Flashcards in Chapter 20 Deck (84):
Right side of the heart
Left side of heart
Functions of the heart
One way blood flow
Regulating blood supply
Double-layered closed sac that surrounds the heart
Inflammation of serous pericardium
Large volume of fluid or blood accumulates in pericardial cavity and compresses the heart from the outside
Tough, fibrous connective tissue outer layer
Thin, transparent inner layer
Function of fibrous pericardium
Prevents overdistension of heart and anchors it within mediastinum.
Serous pericardium lining fibrous pericardium
Serous lining that covering surface of heart
Space between visceral and pericardia, filled with pericardial fluid
Function of pericardial fluid
Reduce friction as heart moves in pericardial sac
3 layers of heart wall
Epicardium, myocardium, endocardium
Thin serous membrane. Smooth outer surface of heart
Thick, middle layer of heart. Cardiac muscle
Smooth, inner surface of the heart chambers
Muscular ridges in auricles and right atrial wall
Ridge separate pectinate muscles from smooth atrial wall
Interior walls of ventricles. Large muscular ridges and columns
Extensions of atria that be seen anteriorly between each atrium and ventricle
Superior and inferior vena cava
Carry blood to right atrium
Four pulmonary veins
Blood from lungs to left atrium
Two arteries that exit heart
Aorta, pulmonary trunk
Runs obliquely around the heart, separates atria from ventricles
Anterior and posterior interventricular sulcus
Division between left and right ventricles
Right and left coronary arteries
Supply heart. Lie within coronary sulcus and interventricular sulci
Direct connection between arteries of heart
Veins from heart itself drain into here, then right atrium
Right atrium openings
Superior/inferior vena cava and coronary sinus
Divides two atria
Oval depression on right side of septum marking former location of foramen ovale
Opening between the right and left atria in the embryo and fetus
In both ventricles. Cone shaped muscular pillars
Attached to papillary muscles and atrioventricular valves. Thin, strong connective tissues.
Function of papillary muscles
Contract when ventricles contract. Prevent valves from opening into atria by pulling on chordae tendineae.
Plate Of fibrous connective tissue between atria and ventricles
Connective tissue plate forms fibrous rings around atrioventricular and semilunar valves.
Heart skeleton functions
Support, reinforce valve openings, electrical insulation, point of attachment
Cardiac muscle cells
Elongated, branching cells that have one or two nuclei.
Smooth sarcoplasmic reticulum
Cardiac muscle. Not arranged.
Binds cells end to end
Hold cells together
Allow cytoplasm to flow freely between cells. Low electrical resistance between cells
Relays action potentials through the heart
Sinoatrial node location
SA node. Right atrium, near superior vena cava
AV node. Medial to the right atrioventricular valve.
Bundle of His
Atrioventricular bundle. From AV node. Travels to septum, splits to right and left branches
Inferior terminal branches of the bundle. Electrical signals pass rapidly.
Resting membrane potential
Low permeability to Ca2+ and Na+. Higher permeability to K+.
Any part of the heart other than the SA node that generates a heartbeat
Absolute refractory period
Cardiac muscle cell is completely insensitive to further stimulation
Relative refractory period
Cell is sensitive to stimulation, but greater than normal stimulus to cause AP
Summated record of the cardiac action potentials
Depolarization of atrial myocardium
Ventricular depolarization (contraction)
Repolarization of ventricles. (Relaxation)
When used alone, systole and diastole
Refer to ventricular systole and diastole.
Determines direction of blood movement
First heart sound
Low pitched "lubb". Atrioventricular valves close.
Second heart sound
Higher pitched "dupp". Closure of aortic and pulmonary semilunar valves.
Third heart sound
Thin, young. Turbulent blood flow into ventricles.
Aortic valve closes, causing higher pressure in aortic pressure curve. Pressure caused by recoil creates double pulse
Mean arterial pressure
MAP=CO X PR
Total resistance against which blood must be emptied.
Heart rate X stroke volume
Difference between cardiac output when at rest and maximum cardiac output
Hearts own regulatory function.
Epinephrine and norepinephrine from adrenal medulla
Sympathetic and parasympathetic
Extent to which ventricular walls are stretched
Starling law of the heart
Relationship between preload and stroke volume. Pumping effectiveness
Pressure left ventricle must produce to overcome pressure in aorta.
Vagus nerve. Inhibitory influence. Acetylcholine
Thoracic and spinal nerves. Increase heart rate, force of contraction. Norepinephrine
Epinephrine and norepinephrine from adrenal medulla. Increase rate and force
Regulate blood pressure. Carotid and aorta
Regulate hearts activity. Sensitive to pH and CO2
Cardio regulatory center
Sensory action potentials integrated. Medulla oblongata
Excess K+ in tissue heart rate and stroke volume decrease. Loss of AP conduction
All blood vessels have this internal lining
Between basement membrane and endothelial cells. Fibroblasts, macrophages, smooth muscle