The Endocrine System

The

Endocrine SystemBy Jonathan Gonzalez, Aaron Mednick, Matt Solórzano,

Grant Zitomer

What Does It Mean?

• Endo: within• Crinis: secrete

Opposed to exocrine system, which excretes substances into external environment such as sweat and saliva

Physiology

• Releasing hormones into bloodstream• Many organs and glands work in tandem• Functions:

o Controlling internal chemical environmento Responding to change in case of emergency

(i.e. infection)o Regulating metabolism and energy balanceo Contributing to growth and development

Important Glands and Organs

• Hypothalamus: part of brain, secretes hormones; controls homeostasis

• Pineal Body/Gland: produces melatonin (helps regulate circadian rhythm [i.e. sleep])

• Pituitary Gland: regulates all endocrine gland functions

• Thyroid Gland: important for regulating metabolism

• Ovaries: produce egg cells, estrogen, and progesterone

Important Glands and Organs, cont'd

• Parathyroid Glands: regulate body calcium balance

• Thymus: trains T-Lymphocytes (WBC)• Adrenal Glands: produce and release

adrenaline & cortisol responding to stress• Kidneys: process blood to filter out waste

products• Pancreas: assists in digestion and

hormone production• Testes: produce testosterone and sperm

Hypothalamus

• Located within the brain near optic chiasm• Secretes hormones which control anterior

pituitary• Controls:

o Water Balanceo Sleepo Temperatureo Appetite o Blood Pressure

Hypothalamus, cont'd

• Releases into the pituitary glando Dopamineo Thyrotropin-releasing hormoneo Corticotropin-releasing hormoneo Gonadotropin-releasing hormoneo Growth hormone-releasing hormoneo Somatostatin

Pituitary Gland

• Not part of the brain, but protrudes off of hypothalamus

• Controls:o Growtho Sex organso Metabolismo Water balanceo Temperature

Pituitary Gland, cont'd

• Prolactino Stimulates mammary glandso Causes sexual arousal

• Thyrotropino Stimulates thyroid

• Growth hormoneo Stimulates development and growth

Pineal Body/Gland

• Located in the brain• Produces melatonin that affects:

o Sleep/wake patterns o Seasonal functions

Thyroid Gland

• Located below the Adam's Apple in the neck

• Controls metabolismo How fast the body reacts to hormoneso Protein production rateo Energy usage speed

Thyroid Gland, cont'd

• Thyroid stimulating hormone (TSH) activates:o Triiodothyronine (T3) which controls

Body temperature Heart rate Growth

o Thyroxine (T4) which controls Rate of protein synthesis Growth Produces ATP from glucose

• These two hormones affect almost all physiological processes in the body

Parathyroid Glands

• Located behind to the thyroid gland• Regulates all calcium in the body

o Calcium is the only mineral that has its own regulatory system.

• Provides electrical energy to muscles and nervous system (via calcium regulation)

• Provides strength to skeletal system

(via calcium regulation)

Parathyroid Glands, cont'd

• Produces Parathormoneo Increases concentration of calcium in bloodo Stimulates osteoclastso Increases calcium reabsorption in kidneys (to the bloodstream)

• Produces Calcitonin o decreases concentration of calcium in bloodo Inhibits osteoclast activity in boneso Increases amount of calcium in urine

Thymus

• Trains T-Lymphocytes (also known as T-Cells)

• Part of immune system as well• Part of endocrine for use of hormones in

training

Adrenal (Suprarenal) Glands

• Located superior to both kidneys• Responsible for releasing hormones in

response to stresso Cortisol: stress and low glucoseo Epinephrine: "fight or flight"

• Produce androgeno Controls and maintains

development of male characteristics in vertebrates(primary androgen is testosterone)

Adrenal Glands, cont'd

• Produce aldosteroneo Increase reabsorption of water in kidneyo Results in increased blood pressure

