Heart and Circulation

Question 1

Three paths of circulation

Answer 1

Pulmonary circuit (heart to lungs to heart)
Systemic circuit (heart to body to heart)
Coronary circuit (heart to heart to heart)

Vessels in general
Arteries (efferent)
Veins (afferent)

Question 2

Heart Anatomy and Major Vessels

Answer 2

Chambers (rt. & lft. Atria, rt. & lft. Ventricles)

Epicardium, parietal pericardium, pericardial sac, pericardial fluid

Auricle

Question 3

Heart Anatomy and Major Vessels

Answer 3

Coronary sulcus

Anterior interventricular sulcus

Posterior interventricular sucus

Base and Apex of heart

Question 4

Heart Anatomy and Major Vessels

Answer 4

Interatrial septum

Interventricular septum

Superior and inferior vena cava

Fossa ovalis and foramen ovale

Question 5

Heart Anatomy and Major Vessels

Answer 5

Tricuspid valve (right atrioventricular valve)

Cordae tendineae

Papillary muscles

Question 6

Heart Anatomy and Major Vessels

Answer 6

Pulmonary semilunar valve

Pulmonary trunk, right and left pulmonary arteries

Right and left pulmonary veins

Question 7

Heart Anatomy and Major Vessels

Answer 7

Bicuspid valve (left atrioventricular valve or mitral valve)

Aortic semilunar valve

Aorta (ascending, aortic arch, descending)

Question 8

Heart Wall

Answer 8

Epicardium

Myocardium

Endocardium

Question 9

Cardiac Muscle

Answer 9

Smaller than skeletal
Single nucleus
Contraction = shortening of sarcomeres
Many mitochondria and reserves of myoglobin, glycogen and lipids
Intercalated disks
Areas of interlocking membranes
Allow for rapid propagation of action potentials and “pulling together” of several cells during contraction

Question 10

Heartbeat

Answer 10

Contractile cells
Produce contractions
Depolarization, plateau, repolarization
Conducting system
Control and coordinate activities of contractile cells
Nodal cells (sinoatrial SA and atrioventricular AV)
Conducting cells (AV bundle, bundle branches, Purkinje fibers)
Pacemaker cells (SA node fire 70-80 action potentials per minute)

Question 11

Heartbeat

Answer 11

Conducting system
SA node is electrically connected to the AV node
Under certain circumstances AV can also function as a pacemaker (40-60 action potentials per minute)
AV bundle (bundle of his)
Left and right bundle branches
Purkinje fibers

Question 12

Abnormal heart rate or rhythms

Answer 12

Bradycardia
( 100 bpm)
Arrhythmia
Abnormal patterns

Question 13

ECG (EKG)

Answer 13

Segments and Intervals
P-wave
QRS complex
T-wave
T-P segment and heart rate