Download MBBS Hormone 1 Lecture PPT

Download MBBS (Bachelor of Medicine and Bachelor of Surgery) Latest Hormone 1 Lecture PPT


HORMONES

o Term hormone was introduced by Starling and

Bayliss in 1905.

o Hormones are the chemical messengers produced by

endocrine gland and transported by blood to other

tissue or organ where these stimulate a change in

some metabolic activity.

o They are produced from by one type of cell and have

regulatory effect on the activities of other type of cell

or on itself.

o The tissue or organ stimulated by a specific hormone

are called Target Tissue/ Target organ



o .

Hormones act on specific cells and organs called

target cell or target organ.

o Target cell or organ is that cell which has specific

receptors for the hormone which bind to them

with or without any demonstratable biochemical

or physiological response

o Concentration of hormone is very low in blood

but..

o Presence of receptors on target tissue
Specific binding between hormone and receptor
Very high local concentration
o Makes the target tissue highly specific to

hormones
CLASSIFICATION OF HORMONES BY

MECHANISM OF ACTION

I. Hormones that bind to intracellular receptors

1. Androgens
2. Calcitriol (1,25[OH]2-D3)
3. Estrogens
4. Glucocorticoids
5. Mineralocorticoids
6. Progestins
7. Retinoic acid
8. Thyroid hormones (T3 and T4)
II. HORMONES THAT BIND TO CELL SURFACE

RECEPTOR

A. The second messenger is cAMP
? 2-Adrenergic catecholamines
? -Adrenergic catecholamines
? Adrenocorticotropic hormone (ACTH)
? Antidiuretic hormone (vasopressin)
? Calcitonin
? Human Chorionic gonadotropin, (HCG)
? Corticotropin-releasing hormone
? Follicle-stimulating hormone (FSH)
? Glucagon
? Luteinizing hormone (LH)
? Melanocyte-stimulating hormone (MSH)
? Parathyroid hormone (PTH)
? Somatostatin
? Thyroid-stimulating hormone (TSH
B. The second messenger is cGMP

? Atrial natriuretic factor
? Nitric oxide
C. The second messenger is calcium or

phosphatidylinositols (or both)
? Acetylcholine (muscarinic)
? 1-Adrenergic catecholamines
? Angiotensin II
? Antidiuretic hormone (vasopressin)
? Cholecystokinin
? Gastrin
? Gonadotropin-releasing hormone
? Oxytocin
? Thyrotropin-releasing hormone (TRH
D. The second messenger is a kinase or phosphatase

cascade

? Adiponectin
? Chorionic somatomammotropin
? Epidermal growth factor (EGF)
? Erythropoietin (EPO)
? Fibroblast growth factor (FGF)
? Growth hormone (GH)
? Insulin
? Insulin-like growth factors I and II
? Leptin
? Nerve growth factor (NGF)
? Platelet-derived growth factor
? Prolactin


HORMONES

STIMULUS
PROPERTY

GROUP I

GROUPII

1.HORMONES

Adrenal steroids, thyroid Hypothalamic

hormones,

hormones, sex hormones, pituitary

hormones,

calcitriol ,retinoids

pancreatic

hormones,

Adrenal hormones

2.Chemical nature

Steroids,

iodothyronines, Peptides & polypeptides,

retinoids

proteins,

glycoproteins,

Catecholamines

3.Solubility

Hydrophobic,

Water Hydrophilic Water soluble

insoluble

4.Transport Protein

Required

Not required

5.Receptors location

Cytoplasm and nucleus

Cell membrane

6.Mediators of action

Hormone

-Receptors cAMP

Complex

cGMP
Ca ++
Phosphoinositides,

kinase Cascade etc.
SUBCLASSIFICATION OF GROUP II.A HORMONES

Hormones That Stimulate Hormones

That

Inhibit

Adenylyl Cyclase (HS)

Adenylyl Cyclase (HI)



ACTH

Acetylcholine

ADH

2-Adrenergics

-Adrenergics

Angiotensin II

Calcitonin

Somatostatin

CRH



Glucagon



TSH


This post was last modified on 30 November 2021