Your SlideShare is downloading. ×
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Lec16(cvs)
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Lec16(cvs)

1,409

Published on

0 Comments
3 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
1,409
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
37
Comments
0
Likes
3
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. The Heart as Pump and Function of the Heart Valves
  • 2. The Heart Pumps
    The Heart Two separate pumps
    Right heart that pumps blood through the lungs
    Left heart that pumps blood through the peripheral organs
    Each of these hearts compose of an atrium and a ventricle
  • 3. Pulmonary circuit
    blood to and from the lungs
    Systemic circuit
    blood to and from the rest of the body
    Vessels carry the blood through the circuits
    Arteries carry blood away from the heart
    Veins carry blood to the heart
    Capillaries permit exchange
    The cardiovascular system is divided into two circuits
  • 4. Heart Chambers
    Two Atria- upper chambers
    Interatrialseptum- separates right and left atrium
    Right atrium receives blood from the systemic circulation via superior and inferior vena cavae, while left atrium receives blood from the lungs via pulmonary veins
    Two Ventricle- lower chambers
    Interventricular septum- separates right and left ventricles
    Right ventricle supplies the lung circuit via pulmonary artery. Left ventricle supplies the systemic circuit via aorta
  • 5. Heart Wall
    Pericardium
    Double layered structure enclose the heart
    Myocardium
    Compose of cardiac muscle, thick muscular layer
    Endocardium
    smooth inner lining
  • 6. Heart Wall
    Pericardial cavity contains 5-30 ml of pericardial fluid
  • 7. Heart Valves
    Atrioventricular valves (A- V valves) prevent backflow of blood from the ventricles to atria during systole
    Tricuspid valve- between right atrium and right ventricle
    Bicuspid valve- between left atrium and left ventricle
    The tricuspid and mitral valves consist of flaps which are attached at the periphery of the valve ring
    Chordae Tendinae, cord like structures originate from papillary muscles are attached to the free edges of the valve flaps
  • 8. Semilunar valves- prevent backflow from the aorta and pulmonary arteries into the ventricles during diastole
    Pulmonary valve- between pulmonary artery and right ventricle
    Aortic valve- between aorta and left ventricle
    Heart Valves
  • 9. Heart Valves
    Except the mitral valve, all the remaining heart valves consist of 3 flaps
  • 10. Internal Anatomy Anterior Aspect
  • 11. Heart Flow
    Blood flows through the heart from areas of higher blood pressure to lower
    Deoxygenated blood from the body enters the right atrium of the heart through the vena cava
    Blood flows from right atrium through the tricuspid valve into the right ventricle
    Ventricular pumping pushes blood through pulmonary valve out the pulmonary trunk to the lungs
  • 12. Heart Flow con’t.
    Blood becomes oxygenated in the lungs and enters the left atrium
    Blood flows through the bicuspid valve into the left ventricle
    Ventricular pumping pushes oxygenated blood out the aortic valve
    Blood travels to all parts of the body to drop of needed oxygen
  • 13.
  • 14. AV Valve Mechanics
    Ventricles relax, pressure drops, semilunar valves close, AV valves open, blood flows from atria to ventricles
    Ventricles contract, pressure rises, AV valves close, (papillary m. contracts and pulls on chordae tendineae to prevent the bulging of valve into the atria) pressure rises and semilunar valves open, blood flows into arteries
  • 15. Operation of Atrioventricular Valves
  • 16. Operation of Semilunar Valves
  • 17. Physiology of Cardiac Muscle
    The heart composed of three types of cardiac muscle
    Atrial muscle
    Ventricular muscle
    Excitatory and conductive muscle fibers
  • 18. The atrial and ventricular types muscle contraction is similar to skeletal muscle contraction, i.e., sliding-filaments but duration of contraction is much longer
    Excitatory and conductive fibers exhibit automatic rhythmical electrical discharge in the form of action potential
    Physiology of Cardiac Muscle
  • 19. Short, thick, branched cells, 10 to 20 m wide with one central nucleus
    Sarcoplasmic reticulum
    T tubules much larger than in skeletal muscle, admit more Ca2+ from ECF during excitation
    Intercalated discs, join myocytes end to end
    mechanical junctions tightly join myocytes
    gap junctions form channels allowing ions to flow directly into next cell
    Structure of Cardiac Muscle
  • 20. Structure of Cardiac Muscle Cell
  • 21. Differences Between Skeletal and Cardiac Muscle Physiology
    Action potential of skeletal muscle is caused by opening fast sodium channels.
    Action potential in cardiac muscle is caused by fast sodium channels and slow calcium channels
  • 22. Differences Between Skeletal and Cardiac Muscle Physiology
    Action Potential
    Cardiac: Action potentials conducted from cell to cell
    Duration 0.25 sec
    Skeletal, action potential conducted along length of single fiber
    Duration 1 – 5 msec
    Rate of Action Potential Propagation
    Slow in cardiac muscle because small diameter of fibers 0.3-0.5 m/sec.
    Faster in skeletal muscle due to larger diameter fibers 3-5 m/sec.
    Calcium release
    Movement of extracellular Ca2+ through plasma membrane activate the muscle contractile process in cardiac muscle
    Action potential in T-tubule stimulates Ca++ release from sarcoplasmic reticulum
  • 23. Refractory Period of Cardiac Muscle
    The refractory period of the heart is the interval of time during which a normal cardiac impulse cannot re-excite an already excited area of the cardiac muscle.
    Lasts 0.25-0.30 sec in ventricles
  • 24. Refractory Periods
    Skeletal Muscle
    Cardiac Muscle
    Cardiac muscle tissue has a longer refractory period than skeletal muscle. This prevents the heart from going into tetany.

×