Development of Pharyngeal arches and derivatives.pptx

Derivatives of Pharyngeal arches, Pharyngeal pouches, Cervical sinus, Branchial apparatus, Branchial fistula, Development of Tongue, Development of thyroid gland , Congenital anomalies

1. Pharyngeal arches Dr.Nadine.n

2. LEARNING OBJECTIVES : Introduction Components Mesodermal derivatives Ectodermal derivatives Endodermal derivatives Congenital anomalies 9/20/2024 DR.NN 2

3. INTRODUCTION : DURING 5 TH & 6 TH WEEK OF INTRAUTERINE LIFE 9/20/2024 DR.NN 3

4. FORMATION OF ARCHES : CEPHALIC/ PHARYNGEAL PART : FUNNEL SHAPED EXPANSION VENTRAL WALL/FLOOR , DORSAL WALL/ROOF , 2 LATERAL WALLS LATERAL WALL OF PHARYNX – SEPARATED BY SPLANCHNIC MESODERM MESENCHYME UNDERGOES SEGMENTATION CRANIO-CAUDALLY 6 PAIRS OF MESODERMAL BARS 9/20/2024 DR.NN 4

5. ECTODERMAL COVERING , INTERNALLY ENDODERMAL LINING VENTRALLY & MEDIALLY ,FROM MEMBRANOUS CAPSULE OF HIND BRAIN TO MID – VENTRAL LINE HORSE- SHOE SHAPED CYLINDRICAL BARS 2 ENDS , 2 BORDERS 9/20/2024 DR.NN 5

6. BRANCHIAL APPARATUS : PHARYNGEAL ARCHES ECTODERMAL CLEFTS ENDODERMAL POUCHES 9/20/2024 DR.NN 6

7. DERIVATIVES OF ARCHES : MESODERMAL DERIVATIVES : SKELETAL ELEMENTS MUSCLES OF ARCH VESSELS NERVES OF ARCHES 2. ECTODERMAL DERIVATIVES 3. ENDODERMAL DERIVATIVES 9/20/2024 DR.NN 7

8. a. SKELETAL ELEMENTS : DERIVED AS ECTOMESENCHYME FROM NEURAL CREST CELLS OF MIDBRAIN & HIND BRAIN MESODERMAL CORE CARTILAGENOUS PLATES OSSIFIED PERSISTS AS CARTILAGE, BONES , FIBROUS ENVELOPE AS LIGAMENTS 9/20/2024 DR.NN 8

9. SKELETON ELEMENT OF FIRST / MANDIBULAR ARCH : DORSAL MAXILLARY PROCESS : UPPER LIP, UPPER JAW, PALATE VENTRAL MANDIBULAR PROCESS : MECKEL’S CARTILAGE MALLEUS , INCUS ANT LIG OF MALLEUS , SPHENO- MANDIBULAR LIG BODY OF MANDIBLE 9/20/2024 DR.NN 9

10. ii. SKELETON ELEMENT OF SECOND/ HYOID ARCH : REICHERT’S CARTILAGE STAPES STYLOID PROCESS STYLO- HYOID LIGAMENT LESSER CORNU & BODY OF HYOID BONE 9/20/2024 DR.NN 10

11. iii. SKELETON ELEMENT OF THIRD ARCH : DORSAL PART DISAPPEARS GREATER CORNU OF HYOID BONE LOWER PART OF BODY OF HYOID BONE iv. FOURTH ARCH : LAMINA OF THYROID CARTIALGE CUNEIFORM CARTILAGE 9/20/2024 DR.NN 11

12. v. SKELETON ELEMENT OF FIFTH ARCH : DISAPPEARS , NO DERIVATIVES vi. SIXTH ARCH: CRICOID ARYTENOID CORNICULATE 9/20/2024 DR.NN 12

13. b. MUSCLES OF ARCHES : FIRST ARCH : TENSOR TYMPANI TENSOR VELI PALATINI MUSCLES OF MASTICATION ANT BELLY OF DIGASTRIC MYLOHYOID 9/20/2024 DR.NN 13

