Transcript Adv Bio #10 - Cardiovascular

Cardiovascular
System
Evolution Of The
Human Heart
Muscular Tube
Heart
Evolution Of The
Human Heart
2 Chambered Heart
Evolution Of The
Human Heart
3 Chambered Heart
Evolution Of The
Human Heart
3+ or 4- Chambered
Heart
Evolution Of The
Human Heart
4 Chambered Heart
Cardiovascular System:
The Heart
• “Cardio’ refers to
heart.
• ‘Vascular” refers to
blood vessels.
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Cardiovascular System:
The Heart
• Heart pumps 30X it
weight in blood each
minute.
• 1800 gallons of blood
per day
• 50,000 miles of blood
vessels.
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Cardiovascular System:
The Heart
Cardiology is study of
heart and disease.
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Location of the Heart
The Heart
• Lies between the
two lungs.
• 2/3 of heart lies to
left of mid-line.
• Apex is bottom of
left ventricle.
Congestive Heart
Failure
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Pericardium
• Heart is enclosed
by pericardium.
• Composed of:
– Outer fibrous
pericardium
– Inner serous
pericardium.
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Pericardium
• Inner layer creates
pericardial fluid.
• Fluid lies in the
pericardial cavity.
• Fluid prevents
friction.
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Heart Wall
• Composed of three
layers:
– Epicardium (outer)
– Myocardium
(Muscle)
– Endocardium
(Inner)
Video:
Coronary Circulation
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Heart Wall
• Heart has two
different networks
of muscle fibers.
– Atrial
– Ventricular
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Heart Wall
• Each muscle fiber
connects with other
muscle fibers.
– Intercalated discs
connect fibers.
– They aid in
conducting impulses.
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Heart Wall
• Each muscle fiber
connects with other
muscle fibers.
– Intercalated discs
connect fibers.
– They aid in
conducting impulses.
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Heart Wall
• Endocarium lines
the inner surface
of the heart.
• Inflammation of
the lining can occur.
– Epicarditis
– Myocarditis
– Endocarditis
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Chambers of
the Heart
• Right and left atria
– Separated by interatrial
septum.
– Receives blood from
body.
– Pumps blood to the
ventricles.
– Separated from
ventricles by sulcus.
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Great Vessels
of the Heart
• Superior and
inferior vena cava.
– Returns blood from
body back to heart
• Pulmonary trunk
– Branches into rt. and
lt. pulmonary arteries.
– Takes blood to the
lungs.
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Great Vessels
of the Heart
• Pulmonary veins
– 4 in humans.
– Carry oxygenated
blood from lungs to
heart.
• Aorta
– Carries oxygenated
blood to all of the
body.
– Exits from left
ventricle.
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Atrioventriclular
Valves
• Tricuspid
– Three flaps
– Prevents blood from
moving back into the
right atria.
• Bicuspid
– Two flaps
– Prevents blood from
moving back into the
left atria.
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Semilunar Valves
• Pulmonary semilunar
valve.
– Prevents blood from
moving back into the
right ventricle.
• Aortic semilunar
valve.
– Prevents blood from
moving back into the
left ventricle.
– Valve replacement
surgery
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EKG
• Parts of EKG.
– P wave
– QRS Complex
– T wave
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Cardiac Cycle
• Three Phases
• First Phase
– Relaxation period
• All chambers in
diastole.
• Blood fills SL valves
• Blood flows into
atria & ventricles
from pulmonary veins
and vena cava.
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Cardiac Cycle
• Second Phase
– Ventricular filling
• SA node
stimulated
• P wave occurs
• Atria contract
(systole)
• Additional 25%
blood enters the
ventricles.
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Cardiac Cycle
• Third Phase
– Ventricular
Systole
• AV node
stimulated
• Ventricles in
systole.
• QRS wave occurs
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EKG
• Parts of EKG.
– P wave
– QRS Complex
– T wave
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Cardiac Output
• Definition:
– Amount of blood
pumped by either the
Rt or Lt ventricle per
minute.
– Stroke volume X beats
per minute.
– 70ml X 75 /min = 5.25
Liters/min.
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Control of
Heart Rate
• Cardiovascular
center.
– Cardiac accelerator
nerves. (sympathetic )
– Vagus nerve
(parasympathetic)
– Autonomic control
results from opposing
sympathetic and
parasympathetic
systems.
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Factors That
Effect Heart Rate
• Chemicals
– Epinephrine increases heart rate.
– Increased levels of K+ & Na+ slow
heart rate.
– Excess Ca++ increases heart rate.
– Low oxygen demands increase
heart rate.
• Temperature
– Increased heat accelerates heart
– Decreased temperature
decreases heaert rate.
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Risk Factors For
Heart Disease.
•
•
•
•
•
•
•
•
High Blood Cholesterol
High Blood Pressure
Smoking
Obesity
Lack of exercise
Diabetes
Genetics
Being Male until age 70
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Conduction
System Review
• Name structure A,B,C,D.
• Where does the delay
occur.
• Describe the rhythm that
must be created.
• Why is this rhythm needed?
• How does each cell f the
heart receive the impulse?
• What is the name of the
nerve that leads to the SA
node?
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A
B
C
D
Vascular System
• System of blood
vessels.
• 50,000 miles in length.
• Blood vessel types:
– Artery (carries blood
away from the heart)
– Vein (Carries blood to
the heart)
– Capillary (all gas
exchange occurs here)
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Arteries
• Hollow center is referred to
as a lumen.
• Wall is contructed of three
layers.
• Inner layer (Tunic Interna)
– Endothelium
– Elastic tissue
• Middle layer (Tunic Media)
– Smooth muscle
– Elastic fibers
• Outer layer (Tunic Externa)
– Elastic fibers
– Callagen
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Arteries
• Arteries are capable
of elasticity.
– Expand under the
pressure of the
ventricles contracting.
– Constrict when the
ventricles are relaxing.
• Constriction is due to
smooth muscle.
•
Constrict when injured.
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Arteries
• Vasodialation
– Lumen increased in size
due to smooth muscle
relaxation.
– Decreased stimulation
from sympathetic
system.
• Vasoconstriction
– Lumen decreased in size
due to smooth muscle
constriction.
– Increased stimulation
from sympathetic
system.
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Arterioles
• Smaller branches
from arteries.
• Arterioles take
blood to capillaries.
• Small arterioles
have mostly
– Endothelium
– Smooth muscle
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Capillaries
• Connect arterioles
to veins.
• Gas, waste, and
nutrient exchange
takes place here
between blood and
cells.
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Capillaries
• Composed of a single
layer of endothelium
and a basement
membrane.
• All cells must be close
to a capillary.
• Tissues using a lot of
energy must have more
capillaries.
• Capillaries form
networks to increase
surface area.
• Pre-capillary sphincter.
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Veinules
• Blood is returned to
veinules from
capillaries.
• Blood is on way back to
heart.
• Same in structure as
arterioles.
• Veinules get larger as
they move towards
heart.
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Veins
• Similar in structure to
arteries except;
• Middle layer is reduced.
• Inner layer folds
inward to form valves.
• Varicose veins.
• Veins act as blood
reservoirs
• Contain approximately
60% of blood.
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How Blood Is Pumped
Back To The Heart
• Blood Pressure
caused by heart
approx. 5 mmhg
after capillaries.
• Blood is moved due
to skeletal muscle
contraction.
• Backwards
movement is
prevented by valves.
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Coronary Circulation
• Circulation that
serves the heart
muscle.
– leads from the aorta.
– Carries oxygen to
heart muscle.
– Returns to the
coronary sinus
• Effects of
atherosclerosis
• Treatment
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