Kidneys

• A natural "filter" for the endocrine system• Processes the blood to sift out waste

products and extra watero Waste and extra water is excreted as urine

Pancreas

• A dual function organ• Produces several important hormones

o Insulin: lowers blood glucose levelso Glucagon: raises blood glucose levels

• Also secretes digestive enzymes which assist the stomach

Ovaries

• Located in groin area of females• Produces:

o Egg Cells (for reproduction)o Estrogeno Progesterone: the "pregnancy hormone"

Estrogen

• Develops secondary female characteristicso Enlargement of breastso Widening of hipso Growth of pubic hair

• Regulates menstruation

Progesterone

• Effects:o Prepares uterus for implantationo Makes vaginal skin impenetrable to spermo Decreased levels lead to:

Menstruation if not pregnant Labor if pregnant

Testes/Testicles

• Located in groin area of males• Produces:

o Testosterone: develops male reproductive tissues; increases muscle mass

o Sperm: fuse with egg cells during fertilization

Testosterone

• Develops secondary male characteristicso Body hairo Facial hairo Muscle growtho Deepens voiceo Adam's Appleo Sperm creation

Disorders

• Occur due to the increase or decrease of endocrine hormones, which may be caused by:o Problems with endocrine feedbacko Failure of a gland to stimulate another gland

to release its hormoneo Geneticso Infectiono Injury to an endocrine glando Tumor in an endocrine gland

Adrenal Insufficiency

• The adrenal glands do not release enough cortisol and sometimes aldosterone

• Symptoms: o Muscle weakness, loss of appetite, weight

losso Nausea, vomiting, diarrhea, headache,

sweatingo Low blood pressure, low blood glucose

Hyper/Hypothyroidism

• Hyperthyroidismo High heart rateo Tremorso Weight loss

• Hypothyroidismo Low heart rateo Fatigueo Weight gaino Growth stunting

Gigantism and Acromegaly

• Caused by the secretion of excess growth hormone from the pituitary glando Gigantism: during childhoodo Acromegaly: during adulthood

• Usually tumors in the glandcause these disorders

Multiple Endocrine Neoplasia(MEN)

• Rare genetic disorder• Causes tumors which cause

overproduction in affected glands: o Parathyroido Adrenal o Thyroid

Testing for Disorders

• Visit an Endocrinologist: o Conduct urine and blood testso Imagine test pinpoint tumorso Check hormone levels

• Treatmento Difficult because complication with one

hormone balance affects other hormone balances

o Routine blood work to track imbalance

Relationship Between Endocrine System and Other Systems

• Reproductive System - hormones control development of reproductive organ; regulates production of gametes

• Respiration System - hormones regulate breathing rate• Skeletal System - hormones regulate bone growth/

calcium concentration• Muscular System - hormones regulate muscle

metabolism • Excretory System - hormones control water

conservation in kidneys• Immune System - parathyroid regulates calcium levels;

cortisol can be used as an immunosuppressant

To Recap...

• Regulates homeostasis• Is in control of the body's hormones• These hormones tell many things in the

body what to do, from growing to breathing to giving birth

So remember to thank your endocrine system

Works Citedhttp://www.medterms.com/script/main/art.asp?articlekey=3791http://www.britannica.com/EBchecked/topic/118220/circadian-rhythmhttp://www.britannica.com/EBchecked/topic/460967/pineal-glandhttp://www.medterms.com/script/main/art.asp?articlekey=3791http://www.yourhormones.info/hormones/calcitonin.aspxhttp://www.britannica.com/EBchecked/topic/186893/human-endocrine-systemhttp://www.nlm.nih.gov/medlineplus/ency/article/001174.htmhttp://women.webmd.com/guide/understanding-thyroid-problems-basicshttp://www.webmd.com/digestive-disorders/picture-of-the-pancreashttp://www.britannica.com/EBchecked/topic/435788/ovaryhttp://www.nlm.nih.gov/medlineplus/ency/article/002380.htmhttp://www.hormone.org/Pituitary/overview.cfm