14. ii. SECOND ARCH : STAPEDIUS STYLOHYOID POST BELLY OF DIGASTRIC MUSCLES OF FACIAL EXPRESSION PLATYSMA AURICULAR MUSCLES , EPICRANIUS 9/20/2024 DR.NN 14

15. iii. THIRD ARCH : STYLOPHARNGEUS MUSCLE iv. FOURTH ARCH : CRICOTHYROID MUSCLE v. SIXTH ARCH : INTRINSIC MUSCLES OF LARYNX 9/20/2024 DR.NN 15

16. c. VESSELS : VENTRAL ASPECT : AORTIC SAC DORSAL ASPECT : 2 DORSAL AORTAE CONNECTED BY AORTIC ARCHES RUNNING THR’ PHARYNGEAL ARCH 9/20/2024 DR.NN 16

17. VESSELS OF ARCHES : 1 ST AORTIC ARCH : MAXILLARY. A 2 ND ARCH : STAPEDIAL . A 3 RD ARCH : COMMON CAROTID.A , INT CAROTID.A 4 TH ARCH : RT SUBCLAVIAN.A , ARCH OF AORTA 6 TH ARCH : RT & LT PULMONARY.A, DUCTUS ARTERIOSUS 9/20/2024 DR.NN 17

18. d. NERVES : DERIVED FROM HIND BRAIN VESICLE DORSAL END OF BRANCHIAL CLEFT PRE- TREMATIC NERVE : ALONG CAUDAL BORDER POST- TREMATIC NERVE : ALONG CRANIAL BORDER ONLY 1 ST PHARYNGEAL ARCH HAS BOTH ALL OTHER ARCHES : PRE- TREMATIC. N DEGENERATES 9/20/2024 DR.NN 18

19. NERVES OF ARCHES : 1 ST ARCH : MANDIBULAR .N ( POST- TREMATIC ) : CHORDA TYMPANI .N ( PRE- TREMATIC ) 2 ND ARCH : FACIAL. N 3 RD ARCH : GLOSSOPHARYNGEAL. N 4 TH ARCH : SUPERIOR LARYNGEAL.N 6 TH ARCH : RECURRENT LARYNGEAL.N 9/20/2024 DR.NN 19

20. OTHER MESODERMAL DERIVATIVES : CAROTID BODY : 3 RD ARCH AORTIC BODY : 4 TH ARCH FIBRO-AREOLAR STROMA OF FACE , NECK , TONGUE 9/20/2024 DR.NN 20

21. II. ECTODERMAL DERIVATIVES : ECTODERMAL COVERING DIPS IN B/W ARCHES : ECTODERMAL CLEFT 1 ST CLEFT : LINING OF EXT ACOUSTIC MEATUS : CUTICULAR LINING OF TM MAXILLARY & MANDIBULAR COVERINGS : SKIN OF UPPER & LOWER JAW ALVEOLOLABIAL SULCUS 9/20/2024 DR.NN 21

22. 2 ND ARCH : MESODERMAL CORE MIGRATES CAUDALLY IT OVERGROWS 3 RD & 4 TH CLEFT SPACE OBLITERATED CERVICAL SINUS MERGES WITH SURROUNDING TISSUE AT LOWER BORDER CERVICAL SINUS GET OBLITERATED PLATYSMA 9/20/2024 DR.NN 22

23. III. ENDODERMAL POUCHES : LATERAL DERIVATIVES MEDIAN/ MIDLINE DERIVATIVES 4 POUCHES ; 5 TH IS RUDIMENTARY GET OBLITERATED IN VENTRAL ASPECT BY DEVELOPING TONGUE DORSAL ASPECT DORSAL WING VENTRAL WING 9/20/2024 DR.NN 23

24. 1 ST ENDODERMAL POUCH : DORSAL ASPECT FUSES WITH DORSAL WING OF 2 ND POUCH = TUBOTYMPANIC RECESS PROXIMAL PART : AUDITORY TUBE DISTAL PART : TYMPANIC CAVITY MASTOID ANTRUM MUCOSAL LINING OF TM 9/20/2024 DR.NN 24

