Thorax: viscera (Heart) Flashcards
middle mediastinum: features
- centrally placed in thoracic cavity containing:
- pericardium
- heart
- roots of great vessels
- nerves
pericardium: features
- fibro-serous sac enclosing heart and roots of great vessels
- fibrous pericardium
- serous pericardium
(parietal and visceral)
pericardium: fibrous pericardium bounded to
diaphragm:
- pericardiodiaphragmatic lig
sternum:
- sternopericardial lig
pericardium: nerve supply originates from
- phrenic n
- vagus n
- parasympathetic trunks
pericardium: pain sensation from parietal pericardium conveyed by:
- phrenic nn
- commonly referred to skin in supraclavicular and neck region
heart: base directed and consists of
superior and posterior
- L atrium
- small bit of R atrium
- pulmonary veins
- superior/ inf vena cava
heart: apex directed and consists of
- inferior, anterior and to the left
- L ventricle
heart: name surfaces
- anterior
- inferior
- left
heart: ant surface
sterno-costal
heart: inf surface
diaphragmatic
heart: left
pulmonary
heart: name borders
- R
- L
- inferior
- superior
heart: R border
R atrium
heart: inferior border
mainly R ventricle and slightly L ventricle
heart: L border
L ventricle and L atrium
heart: superior border
L and R atria, SVC, aorta, pulmonary trunk
name parts of cardiac cycle:
- diastole
- systole
cardiac cycle: diastole
ventricular filling
cardiac cycle: systole
ventricular emptying
R atrium: features incl. musuli pectinati, crista terminalis, sinus venosum
- R border of heart
- receives deoxygenated blood from SVC, IVC and coronary sinus
- has auricle overlapping ascending aorta
- oval fossa (oval foramen in foetus)
- musculi pectinati (pectinate muscles)
crista terminalis: (smooth muscular ridge btw IVC and SVC)
embryonic sinus venosum (small tissue folds indicate remnants btw coronary sinus and IVC)
development: derived from
- splanchnoplueric mesenchyme in neural plate
development: formation process
cardiogenic region - 2 endocardial tubes form/ fuse = tubular heart - heart chambers develop foramen ovalis (allow blood btw atria) - septum primum seals foramen ovalis at birth
R ventricle: features
- forms most of inf border
- interior of chamber has trabecular carneae/ papillary muscles (muscular elevations) and conus arteriosus (smooth walls), OUTFLOW part
R ventricle: receives blood from
R atrium through AV (atrioventricular) orifice guarded by tricuspid valve
R ventricle: tricuspid valve features
- three cusps
- chordae tendinae attach to free edge of cusps
- papillary muscles (trabeculae carneae) attach cords to ventricular surface
R ventricle: main papillary muscles and attachments
- anterior (largest)
- post (1-3)
- septal (small or absent)
at cone base: attached to ventricular walls
- chordae tendinae arise from apices
R ventricle: pulmonary valve
at apex of conus arteriosus consist of 3 semilunar cusps
L atrium: features
- forms most of base of heart
- interior: larger smooth-walled part
- smaller muscular part (auricle)
- 4 pulmonary veins enter post wall
- interatrial septum w depression of fossa ovale
- AV orifice
L ventricle: interior features
- AV orifice guarded by bicuspid (mitral) valve
- thickest layer of myocardium
- largest conical chamber
- finer trabeculae carneae
- 2 papillary muscles (ant/ post) larger than R ventricle
- aortic valve similar to pulmonary valve (3 semilunar cusps)
aortic valve:
- 3 semilunar cusps project into aorta
- R and L coronary arteries (og. from R and L aortic sinuses)
- blood recoil after ventricular retraction fills aortic sinuses and feeds coronary aa
auscultation: aortic valve
R upper chest, below clavicle
auscultation: pulmonary valve
L upper chest below clavicle
auscultation: tricuspid valve
L mid chest medial, next to nipple
auscultation: mitral valve
L lower chest, laterally under nipple
cardiac skeleton: features
- fibrous ct around AV and aortic orifices,
- pulmonary trunk opening interconnected by L and R trigones
cardiac skeleton: function
- attachment for cusps
- separates atrial musculature from ventricular
- electrical insulator, independent contraction of atria and ventricle
coronary circulation: coronary aa
- branches of ascending aorta
- originate from R and L aortic sinuses
R coronary artery: branches
- sinuatrial nodal branch
- R marginal branch
- post interventricular branch
L coronary artery: branches
- anterior interventricular branch
- circumflex branch
- L marginal aa
cardiac veins:
- great cardiac vein begins at apex of heart - ascends w ant interventricular aa - curves into diaphragmatic surface and coronary sulcus - enlarges and forms coronary sinus which enters R atrium
- middle cardiac v
- small cardiac v
- ant veins of R ventricle
cardiac inn:
- autonomic nervous fibres from cardiac plexuses:
- sympathetic fibres (T1-6) thoracic segments of spinal cord
- parasympathetic fibres (vagus nn)
eg. myocardial infarction:
- blocked blood supply in heart
- usually by excess plaque
- tissue death
eg. referred pain:
- referred to T1-4 dermatomes
eg. angina
chest pain
