Chapter 1 Flashcards
Atria
Two upper chambers of the heart (singular, atrium)
Atrial kick
Blood pushed into the ventricles because of atrial contraction
Afterload
Pressure or resistance against which the ventricles must pump to eject blood
Cardiac output
Amount of blood pumped into the aorta each minute by the left ventricle. Defined as the stroke volume multiplied by the heart rate
What influences heart size?
Age, body weight and build, physical exercise frequency, heart disease
Location of heart?
Lies in the space between the lungs ( mediastinum I in the chest). About 2/3 of the heart lies to the left of the midline of the sternum
What are the surfaces of the heart?
Anterior, inferior, posterior, base, apex
Anterior
- Lies behind sternum and costal cartilages
- Right ventricle lies most directly behind sternum
Inferior
l. Aka diaphragmatic surface
2. Formed by the left ventricle
Base
- upper portion of the heart
- Left atrium
- Small portion of the right atrium
- Proximal portions of the superior and interior venacava and the pulmonary reins
Apex
- Lower portion of the heart
- Formed by the tip of the left ventricle
What are the three layers of the heart?
- Pericardium ( parietal pericardium - outer/ visceral pericardial )
- Myocardium
- Endocardium
Pericardium
- Parietal pericardium - tough outer layer
- Serous pericardium
- Pericardial space contains serous fluid
Organ has to be hollow to pump blood. Layers of heart importance holding heart in position and wall for protection of infection
Endocardium
- Innermost layer
- Lines the hearts inner chambers
- Continuous with innermost layers of vessels
Direct contact with flood. Connected with arteries.
Myocardium
I. Thickest
2. The one that contracts
3. Responsible for pumping action
Epicardium
- outermost layer of heart
- Contains blood capillaries, lymph capillaries, nerve fibers, and fat
Cardiac muscle
- Aka Myocite
- Heart halls formed by cardiac muscle fibers
- myofibrils
-myosin
- actin
- intercalated disks
- gap junctions
Those filaments create the contraction and relaxation
Myosin and actin do the most
Heart chambers
- 4 chambers
- Right and left atria
- Right and left ventricles
Which chambers are bigger?
- Atria - smaller
- Ventricles - bigger
Left ventricle is the biggest chamber. Needs space to hold blood to pump to the rest of the body.
Function of the heart skeleton?
l. Provides secure attachments for heart values
2. Provides for the attachment of the myocardium
3. Helps form the partitions (septa) that separate Tre atria from the ventricles.
4. Part in the middle is septum separates left and right side ( oxygen from CO2)
How many heart valves? What are their functions?
- 4 heart values. 2 sets of atrioventricular valves (AV) and 2 sets of semilunar valves (sl)
- Ensure blood flow in one direction through heart chambers prevent back flow.
Atrioventricular valves (AV)
l. AV separate atria from ventricles
2. Tricuspid valve - lies between right atrium and right ventricle.
3. Valves only allow blood to go one way (one direction)
Mitral value has only 2 cusps. Lies between left and right ventricle
Semilunar value
I. Prevent back flow of blood from the aorta and pulmonary arteries into the ventricles.
Pulmonic Valve - right
Aortic valve - left
Acute coronary syndrome (Acs)
Temporary or permanent blockage of a coronary artery. Excessive demand or inadequate supply of oxygen and nutrients to the heart muscle associated with plaque disruption, thrombus formation, and vast constriction.
3 major syndromes: unstable angina, non-st-elevation myocardial infraction, and ST- elevation myocardial infraction
What does each atrium (left/right) receive and from where?
- Right atrium receives blood low in oxygen from the superior vena cava (carries blood from head & upper extremities ) the interior vena cava which carries blood from the lower body), the coronary sinus (CO2)
2.left atrium receives blood freshly oxygenated blood from the lungs via the right and left pulmonary veins..
Purpose of ventricles
Pump blood
Right ventricle
Pumps blood through the blood vessels of the lungs and then into the left atrium.
Left ventricle
Pumps blood out to the body. Biggest chamber
What are the four heart values?
Atrioventricular valves (2) and semilunar values (2)
What separates atria from ventricles?
AV valves
Name of AV valve between right atrium and right ventricle?
Tricuspid valve
What valve lies between left atrium and left ventricle?
Mitral valve
Systole
Ventricles contracting, causing the pressure within the ventricles to rise sharply
What valves form the semilunar values?
Pulmonic and aortic valves
What are the 2 atrioventricular valve names?
Tricuspid and mitral
What is the name of the 2 semifinal valves?
Pulmonic and aortic valve
Diastole
Ventricle is relaxed
Three major coronary arteries
Lad, cx, RCA
RCA
A branch of the RCA supplies: right atrium/ventricle, inferior surface of left ventricle, posterior surface of left ventricle, senatorial node I AV bundle.
