Endocrine System and Hormonal
Control: Hypothalamic pituitary
endocrine axis
Vibuntita Chankitisakul, D.V.M., Ph.D.
Hypothalamus
 Region of the lower brain
 Receives information from nerves throughout the body
and brain
 Initiates endocrine signals appropriate to the
environmental conditions
 Regulates the Pituitary Gland
Pituitary Gland
 Located at the base of the hypothalamus
 Two lobes: anterior and posterior; numerous functions
 The posterior pituitary stores and secretes hormones that are
made in the hypothalamus
 The anterior pituitary makes and releases
hormones under regulation of the
hypothalamus
Posterior
Pituitary Gland
Contains axon
from neurons
in the
hypothalamus
Posterior Pituitary Gland
Posterior pituitary hormone function
Two hormones
Three internal organs
Antidiuretic hormone
(ADH) or Vasopressin
- Stimulates kidneys
to conserve water
- Increase blood
pressure
Oxytocin
-triggers mammary glands to express milk
-triggers uterine contractions
Anterior
Pituitary Gland
Cells that produce
anterior pituitary
hormones
Consists of
glandular
tissue
Anterior
Pituitary Gland
A specific hormone affects
a specific cell type of ant.
Pituitary cell.
Cell types
Chromophils
Hormones
Somatotrophs
Acidophils
Growth hormone(GH)
Lactotrophs
Acidophil
Prolactin(PRL)
Corticotrophs
Basophil
adenocorticotropichormone(ACTH)
Gonadotrophs
Basophil
Follicle stimulating hormone
(FSH) and luteinizing
hormone (LH)
Thyrotrophs
Basophil
Thyroid stimulating hormone
(TSH)
Five hormones
Many internal organs
Tropic and
non-tropic
hormone
Tropic
hormones
Tropic hormones mean??
•
•
Tropic hormones are hormones that have other
endocrine glands as their target. Most are
produced and secreted by the ant.pituitary gl.
Non-tropic hormones are those that act
directly on targeted tissues or cells to induce
effects.
Tropic hormones and the glands they control
hypothalamus
somatostatin
Inhibiting
hormone
Releasing
hormone
Pituitary gland
PIFs,
dopamine
HYPOTHALAMIC-PITUITARYENDOCRINE AXIS
Hormones of the hypothalamus
Thyrotropin-releasing
hormone (TRH)
Gonadotropin-releasing
hormone (GnRH)
Growth hormonereleasing hormone
(GHRH)
Corticotropin-releasing
hormone (CRH)
Somatostatin
Dopamine
Hypothalamic-Pituitary-Endocrine axis
1. Hypothalamic-pituitary-breast axis
2. Hypothalamic-pituitary-growth hormonesomatotroph axis
3. Hypothalamic-pituitary-gonadal axis
4. Hypothalamic-pituitary-adrenal axis
5. Hypothalamic-pituitary-thyroid axis
1. Hypothalamic-pituitary-breast axis
Thyrotropin-releasing
hormone (TRH)
Gonadotropin-releasing
hormone (GnRH)
Growth hormonereleasing hormone
(GHRH)
Corticotropin-releasing
hormone (CRH)
Somatostatin
Dopamine
Regulation of prolactin secretion
TRH = thyrotropinreleasing hormone
Regulation of prolactin secretion
Physiological effects of prolactin
2. Hypothalamic-pituitary-growth hormonesomatotroph axis
Thyrotropin-releasing
hormone (TRH)
Gonadotropin-releasing
hormone (GnRH)
Growth hormonereleasing hormone
(GHRH)
Corticotropin-releasing
hormone (CRH)
Somatostatin
Dopamine
Regulation of growth hormone
(somatotropin )
Tropic effect
GHRH
Bone and tissue
growth and
nutrient
Regulation of
growth
hormone
Effects of GH: Bone
and tissue growth
and nutrient
metabolism.
Sm= Somatomedin C or Insulin-like
growth factor I (IGF-I)
Negative feedback
= negative feedback
= inhibiting factor
Summarize
(again)!!
inhibit
Let’s read some articles in class
and make the discussion!!
Hypothalamic-pituitary-thyroid axis
Hypothalamic-pituitary-gonadal axis
Hypothalamic-pituitary-adrenal axis