skinspleen皮膚脾ppt課件-在線瀏覽
2025-02-22 03:30本頁面
【正文】 lin granules (no membrane) lamellar granules. 3. Stratum Granulosum（顆粒層） : 4. Stratum Lucidum（透明層） : LM: Eosinophilic, transparent. EM: Matrix of keratohyalin granules+ embedded bundled . = keratin. 5. Stratum Corneum（角質(zhì)層） : LM: Acidophilic, continuously shed. EM: Full of keratin, thickened membrane, degenerated desmosomes (surface layers). Conclusion: The changes of the keratinized cells from Stratum basale to Stratum corneum show the process of the keratinization: ① Morphology: Columnar→ polygonal→ flattened。 ③ : → + → (exocytosis)。 ⑤ Keratin: → + → ++。 scattered→ bundle。 long branched processes. melanosome Tyrosine tyrosinase Melanin （黑色素） melanin granule full of melanin Function EM: melanosomes（黑素體） containing tyrosinase（酪氨酸） . Function: produce melanin granules which prevent ultraviolet radiation from damaging skin. (2) Langerhans cells（朗格漢斯細(xì)胞） : Location： among spinous cells ? LM: starshaped, lobed nucleus. ? Function: Identify, bind and process and present foreign antigens to lymphocytes. (3) Merkel cells（梅克爾細(xì)胞） : Location: among basal cells. Structure: dense granules, chemical synapse formed between the cell base and nerve ending. Function: perception of stimulation /mechanoreceptor. Me
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