1. Anatomy of the Cardiovascular System
Anatomy & Physiology

2. Heart song

3. Location of the heart
In mediastinum behind the sternum between 2nd & 6th ribs. Shifted to left.
Posteriorly between 5th to 8th thoracic vertebrae
Apex (lowest point) lies on diaphragm

4. Pericardium Sac covering the heart
Fibrous pericardium – tough, inelastic
Serous pericardium- 2 layers
Parietal layer- lines fibrous pericardium
Visceral layer (epicardium)- adheres to outside of heart; space between parietal & visceral layer contain small amount of fluid

5. Function of pericardium
Provides protection against friction

6. Layers of the heart Epicardium (also the serous pericardium)
Myocardium-thick contractile layer of muscle cells
Endocardium-cover trabeculae (muscular projections); specialized folds of endocardium make up the major valves of heart

7. Chambers of heart Atria: upper chambers Ventricles: lower chambers
Chambers are separated by an extension of heart wall, septum

8. Atria Receive blood from veins Send blood to ventricles
Thin myocardial wall
Auricle: earlike flap protruding from each atrium

9. Ventricles Receive blood from the atria
Pump blood out of heart into arteries
Thicker myocardium
Myocardium of left ventricle thicker than right ventricle

10. Permit flow of blood in one direction
Heart valves
Permit flow of blood in one direction
Atrioventricular valves
Semilunar valves

11. Atrioventricular valves
Made of flaps of endocardium
Flaps anchored to papillary muscle by chordae tendineae
Rt AV valve: tricuspid valve
Lt AV valve: mitral (bicuspid) valve

12. Semilunar valves Consists of half moon shaped flaps
Pulmonary semilunar valve: at the entrance to the pulmonary artery
Aortic semilunar valve: at the entrance to aorta

13. Flow of blood through the heart

14. Heart video

15. Blood supply to heart
Blood supplied thru the right & left coronary arteries
Coronary arteries are first branches off aorta
After blood has passed thru capillary beds, enters cardiac veins then thru common channel, coronary sinus, then into rt atrium

16. Conduction system of heart
Sinoatrial node (pacemaker): in rt atrium near opening of superior vena cava
Atrioventricular node: in rt atrium along lower part of interatrial septum
Atrioventricular bundle: originate in AV node & extend by 2 branches thru the 2 sides of the interventricular septum
Purkinje fibers: extension of AV bundle out to the lateral walls of the ventricles & papillary muscles

17. Conduction System

18. Blood vessels
Arteries: carry blood away from heart
Arterioles: small arteries
Veins: Carry blood toward heart
Venules: small veins
Capillaries: microscopic blood vessels that carry blood from arterioles to venules

19. 3 layers of blood vessels
Tunica adventitia: outer layer, fibrous connective tissue
Tunica media: layer of smooth muscle & elastic connective tissue
Tunica intima: made of smooth endothelium

20. Blood Vessel Structure
Type of vessel
Tunica intima
Tunica media
Tunica adventitia
artery
Smooth lining
Thicker than in veins
Thinner than tunica media
vein
Smooth lining with valves
Thinner than in arteries
Thicker than tunica media
capillary
Makes up entire wall: very thin
absent

21. Functions of capillaries
Transport materials to and from cells
Capillaries so numerous & so small that blood flows at its slowest rate in capillaries

22. Functions of arteries Function as “distributors”
Arterioles also function as resistance vessels
Smooth muscle cells on arterioles act as precapillary sphincters where a capillary originates

23. Functions of veins
Return blood to heart
Act as reservoir vessels
Ability to stretch by veins called capacitance thus veins are capacitance vessels

24. Circulatory routes
Systemic circulation: blood flow from heart to all parts of body (except lungs)
Pulmonary circulation: blood flow from heart to lungs

25. Arteries
End-arteries: most of the arteries, they diverge into capillaries
A few arteries open into branches of other arteries; this communication is an arterial anastomosis
Incidence of arterial anastomosis increases as distance from the heart increases

26. Aorta
Major artery that serves as trunk of the entire systemic arterial system
First few cm conducts blood up away from lt ventricle-ascending aorta
Then turns 180 degrees- aortic arch
Then downward from arch-descending aorta

27. Veins
Large veins that return blood to heart in systemic circulation are superior & inferior vena cava