the heart sbi 3u ms. raper. the heart is a pump actually it is two pumps one pump deals with blood...
TRANSCRIPT
The Heart
SBI 3U
Ms. Raper
The Heart
• Is a pump• Actually it is TWO pumps• One pump deals with blood to the lungs, the
other pump deals with blood to the body.• Heart is made of Cardiac Muscle• The two sides are separated by a thick wall of
muscle called the SEPTUM• The blood for the two pumps is kept separate in
mammals.
Fetal Heart circulation
• Because the fetus is not using its lungs, the blood is “shunted” between the right and left atria through a hole called the foramen ovale. This usually closes shortly before birth.
• Babies who do not have the foramen ovale closed are born with a “hole in the heart”
This diagram shows the path taken by the blood through the heart.
Use the following link to label the heart.
http://www.bishopstopford.com/faculties/science/arthur/Heart%20drag&drop.swf
http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/table22-3_blood_flow_th.jpg
http://learninglab.co.uk/headstart/
Cardiac Muscle
The synchronous beating of the cardiac muscles are controlled by bundles of nerves.
Structure of the Heart.
• Four chambers, 2 upper called ATRIA
2 lower called VENTRICLES
• The Right side of the heart receives deoxygenated blood from the body via the superior and inferior vena cava.
• The Left side receives oxygenated blood from the lungs via the Pulmonary veins
Valves of the Heart• The atria and ventricles are separated by one way atrioventricular
valves.• Between the right atria and right ventricle is the TRICUSPID valve• Between the left atria and left ventricle is the MITRAL valve.• SEMILUNAR valves are found at the base of the PULMONARY
artery and AORTA.• The purpose of the valves is to prevent blood flowing backwards.• Leaking of these valves can result in a heart murmur
Watch the heart valves at this link
• http://www.wellesley.edu/Biology/Courses/111/HeartValves.MOV
Cardiac Cycle - Heart Beat.
• Phase 1 SYSTOLE – Contraction
“Occurs when the Ventricles contract, closing the AV Valves and opening the SL Valves to pump blood into
two major vessels leaving the heart.”
• Phase 2 DIASTOLE – Relaxation
“Occurs when the Ventricles relax, allowing the back pressure of the blood to closed SL Valves and opening
AV valves.” (Mr. Johnson)
http://www.sirinet.net/~jgjohnso/circulation.html
http://www.biologymad.com/HeartExercise/HeartE3.gif
http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/f22-11_cardiac_cycle_c.jpg
http://www.owensboro.kctcs.edu/gcaplan/anat2/notes/Notes5%20Cardiac%20Cycle.htm
Check out the following link.
EKG - electrocardiogram• Records the electrical activity of
the heart.• S-A node generates an electrical
impulse that spreads over the two atria causing them to contract.
• S-V node causes the ventricles to contract.
• P to Q represents the small electrical voltage increase due to depolarization when the atria contract.
• The large spike Q-S represents the contraction of the ventricles.
• As the ventricles recover, a small spike at T precedes the next firing of the S-A node
• Check this link
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookcircSYS.html
Chemical Regulators of the Heart
• Noradrenaline: increase in CO2 stimulates receptors in the blood vessels. The Medulla oblongata sends impulses to produce noradrenaline, this chemical causes the S-A node to fire more rapidly
• Acetylcholine: increase in blood pressure causes receptors in the blood vessels to send the information to the medulla oblongata which in turn causes the release of acetylcholine. This chemical slows the firing of the S-A node.
Other chemicals that affect the heart….
• Nicotine – increases heart rate• Caffeine - increases heart rate• Amphetamine – increases heart rate• Cocaine – increased heart rate• Anabolic steroids – increased blood pressure.• Barbiturates – slow pulse• Alcohol - decreases heart rate
• http://www.nida.nih.gov/DrugPages/DrugsofAbuse.html
Cardiac Output & Fitness
• Like all muscles, the heart needs exercise• The volume of blood pumped out by the heart is
known as the CARDIAC OUTPUT.• Factors that affect cardiac output are heart rate
and stroke volume• Cardiac output = heart rate X stroke volume
Average person data
• Stroke volume = 70mL
• Heart rate = 70 beats/minute
• Cardiac cycle = 70mL X 70beats/min
• = 4900mL/min
• There is a correlation between heart health and fitness
Relationship between stroke volume, heart rate & and cardiac output
Individual Cardiac output
Stroke Volume
mL/beat
Heart Rate
Beats/min
A 4900 70 70
B 4900 50 98
C 4900 140 35
D 9800 70 140
•C is exceptionally fit has a high stroke volume and maintain a low hear rate.
•B is less fit
•Regular cardiovascular exercise increases the resting stroke volume.
•Fitness is measured by how quickly the heart rate returns to the resting rate before exercise began.
http://www.owensboro.kctcs.edu/gcaplan/anat2/notes/Notes5%20cardiac_equations.htm
Resources that you need to review
• Text – Chapter 9• Mr. Johnson’s biology –chapter 46.• http://www.sirinet.net/~jgjohnso/circulation.html• Professor Fajer – Circulation, Heart & Blood• http://fajerpc.magnet.fsu.edu/Education/
2010/2010_INDEX.HTM• Online Biology Book: Circulation
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookcircSYS.html
Check out these
• Biology animations: http://science.nhmccd.edu/biol/index.html
• Anatomy & Physiology II http://science.nhmccd.edu/biol/ap2.html
• Science animations: http://science.nhmccd.edu/biol/animatio.htm
• And especially -http://science.nhmccd.edu/biol/ap2int.htm
• Check out the section on cardiovascular.• Anatomy of the Heart:
http://www.owensboro.kctcs.edu/gcaplan/anat2/notes/Notes5%20Anatomy%20of%20the%20Heart.htm