Endocrinology Flashcards
What is a hormone?
Chemical signal secreted by specialised cells secreted into the blood in small amounts to act on target cell
How are peptide hormones made?
Transcribed from DNA and translated from mRNA on ribosomes on the ER
Are peptide hormones hydrophilic or hydrophobic?
Hydrophilic
How are steroid hormones synthesised?
From cholesterol
How are steroid hormones released from secreting cells?
Diffusion
Are steroid hormones hydrophobic or hydrophilic?
Hydrophobic
Are steroid hormones lipophilic or lipophobic?
Lipophilic
How are biogenic amines synthesised?
Derived from the AA tyrosine
Name a lipophilic biogenic amine
Thyroxine
Name a hydrophilic biogenic amine
Adrenaline
How are lipophilic biogenic amines released from secreting cells?
Diffusion
How are hydrophobic biogenic amines released from secreting cells?
Exocytosis
What type of hormones can travel freely in the blood?
Hydrophilic peptide hormones
What type of hormones need transporters in the blood?
Hydrophobic steroid and thyroid hormones
Name the main non-specific carrier
Albumin
What is the specific carrier for cortisol?
Transcortin
Why are hydrophobic hormones bound to carriers?
Makes them biologically inactive which lengthens the half life and stops them being degraded by the liver
How do hydrophobic hormones cause a response in the cell?
Into the cytosol, bind to a receptor in the cytosol or nucleus
How do steroid hormones alter the level of protein activity in the cell?
The hormone receptor complex bind to a promoter region on the DNA and activates or inhibits transcription
Name 3 pathways that can be activated by hydrophilic hormones binding to plasma receptors
Receptor operated channels
Cyclic AMP pathways
Tyrosine kinase pathway
What is simple control?
Control only affecting 1 gland
State a simple control in our bodies?
Glucose control