LCA
Supplies oxygenated blood to primary branches- left anterior descending (lad) and circumflex (cx)
Lad
Lies on the outer surface on front of heart
Occlusion of the proximal lad coronary artery has been referred as the “widow” maker because of its association with sudden cardiac arrest when its blocked
Cx
Circumflex - circles around the left side of heart in a groove on the back of the heart that separates The left atrium from the left ventricle called coronary sulcus
Ischemia
Lack of oxygen to tissue - not dead yet
Necrosis
Death of the heart muscle
Arteriosclerosis
Building fat along vessel leads to blood clot
Atherosclerosis
Thickening and hardening of vessel walls are caused by build-up of fat like deposits
Build-ups result in decreased blood flow (ischemia)
Sympathetic stimulation
Fight response. Cannot control heart rate
Baroreceptors
Nerve tissue found in internal carotid arteries/ arch
Detect changes in blood pressure
Chemoreceptors
Are in internal carotid arteries and aortic arch detect changes in the concentration of hydrogen ions, oxygen and carbon dioxide in the blood
Chronotropic effect
Change in heart rate
Positive chronotropic effect refers to increase in heart rate
Negative chronotropic effect refers to a decrease in heart rate
Inotropic Effect
Change in myocardial contractility
Positive inotropic effect results in an increase in myocardial contractility
Negative inotropic effect result in a decrease in myocardial
Contractility
Dromotopic effect
Refers to speed of impulse transmission through the conduction system
Positive DE results in increase in conduction velocity
Negative DE results in decrease in conduction velocity
What separates the right from left of the heart?
Septum
Systole
Contraction
Diastole
Relaxation
Where is the blood from the upper extremities emptied?
Superior vena cava
Where is the blood from the lower body returned?
Inferior vena cava
When does blood from superior and inferior vena cavae and coronary sinus enter the right atrium?
Atrial diastole
What ventricle connects right atrium to right ventricle?
Tricuspid
Where does the left atrium get oxygenated blood from?
Four pulmonary veins (2 from left lung,2 from right lung)
What valve opens to drain oxygenated blood from left atrium to left ventricle?
Mitral valve
Ventricular systole / diastole
Systole- blood is propelled through the systemic and pulmonary circulation
Diastole - ventricles begin to passively fill with blood
How does the blood circulate through heart/body?co2
- Right atrium drains co2 blood from superior and inferior vena cava
- co2 blood passes through tricuspid value into right ventricle
3.blood goes to pulmonic valve to pulmonary trunk - Which divides into right and left pulmonary arteries
- Pulmonary veirs pump blood to left atrium
- Goes through mitral valve into left ventricle
- Lv to aortic valve to aorta ( oxygenated blood goes through all the tissues )
- Tissues produce co2 which then drains back to vena cava
What veins are the exception to carry oxygenated blood?
Pulmonary veins
What is the amount of blood pumped into the aorta each minute by the left ventricle called?
Cardiac output (CO)
Stroke volume
Amount of blood ejected from the left ventricle with each heart beat, multiplied by the hr
What is the percentage of blood pumped out of a ventricle with each contraction called?
Ejection fraction
Stroke volume
Determined by:
1. The degree of ventricular filling when the heart is relaxed (preload)
2. The pressure against which the ventricle must pump (afterload)
3. The myocardium’s contractile state (contracting or relaxing)
Preload
Force exerted by the walls of the ventricles at the end of diastole
Volume of blood returning to the heart (venous return) influences preload
Afterload
Pressure or resistance against which the ventricles must pump to eject blood
Influenced by:
Arterial blood pressure
Ability of the arteries to become stretched - arterial distensibility
Arterial resistance
Which of the following influence a person’s heart size?
A. Age
B. Body weight
C. Heart Disease
D. Physical exercise frequency?
A,B,C,D
A persons heart size and weight are influenced by age, body weight and build, physical exercise frequency, and heart disease
Select the areas of the heart that make up its anterior surface:
A. Left atrium
B. Right atrium
C. Left ventricle
D. Right Ventricle
B, C, D
The front (anterior) surface of the heart lies behind the sternum and costal cartilages. Most of the anterior surface is formed by the right atrium and the right ventricle, with the left ventricle contributing a small portion
The inferior surface of the heart is formed mainly by the:
A. Right and left atria
B. Right and left ventricles
C. Left atrium and left ventricle
D. Right atrium and right ventricle
B
The hearts inferior surface, also called the diaphragmatic surface, is formed by the left and right ventricles and small portion of the right atrium. The left ventricle makes up most of the inferior surface
The pericardium:
A. Is a thick, single-layer of tissue
B. Protects the heart from trauma and infection
C. Uses ligaments to anchor the heart to the sternum and diaphragm
D. Contains about 20mL of serous fluid that prevents friction as the heart beats
B, C, D
The pericardium is a double walled sac that encloses the heart and helps protect it from trauma and infection. The fibrous parietal pericardium is the sacs outer layer that anchors the heart to some of the structures around it, such as the sternum and diaphragm, through ligaments. The pericardium’s inner layer, the serous pericardium, consists of two layers; parietal and visceral. The parietal layer lines the inside of the fibrous pericardium. The visceral layer (epicardium) attaches to the large vessel that enter and exit the heart and forms the hearts outer surface. Between the visceral and parietal layers is a space (the pericardial space) that generally contains about 20mL of serous fluid that acts as a lubricant, preventing friction as the heart beats.
