Unit 9_ Endocrine System PDF

PRAYER BEFORE CLASS Holy Spirit, Divine Creator, true source of light and fountain of wisdom! Pour forth your brilliance upon my dense intellect, dissipate the darkness which covers me, that of sin and of ignorance. Grant me a penetrating mind to understand, a retentive memory, method and ease of le...

PRAYER BEFORE CLASS Holy Spirit, Divine Creator, true source of light and fountain of wisdom! Pour forth your brilliance upon my dense intellect, dissipate the darkness which covers me, that of sin and of ignorance. Grant me a penetrating mind to understand, a retentive memory, method and ease of learning, the lucidity to comprehend, and abundant grace in expressing myself. Guide the beginning of my work, direct its progress and bring it to successful completion. This I ask through Jesus Christ, true God, and true man, living and reigning with You and the Father, forever and ever. Amen.  UST General Santos School of Health Sciences Unit 9: The Endocrine ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGY System Course Content Endocrine System Physiology ○ Principles of Chemical Communication ○ Characteristics of Hormones ○ Functions of Hormones Endocrine glands and hormones Diseases of the Endocrine System relevant to the Philippines Diagnostic Tests for Endocrine Disorders relevant to Medical Technologists Unit Intended Learning Outcomes: At the end of the unit, the student must be able to: describe the general functions of the endocrine system integrate an understanding of its physiology with the pathophysiology of common diseases and conditions affecting this system Formative Assessment 1. What is a chemical messenger that is secreted into the blood, travels to a target tissue, and produces a coordinated set of events? Formative Assessment 1. What is a chemical messenger that is secreted into the blood, travels to a target tissue, and produces a coordinated set of events? 2. List down three (3) endocrine glands. Formative Assessment 1. What is a chemical messenger that is secreted into the blood, travels to a target tissue, and produces a coordinated set of events? 2. List down three (3) endocrine glands. 3. Give three (3) examples of hormones and their function/s. Overview of Endocrine System Composed of glands and specialized endocrine cells that secrete chemical messengers (hormones) into the plasma of the blood homeostasis  ENDOCRINE EXOCRINE endo – within exo – outside krino – to secrete krino – to secrete Hormones diffuse into the blood to be transported to their target tissues (or Have ducts that carry their secretions effectors) to the outside of the body, or into a hollow organ (such as the stomach or Examples: All hormones such as growth hormone, intestines) thyroid hormone, oxytocin, estrogen, etc Examples: Salivary gland → saliva Sweat glands → sweat Characteristics of Hormones Characteristics of Hormones STABILITY Hormone concentrations are stable in the bloodstream half-life Characteristics of Hormones STABILITY COMMUNICATION Hormone Hormones must be concentrations are able to interact stable in the with their target bloodstream tissue in a specific manner to activate a coordinated set half-life of events Characteristics of Hormones STABILITY COMMUNICATION DISTRIBUTION Hormone Hormones must be Many factors concentrations are able to interact affecting stable in the with their target distribution and bloodstream tissue in a specific transport of manner to activate hormones to their a coordinated set targets half-life of events Hydrolytic enzymes Solubility Binding proteins Chemical Nature of Hormones Water-soluble Free hormones Dissolve directly into the plasma Short half-lives → rapidly broken down by hydrolytic enzymes Lipid-soluble Travel in the bloodstream bound to binding proteins Chemical Nature of Hormones Water-soluble Free hormones Dissolve directly into the plasma Short half-lives → rapidly broken down by hydrolytic enzymes Lipid-soluble Travel in the bloodstream bound to binding proteins Control of Hormone Secretion Humoral Neural Hormonal Control by Humoral stimuli Humoral - body fluids, including blood When the blood level of the particular substance changes, the hormone is released in response to the molecule’s concentration Control by Neural stimuli Action potential → neurons release a neurotransmitter → stimulating cells to secrete their hormone Example: Stimuli - stress or exercise Neurons of the Sympathetic division of ANS → adrenal gland → epinephrine and norepinephrine Response - elevated heart rate, increased blood flow to muscles Control by Hormonal stimuli Hormones stimulate secretion of other hormones Example: tropic hormones Regulation of Hormone Levels Negative feedback Positive feedback Negative Feedback Hormone’s secretion is inhibited by the hormone itself once blood levels have reached a certain point AND there is adequate hormone to activate the target cell Self-limiting system Positive