Exam 2 Review Flashcards
Describe the conduction system of the heart
SA node (60-100bpm)(if fails, AV node will kick in)(primary pacemaker, when stimulated it sends impulse to both atria’s)(atrial systole)
AV node (40-60)(if fails, right & left branches & perkinje fibers generate their own impulse)(slows down cardiac impulse to mechanically allow time for the ventricles to fill)(secondary pacemaker)
Bundle of His (40-60bpm)(nerves travel through septum)( if fails, right & left branches & perkinje fibers generate their own impulse)
Right & Left branches (20-40bpm)(split from bundle of his, travel to purkinje fibers)
Purkinje fibers (20-40bpm)(contract ventricles to send blood through aorta & pulmonary trunk)(ventricular systole)
Sympathetic stimulation results
Increased heart rate, increased force of contraction, increased impulse conduction, increased bloow flow through the coronary vessels to support the increased activity.
Parasympathetic stimulation
Slows the heart rate, reduces the force of the contraction, constricts the coronary arteries, saving energy between periods of increased demand.
Describe the differences in the right vs left lung
Right Lung: oblique and horizontal fissures that divide it into three lobes (superior, middle, inferior). Right lung is larger and heavier than the left but shorter and wider
Left Lung: single oblique fissure dividing it into two lobes (superior, inferior), anterior border of the left lung has a deep cardiac notch
Describe what happens at each valve of the heart during systole and diastole.
During diastole, the mitral valve and tricuspid valve open, pulmonary and aortic valve close.
During systole, the mitral valve and tricuspid valve close, pulmonary and aortic valve open.
What nerve innervates the diaphragm, describe the mechanics of inspiration/expiration, how is this affected with injury to the nerve which supplies the diaphragm?
Left and right phrenic nerves, one side is higher than the other, in unilateral diaphragmatic paralysis, the patient is often asymptomatic at rest and has dyspnea only during exertion
What structures provide static support for the arches of the foot, what structures provide dynamic support?
-Static support: plantar aponeurosis, long plantar ligament, plantar calcanecuboid (short plantar) ligament, plantar calcaneonavicular (spring) ligament
-dynamic support: Intrinsic muscles of the foot(longitudinal arch), flexors hallucis and flexor digitorum longus for the longitudinal arch, fibularis longus and tibialis posterior for the transverse arch
Please identify the spinal level associated with the most common deep tendon reflexes of the lower extremity.
Patellar Reflex- muscles involved (quadriceps), nerve supply (femoral), segmental innervation: L2-L4
Achilles Reflex-muscles involved (gastrocnemius, soleus), nerve supply (tibial), segmental innervation S1-S2)
List the accessory muscles of respiration, which are more helpful for inspiration vs expiration?
The scalene, sternocleidomastoid, pectoralis major, trapezius, external intercostals
The muscles more helpful for inspiration are sternocleidomastoid, scalenes, and external intercostals
Describe what happens in the heart during each of the following events on an EKG:
-P Wave;
Atrial Depolarization, two atriums are contracting
-PR Interval;
AV node delays the conduction of the electrical impulse from the atria for one tenth of a second, allowing for the mechanical contraction of the atria to eject blood into the ventricles (atrial kick)
-QRS Complex;
Ventricular Depolarization, ventricles are contracting
-ST Segment;
Depolarization and repolarization of the ventricles
-T Wave
Repolarization of the ventricular myocardium
-RR Interval
Represents the time taken between two QRS complexes
-QT Interval
Represents the time taken for the ventricles to depolarize and then repolarize
Trace the flow of blood from the venous system of the great toe back to the heart, through the lungs, back to the heart and down to the big toe, name each vessel and heart chamber through which the blood flows, in order.
Oxygen depleted blood starts in venous system of the big toe and travels to the heart through the great saphenous vein, external iliac, common iliac, and through the inferior vena cava. Deoxygenated blood goes into the right atrium, through tricuspid valve, into right ventricle. It will then go through the pulmonary semilunar valve, pulmonary artery, lobar artery, segmental artery, pulmonary capillary beds within alveolar walls, segmental veins, lobar veins, blood travels back through pulmonary veins where it will go into the left atrium, through the bicuspid valve, into the left ventricle. Blood then travels up aortic semilunar valve, into aortic arch, descending aorta, common iliac artery, external iliac artery, femoral artery, popliteal artery, anterior tibial artery, arterial system of great toe
Right coronary artery (RCA) origin
right aortic sinus
Right coronary artery (RCA) course
follows coronary (AV) sulcus between atrias and ventricles
Right coronary artery (RCA) distribution
right atrium, SA and AV nodes, and posterior part of IVS
Right coronary artery (RCA) anastomoses
Circumflex and anterior IV branches of LCA
