17-INTERIOR F HEART.ppt
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Transcript 17-INTERIOR F HEART.ppt
Dr. Ahmed Fathalla Ibrahim
RIGHT ATRIUM
RIGHT ATRIUM
• THE CAVITY IS DIVIDED INTO 3 PARTS:
1. The posterior (smooth) part: receives
opening of coronary sinus, superior &
inferior vena cava
2. The anterior (rough) part: formed of parallel
muscular ridges (musculi pectinati)
extending to right auricle. It is separated
from the posterior wall by a vertical ridge
(crista terminalis)
3. The septal wall: formed of an oval
depression (fossa ovalis), bounded
superolaterally by a margin (annulus
ovalis)
RIGHT ATRIUM
• OPENINGS:
1. Opening of SVC: opposite right 3rd costal
cartilage, has no valves
2. Opening of IVC: opposite right 6th costal
cartilage, has a rudimentary valve
3. Opening of coronary sinus: between
opening of IVC & tricuspid orifice, has a
functioning valve which prevents return of
blood into coronary sinus during atrial
contraction
4. Openings of anterior cardiac veins
5. Openings of venae cordis minimi
RIGHT VENTRICLE
•
RIGHT VENTRICLE
THE CAVITY IS SEMILUNAR IN SHAPE &
DIVIDED INTO 2 PARTS:
The lower (rough) inflowing part:
• Formed of irregular muscular ridges
(trabeculae carnae)
• Has 3 papillary muscles (anterior, posterior
& septal): with a base attached to
ventricular wall & an apex attached to
cusps of tricuspid valve by chordae
tendinae
• moderator band: a muscular ridge
extending from interventricular septum to
base of anterior papillary muscle. It carries
the right branch of A-V bundle.
RIGHT VENTRICLE
The upper (smooth) outflowing part:
• It is called the infundibulum or conus
arteriosus
• It leads into pulmonary orifice
ORIFICES & VALVES OF
RIGHT VENTRICLE
• RIGHT ATRIOVENTRICULAR
(TRICUSPID):
• Lies between right atrium & ventricle
• Surrounded by a fibrous ring giving
attachment to the bases of 3 triangular
cusps (anterior, posterior & septal)
• Chordae tendinae of papillary muscles
are attached to the adjoining free edges
of cusps
ORIFICES & VALVES OF
RIGHT VENTRICLE
•
•
PULMONARY:
Lies between infundibulum of right
ventricle & pulmonary trunk
• Consists of 3 semilunar cusps
1. Two situated in anterior wall: anterior
& right cusps
2. One situated in posterior wall: left
cusp
• The wall of pulmonary trunk is slightly
dilated above the 3 cusps forming 3
sinuses (two anterior & one posterior)
LEFT ATRIUM
COMPARED TO RIGHT ATRIUM:
• Its cavity is smooth except the left
auricle which have musculi pectinati
• Its posterior wall receives the openings
of 4 pulmonary veins (have no valves)
LEFT VENTRICLE
LEFT VENTRICLE
COMPARED TO RIGHT VENTRICLE:
• Its cavity is circular in shape
• Its wall is 3 times thicker
• In its lower rough part:
1. Trabeculae carnae are larger & more
numerous
2. Papillary muscles: are only 2, larger,
has fewer but stronger chordae
tendinae
• Its upper smooth part: called aortic
vestibule, leads into aortic orifice
ORIFICES & VALVES OF
LEFT VENTRICLE
•
•
•
1.
2.
LEFT ATRIOVENTRICULAR (MITRAL):
Lies between left atrium & ventricle
Compared to tricuspid valve:
Its orifice is narrower
It has only 2 cusps (anterior &
posterior)
3. Cusps are larger & stronger
ORIFICES & VALVES OF
LEFT VENTRICLE
•
•
AORTIC:
Lies between aortic vestibule of left
ventricle & ascending aorta
• Compared to pulmonary valve:
• Consists of 3 larger semilunar cusps:
1. One situated in anterior wall: right cusp
2. Two situated in posterior wall: left &
posterior cusps
• The wall of aorta is slightly dilated above
the 3 cusps forming 3 sinuses (one anterior
& two posterior)
PULMONARY & AORTIC VALVES
VENTRICULAR SEPTUM
•
It is an oblique septum separating the
ventricles
• It is composed of two parts:
1. An upper smaller membranous part
2. A lower larger muscular part
CONDUCTING SYSTEM
CONDUCTING SYSTEM
•
Consists of specialized cardiac
muscle present in:
1. Sinoatrial node: in the wall of right
atrium, in the upper part of sulcus
terminalis, to the right of opening of
SVC. It is the pacemaker of heart
2. Atrioventricular node: in the lower
part of atrial septum, above tricuspid
valve
3. Atrioventricular bundle: along the
membranous part of ventricular
septum, divides at the upper border of
the muscular part of the septum into:
CONDUCTING SYSTEM
• Right bundle branch: runs along the
moderator band
• Left bundle branch: pierces the
ventricular septum to run on its left
side
• Each branch divides into a network of
branches giving a subendocardial
plexus of fibers (Purkinje fibers) in the
wall of each ventricle