Feedback When stimulated by a tropic hormone, promote further synthesis and secretion of the tropic hormone Stimulates even more secretion of the original hormone Self-propagating system Endocrine Glands and hormones  🧐🤔 What endocrine glands do you know of? Endocrine Glands & their Hormones Pituitary Gland Pancreas ○ Anterior Pituitary → Growth hormone, ○ Alpha cells → glucagon ACTH, LH, TSH, etc ○ Beta cells → insulin ○ Posterior Pituitary → Antidiuretic ○ Delta cells → somatostatin hormone, Oxytocin Reproductive system Thyroid Gland ○ Ovaries →progesterone, estrogen ○ Thyroid hormones: Triiodothyronine ○ Testes → testosterone (T3), Tetraiodothyronine (T4), calcitonin Pineal gland Parathyroid gland ○ Melatonin ○ Parathyroid hormone (PTH) ○ Arginine vasotocin Adrenal glands ○ Medulla → Epinephrine, norepinephrine ○ Cortex → aldosterone, cortisol, androgens  Functions of the Endocrine System Regulation of metabolism Changes in heart rate and Control of food intake and blood pressure digestion Control of blood glucose and Modulation of tissue other nutrients development Control of reproductive Regulation of ion levels functions Control of water balance Stimulation of uterine contractions and milk release Modulation of immune system function Pituitary Gland Anterior Pituitary Posterior Pituitary Pituitary gland Connected to the base of the brain 2 lobes: ○ Posterior PG or neurohypophysis ○ Anterior PG or adenohypophysis Pituitary gland & Hypothalamus Pituitary gland ○ 9 major hormones ○ Regulate numerous body functions & secretory activity of other endocrine glands Hypothalamus ○ Regulates secretory activity of the pituitary gland in response to stimuli (other hormones, sensory info, and emotions) Posterior pituitary gland Neurohypophysis : ○ continuous with the hypothalamus in the brain Neurohormones Storage location for two (2) neurohormones Hypothalamohypophysial tract Posterior pituitary gland: ADH ADH = Antidiuretic Hormone = vasopressin ○ Water-conservation hormone ○ Prevents output of large amounts of urine ○ Constricts blood vessels and raises BP Given these functions, what do you think is the target tissue? _______ Posterior pituitary gland: Oxytocin Stimulates labor by stimulating smooth muscle contraction in the uterus Milk letdown by promoting contraction of cells surrounding the milk ducts in the mammary glands Given these functions, what do you think are the target tissues? ______, _______ glands Anterior pituitary gland: Growth Hormone GH = growth hormone = somatotropin Stimulates growth in most tissues Impt role in determining how tall a person becomes Activates the use of lipids to promote growth and protein synthesis, increases glucose synthesis by liver Daily peak levels of GH correlated with deep sleep Target tissue: most tissues What will happen if there are disruptions in GH secretion? Hypersecretion of GH Gigantism: Chronic hypersecretion of GH before epiphyseal plates have ossified Acromegaly: elevated GH levels but the epiphyseal plates have ossified; no height increase BUT increased diameter of hands, feet Hyposecretion of GH Pituitary dwarfism: insufficient amounts of GH → delay bone growth → short stature Anterior pituitary gland: Prolactin PRL = prolactin = somatotropin Milk production of lactating females Given this function, what do you think is the target tissue? _______ glands Anterior pituitary gland: TSH TSH = Thyroid stimulating hormone = thyrotropin Stimulates synthesis and secretion of thyroid hormones from the thyroid gland Given this function, what do you think is the target tissue? _______ gland Anterior pituitary gland: ACTH & others Adrenocorticotropic hormone (ACTH) ○ stimulates secretion of the hormone, cortisol Given this function, what do you think is the target tissue? _______ gland (specifically cortex) Thyroid Gland + Parathyroid gland  What epithelium? Thyroglobulin: precursor to thyroid hormones Thyroid gland: T 3 and T 4 Thyroid follicles → ○ T3 = triiodothyronine ○ T4 = tetraiodothyronine = thyroxine These hormones are essential for normal growth and maturation Increased metabolic rate Increased protein synthesis Target tissue: most cells of the body Thyroid gland: T 3 and T 4 Thyroid follicles → ○ T3 = triiodothyronine ○ T4 = tetraiodothyronine = thyroxine These hormones are essential for normal growth and maturation Increased metabolic rate Increased protein synthesis Target tissue: most cells of the body What will happen if ⬆ thyroid hormones? If ⬇ ?  