Block 5: The Circulatory System Flashcards
Where is the heart located in relation to other organs?
The heart is located in the thoracic cavity between the lungs. The heart rests on top of the diaphragm.
List the major external features of the heart.
Apex
Base
Right Auricle
Left Auricle
Coronary Sulcus
Anterior Interventricular Sulcus
Posterior Interventricular Sulcus
Ligamentum Arteriosum
Great Vessels
List the great vessels of the heart.
External Features!
Aorta:
Brachocephalic Trunk
Left Common Carotid Artery
Left Subclavian Artery
Arch of Aorta
Ascending Aorta
Descending Aorta
Ligamentum Arteriosum
Veins:
Superior Vena Cava
Inferior Vena Cava
Left Pulmonary Veins
Right Pulmonary Veins
Arteries:
Pulmonary Trunk
Left Pulmonary Artery
Right Pulmonary Artery
What is special about the heart during fetal development?
The heart starts apex up, and turns slowly during fetal development.
The ligamentum arteriosum starts as the ductus arteriosus and is a hole during fetal development.
List the layers of the heart and heart wall from superficial to deep.
Fibrous Layer
Parietal Pericardium
Pericardial Cavity: prevents friction and allows heart to expand
Visceral Pericardium/Epicardium
Myocardium
Endocardium: lubricates chambers
List the major internal features of the heart.
Right Atrium
Left Atrium
Right Ventricle
Left Ventricle
Tricuspid Valve
Bicuspid Valve
Pulmonary Valve
Aortic Valve
Interventricular Septum
Chordae Tendineae
Papillary Muscles
Trabeculae Carneae
Categorize the different heart valves and state which “sound” of the heart beat they make
Atrioventricular Valves (LUB sound)
Tricuspid Valve
Bicuspid Valve
Semilunar Valves (DUP sound):
Pulmonary Valve
Aortic Valve
Where is the Interatrial Septum and what structures does it have?
Interatrial Septum: Internal of Right Atrium
Structures: 2 holes to allow blood flow
Fossa Ovalis - superior hole (unique to fetal heart, closes after birth)
Coronary Sinus - inferior hole
Where are the Pectinate Muscles?
Internal Right Atrium
List the arteries associated with Coronary Circulation.
LAC RMP
Left Coronary Artery: Anterior ventricular artery (A ventricles and interventricular septum), Circumflex artery (L atrium & ventricle)
Right Coronary Artery: Marginal artery (R atrium & ventricle), Posterior ventricular artery (P ventricles and interventricular septum)
List the veins associated with Coronary Circulation.
Great Cardiac Vein (L ventricle)
Middle Cardiac Vein (Posterior)
Small Cardiac Vein (R ventricle)
Coronary Sinus
List the structures involved in electrical activity of the heart.
SA node
AV node
AV bundle
Right bundle branch
Left bundle branch
Purkinje fibers
What does the SA node do?
Sets the heart rate (pacemaker!)
Describe how the nervous system is involved in electrical activity of the heart.
Parasympathetic (rest & digest) slows the heart rate
Sympathetic (fight & flight) increases the heart rate
Describe the histology of cardiac muscle tissue.
Cardiomyocytes joined by intercalated discs
1-2 nuclei
Gap junctions within intercalated discs that allow flow of ions –> electrical signal conduction –> uniform contraction
Describe the segments of an ECG.
P wave: atrial depolarization
QRS complex: ventricular depolarization and atrial repolarization
T wave: ventricular repolarization
PR interval: signal conduction through AV node
QT interval: duration of ventricular depolarization
PQ segment: signal conduction from SA node to AV node
ST segment: ventricular systole and ejection of blood
Define the terminology associated with the different heart rates.
Systole: contraction
Diastole: relaxation
Tachycardia: fast heart rate
Bradycardia: slow heart rate
Stroke Volume: amount of blood pumped out per systole
Cardiac Output: blood output per minute
End-Diastolic Volume: blood in ventricle before ejection
End-Systolic Volume: blood in ventricle after ejection
Equation to find Cardiac Output
CO = Stroke Volume x Heart Rate
CO units: volume/minute
Equation to find Stroke Volume
SV = Cardiac Output / Heart Rate
SV = End-Diastolic Volume - End-Systolic Volume
SV units: volume/ventricular systole
Define the key terminology for blood vessels: anastomosis, trunk, and portal
Anastomosis: vessel that allows for a different blood flow route
Trunk: large, short vessel that immediately branches
Portal: vessel that connects 2 capillary beds in a series
List and discuss the different anastomoses.
Arteriovenous anastomosis: direct connections between small arteries and veins to reduce heart loss by bypassing exposed areas
Arterial anastomosis: direct connections between arteries to provide an alternative route in case of injury
Venous anastomosis: direct connections between veins to help with temperature regulation within the body
Compare vasoconstriction and vasodilation
Vasoconstriction is the contraction of smooth muscle, causing a decrease in lumen size and an increase in blood pressure.
Vasodilation is the relaxation of smooth muscle, causing an increase in lumen size and a decrease in blood pressure.
List the three types of vessels and discuss their functions.
Arteries carry blood away from the heart and branch into smaller arterioles.
Capillaries are very small and are the site of exchange for gases, nutrients, and waste.
Veins carry blood to the heart and merge from venules into larger veins.
List and discuss the features of the three types of arteries.
Elastic arteries are large in diameter and are made of large amounts of elastic fibers to accommodate for higher amounts of pressure.
Muscular arteries are small in diameter and use smooth muscle contraction to propel blood.
Arterioles control blood flow into capillaries and regulate blood pressure.
