Endocrine System Flashcards
Types of endocrine glands
sudoriferous (sweat), sebaceous (oil), mucous, and digestive
Hormone Regulation w receptors
reduction or increase of receptor type in the presence of high or low concentration of hormones
Types of Hormones
peptide, steroid, tyrosine derivatives
Effector
target cell of the hormone
Peptide hormone mechanism
peptide hormones are water soluble and bind to a receptor on the cell membrane. This activates and enzyme which makes a secondary messenger system
Peptide hormone creation
made in ERE where preprohormone is cleaved into a prehormone. It is cleaved again in the golgi and processed. It is packed into a secretory vesicle and secreted.
What are the peptide hormones?
anterior pituitary: FSH, LH, ACTH, HGH, TSH (thyroid stimulating), prolactin
posterior pituitary: ADH (antidiuretic) and oxytocin
Parathyroid hormone: PTH
Pancreatic hormone: insulin, glucagon
thyroid C cell: calcitonin
Steroid hormone creation
done in SER and mitochondria
Steroid Hormone mechanism
they are lipids and requires a protein transport molecule to dissolve in blood stream. They diffuse through cell membrane and attach to a receptor in the cytosol or nucleus. Causes change in gene expression
What are the steroid hormones?
adrenal cortex: aldosterone and cortisol
gonad hormones: estrogen, progesterone, testosterone
What are the tyrosine derivative hormones?
T3 (triiodothyroxine) T4 thyroxine
catecholamines (from adrenal medulla): epinephrine and norepinephrine
Tyrosine derivative creation
in cytosol or RER
Thyroid Mechanism
lipid soluble and carried in blood via plasma protien carriers. Bind to receptors in nucleus. Increases gene transcription
Epinephrine and norepinephrine
water soluble and dissolve in blood. bind to receptors on target cells and act through cAMP
Calcitonin is a hormone that decreases blood calcium levels. If blood calcium is low would the person have high or low levels of calcitonin
Low
the body decreased output to respond to low calcium state
Timing of Hydrophilic and Hydrophobic hormones
Hydrophilic are fast and fleeting. Quickly regulated
Hydrophobic are slow ad sustained. Slowly regulated
Posterior Pituitary hormones
oxytocin and antidiuretic hormone
Oxytocin
promoted uterine contractions and milk ejection when stimulated
Antidiuretic hormone
increases water permeability of kidney’s collecting ducts = reabsorption of water from collecting tubules
anterior pituitary hormones
FSH, LH, HGH, TSH, ACTH, prolactin
Thyroid stimulating hormone
causes thyroid to release triiodothyroxine and thyroxine to increase thyroid cell size, number and rate of T3 and T4 release
negative feedback loop based on T3 and T4 concentration
Adrenocorticotropin hormone
stimulates adrenal cortex to release glucocorticoids
stress response
Human growth hormone
increases rate of mitosis, cell size, rate of protein synthesis, mobilizes fat stores, increases use of FA for E and reduces use of glucose and breakdown of AAs and proteins
Prolactin
milk production; inhibited by progesterone and estrogen
Parathyroid Hormone
increases calcium levels by increasing osterocyte absorption of Ca and increase of osteroclasts which break down Calcified bone. It increases Ca absorption in the kidneys and gut
Thyroid
T3 T4 and Calcitonin
Thyroid hormones
increase basal metabolic rate
regulated by thyroid stimulating hormone
calcitonin
decreases calcium in blood by decreasing osteoclast activity and number
Adrenal Glands
separated into adrenal cortex and adrenal medulla
Adrenal Cortex
glucocorticoids and mineral corticoids AKA cortisol and aldosterone
Glucocorticoids
increase [glucose] and affect fat and protien metabolism
cortisol
mineralcorticoids
affect electrolyte balance
aldosterone
Aldosterone
acts in distal convoluted tubule and collecting ducts to increase Na+ and Cl- reabsorption and K+ and H+ secretion through aquaporins
increases blood pressure
cortisol
increases blood glucose levels by stimulating gluconeogenesis
uses FAs for E and decreases glucose use in cell
increases protien degradation
Adenal medulla
catecholemines - norepinephrine and epinephrine
epinephrine + norep
increase constriction of blood vessels to increase blood and oxygen flow to muscles
Pancreas
insulin and glucagon
insulin
released in pancreas Beta cells
decreases glucose levels be stimulation uptake into cells, increasing storage of fats and CHs and making AAs into protiens
cells become highly permeable to glucose after binding
Glucagon
released in pancreas alpha cells
increases glucose levels by stimulation glycogenolysis (break down of glycogen) and gluconeogenesis
breaks down adipose tissue
