Lecture Notes: Surface Anatomy and Heart Sounds
Introduction
- Presenter: Dr. Mike
- Topics: Surface anatomy of the heart and heart sounds ("lub-dub").
Heart Location and Anatomy
- Position:
- Heart is located within the chest, specifically in the mediastinum.
- Sits behind the ribcage and sternum, with lungs on either side.
- Approximate position: Fist at sternum, move slightly left, tilt towards left hip.
- Base at second rib, apex at fifth intercostal space (midclavicular line).
Finding the Heart's Apex
- Steps:
- Go midclavicular, trace down to nipple, feel below for fifth intercostal space.
- Apex beats against chest wall at this space.
Heart Structure Overview
- Anatomy:
- Heart has two atria (top) and two ventricles (bottom).
- Blood flows: Atria → Ventricles → Out of heart.
Heart Valves
- Atrioventricular Valves:
- Right Side: Tricuspid valve (between right atrium and right ventricle).
- Left Side: Bicuspid/Mitral valve (between left atrium and left ventricle).
- Semilunar Valves:
- Pulmonary Semilunar Valve: Controls blood flow from right ventricle to pulmonary artery.
- Aortic Semilunar Valve: Controls blood flow from left ventricle to aorta.
Heart Sounds
- Lub-Dub Sounds:
- Lub (S1): Closure of atrioventricular valves; heard as the first heart sound.
- Dub (S2): Closure of semilunar valves; heard as the second heart sound.
Auscultation Techniques
- Purpose: To detect murmurs or issues in heart function.
- Heart Sound Locations:
- Mitral Valve: Listen at the apex (fifth intercostal space, left side).
- Tricuspid Valve: Fifth intercostal space, move more medially.
- Pulmonary Valve: Second intercostal space, left side.
- Aortic Valve: Second intercostal space, right side.
Clinical Relevance
- The sternum may muffle heart sounds; specific auscultation points are used to better hear valve functions and detect murmurs.
These notes cover the key points from Dr. Mike's presentation on surface anatomy related to the heart and the associated heart sounds.