Endocrine

بسم الله الرحمن الرحيم

IN THE NAME OF GOD, THE BENEFICENT, THE MERCIFUL

ENDOCRINE SYSTEM

PROF.DR. HUDA AL-KHATEEB
Lec. 2

OBJECTIVES

To study embryology, histology and ultrastructure of the pituitary gland.
Also to through light on its functions.

Pituitary gland (Hypophysis)

It weighs 0.5gm in male
It is slightly heavier in non-
Pregnant
much heavier in pregnant women


Pituitary gland (Hypophysis)

It is enclosed in the sella turcica of the sphenoid bone

(sella turcica is an important radiological land mark).

Pituitary gland (Hypophysis)

double embryonic origin
oral ectoderm –
"Rathke's pouch".
adenohypophysis.
developing nervous system –
neurohypophysis.

Pituitary gland (Hypophysis)

Adenohypophysis – subdivided into:
Pars distalis (Anterior lobe)
Pars tuberalis ( Cranial part)
Pars intermedia (Intermediate lobe)
Neurohypophysis – subdivided into:
Pars nervosa (Posterior lobe)
Stalk (Infundibulum)

Pituitary gland (Hypophysis)

Pars distalis (Ant. Lobe):

Chromophobes (50%)

Chromophils (50%)
Acidophils (40%)
Basophils (10%)

Pituitary gland (Hypophysis)

Acidophils – subgrouped into:
Somatotrophs
growth hormone
Mammotrophs
Prolactin
luteotrophic hormone

Pituitary gland (Hypophysis)

Basophils
Gonadotrophs
Follicular – stimulating hormone (FSH)
Leuteinizing hormone (LH)
Interstitial cell – stimulating hormone (ICSH)
Thyrotrophs
Thyroid stimulating hormone (TSH)

Pituitary gland (Hypophysis)

Corticotrophs
adreno-cortico-trophic hormone (ACTH).

β-lipotropin hormone

(β-LPH),
α-melanocyte-stimulating hormone (α-MSH)
β-endorphins


Pituitary gland (Hypophysis)

Pars Intermedia:

α-melanocyte-stimulating
hormone (α-MSH)

Pituitary gland (Hypophysis)

Pars Tuberalis:
gonadotropins (FSH & LH).

Pituitary gland (Hypophysis)

Neurohypophysis: composed of:
Pars nervosa (posterior lobe)
Infundibulum

"hypothalamo-

hypophyseal tract”


Herring bodies

Pituitary gland (Hypophysis)

paraventricular nuclei
Oxytocin

Supraoptic nuclei

Vasopressin
ADH

Pituitary gland (Hypophysis)

Blood supply

Hypothalamic hypophyseal portal system:

SUMMARY

Thank you