Bio Endocrine Flashcards
As peptide hormones are no polar they can’t pass the plasma membrane, what they do?
Binds to a receptor.
Hormone (1st messenger) binds to a receptor on the outside of the membrane which can activate multiple enzymes that trigger the production of the second messenger inside the cell( cAMP, IP3, Ca)
Most peptide and amino acid derivative hormone have names that end in?
In or ine
Fast onset bug short acting
Most steroid hormones have names end in?
Ol or oid
Slow but longer lasting change
How hormones act?
Peptide have surface receptors and act via second messenger systems
Steroid hormones bind to intracellular receptors and function by binding to DNA to alter gene transcription
What hormones are catecholamines?
Epinephrine and norepinephrine
Bind to G protein coupled receptors
Each step of the signaling cascade can induce what?
Amplification of the signal
What is negative feedback?
When a hormone or product later in pathway inhibits hormones or enzymes earlier in the pathway.
It maintains the homeostasis and conserves energy
What is hypophyseal portal system?
Blood vessel system that directly connects the hypothalamus with the anterior pituitary
What does dopamine do to prolactin?
Decreases it
High and low growth hormone cause in kids?
High - gigantism
Low- dwarfism
In adults high GH - acromegaly
ADH functions
Increased blood volume and higher blood pressure and decrease osmolarity
Does posterior pituitary synthesize its hormones?
No! They are synthesized in hypothalamus and released from posterior pituitary.
When T3 and T4 produced?
By the iodination of the tyrosine amino acid in the follicular cells of the thyroid. Number 3 and 4 refer to the number of iodine atoms attached to the tyrosine.
High T3 and T4 leads to decreased TSH and TRH - negative feedback
Deficiency of iodine in kids may result in?
Intellectual disability and developmental delay (cretinism)
Function of calcium
Decreased by calcitonin
Bone structure and strength
Release of neurotransmitters from neurons
Regulation of muscle contractions
Clotting of blood ( calcium is a cofactor)
Cell movement and exocytosis of cellular materials
High levels of Ca stimulated release of calcitonin
Antagonistic hormones
Glucagon and insulin
Parathyroid hormone and calcitonin