1. The Vascular System

2. Now, let’s talk about blood flow in the rest of the body!!!
The Vascular System:
Taking Blood to the Body and Back

3. The Vascular System Arteries – carry blood away from the heart
Branch into Arterioles
Pulmonary Arteries - carry deoxygenated blood
Systemic Arteries – carry oxygenated blood
Capillaries- exchange
One cell layer thick!
Oxygen and nutrients cross to cells
Carbon dioxide and wastes cross into blood
Veins – carry blood back to the heart
Branch into Venules
Pulmonary Veins – carry oxygenated blood
Systemic Veins – carry deoxygenated blood
Has valves internally!

4. Vascular System Anatomy
Veins & Arteries have three layers (tunics)
Tunic interna
Tunic media
Tunic externa
Opening through which blood flows is called lumen

5. Vascular System Anatomy

6. Arteries
Veins
Direction of flow
Blood Away from Heart
Blood to Heart
Pressure
Higher
Lower
Walls
Thicker
Thinner
Wall Layers
Tunica media thicker than tunica externa
Tunica externa thicker than tunica media
Lumen
Smaller
Larger
Valves
No valves

7. Vital Signs

8. Vital Signs Pulse Blood Pressure Respiratory Rate Body Temperature
All indicate the efficiency of the system

9. Pulse Pulse – pressure wave of blood
Monitored at “pressure points” where pulse is easily felt
Measured on arteries because pressure is strong enough to be felt

10. Pulse
Radial pulse and Carotid pulse most common (helps to have the artery close to the surface & hard surface to press it on)
Average pulse is beats per minute
Pulse influenced by activity, postural changes, and emotions… stress… tests… homework… you know 
Pressure points can also be used as compression point if trying to stop blood flow

11. Blood Pressure
Measurements by health professionals are made on the pressure in large arteries (usually the brachial artery)
Pressure in blood vessels decreases as the distance away from the heart increases (not feeling the pressure created by the left ventricle as much!)

13. Blood Pressure Systolic Pressure (heart ventricles contract)
Diastolic Pressure (heart ventricles relax)
Blood Pressure= systolic/diastolic
Normal= 120/80

14. Measuring Arterial Blood Pressure

15. Changing Blood Pressure
Temperature
Heat has a vasodilation effect
Cold has a vasoconstricting effect
Chemicals
Various substances can cause increases or decreases
Diet

16. Blood

17. Blood Facts Only fluid tissue in human body
Blood heavier than water and 5 times thicker
Slightly basic – pH approximately 7.4
Temperature slightly higher than body temperature (100.4°F)
Approximately 6 quarts (1.5 gallons) in adult

18. Blood Facts Blood stays in a closed system except…
White blood cells travel in and out of the blood stream (lymphatic system)
Water and solutes (ions, nutrients, etc) travel in and out of the blood stream

19. Blood Functions Include…
Distribution & Transport
Respiratory Gases
Nutrients
Wastes
Bacteria, Viruses, Toxins, etc.
Regulation and Maintenance
Hormonal Regulation
pH balance (blood is a buffer!)
Temperature

20. Blood Functions Include…
Protection
Clotting
Immunity

21. Composition of Blood Plasma – 55% of blood Mostly water (90%)
Plasma proteins
Albumin – pH
Clotting Proteins
Antibodies - defense
Salts (electrolytes)
Nutrients
Waste Products
Hormones
Gases

22. Composition of Blood Formed Elements - 45% of blood
Erythrocytes (Red Blood Cells)
Leukocytes (White Blood Cells)
Plateletes

23. Formed Elements Erythrocytes (RBC) No nucleus, very few organelles
Contains hemoglobin
Iron-containing protein that helps transport oxygen
Biconcave disk
Increases surface area for gas transport
Outnumber WBC 1000 to 1
Formed by red bone marrow

24. Formed Elements Leukocytes (WBC)
Only complete blood cell; contain nucleus and organelles
Needed for defense
Can slip in and out of blood vessels where needed for immune response
Also created in bone marrow
Types of WBC…

25. Formed Elements Types of WBC Granulocytes: contain granules
Neutrophils: most common WBC, active phagocytes (destroy harmful particles or cells)
Eosinophils: kill parasitic worms, allergies
Basophils: contain histamine (vasodilator)

26. Neutrophil & Eosinophil
Basophil
Neutrophil & Eosinophil

27. Formed Elements Types of WBC Agranulocytes: no granules
Lymphocytes: produce antibodies, fighting tumors & viruses
Monocytes: largest WBC, fight chronic infections

28. Monocyte
Lymphocyte

29. Formed Elements Platelets Not cells, but rather fragments
Important in blood clotting

30. Steps to Blood Clotting
1. Vessel damage, blood loss; collagen fibers exposed
2. Vascular spasm to decrease blood loss; Platelets become “sticky” and cling to fibers

31. Steps to Blood Clotting
3. Anchored platelets signal to attract more platelets; Platelet plug forms
4. Coagulation; fibers reform body/systems/circulatory/blood3.htm

32. Blood Transfusions
Body can only compensate for a certain amount of blood loss
Loss of 15-30% of blood: weakness
Loss of over 30%: severe shock, usually fatal
Therefore, we need to replace the blood when it is lost!
Blood treated with an anticoagulant (prevents clotting) can be refrigerated at 4°C for about 35 days

33. Blood Transfusions However, blood must be compatible with your body!
All plasma membranes of RBC bear certain proteins (antigens) which are unique
We also have antibodies looking for antigens
We can tolerate our own antigens, but if we get different antigens from another person, antibodies will attack RBC!
This causes RBC’s to clump (agglutination)

35. Blood Transfusions Agglutination is bad because…
Small blood vessels will clot
Oxygen won’t get delivered to tissues
Kidney tubules will block and cause kidney failure
While there are 30 common RBC antigens in humans, some antigens cause a worse reaction than others

36. ABO Blood Groups
Based on if type A antigen or type B antigen is inherited
Lack of either of these antigens is called type O
When blood is transfused, only receive antigens (not antibodies) from donor

37. A, O B, O Blood that can be received A, B, AB, O (Universal Recipient)
O (Universal Donor)

41. In Summary… O can give to all A can give to A and AB
B can give to B and AB
AB can give to AB only
O can receive from O only
B can receive from B and O
A can receive from A and O
AB can receive from all

42. Rh Blood Typing
Named because of the presence or absence of Rh antigens (originally studied in Rhesus monkeys)
Rh+: have antigen
Rh-: don’t have antigen
Rh antibodies are not automatically formed in Rh- individuals; blood must be exposed to Rh+ blood to develop antibodies against it

44. Rh Blood Typing
Rh+ person can get either + or – blood because they have no antibodies!
However, if Rh– person receives Rh+ blood, antibodies can form
Okay for first transfusion, but in 2nd transfusion, antibodies will attack new Rh+ blood = bad.
In summary:
Rh+ can get Rh+ or Rh– blood
Rh– should only get Rh– blood

45. Rh Blood Typing
Also, if Rh- woman becomes pregnant with Rh+ baby, she can develop antibodies
The antibodies would then attack the blood of a second Rh+ baby = BAD!
Mom can be treated so that this doesn’t happen
Erythroblastosis fetalis