Introduction to Endocrine Flashcards
what are the 4 types of hormone signaling
endocrine: send a hormone through the bloodstream
autocrine: hormone is signalled on itsself
paracrine: cell signals onto a cell next to it
Neurocrine: a nerve sends hormone through the blood stream to a cell
What are a couple hormones modified by peripheral conversion
Angiotensin II and Vitamin D
Hormones secreted by the hypothalamus
TRH Thyrotropin releasing hormone CRH Corticotropin releasing hormone GnRH Gonadotropin releasing hormone Somatostatin Dopamine or prolactin inhibiting factor
Hormones secreted by the anterior pituitary
TSH - Thyroid stimulating hormone
FSH - Follicle stimulating hormone
LH - Luteinizing hormone
ACTH - Adrenocorticotropic hormone
MSH - Melanocyte - stimulating hormone
Growth hormone
Prolactin
Hormones released by the Posterior Pituitary
Oxytocin
Antidiuretic hormone (ADH) or vasopressin
Hormones released by the Thyroid
Triiodothyronine (T3) and L-thyroxine (T4)
Calcitonin
Hormones released by the Parathyroid
Parathyroid hormone (PTH)
Hormones released by the Adrenal Cortex
Cortisol (glucocorticoid)
Aldosterone (mineralcorticoid)
Dehydroepiandrosterone (DHEA)
and Anderostenedione
(adrenal androgens)
Hormones released by the testes
Testosterone
Hormones released by the ovaries
Estradiol
Progesterone
Hormones released by the Corpus Luteum
Estradiol
Progesterone
Hormones released by the Placenta
Human Chorionic Gonadotropin (HCG)
Human Placental lactogen (hPL)
Estriol
Progesterone
Hormones released by the Pancreas
Insulin (beta cells)
Glucagon (alpha cells)
Hormones released by the Kidney
Renin
1, 25-dihydroxycholecalciferol
Hormones released by the Adrenal Medulla
Norepinephrine
Epinepherine
What are the three general classes of hormones
Protein/peptide hormones:
- stored in vesicles
- greater than 100 a.a are proteins
- smaller than 100 a.a are peptides
- water soluable
Steroid hormones:
- synthesized from cholestrol
- lipid soluable
- not stored
Amines:
-derived from tyrosine
What is the process of Protein and peptide hormone synthesis
synthesized as non functional prepprohormone
modified in ER to prohormone and then packed into vesicles
once needed they are cleaved by a proteoytic enzyme to form a functional hormone
then stored in vesicle until endocrine cell stimulus causes release
-increased cAMP and PKA activation
What are the steroid hormones and what are they derived from
Cortisol, aldosterone, estradiol, estriol, progesterone, testosterone, and 1,25-dihydroxy cholecalciferol
derived from cholesterol
modifications via the addition or removal of side chains
What are the amine hormones derived from and what are the two groups
Tyrosine
Catecholamines:
- synthesized in cytosol and secretory granules
- act through cell membrane associated receptors
- cant cross cell membrane
THyroid hormones:
- synthesized by thyroid gland stored as thyroglobulin in follicles
- can cross the cell membrane and acts on a nuclear receptor
What is the correlation of a hormones protein binding percentage, plasma half life, and Metabolic clearance
the higher the Protein binding percentage the longer the plasma half life of the hormone and the slower its clearance
What is endocrine positive feedback
some feature of the hormone action causes additional secretion of the hormone
What is endocrine negative feedback
some feature of the hormone action inhibits the further secretion of the hormone
What is a long loop feedback
Hormone released from the 3rd tier (peripheral endocrine) feeds all the way back to the 1st (hypothalamus) and 2nd tier (pituitary)
What is a short loop feedback
Hormone secreted from the 2nd tier back to the 1st tier
Ultra short loop feedback
gland inhibits its own secretion
What are three major neuronal inputs that regulate the hypothalamus
Suprachiasmatic nucleus (SCN) - impose a circadian rhythm on the secretion of hormones
Pineal gland:
-releases melatonin which feedbacks to the SCN information about day and night
Physiological stress influences the release of hormones from the hypothalamus
Up regulation of the receptor ligand interaction
increase the number of receptors or sensitivity of target tissue when hormone levels are low
- increase the synthesis of new receptors
- decrease the degradation of existing receptors
- activating receptors
Down regulation of receptor ligand interaction
Reduce the receptor numbers or sensitivity of target tissue when hormone levels are high
- decrease in receptor synthesis
- increase degradation of existing receptors
- Inactivating/desensitizing receptors
