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2. Immagini e concetti della biologia Sylvia S. Mader
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

3. C10 - Hormone signaling
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

4. The endocrine system
The nervous and endocrine systems work together to control and stimulate the activity of the other systems.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

5. The endocrine system
The endocrine system utilizes chemical signals (hormones).
Hormones act more slowly but are longer lasting than neurotransmitters as they travel in the bloodstream.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

6. Hormones
Peptide hormones are water-soluble, transported in blood but can not cross the membranes.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

7. Hormones
Steroids are lipid-soluble and must be bound to carrier proteins to be transported in blood vessels.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

8. Glands and hormones
The endocrine system consists of endocrine glands that secrete a great variety of hormones.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

9. Glands and hormones
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

10. Glands and hormones
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

11. Glands and hormones
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

12. Hypothalamus and hypophysis
Hypothalamus and hypophysis (pituitary gland) coordinate the endocrine system.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

13. Hypothalamus and hypophysis
The hypothalamus is a part of the nervous and endocrine system and stimulates the pituitary glands secretion.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

14. Hypothalamus and hypophysis
The hypothalamus produces the hormones released by the posterior pituitary:
ADH causes the reabsorption of water by the kidneys.
Oxytocin stimulates the uterus to contract during childbirth and promotes milk letdown while nursing.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

15. Hypothalamus and hypophysis
The hypothalamus produces hypothalamic-releasing and hypothalamic-inhibiting hormones that control the anterior pituitary.
The anterior pituitary gland produces non-tropic and tropic hormones.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

16. Hypothalamus and hypophysis
Non tropic hormones include prolactin (PRL), growth hormone (GH) and melanocyte-stimulating hormone (MSH).
Tropic hormones are thyroid-stimulating hormones (TSH), adrenocorticotropic hormone (ACTH) and the gonadotropic hormones (FSH and LH).
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

17. Negative feedback mechanisms
The hypothalamus stimulates the anterior pituitary to release hormones, which stimulate the target gland to release a third hormone.
Hormone 3 feeds back to control the hypothalamus and anterior pituitary.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

18. Hormones, metabolism, homeostasis
Adrenal glands respond to stress.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

19. Hormones, metabolism, homeostasis
The adrenal medulla releases epinephrine and norepinephrine, which have a short-term effect.
The adrenal cortex secretes hormones that provide long-term responses to stress (sex hormones, glucocorticoids and mineralocorticoids).
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

20. Thyroid
The thyroid and the parathyroid regulate the blood calcium levels.
Calcitonin is secreted by the thyroid and causes blood calcium levels to decrease.
Parathyroid hormone (PHT) reduces the blood phosphate levels and increases the blood calcium levels.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

21. Adrenal and thyroid disfunctions
Cushing syndrome is caused by a disfunction of the adrenal cortex and is characterized by a tendency toward diabetes mellitus, subcutaneous fat accumulation in the trunk and a moon-shape face.
The thyroid regulates development and increases the metabolic rate.
Hypothyroidism is the cause of cretinism and simple goiter.
Hyperthyroidism can lead to exophthalmic goiter, characterized by an enlarged thyroid and protruding eyes.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

22. Pancreas Pancreas regulates the glucose level in the blood.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

23. Epiphysis
Epiphysis (or pineal gland), located in the brain, is involved in biorhythms. The hormone melatonin is produced primarily at night and is involved in the daily sleep-wake cycle.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018