A & P Chapter 19: Cardiovascular system: Heart
Place in the correct order the sequence of events resulting in the action potential for cardiac muscle cells.
1. Na+ ions enter causing depolarization 2. Depolarization causes opening of voltage-gated K+ channels 3. Slow voltage-gated Ca2+ channels open causing a Ca2+ induced Ca2+ release 4. Plateau occurs 5. Voltage-gated Ca2+ channels close 6. Repolarization occurs, returning the cell to the resting membrane potential
Put the sequence of events in the correct order to describe the initiation and conduction of an action potential through the heart.
1. SA node fires action potenial 2. Action potential reaches AV node 3. Action potential is delayed at the AV node 4. Action potential travels down the bundle branches 5. Action potential travels up the purkinje fibers
Place the options in the correct order for the opening of ion channels in a cardiac nodal cell from resting membrane potential through an action potential.
1. Slow voltage-gated Na+ channels 2. Fast voltage-gates Ca2+ channels 3. Voltage-gates K+ channels
In the average normal adult, the heart weighs about _________ grams.
300
An arterial ____________ is when more than one artery is providing blood to a given tissue.
Anastomosis
The left coronary artery typically branches into the ____________ interventricular artery and the ____________ artery.
Anterior, circumflex
Purkinje cells begin within the ______ of the heart and extend through the walls of the _________.
Apex, ventricles
The _____________ are smaller than the _____________.
Atria, ventricles
The fibrous skeleton of the heart is located between the _________ and the __________.
Atria, ventricles
After initiation, the muscle impulse travels from the SA node to the ____________ _____________.
Atrioventricular node
The wrinkled flap-like extensions visible in the anterior view of the heart are the ___________.
Auricles
The posterior-superior surface of the heart is called the _______.
Base
During the final stage of the cardiac cycle as the atria relax and blood returns to fill the ventricle which valves reopen?
Bicuspid, tricuspid
When blood enters the pockets of semilunar valves it causes the cusps to fill and expand and meet at the artery center, effectively ____________ blood backflow.
Blocking
Which events occurs during the atrial contraction and ventricular filling phase of the cardiac cycle?
Blood flow into the atria from the veins is restricted, the ventricles have reached their EDV, SA node initiates atrial contraction
The _______ ions must bind to troponin to allow the cross bridge cycling to begin.
Ca2+
Parasympathetic and sympathetic axons extend from the _________ to the heart.
Cardiac center
A _____________ ________ is the time from the start of one heartbeat to the initiation of the next.
Cardiac cycle
The volume of blood pumped by one ventricle in one minute is defined as __________ _____________.
Cardiac output
__________ ____________ is a measure of how effective the cardiovascular system is in fulfilling its function in transporting life supporting substances through the body.
Cardiac output
An individual with a weak heart may have limitation exerting themselves because they have a little _________ ________.
Cardiac reserve
______________ ______________ is determined by subtracting cardiac output at rest from cardiac output during exercise.
Cardiac reserve
Blood from the coronary circulation returns to the right atrium through one of several ________ _________.
Cardiac veins
Parasympathetic innervation of the heart comes from the ____________ via the left and right vagus nerves.
Cardioinhibitory center
The chordae tendineae are composed of numerous thin stands of __________ fibers.
Collagen
Identify the three major vessels that empty into the right atrium __________, ___________, and ____________.
Coronary sinus, inferior vena cava, superior vena cava
The atria are separated from the ventricles externally by a relatively deep _________ sulcus (or _____________ sulcus) that extends around the circumference of the heart.
Coronary, atrioventricular
A large loss of blood would result in a(n) ____________ in the venous return to the heart.
Decrease
In the pulmonary circuit, _____________ blood is transported from the right side of the heart to the ______________.
Deoxygenated/lungs
The fibrous pericardium is attached to both the ____________ and the base of the ____________vessels.
Diaphragm, great
Stroke volume(SV) is equal to _______ minus _______.
EDV, ESV
Prolonged pumping of unequal amounts of blood by the left and right ventricles can lead to _______
Edema
The visceral layer of the serous pericardium is also called the ____________.
Epicardium
Factors that result in an increase in venous return include _________ and a decreased heart rate.
Exercise
True or false: All arteries carry oxygenated blood.
False
The fossa ovalis occupies the former location of the fetal _____________, which shunted blood from the right atrium to the left atrium during fetal life.
Foramen ovale
Serous fluid is secreted into the pericardial cavity to minimize _____________.
Friction
The ______________ lies within the anterior interventricular sulcus.
Great cardiac vein
__________ ________ multiplied by stoke volume is equal to cardiac output.
Heart rate
Inotropic agents increase stroke volume by _________________.
Increasing contractility, increasing Ca2+ levels
The _____________ are the great vessels.
Inferior vena cava, superior vena cava, aorta
The __________ surface of the heart and the ____________ surfaces of the heart valves are covered by endocardium.
Internal, external
________________ contraction is the beginning of the ventricular contraction.
Isovolumetric
The _______ atrium and ventricle are prominent when viewing the heart from the posterior view.
Left
The circumflex artery supplies blood to the _________ ventricle.
Left
The primitive ventricle forms most of the ______ ventricle.