25. TYMPANIC MEMBRANE : DEVELOPED FROM ALL 3 GERM LAYERS CUTICULAR LAYER : ECTODERM MUCOSAL LAYER : 1 ST ENDODERMAL POUCH FIBROUS LAYER : MESODERM 9/20/2024 DR.NN 25

26. 2 ND ENDODERMAL POUCH : VENTRAL WING : TINY SOLID BUDS : TONSILLAR PITS & CRYPTS RUDIMENTS OF CLEFTS : INTRA TONSILLAR CLEFT 9/20/2024 DR.NN 26

27. 3 RD ENDODERMAL POUCH : DORSAL WING : INFERIOR PARATHYROID VENTRAL WING : THYMIC RUDIMENT SUPERIOR PHARYNGO- BRANCHIAL DUCT 9/20/2024 DR.NN 27

28. 4 TH ENDODERMAL POUCH : DORSAL WING : SUPERIOR PARATHYROID VENTRAL WING MERGES WITH RUDIMENTARY 5 TH POUCH : CAUDAL PHARYNGEAL COMPLEX THYMIC ELEMENT : THYMUS LATERAL THYROID ELEMENT : THYROID GLAND ULTIMOBRANCHIAL BODY : PARAFOLLICULAR C CELLS 9/20/2024 DR.NN 28

29. VENTRAL DERIVATIVES : RUDIMENTS OF DEVELOPING TONGUE THYROID DIVERTICULUM LARYNGO – TRACHEAL GROOVE 9/20/2024 DR.NN 29

30. 1.DEVELOPMENT OF TONGUE : MUCOUS MEMBRANE , MUSCLES , FIBRO-AREOLAR STROMA MUCOUS MEMBRANE : ENDODERM OF FOREGUT VENTRAL 2/3 RD & DORSAL 1/3 RD 3 ENDODERMAL ELEVATION ALVEOLO- LINGUAL SULCUS 9/20/2024 DR.NN 30

31. MEDIAN THYROID DIVERTICULUM : THYROGLOSSAL DUCT FORAMEN CAECUM OF TONGUE HYPOBRANCHIAL EMINENCE / COPULA OF HIS TRANSVERSE SULCUS : DORSAL & VENTRAL PART SULCUS TERMINALIS 9/20/2024 DR.NN 31

32. SENSORY INNERVATION OF TONGUE : 9/20/2024 DR.NN 32

33. ii . TONGUE MUSCLES : 3 OR 4 OCCIPITAL MYOTOMES MIGRATE CAUDALLY ALONG EPICARDIAL RIDGE DRAGS HYPOGLOSSAL .N AFTER THEM iii . FIBROMUSCULAR STROMA : BINDS TONGUE MUSCLES MESENCHYME OF BRANCHIAL ARCHES 9/20/2024 DR.NN 33

34. 2. DEVELOPMENT OF THYROID GLAND : ENDODERMAL CELLS DORSAL TO TUBERCULUM IMPAR PROLIFERATE : MEDIAN RUDIMENT GROWS CAUDALLY THR’ SUBSTANCE OF TONGUE : THYROGLOSSAL DUCT INFRONT OF BODY OF HYOID BONE UPPER END OF TRACHEA : BILOBED MASS – ISTHMUS & LATERAL LOBES DUCTS : INTO DOUBLE CELLULAR PLATES 9/20/2024 DR.NN 34

35. COLLOIDS APPEAR : 1˚ FOLLICLE 2˚ FOLLICLES BUD OUT IODIDE TRAPPING : 12 TH WEEK TSH , T3 , T4 : 18 TH , 22 ND WEEK 9/20/2024 DR.NN 35

36. 3. LARYNGO- TRACHEAL GROOVE : U SHAPED MEDIAN LARYNGO- TRACHEAL GROOVE / FURCULA OF HIS CAUDAL TO HYPOBRANCHIAL EMINENCE DEVELOPMENT OF RESPIRATORY SYSTEM 9/20/2024 DR.NN 36