Effects of T 3 and T 4 Normal function High levels of T3 and T4 Low levels of T3 and T4 Metabolism: Increased up to 60-100% Opposite effect increases rate at which Weight loss Weight gain glucose, lipids, and proteins are metabolized Increase activity of Na+-K+ High body temperature Low body temperature pumps → heat Regulate normal growth and Abnormal nervous system devt, Abnormal nervous system maturation of organs abn growth and maturation devt, abn growth and maturation Hyperthyroidism: Tumors Benign adenoma or cancer Result in either normal or hypersecretion of thyroid hormones Hyperthyroidism: Graves disease Autoimmune disease wherein patients have a TSH-like immunoglobulin (thyroid-stimulating immunoglobulin) in their plasma Clinical manifestations: ○ Goiter (anterior neck mass) ○ Exophthalmos Hypothyroidism: Lack of a thyroid gland Partial or complete surgical removal of the thyroid gland, OR Drug-induced destruction of the thyroid gland as a treatment for Graves disease (hyperthyroidism) Hypothyroidism: Iodine deficiency Causes inadequate T3 and T4 synthesis → elevated TSH secretion Thyroid gland enlarges as a result of TSH stimulation Diagnostic Tests Thyroid Function Tests TSH T3, T4 TSI Thyroid Ultrasound Fine needle aspiration Thyroid gland: Calcitonin Parafollicular cells (C cells) → calcitonin Increased blood Ca2+ → calcitonin → decreased blood Ca2+ Given this function, what do you think is the target tissue? ____ Parathyroid gland: PTH PTH = parathyroid hormone Regulation of calcium levels in the bodily fluids RECALL: what are the target tissues? ____ _______ _____ _________ Adrenal Glands Adrenal glands or Suprarenal glands  Adrenal Glands Adrenal cortex ○ Glomerulosa → aldosterone ○ Fasciculata → cortisol ○ Reticularis → androgens Adrenal medulla ○ Epinephrine ○ Norepinephrine Adrenal Medulla: Epinephrine Epinephrine = Adrenaline Functions: preparation for physical activity ⬆ cardiac output, blood flow to skeletal muscles ⬆ blood glucose levels & glycogen breakdown ⬆ lipid breakdown RECALL: what are the target tissues? _____ _____ _______ _____ Adrenal Cortex: Mineralocorticoids Mineralocorticoids: Aldosterone (greatest amount) Functions: returns BP to its normal range ⬆ rate of sodium reabsorption ⬆ blood levels of sodium What is the target tissue? _______ Higher blood sodium → increased water reabsorption → increased BP Adrenal Cortex: Glucocorticoids Glucocorticoids: Cortisol (primary) Functions: provide energy by stimulating use of lipids and proteins ⬆ blood glucose levels, glycogen deposits in cells Lipid breakdown Stimulate gluconeogenesis (new glucose) Maturation of tissues (ie fetal lungs) ⬇ intensity of inflammatory and immune response Target tissues: peripheral tissues (skeletal muscle, liver, adipose tissue) Immune tissues Adrenal Cortex: Androgens Functions: development of male secondary sex characteristics Note: Some adrenal androgens are converted by peripheral tissues to the potent androgen testosterone, while other adrenal androgens are weak androgens such as androstenedione However, the effects of adrenal androgens in males are negligible, in comparison with testosterone secreted by the testes The Pancreas  Pancreas Pancreatic islets (Islets of Langerhans) ○ Alpha (α) cells → glucagon ○ Beta (β) cells → insulin ○ Delta (δ) cells → somatostatin Target tissues: 1. Liver 2. Adipose tissue 3. Skeletal muscles 4. Satiety center within the hypothalamus - Controls appetite Pancreas: Insulin Primary function: lower blood glucose levels Stimulates glucose transport into body cells Secreted when blood glucose is elevated ○ ie. after a meal Increases ability of target tissue to take up and use glucose ○ If not needed immediately, stored as glycogen Pancreas: Glucagon Primary function: promotes release of glucose from intracellular stores Companion hormone to insulin Secreted when blood glucose levels decline Causes the breakdown of glycogen Increases glucose synthesis in the liver Diabetes Mellitus (T2DM) Genetic basis, unhealthy lifestyle (diet high in calories and sugars, sedentary) involves a gradual failure of cells to respond to insulin and to take up glucose Glucose uptake by cells is very slow → elevated blood glucose after a meal Elevated blood glucose → adipose cells to convert glucose to lipid Diabetes Mellitus (T2DM) Diagnostic tests: Random blood sugar Fasting blood sugar HbA1c Capillary blood glucose Pineal Gland Pineal Gland Secretes hormones that act on the hypothalamus and gonads to inhibit reproductive functions Regulated by photoperiod ○ Dark→ action potentials increase and stimulates secretion of pineal hormones 2 hormones: Melatonin Arginine vasoctocin Pineal Gland MELATONIN ARGININE VASOTOCIN Can decrease secretion of GnRH Works with melatonin to regulate (Gonadotropin Releasing Hormone) function of reproductive system ○ Inhibits reproductive function Regulate sleep cycles by increasing the tendency to sleep Thank you!  UST General Santos School of Health Sciences Unit 9: The Endocrine ANATOMY AND PHYSIOLOGY WITH PATHOPHYSIOLOGY System Dominican Blessing May God the Father bless us May God the Son heal us May God the Holy Spirit enlighten us Give us eyes to see with, ears to hear with, hands to do the work of God with, feet to walk with, and mouth to preach the word of salvation with; And may the angel of peace watch over us, and lead us at last by the Lord’s gift of the kingdom. Amen.