objective 3 pt 1 Flashcards
transport system consisting of two side-by-side pumps
heart
receives oxygen-poor (deoxygenated) blood from tissues
right side
receives oxygenated (oxygen rich) blood from lungs
left side
what are the 2 receiving chambers of the heart?
right atrium
left atrium
receives blood returning from systemic circuit (body tissues)
right atrium
receives blood returning from pulmonary circuit (lungs)
left atrium
what are the 2 pumping chambers of the heart?
right ventricle
left ventricle
pumps blood through pulmonary circuit (lungs)
right ventricle
pumps blood through systemic circuit (body tissues)
left ventricle
what is the weight, size and shape of the heart?
about the size of a fist
weighs less than one pound
cone shaped
where is the heart located?
within the mediastinum between the 2nd and 5th intercoastal space
on superior surface of diaphragm
two-thirds of heart to left of mid-sternal line
anterior to vertebral column, posterior to sternum
flat and broad
referred to as posterior surface
leans toward right shoulder
base of heart
points toward left hip
apex
palpated between fifth and sixth ribs, just below left nipple
apical pulse
what are the 2 layers of the pericardium?
fibrous pericardium
serous pericardium
outer layer
protects and anchors heart to surrounding structures, and prevents overfilling
fibrous pericardium
inner double layer
serous pericardium
what are the 2 layers of the serous pericardium?
parietal layer
visceral layer
lines internal surface of fibrous pericardium
parietal layer
on external surface of the heart
visceral layer (epicardium)
what are the parietal and visceral layers of the serous pericardium separated by?
pericardial cavity
what are the 3 layers of the heart wall?
epicardium
myocardium
endocardium
outermost, visceral layer of the serous pericardium
epicardium
middle, muscular layer
reinforced by cardiac skeleton
myocardium
crisscrossing, interlacing layer of connective tissue
anchors muscle fibers
supports great vessels and valves
limits spread of action potential to specific paths
cardiac skeleton
innermost layer
it is continuous with endothelial lining of blood vessels
lines heart chambers and covers cardiac skeleton of valves
endocardium
what are the four chambers of the heart?
two superior atria
two inferior ventricles
what are the two septum of the heart?
interatrial septum
interventricular septum
separates atria into L & R
interatrial septum
separates ventricles into L & R
interventricular septum
what are the 2 grooves on the surface of the heart?
coronary sulcus
anterior interventricular sulcus
encircles junction of atria and ventricles like a crown
coronary sulcus
marks anterior position of septum separating the ventricles
anterior interventricular sulcus
small, thin-walled chambers
push blood down into the ventricles
contribute little to propulsion of blood
atria: receiving chambers
protruding appendages that increase atrial volume
auricles
receives deoxygenated (oxygen poor) blood from body
right atrium
what are the 3 veins that empty into the right atrium?
superior vena cava
inferior vena cava
coronary sinus
returns blood from body regions above the diaphragm
superior vena cava
returns blood from body regions below the diaphragm
inferior vena cava
returns blood from myocardium
coronary sinus
receives oxygenated (oxygen rich) blood from lungs
four pulmonary veins enter here
return blood from lungs
left atrium
make up most of the volume of heart
the actual pumps of the heart
Thicker walls than atria
When the ventricles contact, they propel
blood out of the heart into circulation
ventricles: discharging chambers
most of anterior surface
Pumps blood into pulmonary trunk
right ventricle
posteroinferior surface
Pumps blood into aorta
left ventricle
irregular ridges of muscle on ventricular walls
trabeculae carneae
project into ventricular cavity
papillary muscles
what are the 2 major types of valves in the heart?
atrioventricular valves
semilunar valves
ensures one way blood flow through the heart
open and close in response to pressure changes
heart valves
located between ventricles and major arteries
prevent backflow of blood into ventricles
open and close in response to pressure changes
each valve consists of three cusps that roughly resemble a half moon
there are 2
semilunar valve
located between atria and ventricles
prevent backflow into the atria
there are 2
atrioventricular valve
right AV valve
made up of three cusps and lies right between right atria and ventricle
tricuspid valve
left AV valve
made up of two cusps and lies between left atria and ventricle
mitral valve or bicuspid valve
located between aorta and left ventricle
aortic valvel
located between right ventricle and pulmonary trunk
pulmonary valve
anchor cusps of AV valves to papillary muscles that function to
hold valve flaps in closed position
prevent flaps from going upward into atria
chordae tendineae
what are the 2 semilunar valves?
pulmonary semilunar valve
aortic semilunar valve
located between right ventricle and pulmonary trunk
pulmonary semilunar valve
located between left ventricle and aorta
aortic semilunar valve
what is the pathway of blood through the right side of the heart?
Superior vena cava (SVC),
inferior vena cava (IVC), and
coronary sinus →
◦ Right atrium →
◦ Tricuspid valve →
◦ Right ventricle →
◦ Pulmonary semilunar valve →
◦ Pulmonary trunk →
◦ Pulmonary arteries →
◦ Lungs (picks up oxygen)
what is the pathway of blood through the left side of the heart?
Four pulmonary veins →
◦ Left atrium →
◦ Mitral (bicuspid) valve →
◦ Left ventricle →
◦ Aortic semilunar valve →
◦ Aorta →
◦ Systemic circulation = arteries –
arterioles- capillaries – venules –
veins (IVC/SVC)
Blood supply to heart muscle itself
◦ Shortest circulation in body
◦ Delivered when heart is relaxed
◦ Left ventricle receives most of coronary
blood supply
coronary circulation
Both left and right arise from aorta and supply
arterial blood to heart itself
◦ Both encircle heart in coronary sulcus
◦ Arteries contain many junctions
◦ Provide additional routes for blood delivery
◦ Cannot compensate for coronary artery occlusion
◦ Heart receives 1/20th of body’s blood supply
coronary arteries
what are the two branches of the left coronary artery?
anterior interventricular artery
circumflex artery
supplies interventricular septum and anterior ventricle walls
anterior interventricular artery
supplies the IT atrium and posterior wall of IT ventricle
circumflex artery
what are the 2 branches of the right coronary artery?
right marginal artery
posterior interventricular artery
serves the myocardium
right marginal artery
supplies the posterior ventricular walls
posterior interventricular artery
collect blood from capillary beds
cardiac veins
empties into right atrium; formed by merging cardiac veins
has 3 tributaries
coronary sinus
what are the 3 tributaries of the coronary sinus?
great cardiac vein
middle cardiac vein
small cardiac vein
