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Immagini e concetti della biologia Sylvia S. Mader Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018
C10 - Hormone signaling Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018
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
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
Hormones Peptide hormones are water-soluble, transported in blood but can not cross the membranes. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018
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
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
Glands and hormones Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018
Glands and hormones Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018
Glands and hormones Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018
Hypothalamus and hypophysis Hypothalamus and hypophysis (pituitary gland) coordinate the endocrine system. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018
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
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
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
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
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
Hormones, metabolism, homeostasis Adrenal glands respond to stress. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018
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
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
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
Pancreas Pancreas regulates the glucose level in the blood. Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018
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