Cardiac anatomy and physiology

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Cardiac anatomy and physiology
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Announcements
Next weeks lab will be a field trip to the
desert. Students should wear appropriate
footwear (not open-toed sandals). It is also
advisable to bring a hat and water. We will
meet in the lab before going on the trip. Be
sure to arrive to lab on time. Assignment for
this lab include pages 129, 130, 131, 132 and
133.
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This lab.

• Cardiac anatomy
• Cardiac physiology
• EKG (rest, exercise, and diving response)
• Blood pressure (sphygmomanometer and stethoscope)

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Cardiac Anatomy
1-Mammalian and avian heart -4 compartments
-Divided circulation (pulmonary and systemic)
-Both sides pump blood at the same rate (
circulatory collapse) -right side contain
the least oxygenated blood while the left
side, the most oxygenated blood. -2 atria at
the base and 2 ventricle toward the apex
-sulcusmark the division of the chambers, adapt
the coronary arteries and is covered with
fat. -pulmonary arteries carry deoxygenated
blood from the right side to the lungs
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Cardiac Anatomy

• pulmonary veins carry oxygenated blood from the
  lung
• to the left side of the heart.
• -Aorta carry oxygenated blood from the left side
  of the
• heart to the rest of the body.
• -Aortic semilunar valve, prevent blood back-flow
  into the
• left ventricles during ventricular
  repolarization
• -Tricuspid valve allow blood flow from right
  atrium to right
• ventricle but not vice versa
• -Bicuspid (mitral valve) do the same function but
  at the
• left side.
• -Chordae tendineae are strands of connective
  tissue that
• anchor flaps of the valves in place.

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Cardiac Anatomy
-Fossa ovalis is the remnant of foramen oval
which allow bypass the lung during foetal life.
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Cardiac Anatomy
2- Fish heart -2 chambers 3-Amphibian heart
-2 atria and one ventricle 4-Reptiles heart
-3 chambers with partially divided ventricle
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Cardiac physiology

• The heart has its own electrical system that is
  able to
• initiate contractions.
• The rate of contractions is under control of the
  nervous
• system (autonomic versus somatic nervous
  system)
• impulse is the way stimuli (excitatory or
  inhibitory) is
• transmitted over the cardiac muscle fibers cell
  membrane.
• It is essentially outflow/inflow of positive and
  negative ions
• across the cell membrane.

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Cardiac physiology
Action potential depolarization
contractionsystole resting potential
repolarization relaxationdistole
---------------
cell mem ----------------
----------------
-70mV
SA node(pacemaker), AV and purkinje
fibers atria contract from top to bottom and
ventricles contract from apex to base
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Cardiac physiology
Electrocardiograph (EKG) -record electrical
changes produced by the heart muscle
contraction. -it compare the electrical
potential difference between 2 electrodes on
the surface of the body (volts) - P waveartial
contraction (0.1 second) QRS waveventricular
contraction (.06.1 second) T
waveventricular relaxation - PR interval is
usually .2 second
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Cardiac physiology
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To do
dissect sheep heart EKG demonstration for group
of (56) measuring blood pressure by
sphygmomanometer and stethoscope