1. Chapter 12
The
Cardiovascular
and Lymphatic
Systems
Lecture Presentation
Mark Manteuffel
St. Louis Community College

2. The Cardiovascular and Lymphatic
Systems
 Cardiovascular system
 Blood vessels
 Heart
 Blood pressure
 Lymphatic system

3. The Cardiovascular System: Moving
Blood through the Body
 The cardiovascular system (or circulatory
system) is built to rapidly transport blood to
every living cell in the body
 Consists of the heart and blood vessels
 The system helps maintain homeostasis by
providing rapid internal transport of substances
to and from cells

4. The Heart and Blood Vessels Make up
the Cardiovascular System
 Cardiovascular system
 1) Heart
 2) Blood vessels
• Arteries: large diameter
• Arterioles: smaller & narrower vessels
• Capillaries: even narrower
• Capillary beds: slow flowing blood moves through these vast
numbers of slender capillaries- substances diffuse into and
out of these from cells
• Venules: blood flows from capillaries into these small
vessels
• Veins: from venules to larger veins that return blood to heart

5. The Heart and Blood Vessels Make Up
the Cardiovascular System

6. The Cardiovascular System Helps
Maintain Favorable Operating Conditions

7. Blood Circulation Is Essential to Maintain
Homeostasis
 Major role in homeostasis
 Blood brings oxygen, nutrients, and hormones to
cells
 Blood removes waste products from cells and
excess heat

8. The Cardiovascular System Is Linked to
the Lymphatic System
 Lymphatic vessels
• Pick up excess extracellular fluid and usable
substances
• Return them to the cardiovascular system
• More on this later

9. The Heart: A Double Pump
 In a lifetime of 70 years, the human heart beats
some 2.5 billion times
 This durable pump is the centerpiece of the
cardiovascular system

11. The Heart Is Divided into Right and
Left Halves

12. The Heart Has Two Halves and Four
Chambers
 Septum: thick wall divides heart in half
 Chambers of the heart
• 2 Atria
• 2 Ventricles
 Coronary arteries: branch off of the aorta, the
major artery carrying oxygenated blood away
from the heart

13. The Heart Itself Is Served by Coronary
Arteries and Veins

14. In a “Heartbeat,” the Heart’s Chambers
Contract, Then Relax
 “Heartbeat”: one cycle of contraction and
relaxation of the heart chambers
 Cardiac cycle
• Systole
• Diastole
• “Lub-dup”
 Cardiac output
• Every 60 seconds ~5 liters/ventricle

15. Blood Travel
Pulmonary & Systemic Circuits

16. Each Half of the Heart Pumps Blood in a
Different Circuit

17. In the Pulmonary Circuit, Blood Picks Up
Oxygen in the Lungs
 Pulmonary Circuit
• Blood from tissue circulates through the lungs for
gas exchange
• Role of pulmonary arteries and veins

18. Heart
 The right side of the heart
• Contains blood low in oxygen
• Pumps blood through the pulmonary circuit
• Transports blood to and from the lungs
 The left side of the heart
• Contains blood rich in oxygen
• Pumps blood through the systemic circuit
• Transports blood to and from body tissues

20. In the Systemic Circuit, Blood Travels to
and from Tissues
 Systemic circuit
• Oxygenated blood pumped by left side of heart
moves through body and returns to left atrium
 Aorta
• Major arteries branch off it

21. Each Half of the Heart Pumps Blood in a
Different Circuit

22. Systemic and Pulmonary Circulation
 http://www.youtube.com/watch?v=0jznS5psypI
 0:30

23. Shunted through the Liver for
Processing
 Hepatic portal system: the vessels involved in this
detour
• Hepatic portal vein: nutrient-laden blood
• Hepatic vein: blood leaving the liver’s capillary bed
enters the general circulation through this vein
• Hepatic artery: the liver receives oxygenated blood
via this artery
• The liver removes impurities and processes
absorbed substances

24. Blood from the Digestive Tract Detours
to the Liver

25. Circulatory system
 http://www.youtube.com/watch?v=D3ZDJgFDdk0
 2:58

26. Blood Pressure
 Heart contractions generate blood pressure,
which changes as blood moves through the
cardiovascular system
 Blood pressure is highest in the aorta
 Then it drops along the systemic circuit

27. Blood Exerts Pressure against the Walls
of Blood Vessels
 Blood pressure: fluid pressure that blood exerts
against vessel walls
 Systolic and diastolic pressure: 120/80
• Systolic pressure: The peak pressure in the aorta
while the left ventricle contracts and pushes blood
into the aorta
• Diastolic pressure: The lowest blood pressure in the
aorta, when blood is flowing out of it and the heart
is relaxed
 Hypertension
• Chronically elevated blood pressure
 Hypotension
• Abnormally low blood pressure

28. Blood Pressure Values (mm of Hg)
http://www.youtube.com/watch?v=tAmLbclSucQ
3:01 High Blood Pressure Impacts

29. A Variety of Factors May Cause
Hypertension

30.  Nearly 1 in 3 adult Americans have it.
 African Americans are especially at risk.
 Learn why hypertension is called the 'silent
killer'.
 http://www.webmd.com/video/hypertension-
silent-killer
 3:06

