The pituitary gland, located at the base of the brain, is responsible for regulating hormone production throughout the body. It produces several important hormones that stimulate other endocrine glands. Pituitary tumors can cause the overproduction of hormones if they are secretory in nature. Non-secretory tumors can also cause issues by pressing on surrounding structures. Symptoms of pituitary tumors include changes in vision, headaches, and altered hormone levels that impact metabolism, growth, and other bodily functions. Most pituitary tumors are non-cancerous and treatment aims to remove the tumor and restore normal hormone balance.

1. Running head: THE PITUITARY GLAND AND PITUITARY TUMORS 1
The Pituitary Gland and Pituitary Tumors
Michelle Stahl
Colorado Technical University
Biology Anatomy and Physiology
144 section 04
Professor Albina
February 22, 2012

2. THE PITUITARY GLAND AND PITUITARY TUMORS 2
The Pituitary Gland and Pituitary Tumors
The pituitary gland is a small bean shaped organ located in the center or base of the brain
and is attached to the hypothalamus by the pituitary stalk (David, Jackie, & Lewis, 2010, p. 492).
It is roughly the size of a pea, and has two regions anterior and posterior. It is the anterior portion
that releases the majority of hormones that then stimulate other endocrine glands in the body.
Hormones are released into the blood stream in response to nerve impulses from the
hypothalamus. There is a blood capillary system in the hypothalamus that carries the secretions
into the blood stream so that the hormones can reach their target organs. For this reason the
pituitary gland is also referred to as the master gland for its role in stimulating hormone
production throughout the body.
(APrevealed Version 3.0,
2011) the pituitary gland in a cadaver, highlighted in purple.

3. THE PITUITARY GLAND AND PITUITARY TUMORS 3
The anterior lobe produces growth hormone, Thyroid-stimulating hormone,
adrenocorticotropic hormone, Follicle-stimulating hormone, luteinizing hormone, and Prolactin.
Growth hormone stimulates the cells to enlarge and divide. During childhood this hormone
stimulates the growth plates in our long bones to produce more cells. As these new cells push the
older cells out, the old cells ossify and become bone. Over time our bones grow longer causing
us to become taller. This process gradually stops after puberty, though growth hormone will
continue to be produced when the hypothalamus senses low blood glucose. Growth hormone also
aids in proteins synthesis and helps our bodies to use fat for energy. Once our growth plates fuse
and become bone they can no longer grow longer. Instead growth hormone begins regulating fat
metabolism.
Thyroid-stimulating hormone controls hormone production from the thyroid which
regulates metabolism. Adrenocorticotropic hormone stimulates the adrenal glands to produce
hormones essential to managing stress. Follicle - stimulating hormone and luteinizing hormone
regulate the reproductive cycles in men and women by stimulating the ovaries or testes to
produce production of the sexual gametes. Finally Prolactin stimulates breast milk production to
enable nursing after child birth.
When a tumor is present in the pituitary gland it can cause an over production of pituitary
hormones. The tumor can be hormone secreting which is called a secretory tumor (The Hormone
Foundation, 2012, para. 13) or non-secretory tumor. Even non-secretory tumors can cause
problems by pressing upon functional sections of the pituitary, or on the optic chiasm, carotid
arteries, or nerves that control eye movements. Pressure on such structures can cause over
production of certain hormones, or cause vision problems, and headaches. An over production of
growth hormone in an adult with result in acromegaly. Since the growth plates of the bones are

4. THE PITUITARY GLAND AND PITUITARY TUMORS 4
sealed the skeleton will grow wherever it can. This means the soft tissues will grow instead, and
the bones will thicken. The hands and feet will become larger, as will the lower jaw, forehead,
and nose (David et al., 2010, p. 497). Untreated the growth will not stop and a person’s physical
appearance will be altered dramatically. Over time this can cause problems with how the body
functions. A larger tongue for example, can cause trouble breathing by obstructing the air ways.
A tumor that presses on the optic nerves can impair vision. This can happen when
pressure on the nerves impairs impulses sent by the nervous system. Obstruction of the artery
leading from the hypothalamus can cause headaches. Other hormone imbalances can also appear
and harm the body’s natural functions. Too much thyroid-stimulating hormone can cause
problems with metabolism; too much adrenocorticotropic hormone can cause the organs to be
under constant stress. Removal and treatment of the tumor is necessary so the body remains
healthy. Most tumors are non-cancerous; it is rare for a cancerous tumor to occur in the pituitary
(The Hormone Foundation, 2012, para. 10).

5. THE PITUITARY GLAND AND PITUITARY TUMORS 5
References
Anatomy & Physiology Revealed 3.0 (Version 3.0) [Computer software]. (2011). Retrieved from
http://www.mhhe.com/sem/apr3/
David, S., Jackie, B., & Lewis, R. (2010). Hole’s Human Anatomy & Physiology (12 ed.). New
York, NY: McGraw-Hill.
The Hormone Foundation. (2012). Pituitary Disorders Overview. Retrieved from
http://www.hormone.org/Pituitary/overview.cfm