Development of Pituitary & Pineal Glands PDF

Module Name: ENDOCRINE module Anatomy Department Prof. Dr. Eman Badawi Elshal Former Vice Dean of Education &Student Affairs external reviewer at the National Authority for Quality Assurance and Accreditation of Education “NAQAAE”...

Module Name: ENDOCRINE module Anatomy Department Prof. Dr. Eman Badawi Elshal Former Vice Dean of Education &Student Affairs external reviewer at the National Authority for Quality Assurance and Accreditation of Education “NAQAAE” Professional Diploma of Medical Education (PDME) Certified Assessor in Health Professions Education from Middle East North Africa FAIMER Official e-mail: [email protected] Mobile number: 01092889189 Prof. Dr. Eman Elshal  DEVELOPMENT OF PITUITARY GLAND It developed from 2 ectodermal sources 1.Rathke's pouch: (Ectodermal pouch form 2.Infundibular process: (Ectodermal pouch forms the (neurohypophysis) posterior lobe). ( adenohypophysis) anterior lobe). 1. The anterior lobe ( Rathke’s Pouch) From Rathke’s Pouch diverticulum from the ectodermal roof Of the stomodeum during 3rd week). - It grows towards the infundibulum forming a vesicle which is connected to the roof of stomodeum with a slender stalk that disappears by the 2nd month. Prof. Dr. Eman Elshal  DEVELOPMENT OF PITUITARY GLAND The anterior lobe - The vesicle is differentiated To form the anterior pituitary I. Anterior wall: is thick to form pars distalis. 2.Posterior wall: is thin to form pars intermedia. 3.The cavity of the vesicle: the pituitary cleft. 4.Pars tuberalis is upward extension of pars distalis (pars tuberalis wraps around the infundibular stalk). Prof. Dr. Eman Elshal  Posterior lobe 2.Infundibular process: (Ectodermal pouch forms the (neurohypophysis) posterior lobe). From infundibular process (a tubular down growth from neuroectoderm Of the floor Of the diencephalon). The fate of infundibulum: Upper end: remain patent giving the infundibular recess of the 3rd ventricle. Upper part: the pituitary stalk. Lower part: expands to form the pars nervosa (it forms the posterior lobe ). Prof. Dr. Eman Elshal Prof. Dr. Eman Elshal Congenital anomalies: 1- A genesis: Absence of the gland(Absence of pt gland cause death of the infant) 2- Pituitary hypoplasia : pituitary gland is Small in size. congenital disorder Pituitary dwarfism due to deficiency of growth hormone is a common clinical presentation 3-Absence of anterior lobe due to failure of development of Rathke's diverticulum. Ectopic along the course of Rathke's pouch: 4-Pharyngeal hypophysis: remnant of Rathike's may remain attached to roof of oropharynx. 5-Congenital tumor of pituitary (Craniopharyngioma): Tumor arises from remnant of Rathke's pouch. Prof. Dr. Eman Elshal Prof. Dr. Eman Elshal  Hypoplastic Pituitary Gland A B Figure 4. Coronal (A) and sagittal (B) T1 images show small pituitary gland and stalk. Prof. Dr. Eman Elshal PINEAL GLAND development Source: Small ectodermal diverticulum arising from posterior part of the roof of the third ventricle of diencephalon Time : At the seventh week of intrauterine life. from , the ependymal area of the roof of the third ventricle becomes thickened with continues enlargement, forming enlarging diverticulum The Process of development: Diverticulum form Initially hollow mass Later, becomes solid structure and connected to the thalamus by stalk which is divided by superior and inferior lamina Congenital anomalies Agenesis of the pineal gland : genetic mutations in the paired box gene 6 (PAX6), the patient has fragmented sleep and wake pattern Prof. Dr. Eman Elshal Prof. Dr. Eman Elshal Prof. Dr. Eman Elshal