17 - Hormone activity - Mech of hormones Flashcards
(21 cards)
What are the types of chemical messengers?
Nt Hormones ( neuro and endocrine) Paracrines Autocrines Cytokines
Which type of cells are excreted into ECF and affect same cell?
Autocrines
What type of cell affect neighbooring target cell?
Paracrines
Which involves inflamatory response?
Cytokines
What are types of hormones
Proteins/Polypeptides
Steroids
Tyrosine derivatives (Amino acid)
What are not described as hormones
Nucleic acid and polysacch ( sugars)
Where are hormones from the polypeptides branch secreted
In the golgi and E.R
What is the fate of a polypeptides hormone
1- Prehormones non active 2- cleaved in E.R 3-Transfered to golgi 4-Packaged 5- activated 6-stored in cytoplasm 7-Secretion thru SNARES
What type of hormones are water soluble?
Peptide hormones
What type of hormones are lipid soluble?
Steroid
Where are Amine or tyrosine derivates formed?
In the cytoplasm of glandular cells
What pattern does a hormone get released in?
Cyclical…
ex: growth hormone released higher in sleep
How are hormones transported
Depends if
- H20soluble ex: proteins .. disolved in plasma
- Lipid soluble
how are hormones eliminated?
Tissue catabolism and Binding
Excretion of liver or kidneys
How do hormones work and where are they found bound to ?
Bound to Receptors
Receptors are found in the cell membrane / Cytoplasm or Nucleus
How are hormones down regulated?
Decr production of R Inactviate the R Inactive intracell protein molecule Sequester R away from cell membrane Destroy by lysosomes
2nd messenger system :
Hormone act PLC
PLC breakdown PIP2
PIP2 -> DAG (act PKC and is precursor to other hormones ) and IP3 ( mobilizes ca stores)
how does a steroid- hormone increase protein synthesis
1-Diffusion across cell membrane to bind to R
2-Difusion to nucleu
3-Bind to DNA
4- Translation of the transcribed protein
What hormones increase transcription of specific genes in nucleus?
T3 and T4
Does the posterior part of the hypothalamus secrete hormones?
no, its the magnocellular neurons from the supraoptic and paraventric nuclei that do
how is thyroxine made?
Tyorsine inclosed in a thyroglobulin, then add iodine form diet
