Heart Dissection Flashcards
identity the structures on the thorax radiograph left lateral view
- thoracic vertebrae
- ribs
- costal cartilage
- costal arch
- manubrium of sternum
- sternebrae
- scapula
heart
- base
- apex
- right ventricle
- left ventricle
- sternopericardial ligament
- caudal vena cava
- cranial vena cava
- aorta
- trachea
- tracheal bifurcation
identify the right cranial pulmonary vein
identify the pulmonary arteries
identify the right cranial lung lobe
identify the right cranial bronchus
identify the right accessory lobe of the lung
identify the right crus of the diaphragm
identify the left crus of the diaphragm
identify the dome of the diaphgram
identify the left cranial lung lobe
identify the structures
- head of rib
- body of rib
- sternebra
- scapula
- base of heart
- apex of heart
- aorta
- caudal and cranial vena cava
- dome of diaphragm
- right crus
- left crus
- ventral lung lobes
identify the pulomary arteries
identify the aorta
identify the ventral mediastiunum
identify the scapula
identify the ventral lung lobes
Where is the apex of the heart?
towards the left of the midline
why does the heart appear to sit to the left of the midline in this dorsal ventral radiograph
Because of the size of the right lung
Which chamber of the heart gives rise to the ‘apex’ of the heart?
left ventricle
identify A, B and C
A= left atrium
B= right ventricle
C= trachea
identify the structures
RA: right auricle (atrium)
RV: right ventricle
LV: left ventricle
LA: left atrium
A: aorta
C: caudal vena cava
T: trachea
identify the structures of the cat thorax
A= heart
B= diaphragm
C= liver
how does the shape of the cat thorax differ than the dogs
shape: narrow and steep, heart sits more at an angle and it is positioned more caudally (4th-7th intercostal space) also little of the heart is covered by the forelimb as the triceps reaches no further than the 4th rib
Identify Manubrium of sternum, First rib, Apex of heart, Base of heart, Diaphragm and First lumbar vertebra
Again note the shape of thoracic cavity. How does it compare to that of the dog?
Narrower particularly about the thoracic inlet
Compare the size, and angle of the heart in each of these two lateral radiographs of the thoracic cavity
Now compare the relative shape of the thorax in each film.
Based on your observations do you think these radiographs come from the same or from different species?
Is there any other visible evidence you could use to support your conclusion?
A= cat
B= small dog (Yorki)
presence of clavicle in cat radiograph
identify the numbered structures on the right lateral view and what are their functions
- coronary groove: demarks position of atria vs. ventricles and is also the route taken by the right and left coronary arteries
- right inter-ventricular or subsinuosal groove: emarks position of the interventricular septum which divides the left and right ventricles
- right atrium: cranial and caudal vena cava, coronary sinus (brings in the flow from the great cardiac vein) and the azygos vein (usually only a right azygos persists but in some species there is also a left azygos which continues into the RA via the coronary sinus)
- cranial margin
identify 1-4 and what view is this
left lateral or auricular view
- right auricle
- paraconal groove or left interventricular groove
- pulmonary trunk
- apex
- left ventricle therefore caudal margin
identify the patterns of blood flow
- pulmonary trunk
- aorta
- pulmonary veins
- cranial vena cava
- caudal vena cava
- bifurcation pulmonary trunk into left and right pulmonary arteries
identify the structures of the left and right views of the bovine heart
identify the blood flow through the heart
- cranial vena cava
- caudal vena cava
- right ventricle passing around cranial margin of heart leading to pulmonary trunk
- intervenous tubercle
which other vessels enter the right atrium besides the vena cava
azygous and coronary sinus (great cardiac vein)
identify the valves
- bicuspid (mitral or left AV valve)
- aortic semilunar valve
The closure of which valves give rise to a) the first heart sound (lub) and b) the second heart sound (dub)?