The right atrium:
A. Pumps blood to the lungs
B. Pumps blood to the systemic circulation
C. Receives blood from right and left pulmonary veins
D. Receives blood from the superior and inferior vena Cavan and the coronary sinus
D
The right atrium receives blood low in oxygen from the superior vena cava (which carries blood from head and upper extremities), the inferior vena cava (which carries blood from the lower body) and the coronary sinus, which is the largest vein that drains the heart. The left atrium receives freshly oxygenated blood from the lungs via the right and left pulmonary veins. The right ventricle pumps blood to the lungs. The left ventricle pumps blood to the systemic circulation.
When a ventricle relaxes in the normal heart, blood is prevented from flowing back into by:
A. Mitral valve
B. A semilunar valve
C. The tricuspid valve
D. An antrioventricular valve
B
The semilunar valves prevent backflow of blood from the aorta and pulmonary arteries into the ventricles. When the right ventricle relaxes, blood is prevented from flowing back into the pulmonic valve. When the left ventricle relaxes, blood is prevented from flowing back into it by the aortic valve.
Which of the following separate the atria from the ventricle?
A. Aortic valve
B. Mitral valve
C. Pulmonic valve
D. Tricuspid valve
B, D
Atrioventricular valves separate the atria from the ventricles. The tricuspid valve is the AV valve that lies between the right atrium and the right ventricle. The mitral valve, also called the bicuspid valve, lies between the left atrium and left ventricle
Select the correct statements about the hearts coronary arteries:
A. The circumflex (Cx) artery is a branch of the left coronary artery
B. The main coronary arteries lie on the pericardial surface of the heart
C. The septal and diagonal arteries are major branches of the right coronary artery (RCA)
D. The right coronary artery supplies the sinoatrial (SA) node and antrioventricular (AV) bundle in most of the population
E. Occlusion of the Cx artery has been referred to as the “widow maker” because its association with sudden cardiac arrest when it is blocked
A, B, D
The main coronary aeries lie on the outer (epicardial) surface of the heart. The three major epicardial coronary arteries include the left anterior descending (LAD) artery, Cx artery, and RCA. The RCA supplies the SA node and AV bundle in most of the population. The left main coronary artery supplies oxygenated blood to its two primary branches: the LAD artery and the Cx artery. The septal and diagonal arteries are branches of the LAD. Occlusion of the proximal LAD coronary artery has been referred to as the “widow maker” because of its association with sudden cardiac arrest when it is blocked
Which of the following factors determine cardiac output?
A. Age
B. Gender
C. Preload
D. Afterload
E. Heart rate
F. Myocardial contractility
C, D, E, F
Four factors determine CO: HR, myocardial contractility, preload and afterload
____________ term refers to a change in myocardial contractility
Inotropy
Their closure at the end of systole prevents backward flow of blood into the ventricles _________
Semilunal Valves
Double-walled sac containing a small amount of serous fluid that reduces friction as the heart beats _______
Pericardium
The percentage of blood that is pumped out of a ventricle with each contraction _________
Ejection Fraction
This vessel supplies the SA node and AV node in most of the population_______
Right coronary artery
Sensory receptors that detect changes in blood pressure________
Baroreceptors
Stroke volume multiplied by the heart rate _________
Cardiac output
Pumps oxygenated blood to the systemic circulation_______
Left ventricle
The anterior descending and circumflex are branches of this vessel_______
Left coronary artery
Detect changes in the concentration of hydrogen ions, oxygen, and carbon dioxide in the blood____
Chemoreceptors
Their closure causes the first heart sound (S1)_________
Antrioventricular valves
Pumps blood low in oxygen to the pulmonary circulation ________
Right Ventricle
The force exerted by the circulating blood volume on the walls of the arteries _________
Blood pressure
Phase of the cardiac cycle during which the greatest flow of blood enters the heart’s chamber _________
Diastole
Term that refers to a change in rate _________
Chronotropy
Why might the patients rapid heart rate be a cause for concern?
A. Rapid heart rates predispose the patient to valvular heart disease
B. Rapid heart rate s shorten diastole and can result in decreased cardiac output
C. Rapid heart rate can lengthen systole but decrease myocardial contractility; which can lead to shock
D. Rapid heart rates are usually accompanied by pulmonary congestion, which leads to heart failure
B
The coronary arteries fill when the aortic valve is closed and the left ventricle is relaxed (diastole). If the length of time for ventricular relaxation is shortened (as with rapid heart rates) there is less time for then to fill adequately with blood. If the ventricles do not have time to fill, the amount of blood sent to the coronary arteries is reduced, the amount of blood pumped out of the ventricles is decreased (cardiac output) and signs of myocardial ischemia may be seen.
