Endocrinology

Objectives

• Understand the basic functions of the endocrine system, including the endocrine glands and the hormones they stimulate or are stimulated by

• Identify the main diseases and disorders caused by any malfunctioning of the endocrine system that relate to the hair removal specialist

• The endocrine system is important to us because it is the system that regulates / stimulates hair growth

• Understanding the endocrine system is key to the requirement of referring a patient to a physician.

• The endocrine system relates to the glands that secrete hormones into the lymph or bloodstream

Hormones

• Substances produced by the endocrine glands which have a regulatory function– Growth– Sexual Development– Digestive System– Metabolism– Overall Health

Glands of the Endocrine System

• There are two types– Exocrine (secrete through a duct)– Endocrine (directly into bloodstream)

Exocrine Glands

• Sebaceous Glands

• Mammary Glands

• Excrete waste material

Endocrine Glands

• Secrete hormones into the bloodstream to either stimulate the target organ or inhibit the organ.

• These hormones can be called chemical messangers

The Brain

• Hypothalamus

• Pituitary Gland– Neurohypophysis (posterior lobe)– Adenohypophysis (anterior lobe)

• Pineal Gland

What’s Important????

• Hypothalamus - The hypothalamus links our endocrine and nervous systems together. The hypothalamus drives the endocrine system.

• Pituitary gland - The pituitary gland receives signals from the hypothalamus. This gland has two lobes, the posterior and anterior lobes. The posterior lobe secretes hormones that are made by the hypothalamus. The anterior lobe produces its own hormones, several of which act on other endocrine glands.

Posterior Lobe

• Secretes two hormones– Oxytocin – stimulates muscles of the uterus to

contract during childbirth and to expel milk during lactation

– ADH (antidiuretic hormone) – causes water retention which concentrates urine

*diabetes insipidus

Anterior Lobe

• “Master Gland”• Produces 7 Hormones

1. ACTH2. TSH3. GH4. MSH5. FSH6. LH7. LTH

ACTH

• Adrenocorticotropic hormone, as its name implies, stimulates the adrenal cortex. More specifically, it stimulates secretion of glucocorticoids such as cortisol, and has little control over secretion of aldosterone, the other major steroid hormone from the adrenal cortex

TSH

• Thyroid Stimulating Hormone– Controls the thyroid gland

GH

• Growth Hormone– Affects skeletal development

MSH

• Melanocyte Stimulating Hormone– Stimulates melanocyte production in the

epidermis

FSH

• Follicle Stimulating Hormone– Affects the ovarian follicles in women and

seminiferous tissue in men

LH

• Luteinizing Hormone– Stimulates ovulation

LTH

• Lactogenic Hormone– Causes mammary glands to produce milk

Thryoid Gland

• The thyroid gland is a soft, butterfly shaped gland that lies wrapped around the windpipe below the Adam's Apple. Its job is to secrete thyroid hormones that help regulate metabolism – in other words, the many chemical processes that keep our bodies ticking over.

• The thyroid gland manufactures two essential hormones – thyroxine (also referred to as T4) and tri-iodothyronine (also referred to as T3)

• There's not much difference between T3 and T4. The numbers refer to the amount of atoms of iodine contained in the hormones. T3 is the more powerful while T4 is released by the thyroid in larger amounts, but is mostly converted to T3 in the liver and kidneys.

• The effect of T3 and T4 is to– increase the basal metabolic rate of almost all the cells in the

body – increase the fat and carbohydrate metabolism – boost protein synthesis – increase heart rate and blood flow to other organs.

Hyperthyroidism

• Hyperthyroidism is when the thyroid becomes overactive and releases too much T3 and T4 into the blood. Another name for it is thyrotoxicosis. A person with too much circulating thyroid hormone finds they are living with a metabolism that is continually 'revved up'. That person notices the following symptoms:– weight loss, despite an increased appetite – nervousness, agitation and anxiety – tiredness – rapid pulse – tremor (shaking) of the hands – sweating and sensitivity to heat – diarrhea.

Goiter• A goiter is a descriptive term rather than an actual

condition. It refers to the enlargement of the thyroid.• Someone with Graves' or Hashimoto's disease may have

a diffuse goiter, which is one that has spread throughout the thyroid gland. A goiter can also be a localized lump or nodule, caused by a single thyroid nodule or a cancer (although cancers are rare in the thyroid). And the term multinodular goiter is used when many lumps have spread throughout the gland.

• Another cause of a diffuse goiter is a shortage of iodine in the diet. Too little iodine means that the thyroid can't make enough thyroid hormone. In response, the hypothalamus and pituitary release TRH and TSH, and as a consequence of stimulation, the size of the gland increases. If the gland still can't make enough thyroid hormone, goiter and hypothyroidism are the result.