31. Structure and Functions of Blood
Vessels
 As with all body parts, structure is key to the
functions of blood vessels
 All our vessels transport blood, but there are
important differences in how different kinds
manage blood flow and blood pressure

32. Blood Pressure Changes as Blood Flows
through the Cardiovascular System

33. Arterioles Are Control Points for Blood
Flow
 Wall built of smooth muscle rings over elastic
tissue
• Dilates when smooth muscle relaxes
• Constricts when smooth muscle contracts
 Offer more resistance to blood flow than other
vessels do

34. Capillaries: Where Blood Exchanges
Substances with Tissues
 Blood enters the systemic circulation moving
swiftly in the aorta, but this speed has to slow in
order for substances to move into and out of the
bloodstream

35. Capillaries Are Specialized for Diffusion
 Thinnest wall of any blood vessel
• Single layer of endothelium
 Site of diffusion of gases, nutrients, and wastes
 Extensive
• 62,000 miles
 Blood pressure drops slowly as blood flows through
them

37. Some of the Substances Pass through
“Pores” in Capillary Walls
 Pores
• Filled with water
• Passages for substances that can dissolve in
water
 Fluid movement in capillaries
• “Bulk flow”: water and solutes forced out of the
vessel
• Lymph vessels return the fluid to the blood

40. A Vast Network of Capillaries Brings
Blood Close to Nearly All Body Cells
 40 billion capillaries
 Every cell is a diffusible distance away from a
capillary
 Blood flow is slowest in the capillaries

42. Blood in Capillaries Flows Onward to
Venules
 Capillaries
branch into
capillary beds

43. Blood Vessels
 Venules
• Capillaries merge to form venules, the
smallest kind of vein
• Venules join to form larger veins
 Veins
• Carry blood back to the heart
• Walls have the same three layers as arteries,
but they are thinner; also have larger lumens
• Serve as reservoirs for blood volume

44. Venules and Veins Return Blood to the
Heart
 Venules
• Function somewhat like capillaries
 Veins
• Large diameters and low-resistance transport of blood
back to the heart
• Outer layer of connective tissue
• Middle layer of smooth muscle and elastic fibers
• Inner layer of endothelium
• Valves prevent backflow of blood
• Varicose veins: overstretched over time due to weak valves

46.  Varicose veins are gnarled, enlarged veins that most
commonly affect legs and feet.
 The reason for this is gravity.
 Walking upright increases pressure in the veins in the
lower part of the body, which can cause varicose
veins.
 In most cases they are harmless, and simply a
cosmetic concern.
• However, for others it can be very painful and cause
severe discomfort.
• In some, rare cases, it can lead to more serious
problems, such as severe disorders of the circulatory
system.

47. The Structure of a Blood Vessel Matches
Its Function

48. Cardiovascular Disease

49. Cardiovascular Disease
 Major risk factors
• Genetics
• High levels of blood lipids, e.g., cholesterol and trans
fats
• Hypertension
• Smoking, obesity, and lack of exercise
• Age
 Infection-related inflammation
• Can promote the formation of artery-blocking
plaques
 and C-reactive protein
• Produced by the liver in response to above; can
lead to heart disease
 Too much homocysteine: an amino acid that is released
as certain proteins break down; too much in the blood may cause
damage leading to atheroslerosis

50. Major Risk Factors for Cardiovascular
Disease

51. Arteries Can Clog or Weaken: Arteriosclerosis
(hardening of the arteries) (1)
 Atherosclerosis
• Lipids build up in the artery wall
• Cholesterol
• Trans fats
http://www.youtube.com/watch?v=qRK7-DCDKEA
0:39
 Atherosclerotic plaque
• Narrowing of artery

52. Plaques and Blood Clots May Clog
Arteries

53. Arteries Can Clog or Weaken (2)
 Coronary arteries
• Narrow and vulnerable to clogging by plaques
• Angina pectoris (mild chest pain)
• “Plaque-busting” drugs: statins
• Ways to repair coronary blockage
• Coronary bypass
• Laser angioplasty
• Balloon angioplasty
• Aneurysm
• When a weakened artery wall balloons outward,
creating a pouchlike weak spot
• Could be fatal if it bursts

54. Plaques and Blood Clots May Clog
Arteries

55. Heart Damage Can Lead to Heart Attack
and Heart Failure
 Heart attack
• Damage or death to cardiac muscle
• Warning signs
• Risk factors
 Heart Failure (HF)
• Weak heart and ineffective pump
• Even walking can become difficult
• May require repeated hospitalization

56. Arrhythmias Are Abnormal Heart
Rhythms
 Electrocardiogram (ECG)
• Recording of the electrical activity of the cardiac
cycle
 Arrhythmias: irregular heart rhythms

57. A Heart-Healthy Lifestyle May Help
Prevent Cardiovascular Disease
 Benefit of a diet that is moderate in fats
 Regular exercise
 Do not smoke

58. Infections, Cancer, and Heart Defects (1)
 Infections may seriously damage the heart
 Streptococcus bacteria: Rheumatic fever
Strep in green 
 Endocarditis
• When microbes attack heart valves directly
 Borrelia burgdorferi:
• may cause heart complications (lyme disease
pathogen)

59. Infections, Cancer, and Heart Defects (2)
 Myocarditis: Heart inflammation; various causes
• Bacterial
• Alcohol abuse
• Drug abuse

60. The Lymphatic System
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