Transcript right ventricle - Blyth-Exercise

• Eric Lindross
• http://www.youtube.com/watch?v=WVeqzYgTELk
• Daniel Alfredsson
• http://www.youtube.com/watch?v=jE5Nz2efcW8
• Marion Hossa
• http://www.youtube.com/watch?v=fY9CmK86fhs
• Sidney Crosby
• http://www.youtube.com/watch?v=yQQ7lmeWqBI
• http://www.youtube.com/watch?v=fFkWTGKNLT8
Colt McCoy
• http://www.youtube.com/watch?v=VASrGGsC234
• Junior Seau
• http://www.youtube.com/watch?v=mxK5MafuNWs
Cardiovascular System
Role of Cardiovascular
System
• Transport O2 and nutrients to tissues
• Remove CO2 and waste products from
tissues
• Maintenance of constant body
temperature
• Prevention of infection
Anatomy of the Heart
• Cardiac muscle
• About size of fist
• Located in thoracic cavity
between lungs directly
behind sternum
• Titled  Apex (pointed
end) is oriented to left
Walls of heart:
1. Pericardium – protective sac (reduces friction)
2. Epicardium – outer layer
3. Myocardium – layer made of cardiac muscle
4. Endocardium – innermost layer
The “Double Pump”
• Right and left heart
• Separated by interventricular
septum
• Right heart = right pump
– Pump deoxygenated blood (just
returned from body) to the lungs
– Pulmonary circulation
• Left heart = left pump
– Pump oxygenated blood (just
returned from lungs) to the rest of
the body
– Systemic circulation
• 4 chambers
– Upper chambers = Atria (right & left)
– Lower chambers = Ventricles (right & left)
• Left ventricle (thickest) – pump blood through entire
body
• Right ventricle – pump blood short distance to lungs
Heart Valves
• Atria & ventricles separated by valve =
Atrioventricular (AV) valves
– Allows only one flow of blood (atria  ventricles)
– Right side of heart  tricuspid valve
• Prevent backflow from right ventricle to right atrium
– Left side of heart  bicuspid (or mitral) valve
• Prevent backflow from left ventricle to left atrium
• Valves where blood leaves ventricles
– Right side of heart  Pulmonary semilunar valve
• Prevent backflow from pulmonary arteries to right ventricle
– Left side of heart  Aortic semilunar valve
• Separates aorta from left ventricle
Pathway of Blood Flow
• Right atrium receives deoxygenated blood from superior
& inferior vena cava
– Superior vena cava = returns blood from upper body
– Inferior vena cava = returns blood from lower body
• Blood moves from right atrium (through tricuspid vavle)
to the right ventricle (passes tricuspid valve)
• Pumped out of pulmonary arteries (through pulmonary
semilunar valve) to lungs pumps it to the lungs
(pulmonary circulation)
• Oxygenated blood returns from lungs  now
O2-rich
• Through pulmonary veins into left atrium (only
time a vein carries O2-rich blood!)
• Blood travels from left atrium (through bicuspid
valve) to left ventricle
• Blood enters aorta (through aortic semilunar
valve) & pumps to the whole body
This is known as SYSTEMIC CIRCULATION
Cardiac Cycle
• Series of Events that lead to one heart
beat
• Relaxation = diastole
• Contraction = systole
• When blood pressure is measured it’s
systolic pressure (120 mm Hg)/diastolic
pressure (80 mm Hg)
Arteries, Veins & Capillaries
• Arteries = vessels that carry blood away from heart
• Veins = vessels that carry blood toward heart
• Capillaries = microscopic vessels, 40, 000 km in length,
exchange gasses and nutrients by diffusion between blood
and tissues
• In systemic circulation, arteries carry
oxygenated blood from heart to body tissues,
while veins carry deoxygenated blood back
to heart
• In pulmonary circulation, pulmonary
arteries carry deoxygenated blood from heart
to lungs, while pulmonary veins carry
oxygenated blood from lungs back to heart
Excitation of the Heart
• SA node = Pacemaker
• AV node passes signal
from atrium to ventricle
• Purkinje fibres contract
ventricles to push
blood through
pulmonary
veins/arteries
EKG
• P wave-atrial depolarization
and immediate
repolarization
• QRS complex-depolarization
of ventrical
• T wave-ventricular
repolarization
Blood Composition
Cardiac Output
• Q = L/min
• At rest Q = 5-6 L/m, during exercise Q =
30 L/min
Stroke Volume
• Is the amount of blood that is ejected from
the left ventricle in a single beat
• SV (mL) = LVEDV (mL) – LVESV (mL)
• SV is regulated by 3 main factors:
– LVEDV
– Aortic blood pressure
– Strength of ventricular contraction
Heart Rate (HR)
• Number of times the heart contracts per minute
• Cardiac output is the product of stroke volume
and heart rate:
• Q (L/min) = SV (mL) x HR (beats/min)
• Avg HR at rest = 72 b/min, average SV = 71 mL,
therefore Q = 5040 mL/min or 5L/min
Cardiovascular Drift
• Initially during exercise, both SV and HR
will increase, but after prolonged exercise
SV may drop while HR continues to rise to
maintain Q. This phenomena is called
cardiovascular drift.
Blood distribution changes during exercise:
• moving blood from less important systems and organs
like the digestive tract, to more important areas, like
muscles and the heart.
• The brain always receives a constant supply (by volume)
of blood, while the heart receives a constant % of blood.
• Training will increase the efficiency of all of these factors
at rest:
– (BP (down), Q (up), HR (down), SV (up))
• may increase the diameter of the coronary arteries and
even blood volume.