5.0 Gross anatomy of heart Flashcards
what does right and left side of pulmonary circuits do
right side: brings blood to the lungs
left side: bring bloog to the body
where is the heart located?
- in mediastinum
2/3 of left is to the left of midsternal line
- located posterior to sternum but anterior to vertebral column
- on superior face of diaphragm
what is the pericardium
- has 3 layers (usually just 2 i think)
- superficial fibrous pericardium:
- protects, anchord nd prevents overfilling
- considered the “extra” layer
- Deep two layered serous pericardium
- parietal layer of serous pericardium
- lines cavity
- Visceral layer of serous pericardium
- on heart
- aka epicardium
- parietal layer of serous pericardium
*Pericardial cavity is between the parietal and visceral layers of serous pericardium
what are the serosas of the body
- pericardium heart)
- pleura (in lungs)
peritoneum (abdomen)
what is the first layer of the heart wall
Epicardium aka visceral layer of serous pericardium
- often infiltrated with fat
most superficial layer of the heart
describe the second layer of the heart wall
what does it make up
- spiral bundles of cardiac muscle (spiral so when it contracts it squeezes the blood out)
- makes up fibrous skeleton of the heart: crisscrossing, interlacing layer of connective issue that
- > limits spread of AP to specific paths
- > anchors cardiac muscle fibers
- > supports great vessels & valves (pathways into and out of heart)
what is the innermost layer of the heart wall
endocardium: continuous with endothelium that lines vessels
- made of simple squamous epithelium
*lines inside of heart (all chambers)
Which layer of the heart wall consumes the most muscle
myocardium
How is the heart orientated
- Base
- at top
- is posterior and directed towards right shoulder
- mainly located in left atrium
- Apex
- bottom part
- points twds left hip
- points inferiorly towards left hip
superficial anatomy of atria
*atria are receiving chambers
- Coronary sulcus (atrioventricular groove): encircles junction of atria and ventricles (aka separates atria from ventricles)
- Auricles increase atrial volume: closet of heart, gives more room for blood
describe the internal anatomy of the atria
- interatrial septum: separates left/right atria
Pectinate muscles: muscles ridges that lines walls of aria
Fossa Ovalis: fetal remnant of foramen ovale (in fetal circulation blood goes from L->R atrium, skips lungs)
What are the receiving chambers in the atria
- Vessels entering right atrium (3)
- coronary sinus (blood ocming back from heart itself)
- inferior vena cava (blood from inferior of diaphragm
- superior vena cava
- Vessels entering left atrium (4)
- left superior and inferior pulmonary veins
- right superior and inferior pulmonary veins
*7 total
what separates the ventricles
interventricular septum (marked by interventricular sulci externally)
what lines the walls of the ventricles
trabeculae carneae
aka meat lattice
- ruffles on walls, made of myocardium
(all trabeculae carneae made of myocardium, but not all cyocardium is trabeculae carneae)
what are the discharging chambers of the ventricles
Vessel leaving right ventricle = pulmonary trunk
vessel leaving left ventricle = aorta
what do heart valves do?
What heart valves does our body have?
- ensure unidirectional blood flow through heart
- two sets:
- > Atrioventricular (AV) valves (btwn atira & ventricles)
- > Semilunar values (btwn ventricles and great vessels (pulmonary trunk and aorta)
what are the AV valves in the body?
How are they anchored?
two AV values:
- > Tricuspid valve: Between right atria + right ventricle
- > Mitral (bicuspid) valve: Between left atria + left ventricle
*try b4 u buy, goes through tricuspid then bicuspid)
- anchord to papillary musclces by chordae tendineae
what causes the AV valves to open?
- when atrial pressure > ventricular pressure
1. blood returning to heart fills atria -> puts pressure against AV valves forcing them to open
2. as ventricles fill, AV valve flaps hang limply into ventricles
3. Atria contract forcing additional blood into ventricles
what causes the AV valves to close
atrial pressure < ventricular pressure
- ventricles contract, forcing blood against AV valve cusps
- AV valves close
- Papillary muscles contract & chordae tendineae tightens -> preventing valve flaps from everting into atria
what are the semilunar valves of the heart
aortic and pulmonary semilunar valves
*named after the vessel they are found in
*3 cusps
what causes the semilunar valves to open
- ventricles contract & intraventricular pressure inc
blood is pushed against semilunar vlaes forcing them open
*flatten against the walls
what causes the semilunar valves to close
- ventricles relax and intraventricular pressure dec
- blood flows back from arteries filling cusps of semilunar valves -> forces them closed
overiew of how blood is pumped through heart
- O2 poor blood from body enters heart -> enters from SVC, IVC and coronary sinus
- blood enters right atrium then goes through tricuspid valve
- enters right ventricle, contracts and opens pulmonary semilunar valve
- exits via pulmonary trunk to lungs to be oxygenated
- O2 rich blood returns to heart via 4 pulmonary veins
- blood from 4 pulmonary veins empty into left atrium, press agsint mitral valve
- goes thru mitral valve and enters left ventricle, deos out aortic semilunar valve
. O2 rich blood goes into systemic circularion
blood goes through pulmonary vs systemic circuits
equal volumes of blod are pumped to pulmonary and systemic
- pulmonary circuit is short, low pressure -> not a lot of resistance and lugns are close to less meaty right ventricle
- systemic cirucit encounters much more resistance in long pathways
*left ventricle much thicker
