Lecture 1- Anatomy and Physiology Flashcards
Where is the heart located?
In the L thoracic cavity
Where is the base of the heart located?
It is located superiorly between the 2nd and 3rd rib
Where is the Apex located?
It is located inferiorly on the level of the 5th rib
What plane does the Right Ventricle occupy?
Frontal plane
It is located in the area of the 2nd ICS and angle of Louis
Right Atrium
It is a bump that demarcates manubrium from body of sternum
Angle of Louis
It is lateral and slightly below the angle of Louis and an important auscultatory landmark
2nd ICS
Auscultation point that is at the right of the sternum and on the 2nd ICS
Aortic
Auscultation point that is at the left of the sternum and on the 2nd ICS
Pulmonic
Left and on the 4th ICS
Tricuspid Valve
- On the Left and level of 5th ICS
- Point of maximal impluse
Mitral Valve
Striated, a syncytium or syncytial
Heart tissue
Oblong like structures
Intercalated disc
Pacemaker of the heart
Sinoatrial Node
Has more positive ion
Extracellular
Has more negative ion
Intracellular
- It stops or regulates the Ca+ from entering
- Used for hypertension
Calcium channel blockers
It is a double walled sac outermost layer of the heart
Pericardium
Outer tough fibrous layer of dense irregular connective tissue
Parietal Pericardium
Acts as a protective sac for the heart
Visceral Pericardium
Lubricant that allows the two surfaces to slide past one another
Pericardial fluid
It is an infection with resultant inflammation of the pericardium
Pericarditis
Compression of the heart cause by fluid build-up in the space between the myocardium and pericardium
Cardiac Tamponade
- It is the middle of the heart
- It facilitiates the pumping action of the heart to move blood to the entire body
Myocardium
It is the alterations in the muscular wall of the heart
Cardiomyopathies
Is evidence by ventricular dilation and altered cardiac muscle contractile function
Dilated Cardiomyopathy
Inflammaton of the heart muscle
Myocarditis
Presents as diastolic dysfunction with an increased ventricular mass
Hyperthrophic Cardiomyopathy
Presents as diastolic dysfunction owing to the presence of excessively rigid ventricular walls, resulting in decrease compliance
Restrictive Cardiomyopathy
Innermost layer of the heart
The tissue forms the inner lining of the chambers of the heart
Endocardium
Infections to the endocardium are at risk for ?
Valvular dysfunction
Originates in the sinus of valsalva located in the wall of the aorta neart the aortic valve
Coronary Arteries
Originates from the area near the right aortic leaflet
Right coronary
Originates from the area near the left aortic leaflet
Left Coronary
Begins at the left main and branches into the left anterior descending and circumflex
Left Coronary Artery
- May also have branches known as marginal branches
- Suppy the lateral and part of the inferior surface of the Left ventricle and portions od the Left Atrium
Circumflex
Supply the anterior and apical surfaces of the Left Ventricle, as well as portions of the interventricular septum
Left anterior descendingCA
Supplies the Right Atrium, most of the Right Ventricle, part of the inferior wall of the left Ventricle, portions of the interventricular septum and conduction system
Right Coronary Artery
Most commonly a branch of the RCA and perfuses the posterior heart
Posterior Descending artery
It is the inner diameter of the arteries through which blood flows
Lumen
Increase in lumenal diameter (smooth muscle relaxation)
Vasodilation
Decreased in lumenal diameter (smooth muscle contraction)
Vasoconstriction
Most common vasodilator and used for angina
Nitroglycerin
Most common vasospasm of coronary artery
Angina
- Lining of the coronary artery that is in direct contact with the lumen
- Plays the central role in controlling the biology of the vessel wall
Endothelium
Name the important function of the endothelium
- Anti-inflammatory actions
- Antithrombotic activity
- Vasodilation
It facilitates vascular smooth muscle relaxation
Endothelial-derived relaxing factor (EDRF)
Most prevalent EDRF
Nitric Oxide
What does injury to endothelium do?
Impairs NO release and decreases vasodilation
Factors that influence NO release
- Acetycholine
- Norepinephrine
- Serotonin
- Adenosine
- Diphosephate
- Bradykinin
- Histamine
It is the narrowing of the coronary artery resulting from smooth muscle contraction within the walls of the artery
Coronary Spasm
Where does coronary spasm occur?
In arteries that have endothelial injury and arteries that exhibit hyperreactivity to vasoconstrictor stimuli
It is a valve that is positioned between Right Atrium and Right Ventricle
Tricuspid Valve
Left atrioventricular valve that is located beween the left atrium and ventricle
Mitral Valve
Located between the ventricles and arteries
Semilunar valves
- It is located on the right side in association with the pulmonary artery
- Carries deoxygenated blood
Pulmonic Valve
- Located on the left side relating to the aorta
- Carries oxygenated blood
Aortic valve
- It guards the heart valve openings
- It is attached to the papillary muscles of the myocardium by chordae tendinae
Leaflets or Cusps
Its has 3 cusps
Right Atrioventricular Valves / Tricuspid
It has 2 cusps
Left Atrioventricular valves / Bicuspid
Heart strings
Chordae Tendinae
It prevents the backflow of blood into the atria during ventricular contraction or systole
Atrioventricular valves
Prevents the backflow of blood from aorta and pulmonary artery in to the ventricles during diastole
Semilunar Valves
It is define by the presence of normal heart sounds, S1 and S2.
