Download Dog heart coronary artery cast - Online Veterinary Anatomy Museum

Dog heart
Coronary artery cast
left subclavian a.
brachiocephalic a.
descending aorta
aortic arch
ascending aorta
left coronary a.
right coronary a.
circumflex branch
aortic bulb
(swelling of the 3 aortic sinuses)
septal branch
subsinuosal interventricular a.
paraconal interventricular a.
2012 Murdoch University. !
Shared under Creative Commons Licence (CC BY-NC-SA 3.0) !
for the OVAM (Online Veterinary Anatomy Museum) project!
]L
C O R O N A RA
Y. R T EIRE S
f,|g: C: I
aorta
descenciing
subcLauian
Left
hnnnhi
n , ' o anYht n
L q7u u v
urqvtLuve
i n
artez'u
aor Lic
z Ln
4
ascending
f
v eal
vttt
Y
Left
Tiqht
coronarA
arteru
in the dog (as in the
ruminants also) the right
coronary artery
is
ral:IirraIrr
cmr'lI
and
nn'lrr
wall
the peripheral
supplies
n€ fha riahf ventricle
and
(In horses, pigs and
atrium.
coronary
oursel-ves, the right
supplying
artery
dominates,
septum
the interventricul-ar
and part of the left
ventricle)
.
u ar e
!
4Y r r e
arch
aoz.ta
corlona.TA arterA
branching patterns are
variabfe (and unimportant)
but those shown here are
apparently typical:
ciz.cunfler
in coronary groove
subsinuosaL
uentricular
Left
bulb
forned by
the swelling
sinuses
the three aortic
r^'hich assist
the function
valve and
of the aortic
from which the coronary
arise
arteries
interbv,anch
uentTiculaz,
s eptaL
aortic
branch
bz.anches
bz,anch
paraeonal
intez,uentv,iculav' branch
via one of the richest
capillary
networks in the boaly, there being
Heart mrscfe is so active i.t is lourished
(other highly vascular tissues include the wall6 of the lung anal
per muscle fibre.
at Least one capillary
parts of the central nervous 6ysten).
The living
wall i6 so permeated by vascular spaces that it may be thought
pulsating
of as a
sponge of blood'.
ahe arteries
run lnost of tllei!
cou!6e over the surface of the heart whele they will not be compressed during
are within the nlrocardiu$ so that flow to the left ventricle
systole.
Even so, the terninal
rsmifications
occurs rnostly during diastole
lrhen the myocardilrm is relaxed (f1ow dufing diastole: aystol.e = 4:1), in the
right ventricular
walf, holsever, the pressure iE never hlgh enough to affect the fl.or,r significantly.
The
rdith the retlograale flow of btooil occurring
aris€ fron the aortic bulb at an angle consistent
coronary arteries
during diaatole.
Ilowever, anastomoses are pregent at the large arteriolar
on this cast.
Notice that no anaatonoaes are visible
They are, nevertheless,
unable to provide
level aDd in fact are nunerous in the lange 4OI to 350I dianeter.
(blockage) of the rnajor artelies
an aalequate collateral
circulation
should sudden occlusion
occur.
fn this
circunstance
that part of the heart walI supplied by the artery receives inadequate blood (becones ischaemic)
and usually dies through a process of infarction.
Dtrring slow (chronic) occlusion,
hotrever, these anastonoses
circuLation
to aleveLop. Coronary inf,arction
nay provide a framelrork for an effective
collatelaf
and lts
consequences (heart attacks,
angina) are conmon in ourselve6 but rare iD alom€stic anirnals.
prepared by
photography
by
notes by
date
fi1.CnA?A
.v
KI.tUnLgLS
Geoff GrLffiths
Jofui Grmtdage
JuLy 1-983