Hypothyroidism

• Hypothyroidism is the opposite condition. In hypothyroidism, the thyroid fails to make and release enough T3 and T4 into the bloodstream and the metabolism slows to a crawl. This produces a range of physical and emotional changes, including:– lethargy and tiredness – feeling cold (even on warm days) – difficulty concentrating – unusual weight gain – depression – puffiness of the face – hair loss – dry skin – constipation

• Cretinism - hypothyroidism in children (physical stunting and mental retardation)

• Myxedema – hypothyroidism in adults (sluggishness and/or weight gain)

Parathyroid Glands

• Embedded in the thyroid gland

• Secrete para-thormone or PTH (parathyroid hormone)

• PTH maintains the calcium level in the blood by acting on the bones, intestines and kidneys

Thymus

• Its located in the chest

• Importance: before birth it is major source of lymphocytes

• Involved with the development of immune system cells

Adrenal Glands

• Sit on top of kidneys

• Two Sections– Adrenal Cortex– Adrenal Medulla

Adrenal Cortex

• Produce more than 50 adrenal cortical hormones – STEROIDS– Mineralocorticoids– Glucocorticoids– Sex Steroids

Adrenal Medulla

• Secretes two substances

– Epinephrine– Norepinephrine

Cushings Syndrome

• An excess of cortisol is released.

• Often caused by a tumor on the adrenal cortex.

• Results in muscle weakness, puffy face, obesity, hirtuism, and Diabetes

The Pancreas

• Lies behind the stomach

• Contains Islets of Langerhans– Secrete insulin and glucagons

Insulin lowers blood sugar

Glucagon raises blood sugar

*Diabetes – lack of insulin

The Female Gonads

• The ovaries secrete sex steroids known as estrogen and progesterone

• Females produce androgens as well but in lesser quantities

The Male Gonads

• The hypothalmus releases GnRH which stimulates the pituitary to produce FSH and LH which stimulate their targets in the testes.

• FSH stimulates seminiferous tubules

• LH stimulates Leydig Cells to secrete testosterone

DISCUSSION

• 1. Difference between an exocrine gland and an endocrine gland

• 2. Which gland is known as the master gland?

• 3. Hypothyroidism causes what condition in adults?

• 4. Which two main substances does the adrenal medulla secrete?

• 5. Does FSH cause the hair follicles to produce terminal hair?

Hirsuitism and Hypertrichosis

Learning Objectives

• Identify the basic causes of hirsutism

• Explain the basic causes of hypertrichosis

• Differentiate between the two conditions of hypertrichosis

• Recognize when a condition may signal the need for further medical evaluation

Hypertrichosis

• Excessive hair growth on any part of the body that is abnormal for the age, sex, race and culture of the individual

• This type of hair is usually terminal and is not associated with stimulated male androgens and does not follow male hair growth pattern.

Causes

• Genetic

• Natural Occurrences

• Reactions to medical procedures

• Resulting of some cancer treatments

• Reaction to certain medications

• Severe hypertrichosis is quite rare, almost certainly due to unknown genetic defects, and can result in excessive or animal-like hair on both face and body. Some of these people have been displayed in carnival sideshows with names such as "dog-boy" or the "bearded lady." Fedor Jeftichew, Stephan Bibrowski and Annie Jones are well known examples

Hirsutism

• Terminal hair growth in women that is caused by excessive male androgens in the blood.

• Hair does grow in adult male hair growth pattern.

Causes

• Stimulation of male androgens at puberty

• Drugs affecting the endocrine system, increasing the % of male androgens

• Diseases and disorders of the endocrine system

Hair Growth Diseases, Disorders, and Syndromes

• Acromegaly

• Adrenogenital Syndrome

• Archard-Thiers Syndrome

• Cushings Syndrome

• Stein-Leventhal Syndrome

Acromegaly

• Caused by excessive GH

• In Children it can cause gigantism

• In adults can result in enlarged hands, feet and face, and excessive androgen production resulting in hirsutism

Adrenogenital Syndrome

• aka “virilism”

• Results from a blockage of cortisol at the adrenal cortex resulting in overproduction of androgens causing outward signs of overdevelopment of sex organs, deep voices, and excessive hair growth.

Archard-Thiers Syndrome

• Rare condition

• Combination of Cushings and Adrenogenital Syndrome

Cushings Syndrome

• Chronic excess of adrenocortical androgens or glucocorticoid hormones which raise the blood sugar level resulting in hyperglycemia.

• Physical Signs– “moon face”– Rounded abdomen– Striae– hirsutism

Stein-Leventhal Syndrome

• Now known as Polycystic Ovary Syndrome (PCOS)

• Secrete excess androgens

• Signs : irregular or absent menstruation

• Physical Signs: small breasts, sometimes obesity, and often hirsutism of face, neck, chest, and thighs.

Discussion

• 1. Three causes of hypertrichosis

• 2. Two main causes of hirsutism

• 3. Three common syndromes that cause hirsutism

• 4. What is the more common name for Stein-Leventhal Syndrome?

• 5. List 3 inward and 2 outward signs of PCOS