endocrinology

1. Endocrine system
Basics
Presented by:
Yasmeen Mir
M. Pharm ist year (Pharmacology-II)
Roll no.:18155110001

2. The regulating systems of the body are:
Nervous System electrochemical
impulses rapid control
Endocrine System
slow control
hormones
Endocrine System => maintains the
body in balance

3. = substances secreted by endocrine tissue into
the blood
act on the target tissue
produce a specific response
Hormones

4. Chemically hormones can be divided into seven
major classes:
•Amino acid derivatives: Dopamine, Catecholamines
and Thyroid hormones.
•Neuropeptides: Gonadotropin releasing hormone,
thyrotropin releasing hormone and somatostatin.
•Simple proteins: like ACTH.
•Large proteins: Insulin, LH, PTH.
•Glycoprotein: like TSH.
•Steroids: like cortisol, estrogen, progesterone and
glucocorticoids.
•Vitamins: vit. D

5. •Hormone receptor and mechanism of hormone action
There are three major classes of receptors for hormones
•Membrane receptors: primarily bind neuropeptide hormones and
catecholamines. It involves:
1.G-protein coupled receptors working through adenylase-cAMP system (as for NA, E, DA,
TSH, FSH, LH, PTH, and ACTH) or through phospholipase-C-inositol system (as for
oxytocin, vasopressin).
2.Tyrosine kinase receptors like for insulin, growth hormones and growth factor.
3.Cytokine receptor as for prolactin and some growth factors
4.Serine-kinase receptors as for activin, transforming growth factor-β and bone morphogenic
proteins.
•Cytosolic receptors, as for steroidal hormones such as
glucocorticoids, mineralocorticoids, estrogen, progestins and
androgens.
•Nuclear receptors, as for thyroid hormones

6. Endocrine Functions
 Maintain Internal Homeostasis
 Availability of fuel
 Somatic growth
 Sex and reproduction
 Coordinate Development
 Coordinate Reproduction
 Adaptation to stress
 Calcium balance

8. Hypothalamus
Location -lines the walls of 3rd ventricle-above the pituitary gland
Source www.truthonthenet.com

9. Hypothalamic nuclei

10. Contains 2 types of cells:
 Parvocells
-Medial-neurons secrete hypothalamic
releasing hormones
-Dorsal and ventral -some neurons
secrete oxytocin and vasopressin
 Magnocells
-Neurons control endocrine function by
secreting oxytocin and vasopressin
directly into the posterior pituitary
gland
Paraventricular Nucleus

11. Hypothalamo – pituitary axis

12. http://www.bio.miami.edu/tom/courses/protected/ECK/CH09/figure-09-15.jpg
Hypophyseal (pituitary) hormones

15. Source: http://antranik.org/the-endocrine-system/

16. Regulation of Hormone Activity

17. Endocrine cells in various organs
The heart: atrial natriuretic peptide (ANP), stimulates kidney to secrete more
salt. There by decreases excess blood volume, high BP and high blood sodium
concentration.
GI tract & derivatives: Diffuse neuroendocrine system (DNES).
The placenta secretes steroid and protein hormones Estrogens, progesterone,
CRH, HCG.
The kidneys
Juxtaglomerular cells secrete renin.
Renin indirectly signals adrenal cortex to secrete aldosterone.
Erythropoietin: signals bone marrow to increase RBC production.
The skin
Modified cholesterol with uv exposure becomes Vitamin D precursor, Vitamin D
necessary for calcium metabolism: signals intestine to absorb Ca++ .