Endocrine System Endocrine System General Info Works

Endocrine System

Endocrine System—General Info • Works WITH the Nervous system • Main function is to produce hormones— chemical messenger influencing other tissues/organs. • Differs from NS with regard to speed – NS—body will make rapid adjustments to changes – ES—uses chemical messengers (hormones) to affect change. Hormones travel via bloodstream. Generally longer lasting.

Endocrine vs Exocrine glands • Endocrine glands—secrete hormones directly into the blood – anterior pituitary – thyroid – adrenal • Exocrine glands—deliver hormones into the blood via tubes leading from the gland – sweat glands – salivary glands – mammary glands

Major body processes regulated by ES • Reproduction • Growth and development • Maintaining homeostasis of electrolytes, water and nutrients • Regulation of cellular metabolism

Endocrine System—transport hormones… • Hormones travel through the blood and bind to receptor proteins – Steroid hormones (cholesterol derived) • Are lipid soluble and cross the plasma membrane, bind to receptors inside the cell and affect DNA transcription. – Animation – Non-steroid hormones (protein based) • Bind to specific membrane receptors and trigger a signaling cascade inside the target cell which activates necessary enzymes. – Animation…

Target cells and controlling the ES • Hormones travels through the entire body via the blood, but only affect specific target tissues. • The body primarily uses negative feedback loops to determine when to turn on/shut off hormone production. • Other ways the body controls the ES is through the nervous system and biorhythms.

Negative Feedback loops • Works like a thermostat in your house to maintain a constant environment of 68 o. F. – Turns on the furnace to produce heat if the temperature is too cold and off when the desired temp is reached. – Turns on AC to cool the house if temp is too high and shuts it off when back to the desired time. . http: //www. endocrinesurgeon. co. uk/endocrine_conditions/What-is-negative-feedback. html

Homeostasis • Negative feedback loops ensure the body returns to “normal” conditions after stimulus. www. mdmaterials. com 8

Glucose Regulation 10 9 Biology, Campbell. 1987. pg 896

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ENDOCRINE REGULATION A fuzzy balancing act Receive, Reaction, Refine 11

Endocrine Regulation RECEIVE Stimulation – regulation of release /triggered release – "sensory" input • response to substance in the blood (Iodine, glucose) – hormonal regulation • responds to upstream gland regulation (TSH, LH. . . ) – neural regulation • response short term stress 11 12

Endocrine System Regulation • Hypothalamus receives input and reacts to stimulate specific organs to achieve the desired effect. 13

Pituitary Function The MASTER gland • The pituitary gland secretes hormones that regulate other glands in the body and therefore is referred to as the Master Gland. waukesha. uwc. edu 14

Endocrine Regulation REACT Mechanism of Release – Steroids • Lipid soluble - readily enter cells – stimulus leads to biosynthesis – transport in blood assisted by carrier proteins (serum albumin) 14 15

Endocrine Regulation REACT Mechanism of Release – Hormones that are NOT steroids or lipids • Water Soluble – interact with membrane receptors – synthesized, packaged into vesicles via golgi – vesicles migrate to and collect at release site – activated release, exocytosis to dump contents – typically Ca++ sensitive; regulate Ca++ / 14 regulate release 16

Endocrine Regulation Endocrine System Endocrine. System REFINE • Down Regulation-Negative Feedback loop Blood Ca++ levels Decrease stimulates Parathymus + s bit hi in - PH Blood Ca++ levels Increase Bone is degraded 17 15 17

Endocrine Regulation Endocrine System REFINE Removal of hormones • The bulk of hormone is cleared by the liver and kidneys • Only a small fraction is removed by target tissue – protein and amine hormones bind to receptors and are internalized and degraded • action and elimination is usually quicker (minutes) – Steroid and thyroid hormones are degraded after hormonereceptor complex binds to nuclear chromatin • action and elimination are slower (hours-days) 15 18

Endocrine Control • Feedback system for the control of ovulation 16 19 Biology: An Exploration of Life, Mc. Fadden&Keeton. 1995. pg 546

Endocrine Problems Endocrine Disorders Dwarfism Characteristics -Short stature, can be caused by any one of more (proportional) than 200 conditions, most of which are genetic and result in disproportionate body structure. Cause shortage of GH (hypophysial dwarfism) or defective receptor (Laron Syndrome). www. blogsmonroe. com

Endocrine Disorders Gigantism Characteristics. Extreme height (8 -9 ft, proportional structures) Cause. Excessive GH during development Gigantism is extremely rare (only a few hundred known cases total). Cause of excess of GH excess varies but often is linked to 21 Acromegaly www. endotext. org

Endocrine Problems Endocrine Disorders Acromegaly. Characteristics Cause-excess GH in adulthood. joint aches abnormal bone growth thick coarse oily adenoma impaired vision Usually benign skin excessive sweating sleep apnea abnormal menstruation skin odor erectile dysfunction headaches fatigue and weakness decreased libido enlarged lips nose and tongue skin tags www. addamsfamily. com

