In the name of God Anatomy: Endocrine System Moradian MD, MPH, PhD candidate Tehran University of Medical Sciences drmoradian@sums.ac.ir 2013 http://www. emc.marico pa.edu/fac ulty/farabe e/biobk/bio bookendocr.html
Endocrine system Controls many body functions exerts control by releasing special chemical substances into the blood called hormones Hormones affect other endocrine glands or body systems
Exocrine: glands transport their hormones to target tissues via ducts. Endocrine :glands release hormones directly into the blood, which in turn transports the hormones to target
Endocrine System A. Exocrine gland Ducts Lumen and surfaces B. Endocrine gland Chemical messengers Blood stream
Hormone + target = change in cell function
Hormone + Receptor
Chemical messenger Secreted by endocrine gland Specific to target Activate cellular change Of 4 different chemical types Hormones
Endocrine System and Homeostasis
Control of Endocrine Function A. Positive B. or Negative Feedback mechanisms Self-regulating system
A. Positive Feedback Not common Classic example: Action of OXYTOCIN on uterine muscle during birth.
B. Negative Feedback Most common control mechanism Level of hormone in blood or body s return to homeostasis shuts off loop at hypothalamus and pituitary
Endocrine Glands
Hypophys Gland
Anterior Pituitary Hormones HORMONE TARGET FUNCTION Thyroid (TSH) Stimulating Thyroid gland TH synthesis & release Growth (GH) Many tissues growth Adrenocortico- Tropin (ACTH) Adrenal cortex Cortisol release (androgens) Prolactin (Prl) Breast Milk production Follicle (FSH) Gonads Egg/sperm prod. Luteinizing (LH) Gonads Sex hormones
Neurosecretory Cells Specialized neurons Synthesize and secrete hormones Extend from HYPOTHALAMUS to POSTERIOR PITUITARY
Posterior Pituitary Hormones Manufactured in Hypothalamus, released from Post. Pit. Oxytocin Target = smooth ms. Uterus and Breast Function = labor and delivery, milk ejection,(pair bonding) ADH (Vasopressin AVP) Target = kidneys Function = water Reabsorption
What happens with excess GH?
GH as Juvenile
GH as an Adult
Hypersecretion of GH
GH = pituitary dwarfism
Thyroid Gland
لوب راست و چپ و بخش میانی تیروکسین: رشد فعالیت فیزیکی حاالت روحی و تغییرات جنسی درجه حرارت
Parathyroid Glands Secretes parathyroid hormone regulates plasma calcium (osteoclast activity) regulates phosphate levels
Adrenal Gland Adrenal gland located atop kidney Outer part = cortex Secretes Cortisol (stress), Androgens, Aldosterone (electrolytes) Inner part = medulla Secretes EPI & NEPI (fight or flight) SNS control
Hypersecretion of Adrenal Cortex
Cushing s Syndrome?
Pineal gland مغز میانی: ارتباط با مسیر بینایی اثر بر سایر غدد مالتونین: رنگ پوست
Pancreas Located slightly behind the stomach Insulin: reduces blood glucose Facilitates glucose transport into the cells Promotes glycogenesis Inhibits gluconeogensis Glucagon: increases blood glucose
Gonads testes (testosterone) = sex characteristics muscle development and maturity ovaries (estrogen) = sex characteristics maturity and coordination
Breasts غدد عرق تغییر شکل یافته نیپل هاله مجاری شیری
Breasts
Other Secretions
Other Secretions