circulatory system
The left atrioventricular valve has _ cusps
2
the left ventricle normally has _ papillar muscles
2
Each semilunar valve is composed of _____ thin, ______ shaped, pocket like semilunar cusps.
3, half-moon
in avg normal human, the heart weighs about _ grams
300
During the cardiac cycle, blood only passes from atria into ventricles if the _ valves are open
AV
The right _ valve is forced close when the right ventricle begins to contract, preventing blood from flowing back to the atrium
AV
After initiation, the muscle impulse travels from the SA node to the
AV node
Sarcoplasmic reticulum is more extensive in smooth muscle fibers than in skeletal muscle fibers
False
T/F:The heart myocardium is nourished primarily through diffusion of nutrients from the blood in the heart chambers
False. The walls do not absorb nutrients or oxygen by diffusion and are dependent on coronary arteries to deliver them
The major wave forms in ECG are _ wave, _ complex and lastly the _ wave
P, QRS, T
2 major intervals in ECG tracing are
PR interval QT interval
segments of ECG
aka plateaus correspond to periods when sarcomeres are shortening
the inferior, conical end of the heart is called the _
apex
Toward the end of ventricular filling, the left and right _ contract simultaneously
atria
the _ of the heart receive blood and the _ pump blood to the lungs and body tissues
atria, ventricles
During ventricular relaxation, blood is allowed to flow through the right atrioventricular valves into the right ventricle
atrioventricular
The _ valves are between the atria and ventricles of the heart
atrioventricular
Purkinje cells
begin in apex and extend through walls of ventricles
when blood enters the pockets of semilunar valves it causes the cusps to fill and expand and meet the artery center, effectively ) blood backflow
blocking
During atrial relaxation
blood enters the right atrium via superior and inferior vena cavae, blood enters the left atrium via pulmonary veins
Endocardium
composed of simple squamous epithelium, called an endothelium and a layer of areolar connective tissue
The atria are separated from the ventricles externally by relatively deep _ sulcus or atrioventricular sulcus that extends around the circumference of the heart
coronary
complications of pericarditis include
death, heart failure, cardiac tomponade
perfusion
delivery of blood per unit time per gram of tissue
QRS complex
electrical changes associated with ventricular depolarization
heart 3 layers
epicardium, myocardium, endocardium
outer portion of pericardium is tough, dense connective tissue layer called the_ pericardium
fibrous
pulmonary circulation
flow of blood from the heart to the lungs and back to the heart for gas exchange
Three components of the cardiovascular system are _, blood vessels and _
heart, blood
three major vessels that empty into the right atrium:
inferior vena cava, coronary sinus, superior vena cava
The _ are 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
right and left ventricles are separated by
interventricular septum
The _ atrium and ventricle are prominent when viewing the heart from the posterior view
left
The interatrial septum forms a thin wall between the right and _
left atrium
As blood is pumped by the ventricles into the arterial trunks, it pushes against the cusps, forcing the semilunar valves to _
open
fossa ovalis
oval depression in the interatrial septum
The systematic circulation includes the movement of _ blood through the left side of the heart
oxygenated
serous pericardium divided into 2 layers
parietal layer - lines the inner surface of fibrous pericardium visceral layer -attached to the surface of the heart
Like the right atrium, the left atrium also has
pectinate muscles
left atriventricular
prevents backflow of blood into left atrium two triangular cusps of dense connective tissue
aortic semilunar
prevents backflow of blood into left ventricle
Right atrioventricular
prevents backflow of blood into right atrium 3 triangular shaped cusps of dense connective tissue
pulmonary semilunar
prevents backflow of blood into right ventricle 3 half moon shaped cusps of dense connective tissue
heart fibroskeleton serves to
provide an attachment site for cardiac muscle, isolate atria from ventricles, stabilize heart valves
The _ carries blood away from the right ventricle and brances into pulmonary arteries
pulmonary trunk
openings of _ are visible in the left atrium
pulmonary veins
circulatory system
responsible for transport of blood throughout body
changes in QT segment
result in accelerated heart rate called tacharrhythmia
right atrioventricular opening is covered by the
right atrioventricular tricupside valve
The boundary between the ventricles and the arterial trunks are the _ valves
semilunar
When the ventricles contract, the _ valves are forced open and blood enters the pulmonary trunk and the aorta
semilunar
space btw the parietal layer and visceral layer of pericardium contains
serous fluid
SA node
sinoatrial node or pacemaker sets the rate of heart contractions by sending action potentials through specialized conduction fibers to the atria and ventricle
cardiac cycle
the time from the start of one heartbeat to the initiation of the next
the myocardium is the _ of the 3 heart wall layers
thickest
serous pericardium
thinner, more delicate membrane that forms a double layer around the heart
serous pericardium
two layers produce and release serous fluid into pericardial sac
Anatomic features that are significant in normal function of heart are
two sets of valves within the heart, two sides of the heart, great vessels attaches to the heart
auricle
wrinkled, flap like extensions visible in the anterior view of the heart
