Transcript Anatomy of the Cardiovascular system Notes

Chapter 15
Cardiovascular System
Organs
• Heart - begins beating in the 4th week
of development.
– Pumps 7,000 liters of blood each day.
– Contracts 2.5 million times in a lifetime.
• Closed Vessel System
– Arteries - carry blood away from the
heart.
– Veins - carry blood toward the heart.
– Capillaries - attach arteries and veins.
Function
• Circulates blood to every cell in the
body and removes waste.
The Heart
• Location and Size
– Size of a man’s fist (14
cm long and 9 cm wide)
– Lies within the
mediastinum - behind
sternum (rests on
diaphragm).
– 2/3 of the heart is on
the left side of the
body.
– Apex is the lower, left
“point” of the heart.
• Stethoscope is placed
here to count the beats.
•
–
Coverings
Pericardium - sac around
the heart - loose-fitting
•
•
–
Fibrous - tough white outer
covering,
Serous parietal - smooth
lining of the fibrous sac.
Epicardium - covers surface
of the heart - smooth
•
–
The Heart
Also called serous visceral
pericardium
Pericardial space - area
between pericardium and
epicardium
•
•
•
Contains fluid - pericardial
fluid
Lubricates beating heart
Pericarditis - inflammation
of pericardium due to
infection - linings stick
together, very painful.
The Structure of the Heart
• The wall of the
heart:
– Epicardium – reduces
friction.
– Myocardium – thick
contractile middle
layer, high in
mitochondria.
– Endocardium – delicate
inner layer.
The Structure of the Heart
Continued
• Cavities
– Upper – atria
– Lower – ventricles
• Larger and thicker
walled
• Carry heavier pumping
burden
• Left is thickest – has
to pump blood to all
parts of the body
The Structure of the Heart
Continued
• Valves and Openings
• Blood flows in one
direction.
– Cuspid valves – between cavities
(atria and ventricles)
• Bicuspid (mitral) valve - left
cavities.
Valve has 2 cusps or leaflets.
Also called the left
atrioventricular valve.
• Tricuspid valve - right
cavities.
Valve has 3 cusps or leaflets.
Also called the right
atrioventricular valve.
The semi-lunar valve moves
blood out of the heart to the
aorta and pulmonary artery.
i.
Cusps of valve are half
moon shaped (‘lunar’)
Found at the base of the
pulmonary arteries (called the
pulmonary valve) and at the
base of the aorta (called the
aortic valve)
•
Attached by fibrous
strings called chordae
tendineae to the papillary
muscles.
Tricuspid valve repair
A murmer is an abnormal sound that
identifies the leakage of blood
though valves in the wrong direction
16
15
4
2
14
(auricle)
13
5
(auricle)
6
11 – left coronary artery
12
10
8
9 - Apex
Left auricle
Right auricle
Auricle = A small, earlike projection
that extends anteriorly from the atrium.
1. Aortic arch
9. Right ventricle
2 . Superior
Vena cava
10. Inferior
Vena cava
3.Right
Pulmonary
Artery
11. Aorta
1
3
12. Interventricular
Septum
18
5
4. Pulmonary trunk
5. Right
Pulmonary
Veins
6. Pulmonary
Valve
4
2
11
17
16
7
13. Left ventricle
14
6
14. Bicuspid valve
(Mitral valve)
8
9
13
15
10
15. Aortic valve
16. Left atrium
7. Right
Atrium
8. Tricuspid valve
12
17. Left pulmonary
Veins
18. Left pulmonary
artery
The Structure of the Heart
Continued
• Blood Supply
– Ventricles get blood from the right and
left coronary arteries.
– Atria get blood from the small branch
coronary artery.
– Anastomosis is branching of the main
arteries (“detours”)
– Myocardial infarction - death of the heart
muscles due to a clot (heart attack).
Blood Vessels
• Structure
– Outer – fibrous tissue,
keeps firm
– Middle – muscle,
constriction, and dilation.
– Inner – endothelium capillaries
Blood Vessels Continued
• Function
– Transportation of nutrients to cells
• Capillaries perform this function
• Arteries = distributors arterioles
capillaries venules veins
• Veins = carry and pool blood
Blood Vessels Continued
• Main Blood Vessels
–
–
–
–
–
ascending aorta
aortic arch
subclavian
common carotid
common iliac
Ascending
Aorta
Blood Vessels Continued
Blood Vessels Continued
• Portal Circulation
– Organs that do not pour blood into inferior
vena cava.
– Blood sent to the liver by the portal vein.
Blood Vessels Continued
• Fetal Circulation
– Gets oxygen and food from mother, not own
lungs and digestive tract.
– Additional vessels
Shed at
birth
• Umbilical arteries (2) – carry fetal blood to
placenta
• Placenta – exchanges oxygen and other
substances between mother and fetus
• Umbilical vein – returns oxygenated blood to
liver of fetus
• Foramen ovale – opening between right and left
atria bypass lungs, closes with first breath.