8 - Cardiovascular system (inked)

Kirby of the Day

  • Piranha Plant Kirby

Cardiovascular Overview

Cardiovascular Part 1: Electrical and Mechanical Events of the Heart

The Cardiac Cycle

  • Definition: A cycle comprising the left and right atrium, oxygenated versus deoxygenated blood flow.

  • Pathway:

    • Right Atrium: Receives deoxygenated blood via Vena Cavae.

    • Right Ventricle: Pumps deoxygenated blood via Pulmonary Arteries.

    • Left Atrium: Receives oxygenated blood from Pulmonary Veins.

    • Left Ventricle: Pumps oxygenated blood via Aorta.

Exam Guide

  1. Describe the cardiac cycle and its electrical and mechanical events.

  2. Identify the two types of cardiac muscle cells.

  3. Understand the conduction pathway: SA node, location, etc.

  4. Compare action potentials of autorhythmic cells and typical neurons, including ion involvement.

  5. Draw and label a cardiac autorhythmic cell AP.

  6. Know the main neurotransmitters from SNS and PNS and their effects on heart rate.

  7. Understand the changes in heart rate with SNS and PNS alterations.

  8. Differentiate effects of SNS and PNS on cardiac AP and graph faster/slower heart rates.

Mechanics of the Heart

Systole and Diastole

  • Systole: Contraction phase; ~1/3 of cardiac cycle.

  • Diastole: Relaxation phase; ~2/3 of cardiac cycle.

Cross Bridge Cycle

  • Involves calcium, troponin, tropomyosin, actin, myosin, and ATP.

Valves of the Heart

  • Important valves: Left AV, Right AV, Pulmonary SL, Aortic SL.

  • Their action during the cardiac cycle.

Blood Flow Trace

  • Pathway of RBC starting from Right Atrium through the system and back.

  • Oxygenation and deoxygenation points:

    • Deoxygenated from right to left circulation.

    • Oxygenated from left atrium to aorta.

Electrocardiogram (ECG/EKG)

Key Components

  • P Wave: Atrial depolarization.

  • QRS Complex: Ventricular depolarization.

  • T Wave: Ventricular repolarization.

  • Understand segments and intervals: PR, QT, etc.

Common Pathologies

  • Tachycardia: HR > 100 bpm

  • Bradycardia: HR < 60 bpm

  • Arrhythmias: Irregular heart rate.

  • Heart Block: Communication issues between SA and AV nodes.

Understanding Autorhythmic Cells

  • Spontaneous generation of action potentials at the SA node.

  • Differences with typical neuron action potentials.

  • Role of ion channels in response mechanisms.

Autonomic Nervous System Influence

  • SNS increases heart rate; PNS decreases it.

  • Interaction between SNS and PNS in heart rate modulation.