Lecture 25: Thorax IV, Heart Flashcards
why is cardiovascular system necessary
for diffusion to occur in all regions in body
3 layers of heart
-epicardium
-endocardium
-myocardium
pericardium: definition and components
-membrane enclosing the heart
-consists of pleura, fibrous layer and parietal layer
the parietal layer forms what
pericardium
visceral layer forms what
epicardium
sternopericardial/phrenicopericardial ligament
connect fibrous pericardium to diaphragm
4 valves in heart
-pulmonary semilunar
-right atrioventricular/tricuspid
-aortic semilunar
-left atrioventricular/bicuspid
2 auricles of heart
right and left
where are auricles located in heart
on dorsal surface of atria
what structure separates the atria from ventricles
coronary sulcus
what structure separates ventricles
interventricular sulcus
conus arteriosus
-cone shaped outflow/bulge tract of right ventricle that indicates narrowing of chamber toward pulmonary trunk
-located between right ventricle and pulmonary trunk
where is right auricle located (next to what?)
next to cranial vena cava
myocardium is
cardiac muscle
tricuspid valve: location
between right atrium and right ventricle
tricuspid valve aka
right atrioventricular valve
bicuspid valve: location
between left atrium and left ventricle
bicuspid valve aka
left atrioventricular valve
interventricular septum
wall of myocardium separating left and right ventricles
what muscles contract atrial walls
pectinate muscles
where are pectinate muscles located specifically
myocardium
what 3 structures constitute atrioventricular valves
-cusps
-chordae tendinae
-papillary muscles
papillary muscle function
anchor chordae tendinae to prevent backflow
function of left AV valve (bicuspid)
prevent leakage of blood back to left atrium during ventricular contraction (Systole)
function of right AV valve (tricuspid)
prevent leakage of blood back to right atrium during ventricular contraction
trabecula septomarginalis aka
moderator band
trabecula septomarginalis vs trabeculae carneae
-trabecula septomarginalis only found in right ventricle in mammals
-trabeculae carneae found in both ventricles
semilunar valves are found where
at the bases of large vessels/arteries located within the heart
aortic semilunar valve: location and function
allow movement of blood from aorta to prevent it from returning to left ventricle
pulmonary semilunar valve: location and function
located between pulmonary artery and right ventricle
-once closed, ventricles can fill with blood
ideal sites for auscultation of heart valves
puncta maxima
which arteries are the first branches of the aorta
coronary arteries (left and right)
where do coronary arteries originate from
aortic semilunar valve
where is coronary sinus located
atrioventricular sulcus (between left atrium and left ventricle)
where do coronary veins drain into
coronary sinus
what structure opens into the right atrium
coronary sinus
what vein runs in the coronary sulcus
coronary sinus
what is the coronary sinus (importance)
largest coronary vein
receives drainage from many veins
small coronary vein location
drains into coronary sinus
where does coronary sinus terminate
right atrium
how conduction/action potentials spread through heart
originates in SA node –> depolarization –> AV node –> right and left bundles –> purkinje fibers
location of sinoatrial node
right atrium
location of right and left bundles
interventricular septum
location of purkinje fibers
apex of heart
where do pectinate muscles end
crista terminalis
extrinsic innervation of the heart: 2 nervous systems
sympathetic and parasympathetic
parasympathetic control of heart: nerve
vagus
cardiac plexus
bundle of nerves located at base of heart that innervate the heart
2 parts of cardiac plexus
-deep/caudal
-superficial/cranial
superficial/cranial portion of cardiac plexus location
beneath aortic arch, in front of right pulmonary artery
what 2 nerves form superficial/cranial part of cardiac plexus
left sympathetic trunk/nerves
left vagus nerves
what 3 nerves form deep/caudal part of cardiac plexus
right sympathetic trunk (T1-T4)
right vagus nerve
right recurrent laryngeal nerve
effect of vagus nerve on heart: parasympathetic
lower heart rate
reduce force of contraction
vasoconstriction of coronary arteries
effect of sympathetic efferent fibers on heart
increase heart rate
increase force of contraction of myocardium
which side of the heart is larger (aka which myocardial layer is thicker)
left
why is the left side of the heart (ventricles) bigger than the right side
has to pump blood to body (vs just the lungs)
endocardium made of what kind of tissue
endothelium
what 3 layers make up the pericardium
-pleura
-fibrous layer
-parietal layer
organzation of pericardium
inner parietal layer
fibrous layer in the middle
pleura is outermost layer
what kind of tissue is fibrous pericardial layer made out of
dense irregular connective tissue
function of fibrous pericardial layer
-anchor heart
-protect heart
-prevent overfilling of blood in heart (not elastic)
interventricular sulcus aka
paraconal groove
coronary circulation process (from left ventricle to pulmonary circuit)
left ventricle –> aortic semilunar valve –> ascending aorta –> right and left coronary arteries –> right coronary artery branches into right circumflex artery, left coronary artery branches into left circumflex artery –> supplies myocardium –> coronary/cardiac veins –> blood drains into coronary sinus –> right atrium –> right ventricle –> pulmonary circuit
what do left and right coronary arteries supply (to heart)
myocardium
3 veins of the heart
-great coronary/cardiac vein
-small coronary/cardiac vein
-coronary sinus
left circumflex artery branches into
interventricular paraconal artery
location of left circumflex and interventricular paraconal arteries
left ventricle
coronary sinus is a large
vein
what kind of blood is located in coronary sinus (from myocardium)
deoxygenated
what kind of blood is moving through coronary arteries (before reaching myocardium)
oxygenated
pulmonary circulation process (from right ventricle to left ventricle)
right ventricle –> pulmonary semilunar valves –> pulmonary trunk –> splits into right and left pulmonary arteries –> through hilum to lungs –> gas exchange b/w alveoli –> blood drains into pulmonary veins –> bring oxygenated blood to left atrium –> mitral valve –> left ventricle
what kind of blood is carried by right and left pulmonary arteries
deoxygenated
arteries function
take blood away from heart
veins function
bring blood back to heart
