Introduciton to the Endocrine System Flashcards
Autocrine
Paracrine
Endocrine
Neuroendocrine
Release H and it effects
Itself or neighboring same cell
Neighboring different cell
Different cell by flowing through the blood to that location
Different cell by flowing (H released by Neuron) though the blood to that location
Peptide Hormone synthesis and secretion
Pre-pro-H—-> pro-H—->H in vesicle that is released
Steroid H secretion and synthesis
Derivative of cholesterol
Hydroxylation or cyclication added
In gonads, corpus luteum, placenta, adrenal medulla
LIPID SOLUBLE so just pass cell membrane
Amine Hormone synthesis and Secretion
Made from derivative Tyrosine
GROUP 1: Catecholamines (Dopamine NorEp., Epi)
In secretory granules
Bind on cell membrane receptors
GROUP2: Thyroid Hormones (TSH, T3, T4)
Synthesized by thyroid and put into follicles inside the thyroid gland
Can cross cell membrane to bind to NUCLEAR RECEPTORS
Thyroid hormones
High protein binding
Long plasma half life
Low metabolic clearance
Protein Hormones
Little protein binding
Short plasma half life
High metabolic clearance
Steroid Hormones
In the middle for protein binding and plasma half life and metabolic clearance
Positive feedback of overies
Overly secretes Estrodiol—-> stimulate AP to secrete H——> stimulates overly to secrete more Estrodiol
Long loop vs Short loop feedback
LONG: Testosterone(from endocrine gland testis) inhibits AP and Hypothalamus
SHORT: AP inhibits Hypothalamus, or Testosterone inhibits Testis
Supraorbital Nucleus and the Paraventricular Nucleus
Make ADH and Oxytocin in their neurons
Their axons travel to PP and release the O and A to the blood capillaries inside
Oxytocin
Milk let down
Uterus contraction
ADH
Reabsorb Solutes back into the kidneys
To regulate BP
Releasing H
Are from the Hypothalamus that go to the AP
TRH
Causes TSH—->thyroid to release TH
ACTH
Causes cortisone from the AP
Prolactin
Made in pituitary gland
Inhibited by dopamine from the hypothalamus
Milk production
And breast growth
How is the hypothalamus regulated
By neural input
Most common is the SCN neurons
SCN neurons pathways go
Light—> eyes—> Lateral Geniculate nucleus—> SCN
SCH——>
1. Pineal gland to secrete melatonin
2. Hypothalamus for sleep/wake cycles
3. Coordinate rhythms of metabolism and behavior and endocrine with help of melatonin
How to regulate H. Receptors
They are very sensitive in the periphery since you don’t have that much hormone there
- Change number of receptors
- Change affinity of receptors to H. = like chemical modifications like phosphorylation
Adenylyl cyclase mechanism and which H.s
ACTH, LH, FSH, TSH, Glucagon
Adenylase cyclase
cAMP —->5’AMP
PKA
Phospholipase C mechanism and which H.s
GnRH, TRH, Oxytocin Activate PLC IP3/DAG/Ca+2 DAG + Ca+2= protein kinase C IP3= Ca+2 from ER
Steroid mechanism and which H.s
Testosterone, Estrogen….?
Hydrophobic H.s (usually bound to a plasma protein)
Bind to cytoplasmic receptors
Go to bind nuclear receptors to activate or suppress genes
Some few bind to membrane receptors
Guanylyl Cyclase Mechanism and H.s
GTP—-> cGMP
cGMP= activates cGMP Kinase (ANP) and also causes vasodilation due to NO
Tyrosine Kinase Mechanism and H.s
Insulin and Nerve Growth
1. Receptor Tyrosine Kinase: intrinsic tyrosine kinase activity
Activated and phosphorylates downstream proteins
GH
2. Tyrosine Kinase-Associated Receptors: JAKSTAT
Non-covalent association to kinase proteins
Activated and phosphorylates downstream proteins
