anatomy, lecture 6, pericardium and the heart (slides)
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Anatomy, Lecture 6, Pericardium and the Heart (slides)TRANSCRIPT
The Middle Mediastinum:The Middle Mediastinum:
Pericardium & HeartPericardium & Heart
MediastinumMediastinum
• The space between 2 lungs
Sup.: thoracic inlet
Inf.: diaphragm
Ant.: sternum & 2-6 CC
Post.: thoracic vertebrae
By Imaginary line By Imaginary line superior & inferior mediastina superior & inferior mediastina
DivisionsDivisions
Superior: Ant.: manubrium
Post.: T1-T4
Sup.: ?? Inf.: ??
Inferior:Ant.: sternal body
Post.: T5-T12
Sup.: ?? Inf.: ??
2 divisions by imaginary line: sternal angle T4-T5
3 parts:
Ant.: from sternum heart covering
(pericardium)
Middle: heart & pericardium
Post.: post. to heart
Inferior MediastinumInferior Mediastinum
PericardiumPericardium
PericardiumPericardium
• Covering fibroserous sac of 2 layers of tissues that encloses the heart
• Outer: fibrous (fibrous pericardium)
• Inner: serous (serous pericardium)
• Fxn.: 1. Protection 2. Lubrication (friction)
Fibrous PericardiumFibrous Pericardium
• Strong single layer
• Attached:
Ant.: sternum (sternopericardial lig.)
Inf.: diaphragm (central tendon)
Sup.: fuse to great vessels (t. adventitia)
• Sensory innervations by phrenic nerve
(very sensitive)
What are the cervical spinal segments of the phrenic nerve origin?
Serous PericardiumSerous Pericardium
• 2 layers of mesothelial cells that are continuous with each other
• Outer (Parietal):
lines over fibrous pericardium
reflects around the roots of large vessels
to become continuous with
• Inner (Visceral):
closely attached to the heart
Epicardium (outer heart layer)
• Sup & Inf mediastinum
• Inf middle:
pericardium & heart
Fibrous: Protection
Serous: Lubrication
visceral epicardium
ReviewReview
HeartHeartRead Your Textbook For DetailsRead Your Textbook For Details
• 3 layers
• 4 chambers
• 3 borders
(examining X-ray)
• 3 surfaces
• Apex & Root
Heart SurfacesHeart Surfaces
1. Anterior (sternocostal):
Rt. Atrium, Rt. V., Lf. V., ant. intervent. groove
2. Inferior (diaphragmatic):
Rt. & Lf. V’s, & post. interventricular groove
3. Posterior:
Lf. Atrium
Base of the heart
4. Apex:
part of Lf. V. (lf. 5th intercostal space, 9 cm from ??)
5. Root:
origin of great vessels
(aorta, pulmonary trunk, SVC)
Inferior Surface
Posterior Surface
Anterior Surface
Site for posterior surface of the heart (Base)
Site for inferior surface of the heart (Diaphragmatic)
Right AtriumRight Atrium
- Receives deO2 bld. From the body
- Forms Rt. Border of the heart
- Composed of:smooth walled chamber &rough out pouch (auricle)
Rough = pectinate muscle
- Border between:crista terminalis
Outside:sulcus terminalis
- Atrial septum (fetal remnants): Fossa ovalis Anulus ovalis
Read Your Textbook For More Details
Openings of Rt. AtriumOpenings of Rt. Atrium1. SVC:
bld. from upper body
2. IVC:
bld. From lower body / larger
3. A-V orifice:
Ant. to IVC
Guarded by tricuspid valve
4. Coronary Sinus:
Between IVC & A-V orifice
Bld form heart wall
5. ant. cardiac veins
Rt. VentricleRt. Ventricle
Crescent shaped from inside (cross-section)
3 muscular projections:
1. Papillary muscles:
Finger-like projections
Attach the cusps of A-V valve via Chordae tendineae
2. Moderator band:
inf. septal wall base of ant. Papillary muscle
contains nervous bundle to Rt. Ventricular wall
3. Trabeculae carneae:
prominent muscular ridges
Read Your Textbook For More Details
OpeningsOpenings
• A-V orifice:guarded by tricuspid valve
• Pulmonary opening:smooth funnel-shaped wall (infundibulum)
infundibulum = conus arteriosus
guarded by pulmonary valve
Lf. AtriumLf. Atrium• Most of the posterior wall
• Small lf. Auricle (muscular ridges)
• Usually 4 openings for P. V.& 1 for mitral valve
Left VentricleLeft Ventricle
• Wall 3x thicker than Rt. V.
• Circular in cross-section
• 2 large papillary m. (groups)
• Aortic vestibule:
smooth surface inf. to
aortic valve
No moderator bandNo moderator band
Heart PositionHeart Position
• Behind the sternum & slightly to the left
strong sounds = left to the sternum
• Dextrocardia:
The heart is on the right side of the chest
heart sounds = right to the sternum
- 1 in 12,000