BODY CAVITIES - PowerPoint Presentation

Slide1

BODY CAVITIES

DR. ZAHRA HAIDER BOKHARISlide2

EXTRA-EMBRYONIC COELOMSlide3

MESODERM

3

RD

WEEK AXIALPrechordal mesenchymeCardiogenic Septum transversum

PARAXIAL

INTERMEDIATE

LATERAL PLATE Slide4

INTRAEMBRYONIC COELOMSlide5

INTRA-EMBRYONIC COELOM

4

th

wk.Inverted U shaped cavity in:Cardiogenic area

Lateral plate mesoderm

Bend –cranial to

prochordal plate – primitive pericardial cavityLimbs of U – lateral half of disc

Limbs :

Pleural cavity

Peritoneal cavitySlide6

INTRA-EMBRYONIC COELOM

Initial part of limbs – flank foregut

Caudal part of limbs – communicate with extra-embryonic coelom

The two limbs are called pericarioperitoneal canalsSlide7

FOLDINGSlide8

HEAD FOLDING

4

th

weekPericardial cavity – ventral - below foregutPericardial cavity bend at right angle – communicate with pericardioperitoneal canalPericardioperitoneal canal

Dorsal to septum

transversum

Lateral to foregutSlide9

TRANSVERSE FOLDING

Pleuroperitoneal

canals –

Ventral aspectMerge – single peritoneal cavitySlide10

The coelome lined by

mesothelium

Derived from:

Somatic mesoderm (parietal layer) Splanchnic mesoderm (visceral layer)Slide11

DIVISION OF INTRA-EMBRYONIC COELOM

Into:

Pericardial cavity

Pleural cavityPeritoneal cavityDivision achieved by:Septum transversum

Paired

pleuropericardial

folds – superior to lungsPaired pleuroperitoneal folds – inferior to lungsSlide12

PLEUROPERICARDIAL MEMBRANE

4

th

weekBronchial buds- pericardioperitoneal canal – future pericardial cavity

Pleural cavity expand – grow ventrally

Common cardinal vein & Phrenic nerve raise ridge in lateral thoracic wallSlide13

PLEUROPERICARDIAL MEMBRANE

Pleural cavity grow in angle between body wall & ridge

Result:

Mesenchyme of body wall splitOuter layer – thoracic wallInner layer – pleuropericardial membraneSlide14

PLEUROPERICARDIAL MEMBRANE

7

th

weekmembrane – grow medially Pleuropericardial – fuse with Each otherMesenchyme ventral to oesophagus

Separate pericardial from pleural cavitySlide15

PLEUROPERICARDIAL MEMBRANE

Right

pleuropericardial

opening close earlierRight common cardinal vein larger – raise bigger foldFused pleuropericardial membrane form FIBROUS PERICARDIUMSlide16

PLEUROPERITONEAL MEMBRANE

Separate pleural from peritoneal cavity

Lung & pleura invade body wall – strip mesoderm

Ridge formed – caudal end of pericardioperitoneal canal

Ridge- fold –

cresentic

free edge- project into pericardioperitoneal canal Slide17

PLEUROPERITONEAL MEMBRANE

Liver develop

Fold become membranous

6th weekPleuroperitoneal membrane grow ventro –medially - fuse with:

Dorsal

mesentry

of oesophagus

Septum

transversumSlide18

MESENTERY

Double layer of peritoneum enclosing a mass of mesoderm

Connects the organ to the body wall

Carries vessels, nerves &

lymphatics

for the organ

Is the site where the visceral peritoneum continues as parietal peritoneumSlide19

MESENTRY

Transverse folding –medial walls of intra-embryonic

coelon

come together – mesentryBetween layers – mesenchyme – B.V. & nervesTransiently divide I.E.Coelom into two halves

Contain gut in themSlide20

VENTRAL MESENTRY

Transitory structure

Limited to stomach & duodenumSlide21

DORSAL MESENTRY

Gut suspended by it – mid plane

Not in pharynx & upper

oesophagusGiven names– mesoesophagus

….

Further development

Some parts specializedSome – secondary attachment

Some disappearSlide22

DEVELOPMENT OF PERICARDIUM

Heart tube

invaginate

pericardium from dorsal aspect

Parietal & fibrous pericardium derived from

somatopleuric

mesoderm lining ventral side of pericardial cavitySlide23

DORSAL MESOCARDIUM

Visceral pericardium derived from

splanchnopleuric

mesoderm lining dorsal side of pericardiumHeart tube suspended in pericardial cavity by dorsal mesocardium - disappears Communication – right & left side of pericardium –

transverse pericardial sinusSlide24

DORSAL MESOCARDIUMSlide25

DEVELOPMENT OF DIAPHRAGM

Four sources

Septum

transversumPleuroperitoneal membranes

Dorsal mesentery of esophagus

Muscular ingrowth from lateral body wallsSlide26

SEPTUM TRANSVERSUM

3

rd

weekUnsplit mesodermCranial to cardiogenic mesoderm

4

th

weekFolding

Septum

transversum

Caudal to pericardium

Ventral to

pericardio

-peritoneal

canalSlide27

SEPTUM TRANSVERSUM

Cranial part - diaphragm

Caudal part

LiverVentral Mesentry

Expand & fuse with

pleuroperitoneal membrane

Form

central tendon Slide28

PLEUROPERITONEAL MEMBRANE

5

th

weekDevelop at caudal end of pericardioperitoneal canalCrescent fold - mediallyFuse with:Septum

transversum

Dorsal

mesentry oesophagus

Myoblast from S.T. –

pleuroperitoneal

membrane

Bulk of muscle form hereSlide29

DORSAL MESENTERY OF ESOPHAGUS

Initially – median part

Finally

mesoesophagus condenses – L1 – L3Two muscle bands Myoblast grow in dorsal mesentry of esophagus

