Introduction To Endocrine System Flashcards
Who performed castration experiments?
Arnold Adolph Berthold
What are thyroid and parathyroid glands responsible for?
Metabolic rate and calcium homeostasis
Myxedema?
Hypothyroidism, deposition of mucopolysaccharides in dermis, swelling of skin.
Cretinism?
Condition of severely stunted physical and mental growth due to congenital hypothyroidism
How much does pituitary weigh?
0.5g
Example of peptide hormone?
Epinephrine pen for anaphylaxis: induces peripheral vasoconstriction
Which hormone has slow onset of action but a long plasma life and long duration of action?
Steroid e.g thyroxine
How do insulin and prolactin work?
Tyrosine kinase receptor, dimerisation, phosphorylate tyrosine components of intracellular regulatory proteins
What is secreted by adipose cells?
Leptin
What did castration do to animals?
No secondary sexual characteristics
How do Gprotein coupled receptors work?
Hormone binds to 7 transmembrane helices receptor activating G protein, causing synthesis of cyclic AMP or inositol triphosphate.
This cause phosphorylation of intracellular regulatory protein, and modify gene expression via CREB
How does tyrosine kinase recpetor work?
One hormone molecule binds to each receptor, to phosphorylate tyrosine components of intracellular regulatory proteins
What happens with steroid hormone receptors?
Hormone binds to receptor in cytoplasm, the complex travels to nucleus and binds to hormone-response element of DNA and influence gene transcription
How does leptin act?
Secreted by adipose cells and acts on hypothalamus to inhibit appetite.
Why cant you produce an extract of pancreas to cure diabetes?
Enzymes will degrade insulin, hence ligation is required