Anatomy + Physiology Of The Cardiovascular System Flashcards
Where is the apex of the heart located?
- The apex of the heart is the the lowest part of the heart
- It projects anteriorly and to the left at the level of the 5th intercostal space and the left midclavicular line
What is the apex formed by?
Formed but the INFEROLATERAL part of the LEFT ventricle
Where is the base of the heart located?
The upper border of the heart involving the LEFT atrium, part of the RIGHT atrium, and the proximal portions of the GREAT VESSELS.
Where is the base of the heart located?
Lies approximately below the 2nd RIB at the level of the 2nd intercostal space
What is the endocardium of the heart?
The endothelial tissue that lines the INTERIOR of the heart chambers and valves
What is the Epicardium of the heart?
The Serous layer of the pericardium.
What does the epicardium of the heart contain?
- The epicardial coronary arteries and veins
- Autonomic nerves
- Lymphatic
What is the myocardium of the heart?
The thick contractile middle layer of the muscle cells that forms the bulk of the heart wall
What is the pericardium of the heart?
The thick contractile middle leader of muscle cells that forms the bulk of the heart wall
Which vessels is the largest artery and the central conduit of blood from the heart to the body?
Aorta
Where is the aorta located?
Begins at the upper part of the left ventricle, and after ascending for short distance arches backward and to the the left (arch of the aorta) and passes into the abdominal cavity (abdominal aorta)
Which vein returns VENOUS blood from the lower body and viscera to the RIGHT atrium?
Interior Vena Cava
Which arteries carry DEOXYGENATED blood from the RIGHT ventricle to the LEFT + RIGHT lungs
Pulmonary arteries
What veins carry OXYGENATED blood from the RIGHT + LEFT lungs to the LEFT atrium?
Pulmonary veins
What vein returns the VENOUS blood from the head, neck, and arms to the RIGHT atrium?
Superior Vena Cava
Name the superior chambers of the heart
Right (RA) and left atrium (LA)
What separates the atria?
The atrial septum
Name the inferior chambers of the heart.
Right (RV) and Left ventricles (LV)
What separates the ventricles?
Ventricular septum
The right heart chambers collect blood from where?
From the body and pump it to the lungs
The left chambers collect blood from where?
From the LUNGS and pump it to the rest of the body
List the four valves of the heart
- atrioventricular valves (AV)-Tricuspid
- Atrioventricular valve (AV)-Mitral
- Aortic valve
- Pulmonary Valve
Where are the atrioventricular valves located (AV)?
- Between the atria and the ventricles
- named by the number of leaflets or cusps
Where is the tricuspid valve located and how many leaflets does it have?
Between Right Atrium and Ventricle
What is the function of the tricuspid valve?
It controls blood flow between the RA and RV.
What is the name of the left AV valve? How many leaflets does it have?
Mitral
2
What is the function of the Mitral Valve?
It controls blood form between the LA and LV
Where is the aortic valve located?
Between the LV and aorta
Where is the pulmonary valve located?
Between the RV and pulmonary artery
Describe the Blood Flow of the heart.
- Venous blood from superior/inferior vena cava enters RA
- Pumped through TRICUSPID valve into the RV
- TRICUSPID closes while the RV contracts to pump blood thru the PULMONARY valve and into the PULMONARY TRUNK (divides R + L lungs)
- Blood picks up O2 and releases CO2 in the pulmonary capillaries and the oxygenated blood returns via the PULMONARY Veins to the LA
- Contraception of LA forces blood through mitral valve into LV.
- Mitral Valve closes when the LV contracts to pump blood thru the aortic valve into the AORTA
- Blood is distributed into the coronary circulation and systemic circulation
Describe the coronary arteries.
Network of progressively smaller vessels that carry oxygenated blood to myocardium
Where to the Right and Left coronary arteries arise form?
The ascending aorta just beyond where the aorta leaves the LV
T or F: The right and left coronary arteries and their branches supply ALL parts of the myocardium
True
What are the branches of the Right Coronary Artery?
- Sinus node artery
- Right Marginal Artery
- Posterior descending arter
What part of the heart does the sinus node artery supply?
Right atrium
What part of the heart does the marginal artery supply?
Right ventricle
What part of the heart does the posterior descending artery supply?
- Left atrium
- Inferior walls of BOTH ventricles
- Inferior portion of the interventricular septum
What are the branches of the Left coronary artery?
- Circumflex artery
2. Left anterior descending artery
What parts of the heart does the circumflex artery supply?
- LEFT atrium
- Posterior and lateral walls of the LEFT ventricle
- Anterior and inferior walls of the LEFT ventricle
What parts of the heart does the left anterior descending artery supply?
Anterior portion of the interventricular septum
Name the coronary veins
- Coronary sinus
- Cardiac veins
- Thebesian veins
Where does the Great cardiac vein drain into (also middle and small cardiac veins)?