Endocrine Disorders Hypothyroidisim Characteristics. Cause- Not enough thyroid hormone. Fatigue, weakness, weight gain or resistance to weight loss, course dry hair, Hasimoto’s disease- autoimmune disease dry rough pale skin, hair loss, cold intolerance, muscle cramps and aches, constipation, depression, irritability, Medical treatments- removal, damage or memory loss, abnormal menstruation, pituitary deficiency. decreased libido. thyroid. about. com High TSH with low T 3/T 4. subclinical hypothyroidism 23 www. datiskharrazian. com

Endocrine Disorders –Causes. Hyperthyroidism Characteristics- palpitations, disease Graves’ Disease, autoimmuneheat intolerance, nervousness, insomnia, (antibodies attach to thyroid and over breathlessness, increased stimulate T 3 production) BM, decreased menstruation, fatigue, fast heart rate, trembling, weight loss, muscle weakness, Benign tumor- nodule (few cells) warm moist skin, hair loss, staring gaze. out of regulation pro. corbis. com Low TSH Thyroiditis- temporary swelling high gland (postpartum) – of T 3/T 4 levels 24 www. avondalevet. com

Endocrine Disorders Cushing’s Disease Characteristicscentral body obesity glucose intolerance Hypertension menstrual irregularity “Buffalo hump” Osteoporosis kidney stones excess hair growth emotional liability “moon” face Cause- Excess Cortisol tumor of the lungs, pituitary or adrenal glands 25 www. netterimages. com

ourlatinamerica. blogspot. com Endocrine Disorders Diabetes. Most common Endocrine disorder Consistent elevated blood sugar Characteristics- frequent hunger, thirst, urination, blurred vision, fatigue, weight loss, poor wound healing, dry mouth, dry itchy skin, impotence, recurrent infections. Erratic blood sugar. – normal blood glucose: 80 -120 mg/100 ml, – diabetes: as much as 600 mg/100 ml of blood 26 www. malluworld. org

Endocrine Disorders Diabetes Causes. Type 1 -insulin deficiency Type 2 -insulin resistance hormone disturbance Agromegaly Cushing’s Gestational diabetes- temporary condition caused by pregnancy placenta metabolizes insulin quickly. 27

Endocrine DISORDERS ENDOCRINE Disorders 28

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Endocrine System • Glands and the hormones they produce…you will need to know these for the test. • Study earlier rather than later!

Review of Endocrine System • Quick review of info…

Pituitary • Known as the master gland as it is not only responsible for many hormones, it also acts as a regulator for other glands in the endocrine system.

Pituitary Gland Hormones • ADH (Antidiuretic Hormone) – Responsible for maintaining water balance in your body.

Pituitary Gland Hormones • Oxytocin – Responsible for causing uterine contractions during and after birth.

Pituitary Gland Hormones • GH (Growth Hormone) – Causes growth in humans…big surprise huh?

Pituitary Gland Hormones • TSH (Thyroid Stimulating Hormone) – Influences your thyroid gland

Pituitary Gland Hormones • ACTH (Adrenocorticotropic Hormone) – Regulates the adrenal glands

Pineal Gland

Pineal Gland Hormone • Melatonin – Helps your body adjust to various amounts of daylight

Thyroid Gland • Location: Surrounds windpipe

Thyroid Hormones • Thyroxine – If iodine is present, it will control the metabolism of glucose in the body.

Thyroid Hormones • Calcitonin – Responsible for depositing blood calcium into bones

Parathyroid Glands • Location— attached behind the thyroid – Years ago, they used to remove the parathyroids with the thyroid if the thyroid was damaged. This lead to death in patients…OOPS!

Parathyroid Hormone • PTH (Parathyroid hormone) – Responsible for pulling calcium from bones and depositing it into the bloodstream.

Thymus Gland • Location: Longish gland in the middle of your chest.

Thymus Hormone • Thymosin – Assists the immune system

Adrenal Glands • Location: Located right on top of kidneys

Adrenal hormones • Aldosterone – Maintain blood salts (primarily Na+, K+)

Adrenal hormones • Cortisone: – Kicks in to help body with long term stress.

Adrenal hormones • Epinephrine – Kicks in when body undergoes short term stress – Test-taking, car accident, caught in a lie…etc.

Pancreas • Location: Found right behind the stomach

Pancreas hormones • Insulin – Decreases blood sugar

Pancreas hormones • Glucagon – Increases blood sugar

Ovaries • Small, almond shaped organs on the ends of the fallopian tubes.

Ovary hormones • Estrogen and Progesterone – Responsible for sex characteristics and controlling the menstrual cycle

Testes • Testosterone – Responsible for male secondary sex characteristics

Other structures and the ES • Heart – ANP will increase the Na+ excretion and inhibit smooth muscle contraction

Other structures and the ES • Kidney – Renin will cause vasoconstriction of the blood vessels (increases blood pressure)

Other structures and the ES • G. I. Tract – There are many polypeptide hormones that act on the GI tract. – Most hormones will increase intestine motion and enzyme production

Other structures and the ES • Placenta – HCG: maintains embryo growth in first 90 days gestation

Other structures and the ES • Placenta – Estrogen and Progesterone help maintain uterus health – Lactogenic Growth hormone help with milk production after birth of baby

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