first sound: both AV valves
second: both semilunar valves
identify the structures
identify the numbered structures
- azygous vein
2 & 3. cranial and caudal vena cava
- pulmonary veins
- trachea
- esophagus
- aorta
- right phrenic nerve
where is the esophagus releative the trachea and aorta in the right lateral view
esophagus is dorsal to and slightly to the left of trachea,
the aorta is to the left of the esophagus and arches so it eventually dorsally positioned
the interior of the right atrium and its auricle have been exposed
identify the structures
- caudal vena cava
- cranial vena cava
- coronary sinus (entrance to great cardiac vein bringing blood back from coronary circulation)
- position of fossa ovalis (remnant of fetal foramen ovale)
- papillary muscles and associated chordae tendineae
- trabeculae septomarginalis or moderator band
what is the functional significance of the papillary muscles and chordae tendineae
prevent valve from inverting into atria when ventricle contracts
what is the functional significance of trabeculae septomarginalis or moderator band
impuse is directed to papillary muscles so that they begin to contract and take up strain on chordae tendineae before the main ventricle contracts
the SA and AV nodes are found in right atrium
where percisely would you locate these structures (they are visible in large domestic species)
SA: at terminal crest just ventral to where the Cr vena cava enters the RA
AV: just cranial to the coronary sinus at the top of the inter-ventricular septum
identify the structures of equine heart
- caudal vena cava
- cranial vena cava
- coronary sinus
- position of fossa ovalis
- papillary muscles and associated chordae tendineae
- trabeculae septomarginalis or moderator band
identify the structures of equine heart
- cranial vena cava
- papillary muscles and associated chordae tendineae
- trabeculae septomarginalis or moderator
identify the structures
- mitral vavle
- aortic semilunar valve
why does the aortic semilunar valve not have chordae tendineae and papillary muscles
it functionally closes in a different way
closes during ventricular diastole rather than systole
how many cusps does the mitral valve have in comparison to the tricuspid valve
2 vs. 3
A remnant of foetal circulation the ligamentum arteriosum is indicated on this specimen [1]. What important foetal structure does this represent and what was its functional role in the foetus?
Ductus arteriosus- in the foetus this is the shunt which takes blood from the pulmonary artery and diverts it away from the lungs into the aorta
With reference to the aortic semi-lunar valve where would you locate the entrance to the right and left coronary artery?
The right CA is located in the aortic sinus (space) of the right cusp, the left CA is located in the aortic sinus (space) of the left cusp of the aortic semi-lunar valve
identify the structures of the cranioventral view of the interior of the right ventricle
identify the structures of the transverse section through the ventricles
identify the structures of the right atrium and ventricle
identify the dorsal view of the base of the bovine heart after atria removed
identify the structures of the tricuspid valve and the right ventricle of the dog
identify the structures of the atrioventricular valve opening and the semilunar valve
identify the structures of the dorsal view of the base of the heart after removal of the aitra
identify the conducting system structures
identify the structures
The individual cusps of each valve are given specific names. Identify each valve in turn and the individual cusps. Note the relative position of the heart valves with respect to cranial, caudal and left and right sides.
Note the difference in structure between the atrio-ventricular valves and the semi-lunar valves in terms of presence/absence of chordae tendineae. Revise how each valve type functions.
identify all 4 valves
identify the structures of the left coronary artery of the heart, viewed from left
identify the patterns of coronary circulation
identify the structures of transverse section of heart
identify the structures of the interior view of right atrium and ventricle
- fossa ovalis
- coronary sinus
- pectinate muscles associated with right auricle
- cusp of right AV valve (tricuspid)
- papillary muscle
- chordae tendineae
identify the pinned structures of all 4 chambers
- Right av valve (tricuspid)
- right ventricle
- left atrium
- left av valve (mitral)
- inter ventricular septum
- moderator band
- aortic semilunar valve
- papillary muscle
- Origins of left coronary artery
identify the structures of fresh bovine heart
- caudal vena cava: compare structure to aorta which arises from middle of the base of heart
- intervenous tubercle
- cranial vena cava
- terminal crest
- approx position of SA node
- pectinate muscles of auricle: compare this to smooth lining of main atrium
- approx position of AV node at top of interventricular septum
- coronary sinus
- fossa ovalis
- interventricular septum: bundle of His/Purkinje fibres run down this septum towards the apex
- moderator band
what is the function of moderator band
Impulse travels to papillary muscles so that they take up the strain on the chordae tendineae in advance of ventricular contraction. The AV valves close passively during diastole due to blood flowing behind the flaps and lifting them away from the ventricle wall, the chordae tendineae prevent the valve flaps from everting into the atria.
