The heart

Independent work 
Theme: “The Heart” 

С.Ж.АСФЕНДИЯРОВ АТЫНДАҒЫ

ҚАЗАҚ ҰЛТТЫҚ МЕДИЦИНА УНИВЕРСИТЕТІ

КАЗАХСКИЙ НАЦИОНАЛЬНЫЙ МЕДИЦИНСКИЙ  УНИВЕРСИТЕТ ИМЕНИ  С.Д.АСФЕНДИЯРОВА

ЖАЛПЫ ГИГИЕНА ЖӘНЕ ЭКОЛОГИЯ КАФЕДРАСЫ

ПРАКТИКАЛЫҚ САБАҚТАРҒА АРНАЛҒАН ӘДІСТЕМЕЛІК ӨҢДЕУ ҚҰРЫЛЫМЫ

Plan

• Anatomy of the Heart
• Relation to Thoracic Cavity
• 3 Layers of the Heart Wall
• Structure of the heart
• Heart Rate

Anatomy of the Heart

• Located directly behind sternum

Y

Figure 20–2a

PLA

Relation to Thoracic Cavity

Figure 20–2b

Surrounded by pericardial sac

Between 2 pleural cavities

In the mediastinum

Superficial Anatomy of the Heart

• 4 cardiac chambers
• Atria - Thin-walled
• Expandable outer auricle
• Coronary sulcus:
• divides atria and ventricles
• Anterior and posterior interventricular sulci:
• separate left and right ventricles
• contain blood vessels of cardiac muscle

Figure 20–3

The Heart Wall

Figure 20–4

3 Layers of the Heart Wall

• Epicardium:- outer layer
• Visceral pericardium , Covers the heart

• Myocardium: middle layer, Muscular wall
• Concentric layers of cardiac muscle tissue
• Atrial myocardium wraps around great vessels
• 2 divisions of ventricular myocardium

• Endocardium: inner layer

• The heart has 4 chambers:
• 2 for pulmonary circuit:
• right atrium and right ventricle
• 2 for systemic circuit:
• left atrium and left ventricle
• Left ventricle has a greater workload
• Is much more massive than right ventricle, but the two chambers pump equal amounts of blood
• AV valves prevent backflow from ventricles into atria
• Semilunar valves prevent backflow from aortic and pulmonary trunks into ventricles

Chambers of the Heart

Heart Rate

• SA node generates 80–100 action potentials per minute
• Parasympathetic stimulation slows heart rate
• AV node generates 40–60 action potentials per minute

4 Phases of the Cardiac Cycle

0. Atrial systole
1. Atrial diastole
2. Ventricular systole
3. Ventricular diastole

Question

• Where is located the heart?
• How called the 3 Layers of the Heart Wall
• How many chambers does it have?
• What can you say about heart rate?