The coronary sinus, emptying into the RA.
Where do the thebesian veins arise from?
Arise in the myocardium
Where do the thebesian veins drain into?
Drain into all chambers of the heart, but primarily into the RA and RV.
What are the components of the cardiac conduction system?
- Sinoatrial (SA) node
- internodal tracts
- Atrioventricular (AV) node
- Common AV bundle or bundle of His
- R and L bundle branches
- Pukinje fibers
T of F: each cardiac myocyte has an intrinsic ability to depolarize and propagate electrical impulses from cell to cell without nerve stimulation
True
Which node is the pacemaker of the heart?
SA node
Describe the Cardiac conduction system.
- SA > AV > atrial musculature
- Bachmann bundle appears to conduct the cardiac impulse preferentially from R to L atrium
- At lower end of the AV node, the nodal fibers form the common bundle of His which passes to the interventricular septum and divides into right and left bundle branches
- Branches divided into purkinje fibers that extend into both ventricular walls
Along cardica automaticity is intrinsic to the SA node, what other system influence the heart rate, rhythm, and contractility?
ANS
What nerves converge to form the cardiac plexus at the base of the heart?
Vagus and sympathetic cardiac nerves
When is sympathetic influence of the heart achieved?
Achieved by release of epinephrine and norepinephrine
What does the sympathetic nerves stimulation the chambers of the heart to do?
Beat faster (chronotropic effect) and with greater force of contraction (inotropic effect)
Sympathetic influence on the heart results in what?
Chronotropic and Inotropic effect
Parasympathetic influence on the heart is achieved by?
Achieved via acetylcholine release from the vagus nerve
What effect does the parasympathetic nervous system have on the heart?
-slows the HR (chronotropic effect) primary through their influence on the SA node
List the neuronal reflexes of the heart.
- Baroreceptor reflex
- Bainbridge reflex
- Chemoreceptors reflex
- Valsalva maneuver
What kind of receptors are baroreceptors?
mechanoreceptors that detect changes in PRESSURE
What is the reflexes by which BP is maintained called collectively?
Baroreflex, which includes arterial baroreceptors (high pressure receptors located in the CAROTID sinus, aortic arch, and origin of the Right subclavian artery) and cardio pulmonary receptors (low pressure receptors)
What does sympathetic activation of the heart lead to ?
- Increased Cardiac contractility
- Increased heart rate
- Venoconstriction
- Arterial vasoconstriction
***Ultimately leading to increased blood pressure (BP) via elevation of total peripheral resistance (TPR) and cardiac output (Q)
What does parasympathetic activation of the heart lead to?
- Decrease in HR
2. Small decrease in contractility, resulting in a decrease in BP
Describe the bainbridge reflex.
- An increase in venous return stretches receptors in the wall of the RA which sends vagal afferent signals to the cardiovascular center within the medulla
- The signals inhibit parasympathetic activity, resulting in an increased HR
Where are chemoreceptors located?
chemosensitive cells located in the carotid bodies and the aortic body
what do chemoreceptors respond to?
Respond to changes in pH status and blood oxygen tension
At an aerial partial oxygen pressure of <50mmHg or in conditions of ACIDOSIS what system will the chemoreceptors stimulate?
- The respiratory centers and increase the depth and rate of ventilation
- In addition, the ensuing activation of the Parasympathetic system reduces HR and myocardial contractility
In the case of persistent hypoxia what will happen to the CNS?
The chemoreceptors will stimulate the CNS with a resultant increase in sympathetic activity
What is the valsalva maneuver.
Forced expiration against a closed glottis produces increased intrathoracic pressure, increased central venous pressure, and decrease venous return
Results in decreased Q and BP
During a valsalva maneuver the resultant decrease in Q and BP is sensed by which receptors?
Baroreceptors, which reflexively increase HR rand myocardial contractile through sympathetic stimulation
Describe what happens with the glottis opens
- venous return increases, BP, contractile
- The increase in BP is sensed by the baroreceptors, which reflexively decreases HR thru the parasympathetic efferent pathways
Atrial Systole
The contraction of the right and left atria pushing blood into ventricles
Atrial diastole
The period between atrial contractions when the atria are repolarizing (filling up)
Ventricular systole
Contraction of the Right and left ventricles pushing blood into the pulmonary arteries and aorta
Ventricular diastole
Period b/t ventricular contractions when the ventricles are repolarizing
Preload
Refers to the tension in the ventricular wall at the end of diastole
Reflects the venous filling pressure that fills the left ventricle during diastole
Afterload
Referees to teh forces that impede the flow of blood out of the heart, primarily the pressure in the peripheral vasculature, the compliance of the aorta, and the mass and viscosity of blood
Stroke volume (SV)
Referees to the volume of blood ejected by each contraction of the LEFT ventricle
What is a Normal SV?
