Nick Pytel Nate Mohney. What are some of the structures associated with the endocrine system? Pituitary Gland Pineal Gland Thyroid & Parathyroid.

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?