Second year – Group B
Morning classes
A presentation by:
Daban Nasih
Nura Omer
Shadiya Najmaddin
Nawzhin Tofiq
Supervised by:
Mrs. Shukrya Karim
Mrs. Daroon Osman
Nursing Department
Academic Year
2022-2023
Oxytocin &
Prolactin
hormones

Oxytocin
▶ Source of Secretion:
▶ Secreted mainly by paraventricular nucleus and partly
supraoptic nuclei.
▶ T
ransported from hypothalamusto posterior pituitary
through the nerve fibers of hypothalamo-hypophyseal
tract.
▶ In the posterior pituitary, the oxytocin is stored in the
nerve endings of hypothalamo-hypophyseal tract.
▶ When suitable stimuli reach the posterior pituitary from
hypothalamus, oxytocin is released into the blood.
▶ Oxytocin is secreted in both males and females.

▶ Actiononmammaryglands
▶ Causes ejection of milk from the mammary glands.
▶ Oxytocin causes contraction of the myoepithelial
cellsand flow of milk from alveoli of mammary
glands to the exterior through duct system and
nipple.
▶ The process by which the milk is ejected from alveoli
of mammary glands iscalled milk ejection reflex or
milk letdownreflex.
▶ It isone of the neuro-endocrine reflexes.

▶ ActiononUterus:
▶ Oxytocin actson:
1
. Pregnant uterus
2. Non-pregnant uterus.

⦁ On pregnant uterus:
▶ Throughout the period of pregnancy, oxytocin
secretion isinhibited by estrogen and progesterone.
▶ At the end of pregnancy, the secretion of these two
hormones decreases suddenly and the secretion of
oxytocin increases.
▶ Oxytocin causes contraction of uterus and helps in the
expulsion of fetus.
▶ Itis also an example of neuro-endocrine reflex and
positive feedback mechanism

▶ Onnon-pregnantutreus:
▶Action of oxytocin on non-pregnant uterus is to
facilitate the transport of sperms through female
genital tract up to the fallopian tube, by producing
the uterine contraction during sexual intercourse.

Prolactin
⯈Human prolactin is a single- chain polypeptide of
199 amino acids. It has a molecular weight of 23
kDa.
⯈ Prolactinis synthetizedin and secretedfrom
specializedcellsof the anterior pituitary gland, the
lactotrophcells.
⯈ Thepituitary gland(also calledasthe master
gland)is an endocrinegland about the size of apea
(weighing0.5 g)and locatedat the baseof the
brain(just belowthe hypothalamus).

FUNCTION
⯈Prolactinis responsibleof:
 Primarily, initiating and sustaininglactation and
 Stimulation of breastdevelopment alongwith Estrogen during pregnancy.

Prolactinsecretioniscausedby;
• Prolactin releasinghormone (PRH)
• Estrogen (during stimulates lactotropes to secrete prolactin)
• Oxytocin (causes muscle contractions to expel milk)
• Vasoactiveintestinal peptide(VIP)
• Thyrotropin releasinghormone (TRH)
• Breast feeding
• Stress
• Sleep
• Dopamine antagonists (eg., antipsychotic drugs)
• Chest wall trauma

Hypoprolactinemia
⯈ Hypoprolactinemia - decreased prolactin hormone secretion by the anterior pituitary
gland.
⯈ Commoncausesof Hypoprolactinemia:
 Sheehan’ssyndrome
 Hypopituitarism
 Excessdopamine
 Autoimmunedisease
 Growth hormonedeficiency
 Head injury
 Infection
⯈ Symptoms:
 Ovarian diseases,delayedpuberty and infertility.
 Impotenceand abnormal spermatogenesis.

Hyperprolactinemia
⯈Hyperprolactinemia– increasedprolactin hormonesecretionbythe anterior pituitary
gland.
⯈ Commoncausesof Hyperprolactinemia:
 Stress
 Medications (e.g,Antipsychoticdrugs)
 Primaryhypothyroidism
 Pituitary glandtumour
 Prolactinoma
⯈ Symptoms:
• Oligomenorrhoea
• Amenorrhoea
• Galactorrhoea
• Infertility
• Hirsutism
• Osteoporosis

DIAGNOSIS
⯈Diagnosis:
• History(medication,oligomenorrhoea,hirsutism)
• Physical examination(Galactorrhoea)
• Laboratory
 Pregnancytest
 Prolactin
 Macroprolactin
 TSH, FreeT4
 U& Es
 Tes, LH andFSH
• MRI scan(Prolactinaemia)
• Visualfieldtests (optic nerve)

• HyperProlactinaemia:dopamineagonists
(e.g., Bromocryptine orCabergoline)
• Surgeryremovaland/or radiationtherapy
(largepituitary tumours)
• Thyroidabnormalities:thyroid hormone
replacement (e.g., levothyroxine)
• Ovarianinsufficiency:hormonaltherapy
(e.g., Estrogen andprogestins)
TREATMENT