Endocrine System Flashcards
What are the functions of the endocrine system?
Regulate homeostasis
Control storage and usage of energy substrates
Regulation of growth, development, and reproduction
Regulate body’s response to environmental stimuli
What are the two broad circumstances that can cause endocrine dysfunction?
Too much/little hormones
Too many/little receptors
What is a hormone receptor antagonist?
Compete with hormones, bind to receptors and block hormone from binding which inhibits the biologic effect
What is a hormone receptor agonist?
Bind to receptor and stimulate a similar response to the original hormone
What is an example of a hormone receptor antagonist?
Naloxone (narcan) and ARBs
What is an example of a hormone receptor agonist?
Methadone and buprenorphine
What are the 5 broad classes of hormones?
Peptide
Modified amino acids
Steroids
Eicosanoids
Cytokines
What are examples of peptide hormones?
ADH, oxytocin
GH, prolactin
Insulin, glucagon
angio II
What are examples of modified amino acid hormones?
Thyroid hormones (T3/T4)
Epinephrine and norepinephrine
What are examples of steroid hormones?
Sex hormones (estrogen, progesterone, testosterone)
Corticoids (cortisol, aldosterone)
What are examples of eicosanoids?
Prostaglandins, prostacyclins, thromboxanes, leukotrienes
What are examples of cytokines?
Interleukins, interferons, TNF
What is a lipophilic hormone?
Non-polar, not very soluble in water
Require a transport protein (albumin)
What are examples of lipophilic hormones?
Sex hormones, steroids, thyroid hormones
What is a hydrophilic hormone?
Polar, easily dissolvable in water
Don’t require transport protein
Majority of hormones
What are examples of hydrophilic proteins?
ADH, oxytocin
GH, prolactin
insulin, glucagon,
epinephrine, norepinephrine
angio II
Where are most carrier proteins produced?
Liver
How does liver pathology affect the endocrine system?
Since most carrier proteins are produced in the liver, liver pathology can seriously impact the endocrine system
What is autocrine signaling?
Hormone exerts its effect on the same cell it is produced from
What is paracrine signaling?
Hormone exerts its effect on nearby/neighboring cell
What is autocrine signaling?
Hormone exerts its effect on the same cell it is produced from
What is endocrine signaling?
Hormone travels through bloodstream to another distant cell to exert its effect
How does hydrophilic signaling work?
Hydrophilic hormones can’t cross phospholipid bilayer, require secondary messenger to produce its biologic effect
How does lipophilic signaling work?
Lipophilic hormones can pass easily through the cell membrane
Bind to intracellular receptor to exert biologic effect
Hormone receptors are ____________ and not a ___________________
expressed; fixed quantity
Hormone receptors have _________________
Continuous receptor turnover
Increased sensitivity
Upregulation
Response to “too little hormone”
Increase number of receptors and efficiency of receptors
Decreased sensitivity
Downregulation
Response to “too much hormone”
Decrease number of receptors and efficiency
What stimulates increases sensitivity/upregulation?
Too little hormone
Exercise
What stimulates decreased sensitivity/downregulation?
Too much hormone
Sedentary lifestyle
Obesity
