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3-Glandular Epithelium. The third type of epithelium specialized to produce secretion Classification of gland 1-According to produce or absence of ducts The glands are classified into:.
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3-Glandular Epithelium • The third type of epithelium specialized to produce secretion • Classification of gland • 1-According to produce or absence of ducts • The glands are classified into:
a-Endocrine: secreting hormones directly in the blood as: thyroid ,parathyroid,pituitary,suprarenal,pineal body:islets of langherhans,placenta,testis,ovary • b-Exocrine glands:they have ducts carry their secretion • as:salivary glands,sweat&sebaceous glands • c-Mixed glands: posses the exocrine&endocrine function • as: pancreas,testis,ovary
2-According to changes in the secretory cells • a-merocine glands:there is no cellular change in their secretory cells ex. Salivary glands • b-Apocrine glands:secretory product of the glands ex.mammary glands(secret milk) • c-Holocrine gland:sebaceous glands may come out with their secretion
3-According to the secretion • a-serous secretory glands: as parotid glands,von-Ebner gland of the tongue • Mucous secretory glands: bruners glands&goblet cell • C-fatty secretory glands: sebaceous glands • d-mucous gland:submandibular &sublingual glands • e-watery secretory glands: sweate glands • f-waxy secretory gland: glands of external ear • g-cellular secretory gland: testis&ovary
4-According to the shape&branching of the secreting part • Tubular,acinar,or tubulo-acinar • A-Tubular glands • a-simple tubular glands: intestinal glands or the crypts of lieberkuhn • b-simple branched tubular:glands of stomch • c-simple coiled tubular:sweat glands • d-compound tubular glands:kidney&testis
B-Acinar glands • Acinar glands are classified into: • a-simple acinar:urethral glands&sebaceous • b-simple branched acinar:sebaceous glands,eye lid glands • c-compound acinar:mammary glands
C-Tubulo-acinar glands • a-tubulo-acinar gland not found in man • b-branched tubulo-acinar:glands of the mouth cavity • c-compound tubulo-acinar: pancreas,prostate,salivary glands
5-According to their function • A-secretory glands:secrete in the body as salivary glands&endocrine • B-Excretory glands: eliminate&excrete the wast produced out side the body as kidney&sweat gland
4-Neuro-Epithelium • Four type of epithelial tissue(simple,stratified glandular&neuro-epithelium • This type epithelial cells act as sensory receptor for special stimuli • -neuroepithelial cells are provided with small hairs • -receptor cells:hair cells or tast cells • -supporting cells • -basal cells
present: • 1-taste buds(tongue) • 2-organ of corti(internal ear(for hearing • 3-crista ampularis in theampullae of the semicircular canal in the internal ear for(equilibrium) • 4-macula utriculi&macula saccul(in internal ear)
Function of epithelial tissues • 1-Protection: against injuries,bacteria,chemical&water as epithelium of skin&stomch • 2-secretory: as glandular epithelium of pancreas,prostate,salivary &endocrineglands
3-Absorption:intestine&kidney • 4-Sensation:taste buds&organ of cort • 5-Reproduction: as the cells of testis&ovary
6-Excretion as the cells of kidney&sweat gland • 7-covering surface as skin lining cavitiesas stomch • 8-respiration as the epithelium of lung alveoli
Epithelial cell-derived tumours Benign or malignant
General biology of epithelial tissues 1-polarity 2-innervation 3-renewal of epithelial cells 4-metaplasia 5-Control of glandular activity 6-Cells that transport ions 7-Cells that transport by pinocytosis 8-Serous cells 9-Mucus- secreting cells 10-The diffuse neuroendocrine system (DNES) 11-Myoepithelial cells 12-Steriod – secreting cells 13-Epithelial cell-derived tumours
Duct Types of Compound Exocrine Glands
Lobulation of Compound Exocrine Glands Submaxillary Gland Connective (salivary gland) Tissue Septum Acini Interlobular Intralobular Duct Duct
Submandibular Gland Compound Exocrine Glands Pancreas