Download the endocrine system

INTRODUCTION TO THE ENDOCRINE
SYSTEM AND THE PITUITARYHYPOTHALAMIC AXIS
D. C. MIKULECKY
PROFESSOR OF PHYSIOLOGY
COMPARISON OF ENDOCRINE
AND NERVOUS SYSTEMS
NERVOUS SYSTEM
“WIRED”
CHEMICAL SIGNAL
AT TARGET CELL
RAPID
BRIEF DURATION
 ENDOCRINE SYSTEM
“WIRELESS”
CHEMICAL SIGNAL
AT TARGET CELL
SLOW
LONG DURATION
CATEGORIES OF
HORMONES
PEPTIDES
AMINES
STEROIDS
PEPTIDES
HYDROPHILIC
DISSOLVED IN PLASMA
RECEPTOR ON CELL SURFACE
SECOND MESSENGERS
MAY ACTIVATE SPECIFIC GENES TO
REGULATE PROTEIN SYNTHESIS
PEPTIDE HORMONES
HYPOTHALAMIC
PITUITARY
PANREATIC
PARATHYROID
GI
KIDNEY
LIVER
HEART
AMINES
THYROID HORMONE
CATECHOLAMINES
ALL DERIVED FROM AMINO ACID
TYROSINE
UNIQUE SYNTHETIC AND SECRETORY
PATHWAYS
STEROIDS
DERIVED FROM CHOLESTEROL
LIPOPHILIC
RECEPTOR IN CYTOPLASM
MAY ACTIVATE SPECIFIC GENES TO INITIATE
PROTEIN SYNTHESIS
ADRENAL CORTICAL
GONADAL
PLACENTAL
PLASMA CONCENTRATION
OF HORMONES
DEPENDS ON RATE OF SECRETION
NEGATIVE FEEDBACK
NEUROENDOCRINE REFLEXES
DIURNAL RHYTHMS
TYPES OF ENDOCRINE
DISORDERS
HORMONE EXCESS
HORMONE DEFICIENCY
DECREASED RESPOSIVENESS OF
RECEPTORS
THE PITUITARYHYPOTHALAMIC AXIS
INTERFACING THE
NERVOUS SYSTEM WITH
THE ENDOCRINE SYSTEM
HYPOTHALAMUS AND
POSTERIOR PITUITARY
NEUROSECRETORY
NEURONS
VASOPRESSIN
OXYTOCIN
ANTERIOR
PITUITARY
HYPOTHALAMUS
POSTERIOR
PITUITARY
SYSTEMIC
ARTERY
SYSTEMIC
VEIN
HYPOTHALAMUS AND ANTERIOR
PITUITARY
NEUROSECRETORY
NEURONS
ANTERIOR
PITUITARY:
•TSH
•ACTH
•PROLACTIN
•GROWTH
HORMONE
•LH
•FSH
HYPOTHALAMUS
POSTERIOR
PITUITARY
CLASSIFICATION OF ANTERIOR
PITUITARY HORMONES
GLYCOPROTEIN FAMILY: TSH, FSH,LH
GROWTH HORMONE PROLACTIN FAMILY:
GH OR STH
PROOPIOMELANOCORIN FAMILY: ACTH,
-LIPOTROPIN, -ENDORPHIN
HYPOTHALAMIC-HYPOPHYSEAL
PORTAL SYSTEM
SECRETED BY NERVE CELLS IN
HYPOTHALAMUS
VESSELS PASS THROUGH STALK OF
PITUITARY FROM HYPOTHALAMUS TO
ANTERIOR PITUITARY
CARRY HYPOTHALAMIC REGULATORY
HORMONES
HYPOTHALAMIC REGULATORY
HORMONES
HYPOPHYSIOTROPIC HORMONES
CONTROL THE SECRETION OF OTHER
HORMONES BY ACTING ON ENDOCRINE
TISSUE
HYPOTHALAMIC RELEASING AND
INHIBITING HORMONES
(HYPOPHYSIOTROPIC)
 CONTROL THE SECRETION OF ANTERIOR PITUITARY
TROPIC HORMONES
 TRH:THYROTROPIN-RELEASING HORMONE
 PRF:PROLACTIN RELEASING FACTOR
 PIF:PROLACTIN INHIBITING FACTOR
 GHRH:GROWTH HORMONE RELEASING HORMONE
 SRIF: SOMATOTROPIN RELEASE-INHIBITING FACTOR
 CRH:CORTICOTROPHIN RELEASING HORMONE
 GnRH: GONADOTROPIN RELEASING HORMONE
HIERARCHICAL CONTROL
INPUT
HYPOTHALAMUS
HORMONE 1 (RELEASING/INHIBITING)
H/H PORTAL SYSTEM
ANTERIOR PITUITARY
ENDOCRINE GLAND
HORMONE 2 (TROPIC)
SYSTEMIC CIRCULATION
HORMONE 3
SYSTEMIC CIRCULATION
TARGET
CELLS
NEGATIVE FEEDBACK
INPUT
HYPOTHALAMUS
HORMONE 1 (RELEASING/INHIBITING)
H/H PORTAL SYSTEM
ANTERIOR PITUITARY
ENDOCRINE GLAND
HORMONE 2 (TROPIC)
SYSTEMIC CIRCULATION
HORMONE 3
SYSTEMIC CIRCULATION
TARGET
CELLS
ANTERIOR PITUITARY
HORMONES:TSH
THYROID GLAND
THYROID HORMONES (T3 & T4 )
ANTERIOR PITUITARY
HORMONES:ACTH
ADRENAL CORTEX
CORTISOL
ANTERIOR PITUITARY
HORMONES:PROLACTIN
MAMMARY GLANDS
BREAST GROWTH AND MILK SECRETION
ANTERIOR PITUITARY HORMONES:
GROWTH HORMONE
LIVER
SOMATOMEDINS
BONE
SOFT TISSUE
GROWTH
MANY TISSUES
INTERMEDIARY
METABOLISM
INCREASE OR
DECREASE
ANTERIOR PITUITARY HORMONES:
LH & FSH: ACT ON GONADS
LH:LUTEINIZING
HORMONE
SEX HORMONE
SECRETION
F: ESTROGEN AND
PROGESTERONE
M: TESTOSTERONE
FSH:FOLLICLE
STIMULATING
HORMONE
GAMETE
PRODUCTION
OVA
SPERM