ENDOCRINE SYSTEMGlands, Hormones, and intercellular communication

WHAT IS A HORMONE?

Similar, sometimes identical substances that have a similar mechanism of action wherever they’re produced.

WHY ARE HORMONES IMPORTANT?

Regulate Homeostasis Keeps everything

balanced

Regulate function of other body systems i.e. structural/skeletal

Bone formation i.e. digestive system

metabolism i.e. reproductive system

menstrual cycle

HOW DO HORMONES WORK ANYWAY?

Endogenous substance

Made by a cell or gland

Travels to target cells via the bloodstream Enter the cell by

endocytosis or… Binds and initiates a

response

Sonic Hedgehog“faster than the naked eye!”

WHAT ARE SOME CAUSES OF HORMONE IMBALANCE?

Genetic:

Genes may not function Proteins may not be

synthesized correctly Ex. Myostatin Protein Ex. Collagen Production

Dude looks like a lady!

MY, OH MY, OH MYOSTATIN! Protein that inhibits muscle growth

Mighty Mouse!

I’ll have what he’s havin!!!

THE DIFFERENCE BETWEEN THE ENDOCRINE AND EXOCRINE SYSTEM

Gland: Structure that synthesizes a product to be exported from the cells.

Endocrine glands: NO DUCTS!

Exocrine glands: DUCTS!

i.e. sweat, oil for hair/skin Move substances to a body organ or to the

surface

LET’S MEET THE GLANDS THAT MAKE THE MAGIC HAPPEN!

THE PITUITARY GLAND

Posterior: Oxytocin: Uterine Contractions Anti-Diuretic Hormone (ADH)

Controls blood fluid volume Targets the kidneys More water is removed from urine

Anterior: Melanocyte stimulation growth hormone

Growth Hypo= Dwarfism Hyper= GIGANTISM!

A QUICK STORY ABOUT LIFE, LOVE, AND FROG PITUITARY GLANDS!

Xenopus laevis “The African Clawed Frog” Hypophysectomy

THYROID GLAND: G. THYREOS=SHIELD

Affects almost every physiological process in your body

Looks like a butterfly landed on your windpipe

2 lobes connected by isthmus Think “isthmus of Panama!”

THYROID CONTINUED:

Main duties of the thyroid: Regulate cellular metabolism Regulate cellular respiration Rate cells use glucose Rate of glycogen breakdown Maintains 98.6 Regulate growth Stimulate mental processes THE LIST CONTINUES!

THYROID PROBLEMS

Thyroid Cancer Goiter Hypothyroidism

Hypothyroidism: Underproduction of thyroid hormone Leads to Weight Gain

Hyperthyroidism: Overproduction of thyroid hormoneLeads to Weight Loss

INTERMISSION! LET’S RELAX A MINUTE!

ADRENAL GLAND

Located on top of kidneys “Ad”= “renal”= Produces

Epinephrine a.k.a.-

Fight or Flight! What happens when

the fight or flight response is activated?

MOOORTALLL COMMBAAAAAATT!!!TEST YOUR MIGHT!

Eyes:

Lungs:

Bowel:

Blood Vessels:

Saliva:

Skin:

Heart:

Stomach:

Muscles:

TESTES/OVARIES

Testes produce estrogen Ovaries produce testosterone

Both lead to development of secondary sex characteristics

TESTOSTERONE

ESTROGEN

HORMONE MANIPULATION: REPLACEMENT THERAPY

Testosterone High Levels: Men

Increased Sex Drive Increased Muscle Mass

Low Levels: Men

Estrogen High Levels: Women

Decreased Sex Drive Decreased Muscle Mass

Low Levels: Women

Hormone replacement therapy may be used to combat these symptoms! OR . . . .

It can do other stuff!