Lecture 19: Circulatory System 1 Flashcards
explain contents of mediastina
heart
large vessels
esophagus
trachea
thoracic aorta
explain borders of mediastina
bounded anteriorly by sternum and costal
cartilages, laterally by lungs, and posteriorly by the bodies of thoracic
vertebrae
explain subdivisions mediastina
divided into superior and infeior by a transverse plane passing thru sternal angle
superior mediastinum:
inferior mediastinum
middle mediastinum: heart & pericardium
anterior mediastinum: by ribs
posterior: by thoracic vertebrae
discuss external features heart
heart sulci- coronary sulcus separates atria from ventricles. anterior and posterior interventricular sulci are btw ventricles.
heart surfaces- anterior, inferior, left and right pulmonary surface
heart borderes- superior, right, eft, inferior
heart base- faces posteriorly, mainly left atrium
heart apex- formed by left ventricle and is directed anteriorly, inferiorly, to the left
discuss internal features heart
R atrium: receives venous blood from SVC, IVC, coronary sinus
R ventricle: pulmonary artery arises
L atrium: receives oxygenated venous blood from R and L pulmonar veins
L ventricle: aorta arises from here
explain blood supply/venous drainage heart
right atrium receives deozxygenated blood from entire body, passes it to right ventricle. right ventricle pupms blood to lungs, left atrium receives oxygenated blood from lungs, pumps to body
contents of superior mediastinum
Arch of aorta
R and L brachiocephalic veins
Inferior part of superior vena cava, azygos vein
Right and left phrenic and vagus nerves
Trachea, esophagus, thynus gland, thoracic duct
explain contents inferior mediastinum
anterior: thymus gland
middle: heart, pericardium, ascneindg aorta, pulmonary trunk/veins. phrenic nerves. bronchi
posterior: descending aorta, azygos and hemiazygos viens, vagus nerves, splachnic nerves, thoracic duct, esophagus
what is circled in orange? green? blye?
orange: anterior mediastinum
green: middle
blue: posterior
- right pulmonary surface
- diaphragm
- left pulmonary surface
- apex of heart (L side)
- inferior surface
what are the four corners of the surface anatomy of the heart?
Upper left corner= left 2nd intercostal space, 1 in ch away from midline
Upper right corner is right 3rd costal cartilage, 1 inch from mid
lower right corner is at 6th costal cartilage, 1 inch from midline
lower left corner is 5th intercostal soace, 3-4 inches from midline
what is the heart surrounded by? what is this made of?
=pericardial sac which is composed of outer layer (fibrous pericardium) and inner serous layer (serous pericardium)
what is the serous pericardium? whats it made of
inner layer of pericardium. hhas two layers
- parietal layer: lines inner surface of fibrous pericardium
- visceral layer: attaches to heart surface
pericardial cavity in btw the layers, filled with serous fluid
what is the visceral layer of serous pericardium AKA
epicardium (outermost part of heart)
what is the myocardium
middle muscular layer of heart
what is endocardium
inner layer of heart. blood.
which part of heart receives oxygen rich blood?
LEFT ATRIUM, then blood goes to left ventricle, blood pumped into systemic circulation
which part of heart receives deoxygenated bloo?
right atrium. pumped into right ventricle, then to lungs
label and explain fxn
- inferior vena cava= biggest vein in body. receives venous blood from lower limbs. drain into left atrium
- superior vena cava=receives venous blood from head, neck, upper limbs, thorax to left atrium
- pulmonary trunk: carries deoxygenated blood to lungs. divides into L and R arteries
1:auricle of right atrium
2: corony sulcus/atrioventricular groove
3: auricle of left atrium
4: anterior interventricular sulcus
- descending aorta
- arch of aorta
- SVC
- IVC
- left ventricle
- left atrium
- r atrium
label and explain fxn
- left pulmonary artery: gives oxygen poor blood to lungs
- left pulmonary veins: bring oxygenated blood to heart
- right pulonary artery
- right pulmonary vein
label
- pulmonary trunk
- pulmonary veins
- interventricular septum
- IVC
- opening of coronary sinus
- R pulmonary vein
- SVC
what is fossa ovalis?
remnant of embryonic foramen ovalis, that used to connect the R and L atrium.
located in R atrium
with is ligamentum arteriosum
during fetal development, diverst blood from pulmonary trunk back to aorta. after birth it becomes fused, known as ductos aerolis in embryo
what separates R and L ventricle
interventricular septum
what valve separates L ventricle and atrium
left atrioventricular valve (Bicuspid/mitral)
what valve separaates R atrium and ventricle
right atrioventricular valve (tripcuspid)
what is the pulmonary valve?
prevents blood flowing back into right ventricle.
semilunar valve at beginnig of pulmonary artery
what is aortic valve
at beginning of aorta, semilunar valve. prevents blood from flowing back to left ventricle
1.traneculae canae
2. tricsupid valve (R atrioventricular)
3. mitral valve (L atrioventricular, bicuspid)
4. chordae tendinae
5. papillary muscles
6. interventricular semptum
what are papillary muscles
thing muscles, control valves
connected to valve leaflets through chordae tendinae. prevent prolapse
what are trabeculae canae
muscle ridges in right ventricle
which major veins supply the right atrium? what type of blood
SVC, IVC, coronary sinus. deoxygenated blood
which arteries does the left ventricle suppply? what type of blood
aorta, coronary and systemic artiers. oxygenated
arterial supplyo of heart
= right and left coronary arteries
R: one branch= posterior interventricular artery. arises from right side ascending aorta, supplies RA and RV
L: two branches: anterior interventricular artery and circumflex artery. arises from left side ascending aorta
what are the three major cardiac veins that drian the heart
great cardiac vein
middle cardiac vein
small cardiac vein
all drian into coronary sinus, which drains into RA
SinoAtrial (SA) Node)
heart pacemaker. located on right atrium wall close to SVC opening
Aterioventricular node (AV)
located on right side of interatrial septum close to opening of coronary sinus
- SA node (pacemaker)
- AV node
atrioventricular bundle (bundle of His)
starts from AV node. give rise to Purkinje fibres that distribute to R and L ventricular walls
how does electric impulse propagate in heart
starts from SA node, propagates through and contracts atrial walls before reaching AV node. impulse passes thru ventricular walls via AV bundle/Purkinje fibres and lead to ventricular contraction
what affect does vagus nerve have on heart
PSN
decrease HR
arises from dorsal motor nucleus of vagus
what effect do sympathetic nerves have on heart
increase HR and force of contraction. arise from sympathetic trunk ganglion at the thoracic spinal cord
explain arterial supply heart
right coronary artery (from r side aorta) runs along r coronary sulcus. terminal branch= posterior interventricular artery
left coronary artery gives rise to anterior interventricular artery and circumflex artery
explain venous drainaige heart
3 veins
great cardiac vein: runs in anterior IV sulcus
middle cardiac vein: runs in posterior IV sulcus
small: follows r side coronary sulcus
all drain int coronary sinus located in coronary sulcus on inferior surfaace heart
this drains into RA
