1. The Circulatory System
You Gotta Have
The Circulatory System

2. Circulatory System Consists of…
Blood Vessels
Blood
Heart

3. Overview
The Heart pumps blood through the body through blood vessels (arteries, capillaries and veins)
Arteriestake blood away from the heart, veins return blood to the heart
Blood carries O2 (food) towards and CO2 (waste) away from tissues
The lungs are not part of the circulatory system!!

4. Circulatory System
BLOOD VESSELS

5. Two Pathways Pulmonary Circulation Systemic Circulation
Carries blood to lungs and back
Systemic Circulation
Carries blood to body and back

6. Your Blood Vessels: Pathway of Circulation
3 types of vessels
Arteries(Shown as Red because blood has O2)
Capillaries(Red and Blue because some O2 lost to tissues)
Veins(Shown as Blue because O2 lost to tissues)

7. Red Blood and Blue Blood
Blood is never blue!!!!!!!!!!!!!!!!!!
Oxygenated blood is bright red and deoxygenated blood is dark red
Veins appear blue because of the way light reflects off the blood vessel
We don’t see arteries because they are too deep.
We draw them blue to distinguish them on diagrams and simplify things

8. Arteries vs. Veins
What you need to know about the STRUCTURAL differences between Arteries and Veins:
Artery walls are much thicker, very elastic and have more muscle.
Veins are thin walled and contain valves to psh the blood along

9. Arteries vs. Veins Why are arteries and veins the way they are?
Blood is under very high pressure when it leaves the heart and enters the arteries
Therefore, arteries need to be strong!
Once it has left the tissues and enters the veins, the blood is under a very low pressure
Therefore, veins are weak

10. Arteries: carries blood Away from heart
Large
Thick-walled, Muscular
Elastic
Oxygenated blood
Exception Pulmonary Artery
Carried under great pressure
Steady pulsating (used to measure pulse)
Arterioles: smaller vessels, enter tissue

12. Capillaries Smallest vessel Microscopic Walls one cell thick
Located at the tissue
Nutrients and gases (O2, CO2) diffuse here

13. Veins: Caries blood to the heart
Carries blood that contains waste and CO2
Exception pulmonary vein
Blood under low pressure
Valves to prevent back flow due to gravity
Venules: small veins, larger than capillaries

14. Blood Vessels http://www.kscience.co.uk/animations/blood_system.swf
Animation of blood flow

15. The Aorta – The largest blood vessel
Blood Vessel Animation

16. Circulatory System
BLOOD

17. The Blood Body contains 4-6 L Consists of Water Red Blood Cells Plasma
White blood cells and platelets

18. Your Blood: Fluid Transport
Liquid Portion Carries
Blood cells (made in bone marrow)
Erythrocytes (RBC - red blood cells)
Leucocytes (WBC - white blood cells)
Platelets (fragments of the cells in bone marrow – no nucleus)
Proteins
Nutrients - digestive system
Gases - Respitory system

19. Oxygen in the Blood O2 O2 O2 O2 Hemoglobin , iron containing molecule
Loosely picks up oxygen in the lungs
Releases oxygen in areas low in oxygen – body tissues O2 O2 O2 O2

20. Carbon Dioxide in the Blood
Hemoglobin also carries CO2
CO2 is a waste product of cellular respiration
Travels to the lungs to be exhaled

21. What does blood contain?
50% Water
45% Erythrocytes (RBC)
4% Plasma with Substances
1% Leukocytes (WBC) + Platelets

22. Erythrocytes (RBC) Transporters of Oxygen Carbon dioxide RBC
Lack a nucleus
Contain hemoglobin
Disk-shaped
RBC are produced in the bone marrow
Lives for ~120 days
Old RBC are destroyed in liver and spleen

23. Leukocytes (WBC) WBC fight infection Less abundant
Attack foreign substances
Less abundant
Created in bone marrow
Some live for months
Most just a few days
Several types
ALL contain nuclei
Difference between red and white ?

