Download Heart Anatomy and Physiology Presentation

Chapter 15
Cardiovascular System
• heart
• blood vessels
Average Size of Heart
• 14 cm long
• 9 cm wide
15-2
Location of Heart
• posterior to sternum
• medial to lungs
• anterior to vertebral column
• base lies beneath 2nd rib
• apex at 5th intercostal space
• lies upon diaphragm
15-3
Coverings of Heart
15-4
Wall of Heart
Three layers
• endocardium
• forms protective inner lining
• membrane of epithelial and
connective tissues
• myocardium
• cardiac muscle
• contracts to pump blood
• epicardium
• serous membrane
• protective covering
• contains capillaries and
nerve fibers
15-5
Heart Chambers
Right Atrium
• receives blood from
• inferior vena cava
• superior vena cava
• coronary sinus
Right Ventricle
• receives blood from
right atrium
Left Atrium
• receives blood from
pulmonary veins
Left Ventricle
• receives blood from
left atrium
15-6
Heart Valves
Tricuspid Valve
• right A-V valve
• between right
atrium and right
ventricle
Bicuspid Valve
• left A-V valve
• between left
atrium and left
ventricle
Pulmonary Valve
• semilunar valve
• between right
ventricle and
pulmonary trunk
Aortic Valve
• semilunar valve
• between left
ventricle and aorta
15-7
Coronal Sections of Heart
15-8
Heart Valves
Tricuspid Valve
Pulmonary and Aortic Valve
15-9
Skeleton of Heart
• fibrous rings to which the heart valves are attached
15-10
Path of Blood
Through the Heart
15-12
Path of Blood
Through the Heart
15-11
Blood Supply to Heart
15-13
Cardiac Cycle
Atrial Systole/Ventricular Diastole
• blood flows passively into ventricles
• remaining 30% of blood pushed into ventricles
• A-V valves open/semilunar valves close
• ventricles relaxed
• ventricular pressure increases
Ventricular Systole/Atrial diastole
• A-V valves close
• chordae tendinae prevent cusps of valves from bulging too far
into atria
• atria relaxed
• blood flows into atria
• ventricular pressure increases and opens semilunar valves
• blood flows into pulmonary trunk and aorta
15-17
Heart Actions
Atrial Systole/Ventricular Diastole
Atrial Diastole/Ventricular Systole
15-16
Heart Sounds
Lubb
• first heart sound
• occurs during ventricular contraction
• A-V valves closing
Dupp
• second heart sound
• occurs after ventricular contraction
• semilunar valves closing
Murmur – abnormal heart sound
15-18
Heart Sounds
15-19
Cardiac Muscle Fibers
Cardiac muscle fibers form functional syncytia
• group of cells that function as a unit
• atrial syncytium
• ventricular syncytium
15-20
Cardiac Conduction System
15-22
Muscle Fibers in
Ventricular Walls
15-23
Regulation of Cardiac Cycle
• physical exercise
• body temperature
• concentration of various ions
• potassium
• calcium
15-28
Pulmonary Circuit
• consists of vessels that carry blood from the heart to the lungs
and back to the heart
15-50
Blood Flow Through Alveoli
• cells of alveolar wall are tightly joined together
• the high osmotic pressure of the interstitial fluid draws
water out of them
15-51
Systemic Circuit
• composed of vessels that lead from the heart to
all body parts (except the lungs) and back to the
heart
• includes the aorta and its branches
• includes the system of veins that return blood to
the right atrium
15-52