The pituitary gland or hypophysis is called the 'master gland' because it is so important in the functions of many body organs and functions. As a result malfunctions of this gland due to tumors and other disorders can cause severe symptoms and disease.
Symptoms of Disorders in the Pituitary Gland
Often called the "Master Gland" for its role in orchestrating the function of many organs of the body, the pituitary is a small, pea-sized organ at the base of the brain. It is also called the hypophysis and is located in a bony cavity called the pituitary fossa, below the hypothalamus and the optic nerve to the eye.
The Function of the Pituitary
This important endocrine gland sends chemicals into the bloodstream that influence the thyroid gland, adrenal glands and the gonads, the ovaries and the testes. The pituitary gland produces, stores, and secretes chemicals which regulate homeostasis in the body and stimulate other endocrine glands to produce hormones such as thyroid hormone, cortisol, estrogen, and testosterone. These hormones are vital in regulating homeostasis in the body and have effects on metabolism, fluid and temperature regulation, blood pressure, reproduction, and other functions. Additionally, the pituitary gland produces growth hormone which is important for normal development, the hormone oxytocin to induce uterine contractions during childbirth, and the hormone prolactin which is needed to stimulate lactation after childbirth.
The pituitary is composed of two lobes, the anterior pituitary or adenohypophysis and the posterior pituitary or neurohypophysis, which produce and store different hormones. Both lobes are controlled by the hypothalamus and are physically connected to it by the pituitary stalk.
Tumors and Disorders of the Pituitary
The pituitary gland controls a wide variety of vital body functions, hence there are varying symptoms of a malfunctioning pituitary gland. These symptoms depend on the type of disorder and malfunction as well as the age at which they occur.
Pituitary tumors are one of the most common types of brain tumors particularly in young and middle aged adults. One in ten brain tumors are actually pituitary tumors and are sometimes called adenomas. Most of these tumor are benign and though they do not spread beyond the pituitary, they do cause malfunctioning in the gland and drastic symptoms in the body. Pituitary tumors may be either hormone secreting or non-secreting. Most hormone secreting tumors occur in the anterior lobe of the pituitary.
Symptoms of Pituitary Malfunction
Symptoms of pituitary tumors and other malfunctions of this gland result from direct dislodging of cells or pressure from the tumor or by changing hormone levels in the body causing other glands to also malfunction. Symptoms of other secreting tumours will relate to the hormones that are released.
These symptoms include:
- Headache and sight problems (due to pressure from a pituitary tumor on the optic nerve).
- Absence of menstruation and reduced milk production in women with prolactin-secreting tumors. This type of pituitary tumor causes impotence in men.
- Infertility in both men and women.
- Malfunctioning in the posterior pituitary may cause diabetes insipidus which causes excessive thirst and large volumes of urine.
- Growth hormone secreting tumors can cause severe abnormal growth in a disease called giantism or acromegaly. This causes disproportionate enlarging of the hands, feet, lower jaws and brow and may also cause high blood pressure.
- Adrenocorticotropic or ACTH secreting tumors can produce a number of symptoms related to Cushing’s syndrome such as weight gain, facial hair growth, depression, and round or moon face.
- Tumors which secrete thyroid stimulating hormone of TSH disrupt the metabolism of the body.
- Tumors which secrete reproductive hormones such as follicle stimulating hormone or FSH may cause infertility.