2.1 Heart Flashcards
Pulmonary veins?
4 into left atria
Heart ventricles? (3)
Thicker than atria
left ventricle thicker than right
greater bp than atria
Heart (4)
Hollow fibromuscular organ
Ant. Mediastinuum
Fibrous sac
Flattened cone/deformed pyramid
Heart - base to apex
12cm
Heart weight, m and f
M 300g
F 250g
During cardiac cycle - the apex?
Does not move
Where is diaphragmatic face? Septal plane?
Inferiorly. Mainly rep. By ventricles
45* to saggital. Divides L and R heart
Iv groove?
Ant and post of heart
Sterrnocostal face?
Front of heart. Behind breastbone
Coronary sinus
Rv - vein draining heart
Right atrium post
Sinus vena cavae - smooth
Right atrium ant
True atrium - pectinate and cristae terminalis - auricle (sulcus terminalis externally)
Triangle of koch (4)
Tendon of todoro
Avn - apex of triangle
Central fibrous body
Coronary sinus at base
Rv 3 regions
Inflow, trabeculated, outflow
Left atrium (4)
Smooth surface
Less muscle pectinate
4 pv, no valves
Foramen ovale
Chordae tendinae
Dct
Av valves
Fibrous lamina - tfibroelastic tissue with overlying endocardium.
3 cusps.
No bv.
Smooth atrial surface
Chordae tendinae - ventricular surface - prevent extra flexion during ventricle contraction
Semilunar valves
3 cusps, nodules, lunules.
Aortic valve - rca, lca sinuses
Closure - end of systole - due to filling of cusps when ventricles contract
Valves - 3 layers
Fibrosa - core - fibrous extensions of dct of fibrous ring
Spongiosa - lct - atrial/bv side - shock absorber
Ventricularis - adjacent to ventricular or atrial surface. Endothelium.
Diastole, systole
Diastole - atria contract
Systole - ventricle contract
What main in cardiac tissue?
Proteoglycans, collagen fibres, elastic fibres
Papillary muscles
Attached to cusps via chordae tendinae. Prevent inversion of valves
Nodule of aranzio and morgagni?
Aorta and pulmonary
Sinus of valsalva?
Prevent adhesion of the cusps to the arterial wall
Adhering portions of valves?
Close to each other - form commisires
Free margin line?
Not closure line. Actual few mm below
How semilunar valves work?
Fibrous lamina (loose ct) - thickened in nodule. Modification - fibrocalcific - assosiated with dilation of aorta -> surgery replace valves
Fibrous skeleton (4)
Fibrous ct, 4 rings L and R trionge
Membranous part of septum
Fibrous part of skeleton functions
Attachment of cardiac muscle of atria and ventricle - vascularised stroma
Attachment of cusps
Separates physically and chemically - atria from ventricles
Maintains opening of valves
Cardiac muscle layers
2 layers - 1 common, 1 proper
Atria musculature
Deep layer - specific - circular muscle fibres - around opening of veins - form pectinate muscles
Specific layer - common - transverse and vertical system
Ventricle musculature
Specific - ascending : sub endocardium and papillary muscles
Common - descending : sub epicardium
Pericardium outer layer
Serosa - fibrous
- serous - pericardiac space
- visceral ( serosa (epicardium) )
Between serous -> pericardial cavity (20 ml fluid for unhibited movement)
Structure of heart
Endocardium - endothelim (ss) + CT
Myocardium - cmmon and specific myocardium
Epicardium (visceral and serous layer) - serosa - mesothelium + ct lamina
Fibrous skeleton in av plane
Epicardium. Mesothelium and lamina
Sub epicardiac layer
Meso - covered by lq veil
Lamina - elastic fibres
Sub epicardiac layer - cont with muscle layer. Branches of coronary art surrounded by fat
Endocardium 3 layers
Internal - endothelium
Middle - myocytes, parallel col fibres, elastic fibres
Outer :’purkinje fibres , bv nv
Atrium special
Myoendocrine cardiomyocytes produced, stored, secret ANP
Rel in response to high bp
Kidney - na loss, water loss therefore increase urine
ANP released in response to….
Angiotensin 2, rise in na, atrial wall stretching, endothelin, stim sympat of b-adrenoreceptors
Purkinje fibres (2)
Specific myocardium
Modified cardiac muscle cells : less actin and myosin
Conduction system of heart
San - pacemaker - central artery - 55% rca, 45 lca
Avn - nodal fibres, bundle of his - extend into membranous portion of skeleton (iv septum)
L+R branch
Purkinje fibres
San node innervation
Parasympathetic - vagus
Sympathetic - t1-t4 spinal nerves - also innervate atria and ventricles - therefore influence force of contraction
San node cells
Nodal cells, transitional cells, purkinje cells
Elongated nodal cells,
increase in vol, purkinje cells, - subendocardium.
Contain glycogen around nucleus, binucleated
Seperate by collagen and cardiac skeleton from other cardiac cells
Stain lighter,
Contractile waves from purkinje fibres
Apex of ventricles - from inside out (subendocardium to subepicardium)
Coronary artery - diammeter. R and L
1-2mm large to med muscular artery
Right - continue rigt of tv septum. Reach ant papillary
Left - ribbon - 1cm width - divide into 3 bundles at apex of heart - papillary muscle
San…..
San - avn to his to 2 branches + purkinje to the ventricles
Coronary veins (4) drain into?
Great ant iv vein Middle post iv vein Small Post Drain into coronary sinus
Coronary art anastomoses
Not efficient - not provide alt route - block lead to cardiac arrest - ishemia death of cardiac cells
Lca divides into!
Circumflex, iv artery and left marginal
Rca (2) and
divides into..
Branches…
Dominant.
Post iv branch - provide san and avn (70-80%) of people
Runs in coronary sulcus.
Branches - sternocostal face, diaphragmatic face
What does rca supply?(5)
San avn Right atria and ventricles Iv septum Left atrium Post inf 1/3 of iv septum Post of left ventricle
Origin of rca
Ascending aorta
Lca divides into? And where?
Circumflex, iv artery, left marginal
Behind pulmonary trunk. Enters the coronary sulcus
