Transcript Cardiac anatomy and physiology

Cardiac anatomy and physiology
Announcements
*Next week’s 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.
This lab.
•Cardiac anatomy
•Cardiac physiology
•EKG (rest, exercise, and diving response)
•Blood pressure (sphygmomanometer and stethoscope)
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
-sulcus:mark 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
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 righ
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.
Cardiac Anatomy
-Fossa ovalis is the remnant of foramen oval which allow
bypass the lung during foetal life.
Cardiac Anatomy
2- Fish heart
-2 chambers
3-Amphibian heart
-2 atria and one ventricle
4-Reptiles heart
-3 chambers with partially divided ventricle
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.
Cardiac physiology
*Action potential= depolarization =contraction=systole
resting potential= repolarization =relaxation=distole
++++++++++ ---------------+++++++++++
---------------- +++++++++++----------------
cell mem
-70mV
*SA node(pacemaker), AV and purkinje fibers
*atria contract from top to bottom and ventricles
contract from apex to base
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 wave…artial contraction (0.1 second)
QRS wave…ventricular contraction (.06~.1 second)
T wave…ventricular relaxation
- PR interval is usually .2 second
Cardiac physiology
To do
*dissect sheep heart
*EKG demonstration for group of (5~6)
*measuring blood pressure by sphygmomanometer and
stethoscope