Develop into

Right & left

crura Slide30

CONTRIBUTION FROM BODY WALL

9

th

– 12th weekLungs & pleural cavity enlarge

Burrow into body wall

Mesenchyme split

External – abdominal wallInternal – peripheral part of diaphragm

Slide31

CONTRIBUTION FROM BODY WALL

Pleura extend further

Costodiapharagmatic

recessDome shaped configurationSlide32

DIAPHRAGM

6

th

week :

Three

basic components:

Pleuroperitoneal membranes

Mesoesphagus

Septum

transversum

Fuse - form

a

complete partition

between

thoracic

and

abdominal cavitiesSlide33

Body wall

:

Peripheral

muscular part

Pleuroperitoneal

membranes

:

Form

large portion of fetal diaphragm

represent

a smaller portion in infants

Septum

transversum

:

Central tendon

Dorsal mesentery of esophagus

:

CruraSlide34

POSITIONAL CHANGES & INNERVATION OF THE DIAPHRAGM

4

th

week

Septum

transversum

opposite 3

rd

– 5

th

cervical

somites

5

th

week

Myoblasts from

somites

- developing diaphragm bringing their nerve fibers with them Slide35

Rapid growth of the body

-

descent of diaphragm

6

th

week

the diaphragm - level of the

thoracic

somites

End of

8

th

week

- diaphragm - level of

first lumbar vertebraSlide36

4 parts

of the diaphragm fuse

Mesenchymal

cells from the septum

transversum

- other three parts,

Change into myoblasts -muscles of the diaphragm.

Phrenic nerve

supplies all the muscles of diaphragm

Phrenic nerve

-

sensory to

diaphram

except

peripheral region derived from the body wall and brings its nerve supply

(lower intercostal nerves)

with itSlide37

POSTEROLATERAL DEFECTS OF DIAPHRAGM

Only common anomaly

1 in 2200 newborns

Associated with CDHInhibition of development & inflation of lung- breathing difficultiesLung hypoplasia – infant may dieSevere lung hypoplasia – alveoli rupture – pneumothorax

Polyhydramnios

maybe presentSlide38

POSTEROLATERAL DEFECT OF DIAPHRAGM

Cause:

Defective formation / fusion of

pleuroperitoneal membrane with...Large opening in

posterolateral

part of diaphragm

Peritoneal & pleural cavities communicate85-90% on left

side – foramen of

BochdalekSlide39

POSTEROLATERAL DEFECTS OF DIAPHRAGM

Foramen closes at 6

th

wk.If open –viscera in thorax – lyingLungs & heart pushed anteriorly

Most defects on left side – heart pushed to right

Severity of lung development – extent of viscera in thorax – no room for development

Treatment

Repair of defect – post

natally

Lung achieve normal sizeSlide40

EVENTRATION OF DIAPHRAGM

Half of diaphragm – defective musculature – diaphragmatic pouch

Superior displacement of viscera

Cause:Failure of muscular tissue from body wall to extend into

pleuroperitoneal

membrane

Clinical manifestation – CDHTreatment:

Surgical repair

Latissimus

dorsi

flap

Prosthetic patchSlide41

GASTROSCISIS & CONGENITAL EPIGASTRIC HERNIA

Herina

– between xiphoid process & umbilicus

Cause:Failure of lateral body folds to fuse completely when forming anterior abdominal wall during foldingSlide42

CONGENITAL HIATAL HERNIA

Herniation of part of fetal stomach through excessively large esophageal hiatus

May be a predisposing factor in adult acquired hiatal herniaSlide43

RETROSTERNAL (PARASTERNAL) HERNIA

Herniation through the

sternocostal

hiatus (foramen of Morgagni) – opening for superior epigastric B.V.Hiatus – between sternal & costal parts of diaphragmHerniation of:

Intestines into pericardial sac

Heart into peritoneal cavity

Large defects associated with body wall defectsSlide44

ACCESSORY DIAPHRAGM

Most often on right side

Associated with lung hypoplasia & respiratory

comlicationsDiagnosis:MRITreatment:Surgical excisionSlide45

ASlide46

BSlide47

CSlide48

DSlide49

ESlide50

FSlide51

GSlide52

mesentryDouble layer of peritoneum enclosing a mass of mesoderm

Connects the organ to the body wall

Carries vessels, nerves &

lymphatics for the organIs the site where the visceral peritoneum continues as parietal peritoneumSlide53
Slide54