1. The pharyngeal arches form pouches and clefts that give rise to important structures. The parathyroid glands arise from the third and fourth pharyngeal pouches. 2. The tongue develops from the first, second, third and fourth pharyngeal arches. A median tuberculum impar later merges with two lateral lingual swellings to form the anterior two-thirds of the tongue. 3. The thyroid gland develops from an endodermal thickening that descends as the thyroglossal duct. The duct normally disappears but sometimes leaves remnants that can form cyst

1. PHARYNGEAL POUCHES
TONGUE, THYROID
Dr. G.Prabavathy
Assistant Professor
Pharyngea
l
apparatus

2. OBJECTIVES
 Pharyngeal pouches – derivatives
 Development of tongue
 Development of thyroid

3.  Pharyngeal arches
 Pharyngeal clefts
 Pharyngeal pouches
 Pharyngeal membranes
PHARYNGEAL APPARATUS

5. Pharyngeal arch Nerves
First arch Maxillary and Mandibular
nerves
Chorda tympani nerve
Second arch Facial nerve
Third arch Glossopharyngeal nerve
Fourth arch Superior laryngeal branch
of vagus
Sixth arch Recurrent laryngeal branch
of vagus
DERIVATIVES OF PHARYNGEAL ARCHES
Nerves of the pharyngeal arches

6. MUSCLES OF PHARYNGEAL
ARCHES
Pharyngea
l arch
Muscles
First arch Muscles of Mastication (Temporalis,
Masseter, Medial and Lateral Pterygoid)
Anterior belly of digastric, Mylohyoid,
Tensor tympani & tensor veli palatini
Second arch Muscles of facial expression, posterior belly
of digastric, stylohyoid, stapedius
Third arch Stylopharyngeus
Fourth arch Cricothyroid, levator palati, contrictor of
pharynx and intrinsic muscles of larynx
Sixth arch

7. SKELETAL ELEMENT OF PHARYNGEAL
ARCHES
Pharynge
al arch
Skeleton Ligaments
First arch
(Meckes’s
cartilage)
Malleus, and Incus
Premaxilla, maxilla
,zygomatic bone, part of
temporal bone, mandible,
Anterior ligament of
malleus
Sphenomandibular
ligament
Second arch
(Reichert’s
cartilage)
Stapes, styloid process,
Smaller cornu of hyoid bone,
superior surface of body of the
hyoid bone
Stylohyoid ligament
Third arch Greater cornu and lower part
of body of hyoid bone
Fourth arch Laryngeal cartilages (thyroid,
cricoid, arytenoids,
corniculate, cuneiform)Sixth arch

9. PHARNYGEAL POUCHES

10. PHARNYGEAL POUCHES
 Four pairs of pouches – evaginations of endoderm,
lining between two arches

11. FIRST PHARYNGEAL POUCH
First pharyngeal pouch – tubotympanic recess
 Distal part of tubotympanic recess – middle ear
cavity and mastoid antrum
 Proximal part – eustachian/auditory tube

12. SECOND PHARYNGEAL POUCH
• Endoderm proliferates to Form solid buds, central core
of these buds breaks down to form Tonsillar crypts
• Part of this pouch remains as intratonsillar crypt
(crypta magna)

14. THIRD PHARYNGEAL POUCH
 Dorsal bulbar part – parathyroid III or inferior
parathyroid gland
 Ventral tubular part - thymus

15. FOURTH PHARYNGEAL POUCH
 Dorsal bulbar part – superior parathyroid gland IV
 Fifth pouch incorporated with fourth pouch – caudal
pharyngeal complex – para follicular cells or c cells

19. SUMMARY
 Pharyngeal arches – five in number, present in
lateral wall and floor of the primitive pharynx
 Pharyngeal clefts- four in number, present externally
between the arches, lined by ectoderm
 Pharyngeal pouches – four in number, present
internally between the two pharyngeal arches, lined
by the endoderm
 Pharyngeal membranes – four in number and located
between adjacent arches

