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 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.

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 mV *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