الفهرس 
Introduction
Embryogenesis of the pituitary glandOnly 14 pages are availabe for public view
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Abstract
The pituitary gland known as the hypophysis is a roundish organ that lies immediately beneath the hypothalamus, resting in a depression of the base of the skull called the sella turcica.
Classification
The anterior pituitary or adenohypophysis is a classical gland composed predominantly of cells that secrete protein hormones.
The posterior pituitary or neurohypophysis is not a separate organ, but an extension of the hypothalamus. It is composed largely of the axons of hypothalamic neurons which extend downward as a large bundle behind the anterior pituitary. It also forms the so-called pituitary stalk, which appears to suspend the anterior gland from the hypothalamus.
Anterior lobe hormones and its disorders
The anterior lobe contains six types of secretory cells, all but one of which are specialized to secrete only one of the anterior lobe hormones. All of them secrete their hormone in response to hormones reaching them from the hypothalamus of the brain.
•Thyroid Stimulating Hormone (TSH)
The secretion of TSH is stimulated by the arrival of thyrotropin releasing hormone (TRH) from the hypothalamus. Inhibited by the arrival of somatostatin from the hypothalamus. TSH stimulates the thyroid gland to secrete its hormone thyroxine (T4). Hypersecretion of T4 called thyrotoxicosis or Graves’ disease. Hypofunction of the gland in infancy caused cretinism but in middle age lead to myxodema.
•Follicle-Stimulating Hormone (FSH)
Synthesis and release of FSH is triggered by the arrival from the hypothalamus of gonadotropin-releasing hormone (GnRH). The effect of FSH depends on sex
FSH in sexually-mature females, FSH (assisted by LH) acts on the follicle to stimulate it to release estrogens.
FSH in sexually-mature males, FSH acts on spermatogonia stimulating (with the aid of testosterone) the production of sperm.
•Luteinizing Hormone (LH)
LH is synthesized within the same pituitary cells as FSH and under the same stimulus (GnRH).
LH in sexually-mature females, a surge of LH triggers the completion of meiosis I of the egg and its release (ovulation) in the middle of the menstrual cycle; stimulates the now-empty follicle to develop into the corpus luteum, which secretes progesterone during the latter half of the menstrual cycle.
LH in males acts on the interstitial cells (also known as Leydig cells) of the testes stimulating them to synthesize and secrete the male sex hormone, testosterone.
•Prolactin (PRL)
During pregnancy it helps in the preparation of the breasts for future milk production.
After birth, prolactin promotes the synthesis of milk.
Prolactin secretion is stimulated by TRH repressed by estrogens and dopamine.
•Growth Hormone (GH)
The GH-secreting cells are stimulated to synthesize and release GH by the arrival of growth hormone releasing hormone (GHRH) from the hypothalamus. GH promotes body growth.
In childhood, hyposecretion of GH produces growth retardation.
Hypersecretion leads to gigantism.
•ACTH — the adrenocorticotropic hormone
ACTH acts on the cells of the adrenal cortex, stimulating them to produce glucocorticoids, e.g. cortisol; mineralocorticoids, e.g.Aldosterone; androgens and male sex hormones, e.g testosterone).
Production of ACTH depends on the intermittent arrival of corticotropin-releasing hormone (CRH) from the hypothalamus.
Hypersecretion of ACTH is a frequent cause of Cushing’s disease. Hyposecretion lead to Addison′s disease.
•Alpha Melanocytes-Stimulating Hormone (α-MSH)
Hypersecretion Alpha MSH Causes skin pigmentation.
Posterior lobe hormones and its disorders
The posterior lobe of the pituitary releases two hormones, both synthesized in the hypothalamus and realsed in the circulation.
• Vasopressin
Vasopressin acts on the collecting ducts of the kidney to facilitate the reabsorption of water into the blood. It acts to reduce the volume of urine formed (antidiuretic hormone).deficiency of vasopressin leads to excessive loss of urine, a condition known as Diabetes insipidus. Hypersecretion lead to Syndrome of inappropriate ADH.
• Oxytocin
It acts on certain smooth musclestimulating contractions of the uterus at the time of birthand stimulating release of milk when the baby begins to suckle.
Oxytocin also enhancesbonding between a mother and her newborn.
Disorders Of Puberty
Puberty isconsidered to be one of the most important peroid as it relates to hormonal changes and multiple physical and psychological changes. signs of puberty usually begin in children males and females at the age of eight or nine , which is linked to greater maturity or bone age than with the age the child’s real and it is also associated with factors genetic and pathological factors .
The first signs of puberty in girls breast growth and it is usually at about the age of ten or eleven, was preceded by the appearance of pubic hair about six months or twelve months, and is usually the time interval between the onset of menstruation and the enlargement of breast two to three years.
As it is for boys, so the first signs of puberty is testicular growth and thinning of the scrotum, and followed by pigmentation of the scrotum and penis growth . Then the appearance of pubic hair armpit hair usually appears in mid- adulthood. The appearance of facial hair, beard or Kalsharb is the first signs of puberty observed. While change is the sound is one of the signs is somewhat late.
One of the disorders of puberty is precocious puberty, which may occur when some of the features defined as the onset of secondary sex before the age of eight years. The natural causes as the reasons are genetic or pathological, such as the occurrence of brain tumors or pituitary gland disorders or any brain injuries or infections meningiomas or ovary diseases in the case of girls or testis diseases in the case of boys.
In case of suspicion in the diagnosis and when you see the complete clinical examination and laboratory tests conducted hormonal specialized according to the age of the child. After conducting the necessary tests and X-rays rely appropriate treatment plan for every cause to be discovered and are usually convert these cases to a specialist doctor as needed constant monitoring to avoid complications.