20. TONGUE
THYROID GLAND

21. TONGUE
• Muscular organ located in the oral
cavity.
• Consists of connective tissue and
interlacing skeletal muscle fibres
• Covered by surface elevations
called papillae
i. Fungiform papillae
ii. Filliform papillae
iii. Circumvallate papillae
iv. Foliate papillae

22. TONGUE
Circumvallate
papillae
Filliform
Fungiform
Anterior 2/3rd
Posterior
1/3rd
Posterior
most part
V shaped
sulcus
terminalis

23.  Tongue develops in the floor of developing mouth from
first, second, third and fourth pharyngeal arches
 Tuberculum impar – small median swelling develops
cranial to foramen caecum

24.  Lingual swelling – two lateral oval swellings on each
side of tuberculum impar
 Hypobrachial eminence (Copula of His) – large
median swelling develops in relation to second, third
and fourth pharyngeal arches

25. DEVELOPMENT OF VARIOUS PARTS OF
TONGUE
 Two lateral lingual swelling overgrow tuberculum impar and merge
with each other – anterior two- third of tongue
 Cranial part of hypobrachial eminence – posterior one-third of
tongue including circumvallate papillae
 Caudal part of hypobrachial eminence – posterior most part of the
tongue and epiglottis

27. GROWTH OF THIRD ARCH OVER SECOND ARCH

29. MUSCLES OF THE TONGUE
 Develops from myoblasts that migrate into
developing tongue from occipital myotomes

30. CORRELATION OF NERVE SUPPLY OF TONGUE WITH ITS
DEVELOPMENT

31. SEPARATION OF TONGUE FROM FLOOR OF
MOUTH
 Separation of tongue from the floor of the mouth
by deepening of linguogingival sulci

32. ANAMOLIES OF TONGUE
TONGUE TIE(Ankyloglossia)
 Due to frenulum of tongue extends to the tip of the
tongue, thus preventing its protrusion and causing
difficulty in speech

33. BIFID TONGUE MACROGLOSSIA

34. CONGENITAL ANOMALIES

35. FISSURED TONGUE

36. THYROID GLAND

37. THYROID GLAND
• Highly vascular
endocrine gland
• Two lobes connected by
isthmus

38.  Thyroid gland develop during third week of IUL as
endodermal thickening- diverticulum
thyroglossal duct

39. PATH OF THYROGLOSSAL DUCT

41. HISTOGENESIS OF THYROID GLAND
Parafollicular cells (C
cells) – neural crest of caudal
pharyngeal complex

42. I Anomalies of position of thyroid:
 Lingual thyroid – 10%
 Sublingual thyroid
 Intrathoracic thyroid
II Ectopid thyroid:
 Larynx
 Trachea
 Esophagus
 Pericardium
 Pleura
 Ovaries
CONGENITAL ANOMALIES

43. Lingual thyroid

44. THYROGLOSSAL CYST:
 May form anywhere along the course
of the Thyroglossal duct.
 Persistense of a part of thyroglossal
duct turned into a cyst called
Thyroglossal Cyst.
 always formed in the midline of the
front the Neck and observed by the age
of 5 years.
 Cyst Ruptures-Fistula.

45. CONGENITAL ANOMALIES
PYRAMIDAL LOBE
ACCESSORY LOBE

47. 1. parathyroid gland arises from
A) 1st and 2nd pharyngeal pouch
B) 3rd and 4th pharyngeal pouch
C) 5th and 6th pharyngeal arch
D) 3rd and 4th pharyngeal arch

48.  2. nerve of III pharyngeal arch supplies
 A)cricothyroid
 B)stylopharyngeus
 C)stapedius
 D)stylohyoid

49. 3.All the muscles of tongue are supplied by
A) Facial nerve
B) lingual nerve
C) Hypoglossal nerve
D) Occipital nerve

50.  Enumerate the Derivatives of second pharyngeal
arch
 Name the Derivatives of first pharyngeal arch
 Development oy hyoid bone [apr 2002]
 Explain Cervical sinus
 Development of parathyroid [dec 2010]
 Thyroglossal duct [dec 2011]
 Explain the Development of thyroid gland
 Brief account of Development of tongue