Development and Anatomy of Heart Flashcards
During development, how many blood vessels fuse together to form the heart? What does the sinus venosus, bulbus cordis, and truncus arteriosus develop into?
2 blood vessels form heart
sinus venosus - absorbed into atrium
bulbus cordis - absorbed into ventricle
truncus arteriosus - part of the bulbus cordis that develops into the pulmonary trunk and aorta
Where is the heart located? Describe what is in the middle, superior, anterior, and posterior mediastinum
heart is located in middle mediastinum
superior - thymus (child), trachea, esophagus, aortic catch, superior vena cava, vagus and phrenic nerves
anterior - thymus (remnants in adult)
posterior - thoracic aorta, esophagus, vagus and phrenic nerves
Describe what these borders and surfaces of the heart mean:
anterior surface
inferior border
posterior surface
anterior surface - most of right ventricle
inferior border - right ventricle
posterior surface - left atrium and most of left ventricle
Describe what these borders and surfaces of the heart mean:
anterior surface
inferior border
posterior surface
anterior surface - most of right ventricle
inferior border - right ventricle
posterior surface - left atrium and most of left ventricle
What does the pericardial cavity contain? Where does the heart sit in respect to it?
pericardial cavity only contains serous fluid that acts as lubricant for heart movement
- encases heart with double layers
- heart is not IN pericardial cavity - SURROUNDED by it
Describe the following layers of the heart wall:
epicardium, myocardium, endocardium
epicardium - visceral serous pericardium
- most superficial layer
- SS epithelium with layer of loose CT and adipose tissue
myocardium - cardiac muscle
- involuntary, striated, single nucleus, branching
- CT - fibrous skeleton of the heart
endocardium - lining of the heart
- continuous with endothelium of the blood vessels
- SS epithelium + loose CT
- attached to myocardium via loose/dense irregular CT
- contains autorhythmic cells in sub endothelial tissue
What are the layers of the pericardial cavity?
parietal fibrous pericardium - outer most layer of pericardial cavity
- prevents stretching, protects heart, anchors to mediastinal space
- tough, dense irregular CT
parietal serous pericardium - SSET + loose CT
- continuous with visceral serous pericardium
- attached and forms inner lining for fibrous pericardium
visceral serous pericardium - epicardium - SSET + loose CT
- serous membrane - secretes watery fluid into pericardial cavity
- attached directly to myocardium
What is pericarditis?
increased fluid or irritation/inflammation of the pericardial cavity
What is a cardiac tamponade?
too much fluid in pericardial cavity - limits expansion of the chambers when filling with blood
- heart beats faster to try and compensate for decreased volume output
- can be caused by pericarditis
Describe the muscle cell structure of the myocardium
short, flat, branches cells joined by intercalated discs
- intercalated discs - formed by desmosomes and gap junctions
- striations due to sarcomeres
- many mitochondria
Describe the difference between the R and L atrium
Right - received deoxygenated blood from:
- superior vena cava - chest, upper extremities, neck, head
- inferior vena cava - abdomen, lower extremities
- coronary sinus - venous drainage from the heart
CONTAINS THE REGULATORY STRUCTURES
- sinoatrial node
- atrioventricular node
fossa ovalis more pronounced on R side
Left - receives oxygenated blood from the pulmonary veins of R and L lung
- NO REGULATORY STRUCTURES
Describe the following features found in the ventricles: trabeculae carnae, papillary muscles, and chordae tendinae
trabeculae carnae - ridges of cardiac muscle that line the ventricle walls
papillary muscles - from ventricular wall, attached to AV valves via chordae tendinae
- prevents AV valves from turning inside out
chordae tendinae - connective tissue cords that attach to the AV value and papillary muscles
- prevents AV valves from turning inside out
Describe auricles. Where are they found?
made of ridges of cardiac muscle called pectinate muscle
- only found in atria
Describe the L and R AV valve. What are the other names for the valves?
Right atrioventricular valve - tricuspid valve - 3 leaflets
left atrioventricular valve - bicuspid valve - mitral valve
Describe the L and R AV valve. What are the other names for the valves? What do they look like at rest?
Right atrioventricular valve - tricuspid valve - 3 leaflets
left atrioventricular valve - bicuspid valve - mitral valve
both are open at rest bc P atrium > P ventricles when heart is not contracting
- when ventricles contract - leaflets close
Describe the R and the L ventricle. What is a moderator band? What do the s
Right ventricle - received deoxygenated blood from R atrium
- empties into the pulmonary trunk via pulmonary semilunar valve
- contains moderator band
Left ventricle - receives deoxygenated blood from the L atrium
- empties into the ascending aorta via aortic semilunar valve
Describe the R and the L ventricle. What is a moderator band? What do the semilunar valves look like a rest?
Right ventricle - received deoxygenated blood from R atrium
- empties into the pulmonary trunk via pulmonary semilunar valve
- contains moderator band
Left ventricle - receives oxygenated blood from the L atrium
- empties into the ascending aorta via aortic semilunar valve
moderator band - specialized muscle cells that are not contractile
- carry electric current from SA to AV node across and down AV septum
The aortic semilunar valves have special openings. What are they for?
aortic semilunar valves have openings for the R and L coronary arteries
- oxygenated blood goes to heart before rest of the body
- heart only gets blood when the valve is closed/heart relaxed
What is the pulmonary circuit and the systemic circuit? Describe the flow of blood through the heart
pulmonary - venous system
- R side of heart to lungs, back to L side heart
- low pressure
systemic - arterial system,
- L side of heart to body ad back to R side of heart
- high pressure
Superior VC - R atrium - R AV valve - R ventricle - pulmonary semilunar valve - pulmonary trunk and arteries
LUNGS
pulmonary veins - L atrium - L AV valve - L ventricle - aortic semilunar - ascending aorta
What is the pulmonary circuit and the systemic circuit? Describe the flow of blood through the heart
pulmonary - venous system
- R side of heart to lungs, back to L side heart
- low pressure
systemic - arterial system,
- L side of heart to body ad back to R side of heart
- high pressure
Superior VC - R atrium - R AV valve - R ventricle - pulmonary semilunar valve - pulmonary trunk and arteries
LUNGS
pulmonary veins - L atrium - L AV valve - L ventricle - aortic semilunar - ascending aorta
What is congestive heart failure? What’s the different in CHF in the L and R side?
myocardium of the ventricles becoming stiff or weakened - unable to move blood out of the ventricle at same rate that it is entering the atria
R CHF - unable to keep up with amount from body - blood backs up into body
- systemic (pitting) edema
L CHF - blood backs up into lungs
- pulmonary edema - leakage of fluid out of pulmonary capillaries of alveoli
What is mitral valve stenosis?
thickening/stiffening of L atrioventricular valve
- narrows opening between L atrium andL ventricle
- decreased volume of blood that passes thru
What is mitral valve prolapse?
L atrioventricular valve flaps move into L atrium during ventricular contraction
- allows blood from L ventricle to flow back into L atrium instead of all to aorta
- associated with murmurs, enlargement of L side of heart
What is patent foramen ovale?
when foramen oval does not close shortly after birth to form the fossa ovalis
- typically closes within 6-12 months after birth
- known unless they get blood clots - then stroke