24. Platelets PLATELETS are for CLOTTING blood Cell fragments
Produced in bone marrow
Short life span (1 week)
Form a web trapping blood cells

25. Blood Clotting Break in Capillary Wall Blood vessels injured.
Clumping of Platelets
Platelets clump at the site and release a protein
Clot Forms
Protein creates a net creating a clot. The clot prevents further loss of blood.

26. Circulatory System
HEART

27. Your Heart Pumps blood around your body to keep you alive!
If your heart stops you will die!

28. Heart: Structure and Function
Keeps blood moving
Large organ composed of
Cardiac Muscle
Rich in Mitochondria

29. The Structures of the Heart
Inferior Vena Cava
Vein that brings oxygen-poor blood from the lower part of the body to the right atrium
Pulmonary Veins
Bring oxygen-rich blood from each of the lungs to the left atrium
Superior Vena Cava
Large vein that brings oxygen-poor blood from the upper part of the body to the right atrium
Aorta
Brings oxygen-rich blood from the left ventricle to the rest of the body
Pulmonary Arteries
Bring oxygen-poor blood to the lungs
Left Atrium
Right Atrium
Left Ventricle
Right Ventricle

30. Structure of Heart (cont)
Four chambers
Two upper (Atria)
Walls thinner
Less Muscular
Two lower (Ventricles)
Walls thicker
More muscular
Do more work
Heart Structure Animation

31. Blood Flow Through the Heart
©COPY 1997 HeartPoint

32. Bloods Path Through the Heart
Both Atria fill at same time
Rt atrium receives oxygen poor blood from body from vena cavas
Left atrium receives oxygen Rich blood from lungs through four pulmonary veins
After filled with blood atria contract, pushing blood into ventricle

33. Both ventricles contract
Right ventricle contracts and pushes oxygen- poor blood toward lungs
through the pulmonary arteries

34. Bloods Path Through the Heart
Left ventricle contracts and forces oxygen rich blood out of heart
Through Aorta (Largest Vessel)

35. The cardiac cycle
Animation of blood flow

36. Heart Rate during exercise
Control of Heart Rate
Resting Heart Rate
Heart Rate during exercise 58 80

37. Control of the Heart
The Heart is controlled by nerves and hormones:
Nerves:
Its own nerves à Pacemaker which keeps a constant beat
Heart will beat even if it is disconnected from the brain
Can be substituted by an artificial pacemaker
- The Brain à can speed-up (exercise) or slow down the heart (sleep) if needed

38. Control of the Heart Hormones:
Certain hormones such as epinephrine (adrenalin) impact how the heart operates

39. Your Heart: The Vital Pump
At REST, the heart beats about times per minute (~4.7L)
During EXTREME EXERTION (exercise) it can beat between times per minute (~38L)

40. Heart Rate Discussion Why?? Brain sends a signal to increase HR
Adrenal Gland secretes epinephrine
Both work together to increase blood flow around the body
Increased blood frow = increase 02/glucose delivery to cells and CO2 removal

41. DISORDERS Coronary Artery Disease Your heart needs Oxygen too!
Is supplied with Oxygen by coronary arteries
Coronary arteries can become partially blocked by plaque (fat and cholesterol mainly)
Causes by lifestyle choice and genetics
This block limits the amount of oxygen delivered to the heart
Can cause à tiredness, dizziness and pain

42. Coronary Artery Disease
Can be diagnosed with an angiogram whereby a fluorescent dye is injected into the bloodstream.
This dye shows up on an x-ray and shows where flow is disrupted

43. Disorders (cont) Heart Attack
Coronary artery(ies) become completely blocked
No Oxygen can reach the heart muscle
Heart muscle begins to die and eventually stops beating
Symptoms
Nausea, Shortness of breath, Severe chest pain, sweating, dizziness, fatigue
IMMEDIATE MEDICAL ATTENTION NECESSARY

44. Disorders (cont) Stroke Heart atack for the brain
Blood cannot reach the brain due to a blockage in its blood vessels
Brain cells die due to lack of oxygen
Can lead to paralysis,
loss of ability to speak
death

45. Current PREVENTION Recommendations
Regular exercise
Weight control
Well balanced diet
Do not smoke
Diet low in saturated fat
Heart Transplant Interactive Activity