Ranges from 60 to 80 ml depending on age, sex and activity
Cardiac output (CO/Q)
The amount of blood pumped from the left or right ventricle per MINUTE.
CO= SV x HR
What is Normal CO for an adult male at rest ?
4.5 to 5.0 L/min
What is normal CO for women an rest?
Women produce slightly less than men
How much can CO increase during exercise?
25 L/min during exercise
Venous return
The amount of blood that returns to the rights atrium each minute.
This is similar in volume to CO because the Cardiovascular system is a closed loop, venous return must equal CO when averaged over time
The systemic ARTERIAL circulation carries ___________ from the ______ ventricle through the ________, ________, and _________ to the capillaries in the tissues of the body.
- Oxygenated blood
- Left ventricle
- Aorta, arteries, and arterioles
From the capillaries, ________ returns through a series of venues and veins
Deoxygenated blood
What are the veins of the UE and LE subdivided into?
Superficial and deep
Where do the superficial veins lie?
Lie beneath the skin between the two layers of superficial fasica
Where do the deep veins run?
Deep veins accompany the arteries
T or F: Both types of veins have valves
True, but they are more numerous in the deep veins than superficial and in LE veins than UE veins
What is the function of blood?
Transports O2 and nutrients to the cells of the body and returns waste products from these cells.
What is normal blood volume for an adult?
Between 4.5 - 50 L, which women’s volume being slightly less than men
What is hypovolemia?
Decreased blood volume, specifically the volume of plasma
What are causes of hypovolemia?
Bleeding, dehydration form vomiting, diarrhea, sweating, sever burns, and diuretic medications used to treat hypertension
What are some signs and symptoms of hypovolemia
- Orthostatic hypotension
- tachycardia
- elevated blood temperature
What is hypervolemia (fluid overload)?
Referees to increased blood plasma.
What are causes of hypervolemia?
Excess intake of fluids (IV or blood transfusion)
Sodium or fluid retention (heart failure, kidney disease)
What are some signs and symptoms of Hypervolemia?
Swelling in the legs
Ascites (fluid in abdomen)
Fluid in the lungs
What is the plasma of blood?
The liquid component of blood, in which the blood cells and platelets are suspending
What does plasma consist of ?
Water, electrolytes, and proteins, and accounts for more than half of the total blood volume
Why is plasma important?
Important for regulating BP and temperature
T or F: Erythrocytes (RBCs) make up approximately 40% of blood volume
True
What do erythrocytes contain?
Hemoglobin (a protein that gives blood its red color and enables it to bind with O2)
Describe anemia.
When the number of erythrocytes is too low
the blood carries less O2, resulting in fatigue and weakness
What is polycythemia?
The number of erythrocytes is too high, the blood is too thick, increasing the risk of stroke or heart attack
Thrombocytes (blood platelets) assist in what?
Assist in blood clotting by clumping together at a bleeding site and forming a plug that helps to seal the blood vessel
Describe thrombocytopenia
A low number of platelets, which increases the risk of bruising and abnormal bleeding
Describe Thrombocythemia.
A high number of platelets, the blood becomes too thick.
This increases the risk of thrombosis, which may result in stroke or heart attack
What is the function of leukocytes (WBCs)?
Protect against infection
Describe leukopenia?
Low number of leukocytes which increases the risk of infection
Describe leukocytosis.
Abnormally high amount of leukocytes (WBCs); can indicated infection or leukemia
Name the 5 types of leukocytes (WBCs).
- Neutrophils
- Lymphocytes
- Monocytes
- Eosinophils
- Basophils
What is the function of a neutrophil?
Help protect the body against infections by ingesting bacteria and debris
What are the 3 types of lymphocyte?
Consist of the 3 main types:
- T-lymphocytes
- Natural killer cells
- B lymphocytes
What is the function of a T-cell and a natural killer cell?
Help protect against viral infections and can detect and destroy some cells with cancer cells
What is the function of a B-cell?
Develop into cells that produce antibodies
What is the function of a monocytes?
Ingest dead or damaged cells and help defend against infectious organisms
What is the function of eosinophils?
Kill parasites, destroy cancer cells, and are involved in allergic responses
What is the function of Basophils?
Participate in allergic responses
The Right Coronary artery supplies blood to what portion of the LV ?
RCA supplies blood to inferior and posterior aspects of LV
therefore causes inferior and posterior MI
Left anterior descending artery supplies what portions of the heart?
The LAD supplies the Anterior and septal aspects of the LV
Therefore LAD occlusions are likely to produce anterior and septal MIs
The Left circumflex artery supplies what parts of the LV?
L CX supplies blood to the lateral wall (free wall) of LV
There responsible for production Lateral MIs
List the main artsier s of the heart.
A. Left main (LM) B. Left anterior descending (LAD) C. Left circumflex (CX) D. Right coronary artery (RCA) E. Posterior descending (PDA)