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HORMONES IN MAMMALS - Coggle Diagram
HORMONES IN MAMMALS
GENERAL CHARACTERISTICS
SMALL & SOLUBLE
TRANSPORTED BY BLOOD TO TARGET CELLS/TISSUES
BIND TO RECEPTOR MOLECULES ON TARGET CELLS (LOCK & KEY HYPOTHESIS)
EFFECTIVE EVEN IN LOW CONC.
CHEMICAL GROUPS
AMINES
TYROSINE
PEPTIDES & PROTEINS
INSULIN
STEROIDS
TESTOSTERONE
FATTY ACIDS
PROSTAGLANDINS
RELEASE IS CONTROLLED BY
PRESENCE OF SPECIFIC METABOLITE IN BLOOD (EG. EXCESS GLUCOSE)
PRESENCE OF ANOTHER HORMONE IN BLOOD
STIMULATION BY NEURONES FROM ANS
MECHANISM OF HORMONE ACTION
GENE ACTIVATION
EG: STEROIDS
HORMONE SECRETED BY ENDOCRINE GLAND & CARRIED BY BLOOD TO TARGET CELLS
STEROID IS SMALL & SOLUBLE IN LIPID, SO IT CAN CROSS PLASMA MEMBRANE
STEROID THEN BINDS TO SPECIFIC RECEPTOR PROTEIN IN CYTOPLASM / NUCLEUS
HORMONE-RECEPTOR COMPLEX ENTERS NUCLEUS & BINDS TO DNA, CAUSING GENE TRANSCRIPTION TO PRODUCE MRNA
MRNA MOVES OUT, BINDS WITH RIBOSOME & TRANSLATION OCCURS, CREATING SPECIFIC PROTEINS
PROTEINS CARRY OUT ACTIVITIES THAT CHANGE METABOLISM OF TARGET CELL IN SPECIFIC WAYS
CYCLIC AMP
EG: PEPTIDE HORMONES (INSULIN)
HORMONE SECRETED BY ENDOCRINE GLAND & CARRIED BY BLOOD TO TARGET CELLS
INSULIN IS BIG & NOT SOLUBLE IN LIPID, CANNOT CROSS PLASMA MEMBRANE
INSULIN BINDS TO SPECIFIC RECEPTORS IN THE PLASMA MEMBRANE OF TARGET CELLS
ACTING THROUGH G PROTEINS, THE HORMONE-RECEPTOR COMPLEX WILL ACTIVATE ADENYLYL CYCLASE, WHICH CONVERTS ATP TO CYCLIC AMP (CAMP)
CAMP BINDS TO & ACTIVATES PROTEIN KINASE-A, WHICH THEN ADDS PHOSPHATE GROUPS TO SPECIFIC CELLULAR PROTEINS
PHOSPHORYLATED PROTEINS CARRY OUT ACTIVITIES THAT CHANGE METABOLISM OF TARGET CELL
ROLE OF HYPOTHALAMUS
DETECTS THE LEVEL OF METABOLITES / HORMONES IN BLOOD FLOWING THROUGH ITS CELLS
TRANSMITS INFORMATION TO PITUITARY GLAND
BY SECRETING RELEASING HORMONES INTO THE BLOOD, TO BE CARRIED TO ANTERIOR PITUITARY
BY SECRETING HORMONES TO POSTERIOR PITUITARY USING A DIRECT AXON TRACT