminish in smaller arteries and are absent in capillaries and veins

71. Pulse
Radial Pulse
Carotid Pulse
Brachial Pulse

72. Pulse
Posterior Tibial Pulse
Dorsalis Pedis Pulse

73. The End
The End