It is the flow of blood and the different mechanics within the heart from one heartbeat to another heartbeart
Cardiac cycle
It is associated with valvular closings
Heart sounds
Atrioventricular, mitral, and tricuspid valve closure
S1 heart sound
Semilunar, aortic, and pulmonic valve closure
S2 heart sound
It is the contraction phase and occurs between S1 and S2
Systole
It is the filling phase. Ventricles fill with blood from atria via open atriventricular valves
Diastole
Period of rapid filling ventricles
First third of diastole
Small amount of blood normally flows into the ventricles, directly from the atria
Middle third of diastole
Atria contracts and give an additional thrust to the inflow of blood into the ventricles
Last third of diastole
Atrial depolarization + contracting of atrium
P wave
ventricular depolarization + contraction of aortic or pulmonary
QRS wave
- Initial ventricular repolarization + interval between repolarization and depolarization
ST wave
Receptors of the heart that are primarily beta-adrenergic receptors and are located on the sinus node and within the myocardium
Sympathetic receptors
It causes the blood vessels to dilate and stimulates
Beta-adrenergic receptors
Stimulation of these receptors on the peripheral blood vessels causes vasoconstriction and an increase in peripheral vascular resistance
Alpha-adrenergic receptors
It is released as part of the normal exercises responses especially when exercise is continued beyond a few minutes. The increase in heart rate and contractility is due to this hormonal influence
Epinephrine
The amount of blood that the left ventricle pumps out
Stroke voulme
It mimics the action of the sympathetic nervous system
Sympathomimetic
Suppresses sympathetic functioning
Sympatholytic
Frequently used as a sympathomimetic
- Dopamine
- Epinephrine
- Atropine
Suffix for beta blockers
Olol-
Parasympathetic stimulation results in what?
- Depression of heart rate
- Decreased force of atrial contraction
- Decreased speed of conduction through the atrioventricular node
What are the goals of the heart?
- To provide adequate CO to generate energy to meet the metabolic demands of the body
- Must be able to adapt to the changing systemic energy demands, as well as to its own myocardial oxygen needs
What is the amount of blood that leaves the ventricles per minute
Cardiac output
What are the factors that can influence Cardiac Output?
- Heart rate (bpm)
- Stroke volume (mL/min)
It is the volume of the blood ejected with each myocardial contraction
Stroke Volume
What influences the stroke volume?
- Preload aka left ventricle
- Contractility
- Afterload
It is the amount of blood in the ventricle at the end of diastole
Preload aka left ventricle
Ability of the ventricle to contract
Contractility
A force the Left Ventricle must generate during systole to open the aortic valve and overcome aortic pressure
Afterload
What happens during diastole?
The ventricles must be compliant and able to stretch to accommodate the blood entering the ventricles
What happens during systole?
The ventricles must be able to contract adequately to eject the stroke volume
It is a small, flattened, ellipsoidal strip of specialized cardia muscle about 3 mm wide, 15 mm long, and 1 mm thick
AKA pacemaker of the heart
Sinoatrial node
Where is the sinoatrial node located?
Located in the superior posterolateral wall of the right atrium immediately below and slightly lateral to the opening of the superior vena cava
It delays cardiac impulse to allow time for the atria to empty their blood into the ventricles before ventricular contraction begins
Atrioventicular Node
Where is the AV node located?
Posterior wall of the right atrium immediately behind the tricuspid valve
What prevents the action potential to travel backwards from the ventricles to the atria
Atrioventricular bundle
What depends on the delivery of oxygented blood through the coronary arteries and the ability of the mycardial cells to extract oxygen from the arterial blood?
Myocardial Oxygen Supply
The energy cost to the myocardium
Myocardial oxygen demand
How do you calculate for the myocardial oxygen demand? (MVO2)
Heart rate x Systolic blood pressure = Rate pressure product or double product
What happens during exercise? (MVO2)
- Increase in oxygen demand
- Increase in the energy cost of the heart
- Very little increase of the extraction rate done by the heart from its blood supply
It is the main mechanism for increasing myocardial oxygen supply during times of increased demand
Coronary Blood flow
- Has low potassium (usually less than 3.5 mRq/L)
- Produces arrythmias with flattened T waves and depressed ST segments
- Bilateral lower extremity muscle cramping
Hypokalemia
- Low blood serum calcium levels
Hypocalcemia
Low magnesium in blood
Hypomagnesemia