Presentation on: Describe the gross anatomy of heart under following: external features, surface markings and areas of auscultation. List the components of examination of Cardiovascular System. Define cardiac cycle and its phases. Define venous return, stroke volume, cardiac output, preload, afterload and ejection fraction with their normal range.

1. Problem Based Learning
Presented by : Group “C”
Facilitator: Major Dr. Shavana Rana
Nepalese Army Institute of Health Sciences
College of Medicine
1

2. OBJECTIVES
• Describe the gross anatomy of heart under following:
external features, surface markings and areas of
auscultation.
• List the components of examination of
Cardiovascular System.
• Define cardiac cycle and its phases.
• Define venous return, stroke volume, cardiac output,
preload, afterload and ejection fraction with their
normal range.

3. Heart
• Conical hollow muscular organ
• Situated in the middle mediastinum
• Within the pericardium.

4. External Features
•Dimensions – 12 X 9 cm.
•Weight – M=300 gm, F=250 gm
Apex
•Left ventricle
•Left 5th intercostal space, medial to midclavicular line 9 cm
lateral to midsternal line.
Base(Posterior surface)
Consists left atrium(mainly), small part of right atrium
Location
• Supine – T5-T8 vertebra
• Standing – descends by 1vertebra

6. 4 CHAMBERS
• 2 Atria –Right and Left
• 2 Ventricles – Right and Left
GROOVES
1. Atrioventricular (Coronary sulcus)
2. Interatrial groove
3. Interventricular groove.

7. SURFACES
1. Anterior (Sternocostal)
2. Inferior (Diaphragmatic)
3. Left pulmonary surface
4. Right pulmonary surface
BORDERS
1. Superior
2. Inferior
3. Right
4. Left

8. SURFACES
1. Anterior (Sternocostal)
2. Inferior (Diaphragmatic)
3. Left pulmonary surface
4. Right pulmonary surface
BORDERS
1. Superior
2. Inferior
3. Right
4. Left

9. Surface Markings

10. Areas of Auscultation

11. Components of Cardiovascular Examination
INSPECTION
Shape of the precordium
Pulsations in the precordium
Pulsations outside the precordium
Look for distended veins in neck and thorax.
PALPATION
Apex beat
Cardiac thrill
Parasternal heave
Palpable P2
Determination of JVP

13. PERCUSSION
Gives information regarding cardiac borders.
Dullness in the precordium.
AUSCULTATION
Function of heart valves.
State of myocardium and pericardium.
Four areas of auscultation.

14. Cardiac Cycle
• Cardiac events that occur from the beginning of
one heart beat to the beginning of the next.
• Cardiac cycle consists of a period of relaxation
called diastole, during which the heart fills with
blood, followed by a period of contraction called
systole.
Phases of cardiac cycle
1. Atrial Systole
2. Atrial Diastole

15. 3. Ventricular Systole
a. Phase of Isovolumetric Contraction
b. Phase of ventricular Ejection
i. Phase of rapid ejection (lesser duration)
ii. Phase of reduced ejection (longer duration)
4. Ventricular Diastole
a. Phase of Isovolumetric Relaxation
b. Phase of ventricular filling
i. Rapid filling phase
ii. Reduced filling phase

16. Cardiac Cycle
• Cardiac events that occur from the beginning of
one heart beat to the beginning of the next.
• Cardiac cycle consists of a period of relaxation
called diastole, during which the heart fills with
blood, followed by a period of contraction called
systole.
Phases of cardiac cycle
1. Atrial Systole
2. Atrial Diastole

17. 3. Ventricular Systole
a. Phase of Isovolumetric Contraction
b. Phase of ventricular Ejection
i. Phase of rapid ejection (lesser duration)
ii. Phase of reduced ejection (longer duration)
4. Ventricular Diastole
a. Phase of Isovolumetric Relaxation
b. Phase of ventricular filling
i. Rapid filling phase
ii. Reduced filling phase

19. Venous Return
Venous return is the amount of blood that returns to the right
atrium from systemic venous circulation each minute.
Normal value is: 5 L/min
Stroke Volume
Stroke volume(SV) is defined as the volume of blood ejected by each
ventricle with each beat.
Normal Stroke volume is about 70 ml.

20. Cardiac Output
Cardiac output is the quantity of blood pumped into the aorta each
minute by the heart.
This is also the quantity of blood that flows through the circulation.
Cardiac Output = Stroke volume × heart rate
Normal value: For young healthy men: 5.6 L/min
For women: 4.9 L/min
Preload
The degree of tension on the muscle when it begins to contract.
For cardiac contraction it is usually considered to be the end diastolic
pressure when the ventricle has become filled.

21. Afterload
It is the load against which the muscle exerts its contractile force.
Afterload of the ventricle is the pressure in the aorta leading from
the ventricle.
Cardiac output is inversely proportional to the afterload.
Ejection Fraction
The percentage of end-diastolic volume ejected with each beat is the
ejection fraction.
It is the percentage ratio of stroke volume to end diastolic volume,
i.e. EF = SV/ EDV × 100
Normal value: Normally EF is about 65%

22. References
• Textbook of Medical Physiology, Guyton and Hall, 13th
edition, 2016.
• Textbook of Medical Physiology, GK Pal, 2nd edition, 2014.
• Gray’s Anatomy for Students, 3rd edition, 2013.
• BD Chaurasia’s Human Anatomy, volume 1, 7th edition, 2015.
• Macleod’s Clinical Examination, 13th edition,2013.