Term 2 Exam: The Cardiovascular System Flashcards
What are the two circulatory systems?
- Pulmonary
- Systemic (includes pulmonary)
What is the difference between arteries and veins?
Arteries: Carry blood away from the heart
- High in O2 in the systemic circulation
- Low in O2 in the Pulmonary circulation
Veins: Carry blood to the heart
- Low in O2 in the systemic circulation but high in O2 in the pulmonary circulation
Where does the heart lie?
in the mediastinum with 2/3 of its mass to the left of the midline
What is the fibrous pericardium? What are three functions
The superficial, tough, inelastic, dense irregular connective tissue
Functions:
- prevents overstretching of the heart
- provides protection
- anchors heart to mediastinum
What is the serous pericardium?
Thin, double serous membrane
Divided into parietal and visceral pericardium
What is Pericardial fluid?
Secretion in the pericardial cavity that reduces friction between serous membranes
What is the epicardium?
External layer of the mesothelium (simple squamous epithelium) and connective tissue (fibro-elastic and adipose)
What is the Myocardium?
middle, muscular layer
*95% of heart wall
What is the endocardium?
inner thin layer of epithelium
- Covers the valves and is continuous with the endothelium of blood vessels
What are four characteristics of the cardiac muscle fibers?
- shorter and less circular transverse sections than skeletal muscle
- branched
- intercalated discs containing desmosomes and gap junctions
- larger and more numerous mitochondria
what are the three major grooves (sulci) of the heart?
- Coronary sulcus
- Anterior interventricular sulcus
- Posterior interventricular sulcus
What are the two superior chambers of the heart?
Right and left atria
- Recieve blood returning to the heart via the veins
What are the two inferior chambers of the heart?
Right and left ventricles
- Powerful pumps
What does the pulmonary pump consist of?
Right atrium and Right Ventricle
Services the pulmonary circuit
-moves deoxygenated blood through the lungs
What does the systemic pump consist of?
Left atrium and left ventricle
- services the systemic circuit
- pumps oxygenated blood to all systems in the body
What is the coronary sinus?
Receives blood from the wall of the heart
What type of blood does the right atrium receive and from which three blood vessels?
The right atrium receives deoxygenated blood from:
- Superior Vena Cava
- Inferior Vena Cava
- Coronary Sinus
What separates the two atria?
Interatrial Septum
What is the Fossa Ovalis and from which fetal structure does it arise?
The fossa ovalis is a depression on the septum
It is a remnant of the foramen ovale of the fetal circulatory system
What is the valve between the right atrium and the right ventricle?
Right atrial ventricular valve (tricuspid valve)
* has three folds or flaps (cusps)
What are trabeculae carneae and what is the purpose?
Raised bundles of muscles that form deep ridges in the ventricles - allow ventricle to stretch (when filling with blood)
What structure separates the two ventricles?
The interventricular Septum
What structure does blood pass as it heads to the lungs via the pulmonary arteries?
Pulmonary valve
The left atrium receives _______ blood from four _________.
oxygenated blood from four pulmonary veins (2 for each lung).
Which valve is between the left atrium and the left ventricle?
Atrioventricular valve (aka bicuspid valve or mitral valve)
Which valve is between the left ventricle and the aorta?
Aortic valve
Which arteries branching from the ascending aorta supply the walls of the heart?
The right and left coronary arteries
What is the fibrous skeleton of the heart?
dense connective tissue embedded in the walls of the heart
Provide 4 functions of the fibrous skeleton of the heart
- prevent overstretching of the valves
- secure valves to the heart wall
- point of insertion for bundles of cardiac muscle fibers
- Provide electrical (nerve signal) insulator between atria and ventricles
Name the four valves in the heart in the order that blood passes through them:
- Right atrioventricular (AV) valve (tricuspid Valve)
- Pulmonary Valve
- Left Atrioventricular (AV) Valve (Bicuspid valve)
- Aortic Valve
What are the semilunar valves?
The pulmonary valve and the aortic valve
What is the path of blood through the heart starting at the right atrium?
- Right atrium receives deoxygenated blood from the superior vena cava, inferior vena cava and coronary sinus and empties it through the tricuspid valve into the Right ventricle.
- Right ventricle pumps blood through the pulmonary valve and into the pulmonary trunk and pulmonary arteries
- Blood passes into pulmonary capillaries where gas exchange occurs
- The pulmonary veins return oxygen rich blood to the Left Atrium
- The left atrium empties blood through the Bicuspid valve and into the Left Ventricle
- The left ventricle pumps blood passed the aortic valve to the Aorta and systemic arteries which carries blood to the rest of the body for exchange of nutrients and gasses.
What are four key tributaries that carry blood to the coronary sinus?
- Great cardiac vein
- Middle cardiac vein
- Small cardiac vein
- Anterior cardiac vein
Label the structures involved with generating action potentials to stimulate heartbeat
What is a p-wave
Depolarization from the SA node through both atria
What is the QRS wave?
spread of depolarization through the ventricles
Define systole?
contraction of a chamber
define diastole
relaxation of a chamber
What causes the “LUBB” sound of a heart beat?
closure of atrioventricular valves (tricuspid and bicuspid) at the start of ventricular systole
What causes the DUBB sound of a heart beat?
Closure of the semilunar valves (aortic and pulmonary) at the start of ventricular diastole
Label the diagram
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