Left
The systemic circulation is movement of blood from the ________ side of the heart to the systemic cells of the body and back to the _________ side of the heart.
Left, right
A trained male athlete has a larger heart than a woman who does not exercise so we would expect his heart rate to be _____________.
Lower
The resting heart rate for an infant is higher than that of an adult because the smaller heart results in a ___________ stroke volume.
Lower
The heart is located left of the body midline posterior to the sternum in the _______________.
Mediastinum
The myocardium is the _________ layer of the heart wall is composed of _______ muscle tissue.
Middle, cardiac
The __________ cardiac vein runs alongside the ________ interventricular artery.
Middle/posterior
Which are part of the cardiac muscle cells?
Myofibrils, T tubules, sarcolemma
The systemic circulation includes the movement of ____________ blood through the left side of the heart.
Oxygenated
A common error is to describe arteries as the vessels that always transport ___________ blood instead of describing it as a vessel that takes blood ______ from the heart.
Oxygenated, away
The major segments of an ECG (EKG) are the ____________ and the ___________.
P-Q segment, S-T segment
The _____________ ______________ is the ability to reach threshold without stimulation.
Pacemaker potential
The ______________ _____________ contract and anchor the chordae tendineae to the AV valve cusps.
Papillary muscles
The serous pericardium may be subdivided into layers, the ________ layer than lines the inner surface of the fibrous pericardium, and the ____________ layer that is attached to the surface of the heart.
Parietal, epicardium
The delivery of blood per unit time per gram of tissue is called __.
Perfusion
The heart is surrounded by a visceral and parietal ______________.
Pericardium
What is the function of the left atrioventricular valve?
Prevents backflow of blood into left atrium
What is the function of the right atrioventricular valve?
Prevents backflow of blood into right atrium
What is the function of the pulmonary semilunar valve?
Prevents backflow of blood into right ventricle
What is the function of the aortic semilunar valve?
Prevents backflow of blood into the left ventricle
The structure that marks the end of the right ventricle and the entrance into the pulmonary trunk is the _____________.
Pulmonary semilunar valve
The _______________ valves are closed in the isovolumetric phase of the cardiac cycle.
Pulmonary semilunar, mitral, tricuspid, bicuspid
Openings of __________ are visible in the left atrium.
Pulmonary veins
The cardiovascular system consists of two circulations: the _____________ circulation and the ______________ circulation.
Pulmonary, systemic
A component of the conduction system called _____________ ____________ are found within ventricular walls and their larger diameter allow for rapid action potential propagation.
Purkinje fibers
Atrial contraction causes which of the following?
Pushes blood into ventricles, compresses the openings of the great veins
The _____ complex represents the electrical changes which are associated with ventricular depolarization.
QRS
During atrial contraction the atria are contracting and the ventricles are _____________.
Relaxing
The coronary sinus drains directly into the ________ atrium of the heart.
Right
The right atrioventricular opening is covered by the _______________ valve.
Right atrioventricular (tricuspid)
The opening for the coronary sinus is located in the wall of the _________.
Right atrium
The opening for the coronary sinus is located in the wall of the ___________________.
Right atrium
The boundary between the ventricles and the arterial trunks are the _____________ valves.
Semilunar
The second heart sound is produced when the ___________ valves close, producing a "dupp" sound.
Semilunar
The space between the parietal layer and visceral layer of the pericardium contains _______________.
Serous fluid
The endocardium is composed of a __________ squamous epithelium, called an endothelium, and a layer of ____________ connective tissue.
Simple, areolar
The heartbeat is initiated by the specialized cardiac muscle cells of the ___________, which are located in the posterior wall of the right atrium, adjacent to entrance of the ____________.
Sinoatrial node, superior vena cava
The single heart tube develops into what 4 structures?
Sinus venosus, primitive atrium, bulbus cordis, primitive ventricle
Cardiac output is determined by ___________ ___________ and heart rate.
Stroke volume
The major wave forms in an ECG (EKG) are ____ wave, ______ complex and lastly the _____ wave.
T, QRS, P
The long refractory period in the cardiac muscle cells prevents _________ contraction from occurring in the heart and causing pump malfunction.
Tetanic
The anatomic features that are significant in the normal function of the heart are ________________.
The great vessels attached to the heart, the two sets of valves within the heart, the two sides of the heart
Blood enters the right ventricle through _________________.
The right atrium
Right atrioventricular valve structure
Thee triangular-shaped cusps of dense CT
The myocardium is the _____________ of the three heart wall layers.
Thickest
Semilunar valve structure
Three half-moon shaped cusps of dense CT
The internal wall surface of each ventricle displays large, smooth, irregular muscular ridges called ______________.
Trabeculae carneae
True or false: Afterload is the pressure that the heart must work against to pump blood into the systemic circulation.
True
True or false: The cells of the cardiac conduction system do not contract.
True
True or false: The nodal cells of the sinoatrial node are responsible for acting as the "pacemaker" of the heart.
True
The left ventricle normally has ____ papillary muscles.
Two
Left atrioventricular valve structure
Two triangular-shaped cusps of dense CT
The heart is a relatively small, conical organ approximately the size of a person's ________.
clenched fist
The cardiac center is within the ___________.
medulla oblongata
Openings of ______ are visible in the left atrium.
pulmonary veins
