THE PITUITARY GLAND

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THE PITUITARY GLAND

• Jaclyn Monaco
• Kristina Vukaj

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The Pituitary Gland Is In Your Brain It is also
known as the Hypophysis!
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The Pituitary Gland Is

• the size of a pea!
• behind the bridge of the nose, between the optic
  nerves.
• found in a bony hollow beneath the base of the
  brain, in the sella turcica, and beneath the
  hypothalamus.
• divided into two major lobes, the anterior lobe
  and the posterior lobe.

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Chemical ActivityLets Talk Hormones
ANTERIOR LOBE
1. Growth hormone
2. Luteinizing hormone
3. Adrenocorticotrophic hormone
4. Prolactin
5. Follicle stimulating hormone
6. Thyroid stimulating hormone
The different lobes of the pituitary gland
produce entirely different hormones. The hormones
have an impact on all of the other glands of the
body.
POSTERIOR LOBE
1. Oxytocin
2. Anti-diuretic hormone
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What do these hormones regulate?

• Growth
• Breast milk production
• Contractions during birth
• Water retention/removal by the kidneys
• Egg production by the ovaries
• Stress hormone production by the adrenal glands
• Activity of the thyroid gland

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Facts about hormones

• All anterior pituitary hormones are proteins,
  that act through secondary messenger systems and
  are regulated, in most cases, by negative
  feedback.
• The prolactin and growth hormones exert their
  major effects on nonendocrine targets.
• The remaining four are tropic hormones which
  stimulate their endocrine gland targets to
  secrete their hormones, which in effect will
  stimulate other body organs and tissues.
• THIS IS WHY THE PITUITARY GLAND IS THE MASTER
  GLAND!!!

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Molecular Make-Up

• Anterior Lobe GLANDULAR TISSUE
• Types of cells
• 1) acidophils
• 2) basophils
• 3) chromophobes
• Posterior Lobe NERVOUS TISSUE

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Functions of the Pituitary Gland (and its
hormones!)

• The major function of the pituitary gland is to
  secrete hormones.
• HOWEVER, the activity of these hormones is whats
  important because they affect multiple other
  parts of the body.

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Anterior Lobe Hormone Functions

• Gonadotropic Hormones
• Regulate the hormonal activity of the gonads
  (ovaries and testes).
• Follicle Stimulating Hormone (FSH)
• Stimulates follicle development in ovaries in
  women. As they mature, they produce estrogen.
• Stimulates sperm development by the testes in
  men.
• Luteinizing Hormone (LH)
• Triggers ovulation of an egg from the ovary in
  women.
• Stimulates testosterone prudction by the
  interstitial cells of testes in men.

• Growth Hormone (GH)
• Effects growth of skeletal muscles and long
  bones.
• Causes amino acids to be built into proteins and
  stimulates target cells to grow and divide.
• Causes fat to be broken down and used for energy.
• Helps to maintain blood sugar homeostasis.
• Prolactin (PRL)
• Stimulates and maintains milk production by the
  mothers breasts after childbirth.
• Adrenocorticotropic Hormone (ACTH)
• Regulates endocrine activity of adrenal cortex.
• Thyroid Stimulating Hormone (AKA thyrotropic
  hormone) (TH)
• Influences growth and activity of thyroid gland.

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Posterior Lobe Hormone Functions

• Oxytocin
• Released in significant amounts during childbirth
  and nursing in women.
• Stimulates powerful contractions of the uterine
  muscle.
• Causes milk ejection (let-down reflex) during
  nursing.
• Anti-diuretic Hormone (ADH) (diuresis urine
  production)
• Inhibits or prevents urine production.
• Causes kidneys to reabsorb more water from urine.
• Urine volume decreases blood volume increases.
• Increases blood pressure (in large amounts).

• The posterior lobe does not create its own
  hormones. These two hormones are formed by the
  hypothalamus.
• The posterior lobe acts as a storage area for
  these hormones.

