heart Flashcards
1
Q
floor of thoracic cavity
A
diaphragm
3 openings (hiatus):
- aorta
- inferior vena cava
- oesophagus
2
Q
3 spaces of thoracic cavity
A
- 2 lateral: plural cavities: contain lungs
- central (bit to the left): mediastinum: heart, oesophagus, trachea, lymph sinus
3
Q
mediastinum
A
walls:
- anterior: sternum: bone component
- inferior: diaphragm
- lateral: lungs
- posterior: thoracic vertebrae
- line divides superior and inferior regions: at sternal angle/T4-T5 disk
inferior:
- anterior, middle (heart), posterior (oe)
4
Q
relations of the heart
A
- superiorly: no proper relations, location of greater vessels
- anteriorly: thymus +sternum
- inferiorly: diaphragm
- posteriorly: oesophagus
- laterally: lungs
5
Q
heart shape
A
- pyramidal shape
- oblique position
- inferior apex orientated forward and down to the left
- superior base orientated upward and back
- main axis oblique: almost horizontal
- LV rotated posteriorly
- anterior/sternal surface
- posterior/diaphragmatic surface
- 2 lateral borders separate anterior and posterior surfaces: left is obtuse and right is acute
6
Q
anterior surface/aspect of heart
A
- superior region: greater vessels
- externally: auricles: external muscular extensions of atria: right larger, left smaller
- inferiorly: external muscular structures of ventricles
- mainly RV + small part of LV containing apex
- atrioventricular groove: horizontal groove goes around heart: division of As and Vs: passage of coronary vessels: coronary groove/sinus
- anterior interventricular groove: oblique vertical groove on external part of septum separating Vs
7
Q
greater vessels on anterior surface of heart
A
- bordered by auricles
- superior vena cava: end of general circulation: collect all venous blood from organs superior to diaphragm
- aorta: greater artery of circulatory system: beginning of general circulation: supply all organs and tissues with collateral branches: ascending anteriorly - arch -descending posteriorly
- pulmonary artery: starts of pulmonary circulation
8
Q
external posterior surface of heart
A
- superior and inferior region
- no auricles
- superior vena cava: continuation with inferior: vertical venous structure
- vertical straight portion of aorta curved to form the aortic arch: descending posteriorly
- pulmonary trunk splits into right and left pulmonary artery to right and left lung
- 4 pulmonary veins: 2 from each lung complete pulmonary circulation
- posterior interventricular groove: more vertical: passage of vessels
- terminal sulcus: joining of two vena cava
- crux cordis, coronary sinus
9
Q
pericardium
A
- sac
- separates heart from other organs
external fibrous layer: attachment of ligament connecting to other organs: - heart to diaphragm
- heart to sternum to maintain position: sternopericardial ligaments
internal serous layer: corresponds to epicardium: - epicardium: visceral PC
- middle: muscular
- endocardium: epithelium: single layer of squamous cells
10
Q
function of pericardium
A
- protects and anchors heart
- prevents overfilling
- allows heart to work in relatively friction free environment
11
Q
anatomy of pericardium
A
- double-walled sac around heart
- superficial fibrous pericardium
- deep two-layer serous pericardium:
- parietal layer lines the internal surface of the fibrous pericardium
- visceral layer of serous pericardium: epicardium: lines the surface of the heart
- separated by fluid-filled pericardial cavity
- foldings of pericardium onto heart follow large vessels
12
Q
heart wall
A
- epicardium
- myocardium
- endocardium
13
Q
visceral serous layer of pericardium
A
- outer layer: party of epicardium
- smooth muscle
- able to secrete fluid
14
Q
A
15
Q
moderator band of septomarginal trabecula
A
- septum + lateroinferior wall
- Leonardo’s
- 2nd order trabeculi: 2 different walls of ventricle
- specific myocardial tissue
- generates conduct stimulus: higher frequency than average tissues
16
Q
valves from above
A
- on one plane
- pulmonary trunk:most anterior: smeilunar valve: anterior,right and left cusp
- aorta right behind pulmonary: right coronary , left coronary, posterior non-coronary semilunar cusps
- left AVN: mitral/bicuspid valve
- right AVN: tricuspid
- left fibrous trigone: between aortic and mitral
- right fibrous trigone: between tricuspid, mitral and aortic
- space between valves is also insulated
17
Q
papillary muscles
A
- chordae tendinae put under tension since systole
- papillary muscles one of first to contract: thin so depolarisation spreads fast
18
Q
Sino Atrial Node (ASN)
A
- pacemaker
- anterior to where SVC enters RA
- many gap junctions: fires fastest
- internodal branches depolarise atria at the same time
19
Q
AVN
A
- delayed 0.12-014 seconds
- less gap junctions: slower conduction
20
Q
bundle of his/purkinje fibres
A
- at top slightly to right of septum
- right and left bundles
- pass to musculature near apex
- LV contracts earlier: thinner
21
Q
coronary arteries
A
- main run in sulcuses
- left coronary artery: short, most of septum’s circulation, behind aorta in sulcus, 2 branches:
- circumflex branch and anterior interventricular descending branch
- right coronary artery: below auricle, goes around coronary sulcus and AVN posteriorly: ends in posterior interventricular artery
- right marginal branch and posterior interventricular branch
22
Q
dominance
A
- which coronary artery gives rise to posterior interventricular artery
- 70.80% right but not higher flow
- provides blood to nodes
23
Q
crux cordis
A
- lower back side of the heart
- where the coronary sulcus and the posterior interventricular sulcus meet
24
Q
direction of blood flow
A
- only vertical
- horizontal in fetus
25
crista terminalis
- right atrium
- terminal crest: terminal sulcus externally separating atrium from auricle
- posterior to crest: smooth and regular for blood flow from VC
- anterior to crest: irregular: pectinate muscles
26
walls of right atrium
- inferior: floor
- medial: septum
- anterolateral: pectinate muscles of auricle
- posterior: smooth part
- superior: roof
27
floor of right atrium
- AVN opening
- tricuspid valve attached to fibrous skeleton
- smaller opening: coronary sinus: thebesian valve
- inferior vena cava: Eustachian valve: only functional in fetus
- two valves converge into a fibrous band: tendon of Todero
- Koh's triangle: tendon of todero + medial cusp point up to AVN
28
roof of right atrium
- superior vena cava
- SAN
29
medial wall of right atrium
- fossa ovalis: left of foramen ovale in fetus
30
right ventricle
- superior base
- inferior septum
- tricuspid valve connected to papillary muscles by chordae tendinae: prevent prolapsing into atrium
- each cusp to a diff papillary muscle
- anterior, posterior, septal/medial cusps
- inflow and outflow portion separated by supraventricular crest
- outflow: origin of pulmonary trunk: semilunar pulmonary valve: infundibulum, conus arteriosus: The smooth walled outflow tract of the right ventricle located between the right ventricle and pulmonary trunk
- 3 pockets/cusps: anterior, right and left posterior
- union of cusps: nodule of PV
31
left atrium
- think
- largest part posteriorly smooth
- some pectinate muscles on anterior wall for auricle
- 4 pulmonary veins
- floor: AVN valve attaches to fibrous ring
- valve foramen ovale
32
left ventricle
- superior base: AVN valve with 2 cusps
- conically shaped
- -wall 3x thicker
33
trabeculi muscles
1. one end to ventricular wall and one to chordae tendinae: papillary muscles
2. both ends attach to internal surface of ventricle: muscular bridge with middle part free
3. completely attached to ventricular wall
