Diaphragm

Question 1

The diaphragm is a —- -shaped ——- partition separating the thoracic from the abdominal cavities
•It develops from 4 embryonic components, namely:

Answer 1

The diaphragm is a dome-shaped musculotendinous partition separating the thoracic from the abdominal cavities
•It develops from 4 embryonic components:
•Septum transversum
•Pleuroperitoneal membrane
•Dorsal mesentery of esophagus
•Body wall

Question 2

DEVELOPMENT OF DIAPHRAGM
•The diaphragm develops from:
1.———: forms the central tendon
2.———: forms the right & left crus
3.———: posterolateral part (costal part)
4.———: small portion of diaphragm

Answer 2

DEVELOPMENT OF DIAPHRAGM
•The diaphragm develops from:
1.Septum transversum: forms the central tendon
2.Dorsal mesentery of esophagus: forms the right & left crus
3.Muscular ingrowth from lateral body wall: posterolateral part (costal part)
4.Pleuroperitoneal membranes: small portion of diaphragm

Question 3

SEPTUM TRANSVERSUM
•At — week, it is in the form of mass of mesodermal tissue in the cranial part of embryo (opposite the 3rd, 4th & 5th cervical somites)
•At 4th week (during formation of head fold), it moves ——— forming a thick incomplete partition between thoracic & abdominal cavities

•At — week, it expands & fuse with ——of esophagus & pleuroperitoneal membranes to form the ———

Answer 3

SEPTUM TRANSVERSUM
•At 3rd week, it is in the form of mass of mesodermal tissue in the cranial part of embryo (opposite the 3rd, 4th & 5th cervical somites)
•At 4th week (during formation of head fold), it moves ventrocaudally forming a thick incomplete partition between thoracic & abdominal cavities

•At 6th week, it expands & fuse with dorsal mesentery of esophagus & pleuroperitoneal membranes to form the diaphragm

Question 4

INNERVATION OF DIAPHRAGM
•Myoblasts from —,—& — somites migrate into diaphragm & bring their nerve fibers from them
•Nerve fibers derived from ——rami of 3rd, 4th & 5th cervical nerves fuse to form —— nerve that elongate to follow the descent of diaphragm
1.Both motor & sensory supply of the diaphragm is derived from —— nerve
2.The part of diaphragm derived from lateral body wall receives sensory fibers from ———nerves

Answer 4

INNERVATION OF DIAPHRAGM
•Myoblasts from 3rd, 4th & 5th somites migrate into diaphragm & bring their nerve fibers from them
•Nerve fibers derived from ventral rami of 3rd, 4th & 5th cervical nerves fuse to form phrenic nerve that elongate to follow the descent of diaphragm
1.Both motor & sensory supply of the diaphragm is derived from phrenic nerve
2.The part of diaphragm derived from lateral body wall receives sensory fibers from lower intercostal nerves

Question 5

List the ANOMALIES OF DIAPHRAGM

Answer 5

ANOMALIES OF DIAPHRAGM
1.CONGENITAL DIAPHRAGMATIC HERNIA
2.EVENTRATION OF DIAPHRAGM
3.CONGENITAL HIATAL HERNIA

Question 6

CONGENITAL DIAPHRAGMATIC HERNIA
•A —— defect of diaphragm (foramen of ——)
•Cause: defective formation and/or fusion of pleuroperitoneal membrane with other parts of diaphragm
•Effects:
1.Herniation of ———contents into —— cavity
2.Peritoneal & pleural cavities are connected with one another
•The defect usually occurs in the left side 85-90% (WHY?)

Answer 6

CONGENITAL DIAPHRAGMATIC HERNIA
•A posterolateral defect of diaphragm (foramen of Bochdalek)
•Cause: defective formation and/or fusion of pleuroperitoneal membrane with other parts of diaphragm
•Effects:
1.Herniation of abdominal contents into thoracic cavity
2.Peritoneal & pleural cavities are connected with one another
•The defect usually occurs in the left side 85-90% (WHY?)

It is seen more often on the left as a result of an earlier closure of the right pleuroperitoneal opening

Question 7

EVENTRATION OF DIAPHRAGM
•Cause: rare; half of diaphragm has ——muscles and balloons up into chest cavity. Upward displacement of abdominal contents
•Effects: superior displacement of abdominal viscera (surrounded by a part of diaphragm forming a pocket)

Answer 7

Defective

Question 8

CONGENITAL HIATAL HERNIA
• rare; abdominal viscera herniate through a large ——hiatus or opening. Usually an acquired lesion seen in adult life

Answer 8

Esophageal

Question 9

ESOPHAGEAL HERNIA
• If esophagus is ——than normal, part of stomach may appear in the thorax and be —— as it passes through the enlarged esophageal hernia

Answer 9

ESOPHAGEAL HERNIA
• If esophagus is shorter than normal, part of stomach may appear in the thorax and be constricted as it passes through the enlarged esophageal hernia

Question 10

RETROSTERNAL OR PARASTERNAL HERNIA (of Morgagni):
•a rare defect between —- and —— parts of diaphragm. A small peritoneal sac with intestinal loops often seen in chest

Answer 10

RETROSTERNAL OR PARASTERNAL HERNIA (of Morgagni):
•a rare defect between sternum and sternocostal parts of diaphragm. A small peritoneal sac with intestinal loops often seen in chest