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Pituitary Gland MASTER GLAND

• Pituitary-Hypothalamus Relationship
• Pituitary gland controls activity of many other
  endocrine glands
• Its removal or destruction would cause the
  adrenal glands and thyroid glands and gonads
  atrophy
• Release of hormones is controlled by the
  releasing and inhibiting of hormones produced by
  the hypothalamus.
• The hypothalamus releases these regulatory
  hormones into the blood of a portal circulation
  (two capillary beds connected by veins) which
  connects the blood of the hypothalamus with the
  blood of the anterior pituitary.

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What if something goes wrong?

• Pituitary Tumors
• When the cells that make up the pituitary gland
  grow too much or create small growths.
• Interfere with the normal production and release
  of hormones.
• Common in adults.
• Two types of tumors Secretory Non-Secretory
• Secretory produce too much of a hormone.
• Non-Secretory large size interferes with normal
  functions of the gland.
• The consequences include
• Hypersecretion over-production of any hormone.
• Hyposecretion under-production of hormones
  (usually caused by non-secretory tumor).
• Tumor mass effects as a tumor grows and presses
  against the gland and other parts of the brain,
  head aches, vision problems, or other health
  issues may occur.

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Specifically

• Non-functioning Adenoma
• A non-secretory tumor often associated with head
  injury.
• May cause headaches and vision problems and also
  hyposecretion.
• Symptoms/Effects
• Loss of appetite
• Weight loss/gain
• Fatigue
• Irregular menstrual cycle
• Infertility
• Frequent urination at night
• Joint pains
• Dizziness
• Low blood pressure
• Treatment may include transsphenoidal
  microsurgery through the nasal sinuses, hormone
  replacement, or radiation.

• Cushings Disease
• A secretory tumor associated with the
  hypersecretion of ACTH, causing too much cortisol
  by the adrenals.
• Affects 4,000 people in the U.S. per year.
• Symptoms include
• Muscle weakness
• Purple stretch marks
• Rapid weight gain
• Memory loss
• Menstrual cycle disorders
• Skin changes red cheeks
• Depression
• High blood sugar/pressure
• Treatment personalized, but may include
  medication, surgery, and radiation.

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Molecular Images

• Slides A-C normal pituitary obtained at autopsy.
  
• Slides D-F pituitary adenoma in Cushing disease.

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Pituitary Tumor Images

• Image 1 MRI image showing a large nonfunctioning
  pituitary macroadenoma
• Image 2 illustrated image of pituitary tumor.

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Gigantism and DwarfismYES they are diseases!

• Hyposecretion of GH in childhood pituitary
  dwarfism.
• Although body proportions are fairly normal, the
  person as a whole is a living miniature (Max
  adult height 4ft)
• Hypersecretion of GH in childhood Gigantism
• 8 to 9 ft is usual. Most usually caused by tumors
  of affected gland, which begin to secrete
  hormones like the normal glandular cells do.
• If hypersecretion occurs after long bone growth
  has ended (how can we tell??)
• Acromegaly Facial bones including lower jaw and
  bony ridges under eyebrows and also feet and
  hands, enlarge tremendously.
• Malformed facial features because of thickening
  of soft tissues.
• Today, pharmacological doses of GH are used to
  reverse some of effects of aging. Although it is
  proven to help children with dwarfism grow
  normally, help stop the aging process, and even
  help prevent AIDS patients from dying, when
  abused, GH can be fatal.
• This is what you hear about on the news when all
  the baseball players are taking dangerous
  STEROIDS!

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Dwarfism Gigantism Images
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SOURCES

• http//2.bp.blogspot.com/_8Dln2xkR7y8/SEobigknUcI/
  AAAAAAAAAMc/LrgNcExIywg/s400/mayopituitarygland.
  jpg
• www.enotes.com/nursing-encyclopedia/pituitary-glan
  d
• http//www.webhealth.co.uk/a_to_z_of_health/pituit
  ary.asp
• http//www.suite101.com/content/the-pituitary-glan
  d-a68589
• http//www.encyclopedia.com/topic/pituitary_gland.
  aspx
• http//www.answers.com/topic/pituitary-gland
• http//www.thehormoneshop.com/pituitarygland.htm
• http//www.ajmc.com/media/image/A102_04S424_F2.gif
  
• http//www.hormone.org/Pituitary/overview.cfm
• http//instruction.cvhs.okstate.edu/histology/hist
  ologyreference/hrendo.htm
• ANATOMY TEXTBOOK