New A & P 2 Lecture (Bio 2320)-20250305_110418-Meeting Recording

Overview of Cardiac Physiology

Complexity of Material: Understanding heart physiology requires careful examination of images and concepts discussed in class.
Resources and Office Hours: Encourage students to utilize office hours for clarification on complex topics, with specific persons mentioned (Dmitry and Katherine).

Physiology Coloring Book: Emphasizes the complexity of physiology compared to anatomy. Students can opt to submit these coloring pages instead of standard pages from the anatomy coloring book.

Focus on Lower Body Vessels: The complexity of lower body vessels is significant; students are advised to prepare in advance for next week’s lab.

Understanding Action Potential Transmission: Discusses how epinephrine and norepinephrine affect the SA node’s depolarization and the sympathetic nervous system's influence on heart rate.
Calcium Role in Depolarization: Highlights that calcium is crucial for SA node activity, while potassium plays a role in repolarization.

Finish Chapter 20: An objective to complete discussions around key cardiac cycles and EKG readings before moving on to Chapter 21.
Cardiac Cycle Events: Understanding the significance of the P wave, QRS complex, and T wave.

P Wave: Represents atrial depolarization, where the wave travels from the SA node to the AV node—contraction aligns with this segment.
QRS Complex: Indicates ventricular depolarization and the simultaneous repolarization of the atria.
ST Segment: No electrical activity occurs; the ventricles are in contraction but no voltage change present.
T Wave: Indicates ventricular repolarization.

Isovolumetric Contraction: Initial contraction phase following the QRS complex where blood volume remains constant.
Ejection Phase: Ventricles contract, generating pressure to eject blood into the aorta and pulmonary trunk.
End Systolic Volume: Volume remaining in the ventricles post-contraction (about 50-60 milliliters).
Isovolumetric Relaxation: Phase post-ejection where the heart muscle is relaxing, and all valves are closed.
Passive Ventricular Filling: Blood passively flows from the atria to the ventricles.
Atrial Kick: Active portion of filling where atria contract to empty the final blood volume into the ventricles.

Heart Sounds: Understanding turbulence associated with heart sounds is important; 1st sound (lub) occurs at AV closure & 2nd sound (dub) at semilunar valve closure.
EKG Timing: Events are outlined in relation to EKG phases, highlighting transitions from depolarization to contraction and relaxation states.

Ectopic Action Potential: Discuss consequences of neurons firing from atypical locations—can arise from injury or inflammation.
Common EKG Signs: Larger P waves may indicate atrial enlargement; larger Q waves signify a potential myocardial infarction.
Potassium Levels: Noting the significance of hyperkalemia and hypokalemia in relation to cardiac health.

Next Class: Will advance into the next chapter whereas further exploration of cardiac regulatory mechanisms occurs. The importance of linking these physiological concepts within a clinical context is emphasized.