Page 109 - Science Class 08

ENDOCRINE GLANDS v Hormones are secreted directly into blood

It is a gland that secretes a substance (a via capillaries supplying endocrine ssues
hormone) into the bloodstream. The endocrine and no opecial ducts are involved. It is,
glands are “glands of internal secre on”. They therefore, endocrine glands are also called
include the hypothalamus, pituitary gland, ductless glands.
pineal gland, thyroid, parathyroid glands, heart v Endocrine glands release hormones into
(which makes atrial-natriure c pep de), the the bloodstream to reach in par cular body
stomach and intes nes, islets of langerhans in part called target site. The target site
the pancreas, the adrenal glands, the kidney responds to the hormone.

(which makes renin, erythropoie n and v Hormones coordinate ac vi es of the body
calcitriol), fat cells (which make lep n), the and its growth.
testes, the ovarian follicle (estrogens) and the
Endocrine System
corpus luteum in the ovary).
A group of endocrine glands which produce
different types of hormones is called endocrine
Hypothalamus
system. Endocrine system in our body consists
Pituitary gland
Pineal gland 9 number of glands.
Thyroid gland
They are as follows:
Parathyroid
gland
Thymus v Pineal gland v Hypothalamus gland
Pancreas
v Pituitary gland v Thyroid gland
Adrenal
Ovary glands v Parathyroid gland v Pancreas
(in female)
Placenta v Adrenal gland v Testes (male)
(during
Tes cle pregnancy)
(in male) v Ovaries (female)
v Pineal gland : The pineal gland is located
Endocrine Glands in the middle of the brain, in between the

Exocrine Glands two hemispheres.
Exocrine glands are cellular sub-structure Thalamus
organs, in a body that provide a system to Pineal gland

secrete substances out and external to the
body. They are dis nct from the other type of
gland, endocrine, in that exocrine gland
secre ons end up external to the body, while
endocrine secre ons go into the bloodstream. Hypothalamus
Pituitary gland
Exocrine glands secrete their substances
through a ductal system. The pineal gland contains mainly pinealocytes,

Characteris cs of Hormones which are cells that produce the hormone
melatonin and glial cells which are a par cular
v Hormones are secreted by the endocrine
type of brain cells that support neurons (the
glands.
cells that transmit informa on to other cells).

Science-8 109