Download Intro to Endocrinology Comparison of Nervous and Endocrine

Comparison of Nervous and
Endocrine Systems
Intro to Endocrinology
„
Intercellular Communications
„
neurons
action potential
neurotransmitters
communicate short
distances
– very rapid
transmission(ms)
– response short lived
Paracrines
Neurotransmitters
„ Hormones
„ Neurohormones
„
„
Feedback Mechanisms
„
Endocrine System
– chemical
communicators
– hormones
– communicate long
distances
– slower
transmission(mintransmission(mindays)
– response longer lived
Complex (multilevel)
– hormonal feedback
Simple
_
– nonnon-hormonal feedback
„
„
–
–
–
–
– MESSENGERS
„
Nervous System
_
Glucose/Insulin Regulation
HORMONE
ENDO
CELL
-
Hypo
TRH
+
TSH
TARGET
BIOLOGICAL
Anti. Pit.
Thyroid
Thyroxin
(T4, T3)
RESPONSE
Biological
response
Synthesis
Chemical Nature of Hormones
„ Amino
Acid Derivatives
„ Peptide
„ Peptides
and Proteins
„ Steroids
and Protein Hormones
„ Steroids
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Mechanisms of Hormone
Action
„ Proteins
–2nd
messenger
– Activate genes
„ Steroids
– Genomic
Effect
– NonNon-genomic
effect
Functional Components
„
Hypothalamic-Pituitary
Relationships
Anterior pituitary (adenohypophysis
(adenohypophysis))
Introduction
Embyrology
„ Anterior
Pituitary
– Rathke’
Rathke’s pouch
„
Posterior pituitary (neurohypophysis
(neurohypophysis))
„ Posterior
Pituitary
– Infundibulum
Relationship of Hypothalamus
and Post. Pituitary
2
Relationship of Hypothalamus
and Ant. Pituitary
Relationships of Hypo and
Pituitary Review
„
Neural relationships
– Posterior pituitary
„
„
„
Circulatory relationships
– Anterior pituitary
„
„
Anterior Pituitary Cell Types
„
„
Lactotrophs
Coricotroph
„
„
„
„
Thyrotropin releasing hormone(TRH)
– stimulates release of TSH & Prolactin
Corticotropin releasing hormone(CRH)
– stimulates release of ACTH and MSH
Gonadotropin releasing hormone(GnRH)
hormone(GnRH)
– stimulates release of FSH and LH
Gonadotroph
– 1010-15%
– Follicle stimulating hormone(FSH)
– Luteinizing hormone(LH)
– 1515-20%
– Adrenalcorticotrophic hormone(ACTH)
– Melanocyte stimulating
hormone(MSH)
Releasing/Inhibiting Hormones
Thyrotroph
– 3-5%
– Thyroid stimulating hormone(TSH)
– 1010-15%
– Prolactin
„
hypophyseal portal system
releasing/inhibiting hormones
Cell Types(cont)
Somatothroph
– 4040-50%
– Human Growth Hormone(HGH)
„
supra optic nucleus
paraventricular nucleus
„
Growth hormone releasing
hormone(GHRH)
– stimulates release of HGH
„
Growth hormone inhibiting
hormone(GHIH or somatostatin)
somatostatin)
– inhibits release of HGH,
Prolactin inhibiting hormone
(dopamine)
– inhibits release of prolactin
„
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Anterior Pituitary Hormone
Functional Overview
„ Follicle
stimulating hormone(FSH)
– growth and maturation of ovarian follicle
– influences estrogen secretion
– stimulates sperm production
„ Luteinizing
hormone(LH)
– ovulation
– formation of corpus luteum
– secretion of testosterone by Leydig cells
„ Adrenocorticotropic
hormone(ACTH)
– stimulates production of glucocorticoids by the
adrenal cortex
„ Thyroid
stimulating hormone(TSH)
– growth/maintenance of thyroid tissue
– stimulates secretion of thyroid hormone
„ Prolactin
– milk production/secretion in mammary glands
„ Human
growth hormone(HGH)
– role in body growth
– regulates metabolism
Intermediate Lobe Hormone
Overview
„ Melanocyte
stimulating
hormone(MSH)
– no significant role in humans
– role in camouflage in some animals
– ACTH influence
Posterior Pituitary Functional
Overview
„ ADH
– produced by supra optic nucleus
– role in urine production
– also called vasopressin which plays a role
in regulating blood pressure
„ Oxytocin
– produced by paraventricular nucleus
– stimulates milk letdown
– may play a role in parturition
„ Pitocin
Pineal Gland
„ Melatonin
– cycling effect
„ biological clock
„ affective disorders
„ PMS
„ puberty onset
„ seasonal breeding
– antioxidant
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