digestive system function
- 1. Digestive System Function Alimentary System Question And Answers Question 1. Development of tongue. Answer: • Development of the tongue starts in the fourth week of intrauterine life • The medial most parts of the mandibular arches proliferate to form two lingual swellings. • These lingual swellings are partially separated from each other by another swelling called tuberculum impair. • These are derived from 1st branchial arch. • Another midline swelling, hypobranchial eminence is derived from mesoderm of the second, third, and part of the fourth arch.
- 2. Digestive System Function • It is sub-divided into cranial and caudal part. • The anterior two-thirds of the tongue is formed by fusion of 1. The tuberculum impair and 2. The two lingual swelling. • The posterior one-third of the tongue is derived from the cranial part of the hypobranchial eminence. • The posterior-most part of the tongue is derived from the fourth arch. • The musculature of the tongue is derived from the occipital myotomes. • Taste buds are formed in relation to the terminal branches of the innervating nerve fibres. • Nerve supply of the tongue depends on the developmental derivation. • Anterior two-third of the tongue is supplied by lingual branch of mandibular nerve which i branchial arch. • Posterior one third is supplied by the glossopharyngeal nerve, nerve of third branchial arch. • Posterior most part is supplied by the superior laryngeal nerve, nerve of the fourth branchial arch. Question 2. Give a detailed account of development of milk teeth. Answer: • By the sixth week of development of basal layer of the epithelial lining of the oral cavity forms dental lamina. • This lamina gives rise to 16 localized thickened buds called enamel organs. • The enamel organ grows downwards assuming a cup-shaped appearance which is occupied by dental papilla.
- 3. Digestive System Function • This stage is described as cap stage. • The cells of the enamel organ lining the papilla become columnar called ameloblasts. • Mesodermal cells of the papilla form a continuous epithelium-like layer called odontoblast. • The remaining cells form the pulp. • The developing tooth now looks like a bell. • Amelobasts lay down enamel while odontoblasts lay down dentin. • Odontoblasts in the root region lay down dentin. • The dentin is covered by mesenchymal which lay down cementum. • Outside it, mesenchymal cells from the periodontal ligament. Question 3. Structure of tooth (labelled diagram only) Answer: Question 3. Enumerate congenital anomalies of teeth. Answer: • Anodontia – absence of teeth. • Supernumerary teeth – extra number of teeth. • Abnormal teeth. • Gemination – fusion of two/more teeth. • Precocious – early eruption of teeth. • Delayed eruption of teeth. • Ectopic eruption of teeth. • Improper formation of enamel and dentin. Question 4. Development of oral mucosa. Answer:
- 4. Digestive System Function • The oral cavity is derived partly from the ectoderm and partly from the endoderm. • The anterior part of the oral cavity is derived from the ectoderm while tongue, epiglottis and pharynx are derived from the endoderm. • The vestibular lamina separates from the primary epithelial band at about 6 weeks. • Degeneration of the cells in the central part of this process leads to the formation of labial and buccal sulcus. • The tongue is separated from the rest of the mandibular process by linguo-gingival sulcus. • The alveolar process of the upper jaw is separated from the upper lip and cheek by labio-gingival sulcus appears laterally to the linguo-gingival sulcus. • Alimentary System Question And Answers • Anatomy Back Of The Neck Short Essay Question And Answers • Anatomy Contents of The Orbit Short Essay Question And Answers • Anatomy Histology Short Essay Question And Answers • Anatomy Mouth And Pharynx Short Essay Question And Answers • Anatomy Nose And Paranasal Sinuses Short Essay Question And Answers • Anatomy Parotid Region Short Essay Question And Answers • Anatomy Submandibular Region Short Essay Question And Answers • Anatomy Temporal And Infratemporal Regions Short Essay Question And Answers • Anatomy The Human Ear Short Essay Question And Answers • Anatomy The Human The Tongue Short Essay Question And Answers • Anatomy The Larynx Short Essay Question And Answers • Anterior Triangle Of The Neck Short Essay Question And Answers • Biochemistry Hormones Essay Questions And Answers • Biochemistry Plasma Proteins Essay Questions And Answers • Biochemistry Vitamins Essay Questions And Answers • Biological Oxidation Question And Answers • Blood and Nerve Supply of Bone Question And Answers • Bone Question And Answers • Carbohydrates Biochemistry Essay Question And Answers • Cardiovascular System Question And Answers • Cell Physiology Essay Question And Answers • Cementum of Tooth Question And Answers • Central Nervous System Question And Answers • Composition and Functions of Blood Question And Answers • Cranial Cavity Question And Answers • Deep Structures of Neck Short Essay Question And Answers • Dental Anatomy Question And Answers • Dentin Meaning, Development, Structure, Types Question And Answers • Development And Eruption Of Teeth Question And Answers • Development And Growth Of Teeth Question And Answers • Development Of Face And Oral Cavity Essay Question And Answers • Development of Face Nose And Palate Question And Answers • Digestive System Question And Answers • Embryology Formation Of Germ Short Essay Question And Answers
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