Circulatory System III: Heart Flashcards
Heart Location
Left hand side of body in thoracic cavity
Located behind sternum and left ribs
Heart Orientation
Apex - (Bottom Left)
BAse (On top where majority of vessels come out)
Four Chambers of Heart
2 Atrium
2 Ventricles
Heart enclosed in
Pericardium
Pericardium Components
Fibrous Pericardium
Serous Pericardium
Fibrous Pericardium
Outmost layer
Dense CT
Fibrous Pericardium Function
Prevent heart frfom overfilling, restricts heart movement
Serous Pericardium Components
Parietal Layer
Visceral Layer
Parietal Layer
Adhers to fibrous pericardium
Visceral Layer
Adheres to heart wall
Pericardial Cavity
Between the Parital and Visceral Layer, has small amount of fluid so as heart beats, no friction occurs
Heart Layers
Endocardium
Myocardium
Epicardium
Endocardium
Specialized simple squamos epithelium for contact with blood
Endothelium convering a CT Layer
Lines inside of the heart and covers its valves
Myocardium (Cardiac Muscle)
Thickest Layer
Epicardium (Visceral Layer of the Serous Pericardium)
Thin serous membrane and some fat
Right Atrium
Receives venous blood from superior and inferior venae cavae
*Blood will flow from right atrium to right ventricle through right tricuspid valve
Right Ventricle; Papillary Muscles
Three Papilary Muscles
Right Ventricle; Chordae Tendineae
From the papillary muscles to the three flaps of the right AV valve.
Chordae Tendineae function
Strands prevent the flaps from being everted into the atrium by the contracting ventricle
Right Ventricle; Blood Flow
Blood runs from the right ventricle through the Pulmonary Semilunar Valve into the Pulmonary Trunk
*Will now travel into the pulmonary arteries into the lungs
Left Atrium
Receives oxygenated blood from the lungs via 3 or four pulmonary veins
*Blood will flow from the left atrium to the left ventricle via the Left Bicuspid Valve
Left Ventricle
Pumps oxygenated blood into the aorta
Blood is pushed form the from the left ventricle through the Aortic Semilunar Valve
Steps of the Heart (1)
Blood LOW in oxygen enters right atrium
Steps of the Heart (2)
blood from right atrium goes to right ventricle
Steps of the Heart (3)
lood from the right ventricle goes through pulmonary trunk
Steps of the Heart (4)
pulmonary trunk branches into pulmonary arteries, which carry blood to lungs
Steps of the Heart (5)
exchange of gases occurs in the lungs
Steps of the Heart (6)
oxygenated blood travels through pulmonary veins to left atrium
Steps of the Heart (7)
blood from left atrium goes to left ventricle
Steps of the Heart (8)
blood from left ventricle is pumped through the aorta
Steps of the Heart (9)
blood travels through the blood vessels throughout the body, will return to right atrium of the heart, and the cycle repeats!
Right and Left Coronary Artery
These vessels come off of the aorta and take nutrients and oxygen to the tissue of the heart
Venous Circulation
Most of these veins unite/drain into the Cononary Sinus (Back of the Heart)
Conducting System of the Heart
The heart exhibits autorhythmicity which means the heart itself (and not external nerves) are responsible for initiating the heartbeat
Heart Conduction System (1)
Sinocartial (SB) Node: Located in upper wall of right atrium - it is responsible for initiating the heartbeat
*Nerve impulse travels from SA Node to AV Node
Heart Conduction System (2)
Atrioventricular (AV) node: lies in the floor of the right atrium
*Transmits nerve impulse to the atrioventricular bundle
Heart Conduction System (3)
Atrioventricular bundle: a bundle of conducting muscle fibers that runs through the interventricular septum and splits into:
Heart Conduction System (4)
Left and right bundle branches: each bundle branch goes to its respective ventricle
*Bundle branches and sends nerve impulse to Purkinje Fibers
Heart Conduction System (5)
Purkinje fibers: special conduction muscle cells
*Are larger than other cardiac muscle fibers and extend through the walls of the ventricles. This is where contraction of muscle actually occurs.
Sympathetic Innervation can ____ the heart beat
Increase
Parasympathetic Innervation can ____ the heart beat
Decrease
Steps of Heart Conduction System
Sinoatrial Node Atrioventricular Node Atrioventricular Bundle Bundle Branches (L&R) Purkinje Fibers