Endocrine System Flashcards
What is the endocrine system function controlled by?
- Hormones delivered thru circulation
- Hormones produced locally
- Direct Neuroendocrine stimulation
3 components that make up the core of the endocrine system?
- Endocrine glands
- Hormones
- Target organs
What is an endocrine gland?
Ductless gland secretes hormones into interstitial space –> circulation
Classical endocrine glands
Hypothalamus, anterior pituitary, posterior pituitary, pineal gland, thyroid, parathyroid, pancreas
Nonclassical endocrine glands
Heart, intestines, kidney, placenta
What is a hormone?
Chemical product released in small quantities that exert a biological action on a target cell
What are the chemical messengers?
Neurotransmitters, endocrine hormones, neuroendocrine hormones, paracrines, autocrines, cytokines
What are the 3 types of hormones discussed?
Peptide or protein hormones, amine hormones, steroid hormones
T/F: Protein hormones are hydrophilic and unbound (free).
True
How are protein hormones synthesized?
Pre-prohormone
Give a common example of a protein hormone.
Insulin
What amino acid is amine hormone derived from?
Tyrosine
T/F: Steroid hormones are derived from cholesterol.
True
What are the cell surface receptors?
GPCR, ion-channel coupled receptors, enzyme coupled receptors (RTK)
What type of hormones use cell surface receptors?
Protein hormones and amine hormones (except thyroid hormone)
Which type of receptors do thyroid hormones use?
Intracellular receptors
What hormones use intracellular receptors?
Steroid hormones, thyroid hormones, retinoid hormones
T/F: Intracellular receptors can either be cytoplasmic or nuclear.
True
What is hormone clearance?
The rate of the removal of hormone from the blood –> metabolic clearance rate
T/F: Metabolic clearance rate cannot interfere with hormone concentration.
False, it can
What are some ways hormones are cleared from the plasma?
Metabolic destruction by the tissues
Binding with the tissues
Excretion by the liver into the bile
Excretion by the kidney into the urine
How is thyroid hormone transported in the blood and which receptor does it bind to?
Transported by carrier proteins, intracellular receptor
How is insulin transported in the blood and which receptor does it bind to?
Circulate unbound in the blood, bind to receptors in the cell membrane
How are steroid hormones produced and transported?
Derived from cholesterol, produced by adrenal cortex, gonads, placenta. Transported by carrier proteins & bind to intracellular receptors
Metabolic Clearance Rate
Rate of the disappearance of hormone from plasma / concentration of hormone
