PROBLEMS ASSOCIATED WITH THE PITUITARY
GLANDNick Pytel
Nate Mohney
The Endocrine System
What are some of the structures associated
with the endocrine system?
The Endocrine System What are some of the
structures associated with the endocrine system? Pituitary Gland Pineal Gland Thyroid & Parathyroid
Glands Thymus Adrenal Glands Pancreas Ovaries (females) Testes (males)
The Endocrine System
What is the major function of the
endocrine system?
What is the major function of the endocrine system? To maintain
The Endocrine System
HOMEOSTASIS
The Endocrine System
What are some of the processes regulated by the endocrine system?
What are some of the processes regulated by the endocrine system? Hydration (Post. Pituitary) Metabolism (Thyroid) Electrolyte Levels (Thyroid,
Parathyroid, Adrenal) Blood Sugar Levels (Pancreas,
Adrenal) Fight or Flight Response (Adrenal) Reproduction (Ovary, Testis,
Pituitary) Growth (Pituitary, Thyroid) …and many more
The Endocrine System
The Endocrine System
How does the endocrine system regulate these
processes?
How does the endocrine system regulate these processes? Through chemical signals known as
The Endocrine System
HORMONES
Human Insulin
Human Testosterone
Human Growth Hormone
The Endocrine System
What is known as the “Master Gland?”
Why is it called this?
What is known as the “Master Gland?” The pituitary gland
Why is it called this? It is one of the most proximal endocrine glands to the
brain It’s hormones regulate those of other endocrine glands
The Endocrine System
The Pituitary Gland
Remember that the anterior pituitary gland is highly vascularized contains many epithelial cells that secrete
hormones nerves from the hypothalamus stimulate the
pituitary cells to release their hormones Secretes several different hormones, but the
two we will discuss are Growth Hormone (GH) also known as somatropin Adrenocorticotropic Hormone (ACTH) aka
corticotropin
Human Growth Hormone
Human Growth Hormone (aka somatotropin) Indirectly stimulates the growth of muscle,
bone, and other tissues Acts on the liver, which releases
somatomedins that directly affect: Chondrocytes → Cartilage Formation → Bone
Growth Muscle Cells → Protein Synthesis → Muscle
Growth Fat Cells → LipogenesisTriglyceride
Structure
Human Growth Hormone
Operates byNegative Feedback
SOMATOCRININ(GROWTH HORMONE
RELEASING HORMONE –GHRH)
ANTERIOR PITUITARY
HYPOTHALAMUS
LIVER
GROWTH HORMONE(SOMATOTROPIN)
BONE MUSCLESFAT
SOMATOMEDIN
Adrenocorticotropic Hormone
ACTH stimulates the adrenal cortex to produce corticosteroid hormones including cortisol
CORTICOTROPIN RELEASING
HORMONE (CRH)
ANTERIOR PITUITARY
HYPOTHALAMUS
ADRENO-CORTICOTROPI
C HORMONE(ACTH)
Cortisol
Cortisol is produced by the Suprarenal Glands in response to ACTH secretions It is usually produced in response to stress
fasting, psychological (depression, fear, stress), prolonged exercise, hypoglycemia, and illness
It promotes gluconeogenesis the production of glucose from lipids, glycogen,
and proteins (which are broken down to fatty acids, glucose, and amino acids respectively)
Raise blood glucose levels to replenish depleted supplies
Prolonged secretion causes hyperglycemia
Cancer
The basis of cancer is when structural damage to the DNA sequence of a cell compromises the control of cell growth a division Often requires damage to multiple
genes that regulate cell division The result is the cell proliferates
uncontrollably Causes include random DNA
replication errors as well as damage to the DNA sequence (UV light, X-rays, chemical carcinogens)
The Forms of Cancer
Benign Tumors generally, uncontrolled cell proliferation
begins in this way are limited in growth by the presence of
surrounding tissue are made up of cells that are bound to one
another and do not metastasize
What problems may arise from benign
tumors?
The Forms of Cancer
Pressure A growing mass may put pressure on the
surrounding organs: closing vessels and straining organs
Metastasis The increased rate of division correlates to
an increased rate in DNA replication errors, which may lead to loss of intercellular binding function
Lead to malignant tumors (cancer) Adenomas
Particularly in tissue that secretes regulatory hormones, an increase in the number of cells would lead to an imbalance in hormone secretion.
Pituitary Adenomas
Adenoma – A benign epithelial neoplasm in which the tumor cells form glands or gland-like structures
Types of Pituitary Adenomas Prolactinoma - Most Common - ~43% Non-Secreting - ~30% Growth Hormone Secreting - ~17% ACTH Secreting - ~7% TSH Secreting - ~3% All Others… Rare
GH Oversecretion
Gigantism – Abnormal size or overgrowth of the entire body or any of its parts. Abnormally large stature Proportional Before growth plates close in
long bones
12 year old kid with his mother
GH Oversecretion
Acromegaly – Disorder resulting in progressive enlargement of face, hands, feet and soft tissues. Occurs after growth plates have closed Disproportionate growth
Woman suffering from acromegaly at ages 16, 33, and 52. What changes do you notice?
Living with Acromegaly
Severe Headaches Arthritis and Carpal Tunnel Syndrome Diabetes Mellitus Renal Failure Enlarged Heart and Hear Failure
Shortened life span and diminished quality of life!
What are some potential treatments?
Treatments for AcromegalySurgery –
Transsphenoid
Medication – GH Inhibitors with supplemental GH
Radiation
Possible side effects?
Cushing’s Syndrome
Collection of symptoms derived from long term overexposure to cortisol
Cortisol is a key hormone in the body’s response to stress
Pituitary adenomas are most common cause – Cushing’s Disease 5x more common in women
Symptoms of Cushing’s
Increased central body fat – head, neck, torso
Moon face Skin ulcerations Buffalo hump Immunosuppressed Growth suppression (In
children) Mood changes (Depression) Purple Straie
Diagnosis for Cushing’s
24-Hour Urine Free Cortisol Level Measure of how much cortisol is excreted via
urine in a 24 hour period. Normal range for adults… <100
micrograms/day Positive test can be up to several times higher
What might interfere with the results?
Cushing’s Treatment
If it is caused by a pituitary adenoma then the treatment is very similar to the treatment for acromegaly.
Surgical removal of tumor Irradiation of tumor Medications to inhibit tumor secretions or
limit the effectiveness of the synthesis pathway
But What if There’s Too Little Hormone?
Too little Growth Hormone leads to pituitary dwarfism
Too little ACTH leads to Addison’s disease
Pituitary Dwarfism
Severely stunted growth
Proportional development
Treated with regular hGH injections
If treatment starts early the patient can achieve a near normal stature
Addison’s Disease
Symptoms Fatigue Weight Loss Weakness Dizziness Hyperpigmentation
Treated with hormone replacement therapy.
Fun Fact: Do you know someone famous who had Addison’s?
John F. Kennedy
Questions?