Exocrine Glands-Endocrine Glands
Exocrine Glands-Endocrine Glands
Exocrine Glands-Endocrine Glands
Human body has two types of glands based on the presence of ducts-
1. Hypothalmus
2. Pituitary Gland
3. Pineal Gland
4. Thymus
5. Thyroid
6. Parathyroid
7. Adrenal Glands
8. Pancreas
9. Testes
10. Ovaries
Pituitary gland
Anterior
pituitary –pars
anterior
Intermediate
lobe or pars
intermedia
Posterior
pituitary-
neurohypophysi
s or pars
nervosa
Pituitary is connected to
the hypothalamus by a
stalk called
INFUNDIBULUM.
It is connected by the
hypothalamo-
hypophysial portal
system and axons of
hypothalamic neurons.
1. Thyroid stimulating
Hormone (TSH) or
Thyrotropin
2. Adrenocorticotropic
Hormone (ACTH)
3. Follicle stimulating
hormone (FSH)
4. Lutenizing hormone
(LH) –In Females,
5. Interstitial Cell
Stimulating Hormone
(ICSH)- In Males.
6. Somatotrophic
Hormone or
Somatotrophin or
Growth Hormone
1. Prolactin or Lactogenic
or Luteotropic
hormone.
Posterior pituitary
Posterior pituitary is an extension of the hypothalamus connected by
nerve fibers.
It does not secrete any hormone, it stores and releases the hormones
secreted by the hypothalamus.
The hormones released by posterior pituitary are-
1. Anti-diuretic hormone or vasopressin.
It stimulates re-absorption of water from the kidneys and increases
blood pressure by acting as a vasoconstrictor.
2. Oxytocin or pitocin.
It stimulates contraction of uterine muscles during child birth and milk
ejection from mammary glands.
How are the hormone levels regulated?
Feedback mechanism
The endocrine hormones are regulated by feedback mechanism.
The hormones released by the target gland regulates its further
production. This effect may be positive or negative.
In positive feedback the endproduct stimulates the secretion of the
releasing factor.
In negative feedback the endproduct inhibits the secretion of the
releasing factors.
The feedback mechanism can be-
By hormones- when the increase or decrease in the target gland
hormone acts as inhibitor or stimulator respectively.
By metabolites- the blood metabolite level control the hormone
release.
By nervous control- Adrenal medulla hormones are controlled by the
sympathetic nervous sytem.
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