37. CONGENITAL ANOMALIES OF ARCHES : BRANCHIAL CYST : FAILURE OF OBLITERATION OF CERVICAL SINUS PAINLESS CYSTIC SWELLING ALONG SCM , ANGLE OF MANDIBLE 9/20/2024 DR.NN 37

38. TYPES OF BRANCHIAL CYST : LINED BY STRATIFIED SQUAMOUS EPITHELIUM : FAILURE OF OBLITERATION OF CERVICAL SINUS / PERSISTANCE OF PLACODAL VESICLE LINED BY SIMPLE COLUMNAR EPITHELIUM : ENDODERMAL PHARYNGEAL POUCH FAIL TO REGRESS 9/20/2024 DR.NN 38

39. BRANCHIAL FISTULA : 3 TYPES : WITH EXTERNAL COMMUNICATION WITH INTERNAL COMMUNICATION INTO PHARYNX WITH COMPLETE COMMUNICATION B/W PHARYNX & EXTERIOR 9/20/2024 DR.NN 39

40. i . EXTERNAL FISTULA : ALONG ANT BORDER OF SCM INCOMPLETE CLOSURE OF CERVICAL SINUS 9/20/2024 DR.NN 40

41. ii. INTERNAL FISTULA : WITH PHARYNX FAILURE OF NORMAL CLOSURE OF POUCHES TONSILLAR FOSSA – LAT PHARYNGEAL DIVERTICULUM 9/20/2024 DR.NN 41

42. iii. COMPLETE FISTULA : APPROXIMATION OF 2 ND PHARYNGEAL POUCH & 2 ND BRANCHIAL CLEFT RUPTURE OF CLOSING MEMBRANE 9/20/2024 DR.NN 42

43. iv. ECTOPIC THYMIC & PARATHYROID TISSUE : DURING MIGRATION , REMNANTS OF TISSUE ALONG PATHWAY PERSISTS THYMIC : IN NECK INFERIOR PARATHYROID : MORE VARIABLE 9/20/2024 DR.NN 43

44. DEVELOPMENTAL ANOMALIES OF TONGUE : AGLOSSIA : COMPLETE AGENESIS HEMI- GLOSSIA : SUPPRESSION OF 1 OF LINGUAL SWELLING BIFID TONGUE : FAILURE OF FUSION OF 2 LINGUAL SWELLING 9/20/2024 DR.NN 44

45. 4. ANKYLOGLOSSIA / TONGUE-TIE : ALVEOLO- LINGUAL SULCUS IMPERFECTLY SEPARATES 5. LINGUAL THYROID : THYROGLOSSAL DUCT FAILS TO MIGRATE CAUDALLY 9/20/2024 DR.NN 45

46. CONGENITAL ANOMALIES OF THYROID GLAND : THYROGLOSSAL CYST / FISTULA : PERSISTANCE OF FRAGMENTS OF THYROGLOSSAL DUCT LINGUAL THYROID ECTOPIC THYROID : POST TRIANGLE OF NECK / THORAX 9/20/2024 DR.NN 46

47. d. ACCESSORY THYROID : NODULES OF THYROID TISSUE e . AGENESIS OF THYROID : COMPLETE ABSENCE OF THYROID CONGENITAL CRETINISM 9/20/2024 DR.NN 47

48. SUMMARY : PHARYNGEAL ARCHES ECTODERMAL CLEFTS ENDODERMAL POUCHES DERIVATIVES CONGENITAL ANAMOLIES 9/20/2024 DR.NN 48

49. REFERNCES : ESSENTIALS OF HUMAN EMBRYOLOGY – A.K. DATTA – 7 TH EDITION LANGMAN’S MEDICAL EMBRYOLOGY – T.W.SADLER – 13 TH EDITION 9/20/2024 DR.NN 49

50. 9/20/2024 DR.NN 50