pengantar endokrinologi
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Pengantar Pengantar EndokrinologiEndokrinologi
Pengantar Pengantar EndokrinologiEndokrinologi
Pugud SamodroPugud SamodroBag/SMF Ilmu Penyakit Dalam FKIK Unsoed/RSUD Bag/SMF Ilmu Penyakit Dalam FKIK Unsoed/RSUD
Prof Margono SoekarjoProf Margono SoekarjoPurwokertoPurwokerto
• ENDOKRINOLOGICab. Ilmu kedokteran yang pelajari fungsi kelenjar buntu dalam keadaan fisiologis dan patologis.
• HORMONZat yang dihasilkan oleh kelenjar buntu yang dapat pengaruhi sel/jaringan/organ tubuh melalui reseptor khusus
• RESEPTOR KHUSUSReseptor yang terletak pada sel yang jadi sasaran (membran sel/intra sel)
No cell lives in isolation Cells depend on signaling systems to
adapt to changing environmental conditions
Why are signals important?
• Controlling e.g., metabolism, differentiation, cell division
• Development of immunity and Eradication of pathogens
• Prevent excessive growth• Elimination of superfluous cells by
inducing cell death
Components of SignallingWhat can be the Signal? External message to the cell
• Peptides / Proteins- Growth Factors• Amino acid derivatives - epinephrine,
histamine• Other small biomolecules - ATP• Steroids, prostaglandins• Gases - Nitric Oxide (NO)• Photons• Damaged DNA• Odorants, tastants
Signal = LigandLigand- A molecule that binds to a specific site on another molecule, usually a protein, ie receptor
modes of cell-cell signaling
Direct • cell-cell or cell-matrix
Secreted molecules. • Endocrine signaling. The signaling molecules are
hormones secreted by endocrine cells and carried through the circulation system to act on target cells at distant body sites.
• Paracrine signaling. The signaling molecules released by one cell act on neighboring target cells (neurotransmitters).
• Autocrine signaling. Cells respond to signaling molecules that they themselves produce (response of the immune system to foreign antigens and cancer cells).
Gap junction• Protein channels -
connexin• Direct flow to
neighbor– Electrical- ions
(charge)– Signal chemicals
Direct communication(Gap Junction & CAMs)
Contact dependent / Cell-Adhesion Molecules
•Need direct surface contact•Signal chemical
Means of cell to cell communication:
• Chemical : extra cellular signaling– Autocrine & Paracrine: local signaling– Endocrine system: distant, diffuse
target
• Electrical– Gap junction: local– Nervous system: fast, specific, distant
target
Autocrine & paracrine• Local
communication • Signal chemicals
diffuse to target• Example: Cytokines
– Autocrine–receptor on same cell
– Paracrine–neighboring cells
Long distance communication : hormones
• Signal Chemicals• Made in
endocrine cells• Transported via
blood• Receptors on
target cells
oct08 12
Long distance communication: neuronal
• Neurons– Electrical signal down axon– Signal molecule (neurotransmitter)
to target cell
Long distance communication : neurohormones
– Chemical and electrical signals down axon
– Hormone transported via blood to target
pembawa
Kelenjar
* globulin (>>)
* prealbumin * albumin
H H R
post reseptor
Generic Signal Transduction
• PENYAKIT ENDOKRIN Dapat terlihat jelas/ tertutup Mudah diobati bila diagnosis
tegak sebab terjadinya gangguan :
kelebihan atau kekurangan hormon terbentuknya hormon biologik inaktif
antibodi terhadap hormon gangguan reseptor sel (defect
reseptor/post reseptor) gangguan pada reseptor sel
blocking/antibodi terhadap reseptor yang bersifat simulasi
Efek berkurang : pabrik rusak pabrik membuat namun
kualitas menurun pembawanya kurang Reseptornya kurang Post reseptor kurang
Efek berlebih : produksi pabriknya berlebihan
Secara etiologik kelainan endokrin :1. Hipofungsi
- atrofi kelenjar/sebab umum, idiopatik- destruksi kelenjar (infeksi, trauma,
tumor)- kongenital
2. Hiperfungsi- hiperplasia- adenoma aktif- tumor ganas
SEKRESI HORMON
Hormon tidak keluar terus-menerus, ada pemicu :
1. Neuronal : catecholamine2. Biokimiawi : insulin terhadap glukosa3. Hormonal : respon terhadap releasing &
inhibiting hormon4. Kerusakan sel : tiroiditis5. Pengeluaran hormon secara :
- pulsatil : GnRH- siklik : cortisol