6.-The-Cardiovascular-System anatomy.ppt

Anatomy nd physiology

1. Essentials of Human Anatomy & Physiology
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Seventh Edition
The Cardiovascular System

2. The Cardiovascular SystemThe Cardiovascular System
Slide 11.1
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
A closed system of the heart and blood
vessels
The heart pumps blood
Blood vessels allow blood to circulate to all
parts of the body
The function of the cardiovascular
system is to deliver oxygen and
nutrients and to remove carbon dioxide
and other waste products

3. The HeartThe Heart
Slide 11.2a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Location
Thorax between the lungs
Pointed apex directed toward left hip
About the size of your fist

4. The HeartThe Heart
Slide 11.2b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 11.1

5. The Heart: CoveringsThe Heart: Coverings
Slide 11.3
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Pericardium – a double serous
membrane
Visceral pericardium
Next to heart
Parietal pericardium
Outside layer
Serous fluid fills the space between the
layers of pericardium

7. The Heart: Heart WallThe Heart: Heart Wall
Slide 11.4
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Three layers
Epicardium
Outside layer
This layer is the parietal pericardium
Connective tissue layer
Myocardium
Middle layer
Mostly cardiac muscle
Endocardium
Inner layer
Endothelium

8. External Heart AnatomyExternal Heart Anatomy
Slide 11.5
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 11.2a

10. The Heart: ChambersThe Heart: Chambers
Slide 11.6
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Right and left side act as separate pumps
Four chambers
Atria
Receiving chambers
Right atrium
Left atrium
Ventricles
Discharging chambers
Right ventricle
Left ventricle

12. Blood CirculationBlood Circulation
Slide 11.7
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Figure 11.3

14. The Heart: ValvesThe Heart: Valves
Slide 11.8
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Allow blood to flow in only one direction
Four valves
Atrioventricular valves – between atria and
ventricles
Bicuspid valve (left)
Tricuspid valve (right)
Semilunar valves between ventricle and
artery
Pulmonary semilunar valve
Aortic semilunar valve

15. The Heart: ValvesThe Heart: Valves
Slide 11.9
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Valves open as blood is pumped
through
Held in place by chordae tendineae
(“heart strings”)
Close to prevent backflow

16. The Heart: Associated Great VesselsThe Heart: Associated Great Vessels
Slide 11.11
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Aorta
Leaves left ventricle
Pulmonary arteries
Leave right ventricle
Vena cava
Enters right atrium
Pulmonary veins (four)
Enter left atrium

17. Coronary CirculationCoronary Circulation
Slide 11.12
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Blood in the heart chambers does not
nourish the myocardium
The heart has its own nourishing
circulatory system
Coronary arteries
Cardiac veins
Blood empties into the right atrium via the
coronary sinus

19. The Heart: Conduction SystemThe Heart: Conduction System
Slide 11.13a
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Intrinsic conduction system
(nodal system)
Heart muscle cells contract, without nerve
impulses, in a regular, continuous way

20. The Heart: Conduction SystemThe Heart: Conduction System
Slide 11.13b
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Special tissue sets the
pace
Sinoatrial node
Pacemaker
Atrioventricular node
Atrioventricular bundle
Bundle branches
Purkinje fibers

21. Heart ContractionsHeart Contractions
Slide 11.14b
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Figure 11.5

22. Filling of Heart Chambers – Filling of Heart Chambers –
the Cardiac Cyclethe Cardiac Cycle
Slide 11.15
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Figure 11.6

23. The Heart: Cardiac CycleThe Heart: Cardiac Cycle
Slide 11.16
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Atria contract simultaneously
Atria relax, then ventricles contract
Systole = contraction
Diastole = relaxation

24. The Heart: Cardiac CycleThe Heart: Cardiac Cycle
Slide 11.17
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Cardiac cycle – events of one complete
heart beat
Mid-to-late diastole – blood flows into
ventricles
Ventricular systole – blood pressure builds
before ventricle contracts, pushing out
blood
Early diastole – atria finish re-filling,
ventricular pressure is low

25. The Heart: Regulation of Heart RateThe Heart: Regulation of Heart Rate
Slide 11.21
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Increased heart rate
Sympathetic nervous system
Crisis
Low blood pressure
Hormones
Epinephrine
Thyroxine
Exercise
Decreased blood volume

26. The Heart: Regulation of Heart RateThe Heart: Regulation of Heart Rate
Slide 11.22
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Decreased heart rate
Parasympathetic nervous system
High blood pressure or blood volume
Decreased venous return

27. Blood Vessels: The Vascular Blood Vessels: The Vascular
SystemSystem
Slide 11.23
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Taking blood to the tissues and back
Arteries
Arterioles
Capillaries
Venules
Veins

28. Blood Vessels
1. Arteries
--carry blood away from the heart
--usually spurt blood when cut
--all except the pulmonary artery carry oxygenated blood
--thick walled and elastic
pulse: expansion and contraction of the artery walls in
response to the heartbeat

30. Veins
--carry blood toward the heart
--contain valves
--closer to the body surface than the arteries
--all except the pulmonary vein carry deoxygenated
blood
--thinner, less muscular and elastic than arteries
--depend upon muscle and diaphragm movements for
blood flow

32. Capillaries
--most numerous vessels
--connect arteries to veins
--microscopic, one cell thick
walls
--site of much exchange
between the blood and the
intracellular fluid (lymph)
by diffusion

33. Lymph vessels
-have walls one cell thick
-present around all body cells
-Lymph composition is
similar to that of blood except
for the absence of RBC and
some plasma proteins.
-chief site of material
exchange with the tissues

34. Major lymph vessels
have lymph nodes
which contain
phagocytic white
blood cells which
filter bacteria and
dead cells from the
lymph.

35. The Vascular SystemThe Vascular System
Slide 11.24
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Figure 11.8b

36. Blood Vessels: AnatomyBlood Vessels: Anatomy
Slide 11.25
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Three layers (tunics)
Tunic intima
Endothelium
Tunic media
Smooth muscle
Controlled by sympathetic nervous
system
Tunic externa
Mostly fibrous connective tissue

37. Differences Between Blood Vessel Differences Between Blood Vessel
TypesTypes
Slide 11.26
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Walls of arteries are the thickest
Lumens of veins are larger
Skeletal muscle “milks” blood in veins
toward the heart
Walls of capillaries are only one cell
layer thick to allow for exchanges
between blood and tissue

38. Movement of Blood Through Movement of Blood Through
VesselsVessels
Slide 11.27
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Most arterial blood is
pumped by the heart
Veins use the milking
action of muscles to
help move blood
Figure 11.9

39. Capillary BedsCapillary Beds
Slide 11.28a
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Capillary beds
consist of two
types of vessels
Vascular shunt –
directly connects an
arteriole to a venule
Figure 11.10

40. Capillary BedsCapillary Beds
Slide 11.28b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
True capillaries –
exchange vessels
Oxygen and
nutrients cross to
cells
Carbon dioxide
and metabolic
waste products
cross into blood
Figure 11.10

41. Capillary ExchangeCapillary Exchange
Slide 11.42
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Substances exchanged due to
concentration gradients
Oxygen and nutrients leave the blood
Carbon dioxide and other wastes leave the
cells

42. Capillary Exchange: MechanismsCapillary Exchange: Mechanisms
Slide 11.43
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Direct diffusion across plasma
membranes
Endocytosis or exocytosis
Some capillaries have gaps (intercellular
clefts)
Plasma membrane not joined by tight
junctions
Fenestrations of some capillaries
Fenestrations = pores