Endocrine system Flashcards
Endocrine glands
No ducts
Hormone
Chemical messenger that gets dumped in the blood.
Chemical classes of hormones
Steroids - WILL GO INTO THE CELL
Peptides - SECONDARY MESSAGING SYSTEM. (faster actions)
Monoamines
Steroids
Cholesterol, hydrophobic
Gonads and adrenal glands
Estrogens, progesterone, testerone, calcitrol
Peptides
Proteins, ribosomes
pituitary and hypothalamus
Oxytocin, antidiuretic
Monoamines
Derived from amino acids
adrenal, pineal, thyroid gland
melatonin, epinephrine
Hypothalamus
8 hormones. 6 are regulatory and the other 2 are produced here but released somewhere else.
Pituitary (hypophysis)
Anterior Lobe (glandular) Posterior Lobe (neural)
Anterior pituitary (hypophysis) hormones. Adeno
Follicle-stimulating FSH Luteinizing LH Thyroid stimulating TSH (Thyrotropin) Adrenocorticotropic Prolactin Growth hormone
Hypothalamus
Gonadotropin-releasing GRH. Goes down and the adenohypophysis will secrete FSH and LH.
Thyrotropin-releasing. Goes down and adeno will secrete TSH
Corticotropin-releasing
Prolactin inhibiting hormone PIH. ade will not secrete prolactin
Growth hormone-releasing hormone. GHRH
Somatostatin (growth hormone and TSH inhibiting)
Gonadotropins
FSH follicle stimulating
LH luteinizing
FSH
Influences gonads to produce their follicles.
Testes = sperm cells
Ovaries = egg cells
LH
Acts on gonads to secrete its hormones
Testes = testosterone
Ovaries = Estrogen
TSH
Stimulates thyroid to secrete its hormones
ACTH
Adrenocorticotropic hormone stimulates adrenal glands to secrete its hormones
PRL
Prolactin. After birth stimulates the mammary gland to synthesize milk.
In males testosterone in males.
GH
growth hormone
various tissues to undergo mitosis to grow
The initial target organ and cells are in the liver, and it influenced the hepatocytes to produce 2 secondary hormones.
IGF1 and IGF2: because it has a short half-life, these two hormones prolong the life of the hormones. They act like GH hormone (almost an entire day)
Tropic hormones
Influences other glands to secrete their hormones
TSH
LH
Posterior pituitary Neurohypophysis
Antidiuretic hormone ADH
oxytocin
ADH. Supraoptic nucleus
Influences kidney to retain water
Can influence vessels to vasalconstrict
water back to blood, blood pressure increases
Can also influence vessels to constrict
Oxytocin. Paraventricular nucleus
OT
Bonding hormone
influences mammary glands to release milk.
Influences uterus to contract
Secondary messaging system
Allows peptide hormones to have an effect on the cell without having to go in.
Binding to a receptor and then activating the internal protein.
G protein-mediated
Start by activating a G protein (signal molecule)
The peptide hormone cant cross the membrane because it’s not fat soluble. that hormone will bind to the receptor on the outside. Once it binds the G protein becomes active. It splits into 3 subunits. Those subunits can move inside the cell and activate other things. All the subunits bind to a secondary membrane protein adenylate cyclase activating it. Once that it’s activated it will pick up ATP and convert it to cAMP. By doing that 2 phosphates are freed up. cAMP is the secondary messenger, it activates protein kinase (signal molecule). Protein kinase will phosphorylate enzymes. Once pho[horylated the enzymes can start doing whatever they are supposed to do.
Protein kinase
Phosphorylates enzymes, turning them on.
IP3
Calcium has to be present in the cell somehow
MCR. Metabolic clearance rate
The rate at which hormones clear from the blood.
Half-life
Time to remove 50% of hormone from the body
Hypophyseal portal system
It allows us to have a double exchange, and control over pituitary. Extra capillary bed.
Hypothalamus and hypophysis
Pineal gland
Secretes melatonin from serotonin
SADs
May regulate the timing of puberty
Thymus
Endocrine, lymphatic and immune.
T-cell maturation
Thymopoietin, thymosin, thymulin that stimulates the activity of T-lymphocytes
It Shrinks
Thyroid
Largest truest endocrine gland. Composed of follicles that make the thyroid hormone.
Increases metabolic rate
Secretes
Follicular cells
make thyroid hormone.
T3 and T4 are the active forms of thyroid hormone.
Thyroid hormone
increases metabolic rate
T3 and T4
Hypo and Hyper secreted