How can responsiveness to for the ligand receptor hormone interaction
change the number of receptors
change the affinity of the receptors for the hormone
what hormones use Adenylyl cyclase and what is the 2nd messenger and secondary effector
ACTH, LH, FSH, TSH and glucagon
2nd mesenger is cAMP
2nd effector is the Protein Kinase A
what hormones use the Phospholipase C and what is the 2nd messenger and effector
GnRH, TRH, oxytocin
2nd messenger: IP3/DAG/Ca2+
Secondary effector: PKC or calmodulin
What are the two types of Tyrosine kinases and what are some hormones that use them
Receptor Tyrosine kinases
- intrinsic tyrosine kinase activity
- Nerve growth factor (NGF)
- Insulin
Tyrosine kinase associated receptors:
- associate non covalent to proteins that have kinase activity
- Growth hormones
What is the function of: Thyrotropin releasing hormone
stimulation of TSH and prolactin
What is the function of: Corticotropin releasing hormone
Stimulates the secretion of ACTH
What is the function of: Gonadotropin releasing hormone
stimulates the secretion of LH and FSH
What is the function of: Somatostatin or SRIF
Inhibits secretion of growth hormone
What is the function of: Dopamine or PIF
inhibits the secretion of prolactin
What is the function of: Growth hormone releasing hormone GHRH
Stimulates secretion of growth hormone
What is the function of: Thyroid stimulating hormone
Stimulates synthesis and secretion of thyroid hormones
What is the function of: Follicle stimulating hormone
Stimulates sperm maturation in sertoli cells of testes
stimulates follicular development and estrogen sythesis in ovaries
What is the function of: Luteinizing hormone
Stimulates testosterone synthesis in leydig cells of testes
Stimlates ovulation formation of corpus luteum, estrogen and progesterone
synthesis in ovaries
What is the function of: Growth hormone
Stimulates protein synthesis and overall growth
What is the function of: Prolactin
Stimulates milk production and secretion in breast
What is the function of: ACTH
stimulates synthesis and secretion of adrenal cortical hormones (cortisol, androgens, aldosterone)
What is the function of: MSH
stimulates melanin synthesis
What is the function of: Oxytocin
stimulates milk ejection from breasts and uterine contractions
What is the function of: Antidiuretic hormone
Stimulates water reabsorption in principal cells of collecting ducts and constriction of arterioles
What is the function of: T3 and T4
Stimulates skeletal growth oxygen consumption heat production protein fat and carbohydrate utilization Perinatal maturation of the CNS
What is the function of: calcitonin
Decrease serum Ca+
What is the function of: PTH
Increase serum Ca+
What is the function of: Cortisol (gluccorticoid)
Stimulates gluconeogenesis
inhibits inflammatory response
suppresses immune response
enhances vasclar responsiveness to catecholmines
What is the function of: Aldosterone (mineralcorticoids)
Increase renal Na+ reabsorption
renal K+ secretion
and H+ secretion
What is the function of: DHEA (adrenal androgens)
stimulates secondary sex characteristics
What is the function of: Testosterone
Stimulates spermatogenesis
stimulates male secondary characteristics
What is the function of: Estradiol
Stimulates growth and development of female reproductive system follicular phase of mestrual cycle development of breasts Prolactin secretion maintains pregnancy
What is the function of: Progesterone
Stimulates luteal phase of menstraul cycle
maintains pregnancy
What is the function of: Human chorionic gonadotropin
Stimulates estrogen and progesterone synthesis in corpus luteum of early pregnancy
What is the function of: Human placental lactogen
Has growth hormone and prolactin like actions during pregnancy
What is the function of: insulin
decrease blood glucose
What is the function of: glucagon
increase blood glucose
What is the function of: renin
catalyzes the conversion of angiotensinogen to angiotensin I
What is the function of: 1,25-Dihydroxycholecalciferol
increase intestinal absoprtion of Ca+ and bone mineralization
WHat hormones use the Adenyl cyclase mechanism
ACTH LH FSH TSH ADH HCG MSH CRH Calcitonin PTH Glucagn B1 and B2 receptors
What hormones use the Phospholipase C mechanism
GnRH TRH GHRH Angiotensin II ADH Oxytocin A1 receptors
What hormones use the steroid Hormone mechanism
GLucocorticoids Estrogen Progesterone Testosterone Aldosterone 1, 25 Dihydroxycholecalciferol Thyroid hormones
What hormones use the Tyrosine kinase mechanism
Insulin
IGF-1
Growth hormone
Prolactin
what hormones use the Guanylate Cyclase Mechanism
Atrial natriuretic peptide (ANP)
Nitric oxide
