pineal gland

4. PINEAL GLAND
 Small body attached to the roof of the
3rd ventricle of the brain
 Containing nerves that connect to the
hypothalamus
 10mm long, reddish and surrounded
by capsule
 Becomes atrophy after puberty and
calcified later in life
 Secrete the hormone melatonin

5. Function of Melatonin
 Coordinating circadian rhythm.
 As a timing signal to coordinate events
the light-dark cycle in the environment.
 It increasing secretion of GnRH and sex
hormones.
 Inhibits growth and development of sex
organs before puberty.

6. THYMUS GLAND
 specialized organ of the
immune system
 locate at upper part of
the chest, behind the
breastbone, and is made
up of two lobes that join
in front of the trachea.
 Secretes hormone called
thymosin
 thymus produces and
"educates" T-
lymphocytes (T cells)

7. Function of Thymosin
 Its function is to transform lymphocytes
(white blood cells developed in the bone
marrow) into T-cells (cells developed in
the thymus).
 These cells are then transported to
various lymph glands, where they play
an important part in fighting infections
and disease.