pituitary gigantism

(noun)

Pituitary gigantism is usually caused by a tumor on the pituitary gland of the brain.

Related Terms

Examples of pituitary gigantism in the following topics:

  • Hormonal Abnormalities and Height

    • Abnormal production of growth hormone due to tumors on the pituitary or other genetic causes can cause pathological changes in growth.
    • When these non-pituitary tumors are surgically removed, GH levels fall and the symptoms of acromegaly improve.
    • This condition of growth hormone excess is rare in children and is referred to as pituitary gigantism because the excessive growth hormone produces excessive growth of bones, and the child can achieve excessive height: from 2.1 to 2.7 m (6'11" to 8'11") in stature by adulthood if left untreated.
    • The distinction between gigantism (occurring in children) and acromegaly (occurring in adults) can be made by the occurrence of the adenoma in relation to the closure of the epiphyses.
    • If elevated growth hormone levels occur before the closure of the epiphyses (i.e. in prepubertal children), then gigantism ensues.

  • Pituitary Gland Disorders

    • The pituitary is a "small, pea-sized gland" located at the base of the brain .
    • Growth hormone (GH) excess is rare in children and is referred to as pituitary gigantism , because the excessive growth hormone produces excessive growth of bones and the child can achieve excessive height; from 2.1 to 2.7 m (6'11" to 8'11") in stature by adulthood if left untreated.
    • The distinction between gigantism (occurring in children) and acromegaly (occurring in adults) can be made by the occurrence of the adenoma in relation to the closure of the epiphyses.
    • If elevated growth hormone levels occur before the closure of the epiphyses (i.e. in prepubertal children), then gigantism ensues.
    • There are multiple ways of treating pituitary adenomas.

  • Hormonal Regulation of Growth

    • Body growth is controlled by growth hormone (GH), produced by the anterior pituitary, and IGF-1, whose production is stimulated by GH.
    • Growth hormone (GH), produced by the anterior portion of the pituitary gland, accelerates the rate of protein synthesis, particularly in skeletal muscle and bones.
    • Underproduction of GH in adults does not appear to cause any abnormalities, but in children it can result in pituitary dwarfism, in which growth is reduced.
    • Pituitary dwarfism is characterized by symmetric body formation.
    • Oversecretion of growth hormone can lead to gigantism in children, causing excessive growth.

  • Control of the Pituitary Gland by the Hypothalamus

    • The pituitary gland consists of the anterior pituitary and the posterior pituitary.
    • The pituitary gland consists of two components: the anterior pituitary and the posterior pituitary, and is functionally linked to the hypothalamus by the pituitary stalk (also named the infundibular stem, or simply the infundibulum).
    • Whilst the pituitary gland is known as the master endocrine gland, both of the lobes are under the control of the hypothalamus: the anterior pituitary receives its signals from the parvocellular neurons, and the posterior pituitary receives its signals from magnocellular neurons.
    • The posterior lobe of the pituitary gland develops as an extension of the hypothalamus.
    • The anterior and posterior lobes of the pituitary (hypophysis) gland are shown.

  • Overview of the Pituitary Gland

    • The pituitary gland, or hypophysis, is an endocrine gland about the size of a pea.
    • The pituitary is functionally connected to the hypothalamus by a small tube called the infundibular stem, or, pituitary stalk.
    • The pituitary gland secretes hormones that regulate homeostasis.
    • The pituitary gland is divided into two parts, the anterior pituitary and the posterior pituitary.
    • In this image, the pituitary gland is referred to by its other name, the hypophysis.

  • The Posterior Pituitary

    • The posterior pituitary secretes two important endocrine hormones—oxytocin and antidiuretic hormone.
    • The posterior pituitary (or neurohypophysis) comprises the posterior lobe of the pituitary gland and is part of the endocrine system.
    • Despite its name, the posterior pituitary gland is not a gland; rather, it is largely a collection of axonal projections from the hypothalamus that terminate behind the anterior pituitary gland.
    • The posterior pituitary is composed of two parts:
    • Identify the location of the posterior pituitary and the hormones associated with it

  • Hypothalamic-Pituitary Axis

    • The hypothalamus, an endocrine organ, regulates the anterior pituitary gland and transports hormones along the posterior pituitary gland.
    • The pituitary has two distinct regions: the anterior pituitary and the posterior pituitary.
    • The anterior pituitary gland, or adenohypophysis, is surrounded by a capillary network that extends from the hypothalamus, down along the infundibulum, and to the anterior pituitary.
    • The posterior pituitary is significantly different in structure from the anterior pituitary.
    • The pituitary gland is located at (a) the base of the brain and is (b) connected to the hypothalamus by the pituitary stalk.

  • The Anterior Pituitary

    • A major organ of the endocrine system, the anterior pituitary (also called the adenohypophysis) is the glandular, anterior lobe of the pituitary gland.
    • The fleshy, glandular anterior pituitary is distinct from the neural composition of the posterior pituitary.
    • The anterior pituitary is composed of multiple parts:
    • Pars distalis: This is the distal part that comprises the majority of the anterior pituitary; it is where most pituitary hormone production occurs.
    • Identify the location and the hormones produced by the anterior pituitary

  • Overview of Endocrine Glands

    • The pituitary gland consists of two major regions, the anterior pituitary gland (adenohypophysis) and the posterior pituitary gland (neurohypophysis).
    • The hypothalamus also controls the glandular secretion of the pituitary gland.
    • These hormones are released into a capillary network that supplies the anterior pituitary.
    • The hormones then diffuse from this secondary plexus into the anterior pituitary, where they initiate the production of specific hormones by the anterior pituitary.
    • Differentiate among the types of endocrine glands (pituitary [posterior pituitary, anterior pituitary], thyroid, parathyroid, adrenal, and pancreas) in the endocrine system

  • Control of Thyroid Hormone Release

    • The production of thyroxine and triiodothyronine is regulated by thyroid-stimulating hormone (TSH) that is released from the anterior pituitary.
    • The production of thyroxine (T4) and triiodothyronine (T3) is primarily regulated by thyroid-stimulating hormone (TSH) that is released from the anterior pituitary gland.
    • Thyroid hormones also provide negative feedback to the hypothalamus and anterior pituitary gland.
    • Thyroid hormones are produced from the thyroid under the influence of thyroid-stimulating hormone (TSH) from the anterior pituitary gland, which is itself under the control of thyroptropin-releasing hormone (TRH) secreted by the hypothalamus.