Unit 6.1 - Cardiovascular System Functions and Components

Cardiovascular System Functions

Facilitates exchange: nutrients, gases, metabolites, and heat.

Enhances communication: signal molecules like hormones.

Establishes defense: inflammatory response, antibody-antigen interaction, hemostasis.

Cardiovascular System Components

Muscular Pump (Heart)

Distribution Networks (Blood Vessels)

Transport Medium (Blood)

Cardiac Tamponade

Buildup of pericardial fluid within the pericardial sac.

Muscular Pump

Located in the thoracic cavity.

4-chambered heart (2 atria and 2 ventricles).

5 sub-systems: pacemaker and conducting systems, heart muscle (myocardium), heart valves, coronary circulation, autonomic innervation.

Pacemaker & Conducting Systems

2 sets of intrinsic pacemaker tissues in heart: sinoatrial node (70-80bpm) and atrioventricular node (40-60bpm)

Cardiac Action Potential Pathway

1. SA Node

2. Internodal Pathways

3. AV Node

4. Bundle of His

5. Left and Right Bundle Branches

6. Purkinje Fibers

7. Left and Right Ventricular Myocardium

Heart Muscle (Myocardium)

Has various wall thicknesses: atria (2mm), right ventricle (3-4mm), left ventricle (8-9mm).

2 features: intercalated discs that connect cells tightly, gap junctions to allow for quickly passing electrical cells

Heart Valves

4 sets of valves: aortic valve (semilunar), pulmonary valve (semilunar), bicuspid valve (mitral), tricuspid valve.