Anatomy and Physiology 2 Exam 2

• 1. Sinoatrial (SA) node
• 2. Internodal pathways
• 3. Atrioventricular (AV) node
• 4. AV Bundle
• 5. Bundle Branches
• 6. Purkinje Fibers

• P wave-atrial depolarization
• QRS complex-ventricle depolarization, atrial relaxation
• T wave-ventricular repolarization

• Systole
• Diastole

• Atrium contraction to top off the volume in the ventricle
• Sound-S4

• Venticularr contraction and forces the blood upward and the AV valves close
• The first heart sound is heard S1 or lub

The aboutof blood pumped by each ventricle in one minute

CO = HR x SV

• Ventricular relaxation
• The semilunar valves close
• The second heart sound is heard S2 or Dup

blood ejected during ventricular systole

EDV-ESV=SV

at the completion of atrial systole each ventricle is full and the amount in both equal EDV

Increase in HR=Shorter diastole=smaller EDV

Increase in venous return=larger EDV and vice versa

The percentage of the EDV represented by the SV

EF = SV/EDV as a percent

the amount of blood remaining in each ventricle at the end of ventricular systole

EDV - SV = ESV (End Systolic Volume)

Degree of stretch on the heart before it contracts

the forcefulness of contraction of individual ventricular muscle fibers

The pressure that must be exceeded before ejection of blood from the ventricles can occur

The more the heart fills with blood during diastole, the greater the force of contraction during systole

the strength of contraction

Increase=positive inotropic agents-Promote Ca inflow-SNS (NE/E)

Decrease=negative inotropic agents-Reduce Ca inflow- PNS takes over

The pressure that must be overcome before the Semilunar valve will open

Ejection of blood from the heart begins when pressure in rt. ventricle is greater than the pressure in the pulmonary trunk (20mmHg) and pressure in lt ventricle exceeds pressure in the aorta (80mmHg)

Increase after load=decrease in SV

• Autonomic innervation
• Hormones
• Venous return

autonomic headquarters for cardiac control

Increase heart rate (SNS)

slow the heart rate (PNS)

• BP (barorecptors)
• Oxygen levels (chemoreceptors)

• Resting autonomic tone
• Steady background levels of both divisions

• Protects the heart
• Around the heart
• Loose allow heart to move

• Outer layer
• Prevents overstretching, protection, and anchoring

inner thin membranous layer

outer serous membrane lining the cavity

• attached to the surface of the heart
• Also called Epicardium

• filled with serous fluid
• decreases friction acros surface tissues

• The cardiac muscle
• Responsible for the pumping action of the heart

• the innermost layer
• a thin layer of connective tissue covered by endothelium
• continuous with the lining of the blood vessels

Recieves de oxidized blood from the sstemic circulation

Muscular Ridges

• Atrioventricular valve
• movement of blood from right atrium to right ventricle

blood is pumped from the right ventricle into the pulmonary trunk through the pulmonary semilunar valves

papillary muscles that hold the valve closed when the ventricle contracts

• left and right pulmonary arteries
• branch repeatedly in lungs
• at capillaries CO2 is exchanged for O2
• Oxygenated blood dumped into left atrium

receives blood from four pulmonary veins which ha just been oxygenated in the lungs

• guards the entrance to the left ventricle
• also called bicuspid valve/mitral valve

R and left coronary artery in the central sulcus get blood before any cell in the body

Interconnection between arteries

The r and l coronary arteries drain deoxygenated blood into the right atrium on the posterior surface of the heart

• Technique that measure the electrical potentiol changes that occur in the heart during the cardiac cycle
• Monitored by electrodes on the skin
• Electrocardiograph
• Leads detect differences in electrical potential between two points

abnormal sound consiting of a clicking, rushing, or gurgling sound heard before, between, or after normal heart beat