The Endocrine System PDF

The Endocrine System Biomedical Science Coralie Frances GDC Learning Outcomes 1.1.5 Describe relevant and appropriate dental, oral, craniofacial and general anatomy and explain their application to patient management 1.1.6 Describe relevant and appropriate physiology and explain its appli...

The Endocrine System Biomedical Science Coralie Frances GDC Learning Outcomes 1.1.5 Describe relevant and appropriate dental, oral, craniofacial and general anatomy and explain their application to patient management 1.1.6 Describe relevant and appropriate physiology and explain its application to patient management Learning Outcomes At the end of the session the student should have an understanding of the role of the endocrine system By the end of the session students should be able to: Label a diagram of the endocrine system Name the major glands, List the hormones they secrete Describe the different hormone functions Useful References Waugh, A. and Grant, A. (2018) Ross & Wilson Anatomy And Physiology In Health And Illness. 13th ed. Elsevier. Ward, J. and Linden, R. (2017) Physiology At A Glance. 4th ed. Wiley-Blackwell. Assess your knowledge pre lecture What is the role of the endocrine system? Look at the next slide Can you name these endocrine glands? See next slide for answers The role of the endocrine system is homeostasis Maintaining the normal balance of the body’s internal environment How did you do? Rate your knowledge on a score of 1-5 (1 least knowledge; 5 greatest knowledge) Continue with the PPT to refresh your knowledge then answer the same questions again What are your scores now?  Introduction to the endocrine system Video 1 https://youtu.be/NOV0OuYxB7g Homeostasis The endocrine system helps maintain HOMEOSTASIS of the body’s internal environment Along with the autonomic nervous system (ANS) The ANS is concerned with rapid changes The endocrine system is involved in slower changes Homeostasis continued The endocrine system comprises a number of ductless glands The glands secrete hormones directly into the blood Hormones are chemical messengers Endocrine glands Pituitary gland 2 adrenal glands Pancreatic islets Pineal gland Thyroid Gland Thymus 4 parathyroid 2 ovaries glands 2 testes Hormones influence many processes including Growth & Stress response Nutrition Reproduction development Disorders of the endocrine system Disorders are due to too much (hyper). Or too little (hypo) of a hormone E.g. hypoglycaemia, low blood sugar Hyperthyroidism too much thyroxine Disorders will be discussed in a separate face to face lecture in the second term Why study the endocrine system? Oral Clinical manifestations presentation of endocrine diseases Medical Behaviour emergencies Pituitary Gland & hypothalamus Pituitary gland situated in hypophyseal fossa of sphenoid bone below the hypothalamus Attached to hypothalamus by a stalk Together the hypothalamus & pituitary gland work a system called Negative Feedback Regulation Hypothalamus hormones Growth hormone releasing hormone Growth hormone release inhibiting hormone Thyrotrophin releasing hormone Corticotrophin releasing hormone Prolactin releasing hormone Prolactin inhibiting hormone (dopamine, PIH) Luteinising releasing hormone(LHRH) Gonadotrophin releasing hormone GnRH) Video on negative feedback in the endocrine system (13) Negative Feedback Mechanism vs. Positive Feedback Mechanism - Med-Surg - Endocrine | @LevelUpRN - YouTube Hormones secreted by Pituitary gland – Anterior Pituitary 01 Growth Hormone 02 Prolactin 03 Thyroid Stimulating hormone Corticotrophin releasing 04 hormone 05 Gonadotrophins Hormones secreted by Pituitary gland – Posterior Pituitary Oxytocin Antidiuretic hormone Functions of Growth Hormone (GH) Promotes growth of: In children GH is concerned with The skeleton general growth Muscles Connective tissue In adults GH is concerned with maintenance and repair Kidneys Liver Intestines Pancreas Adrenal glands Other Pituitary Gland hormones Thyroid stimulating hormone 01 (TSH) stimulates growth and activity of the thyroid gland 02 Adrenocorticotrophic hormone (ACTH) stimulates activity of adrenal cortex. Increases the output of STEROID hormones especially CORTISOL. 03 Prolactin stimulates LACTATION (milk production) after childbirth. Gonadotrophin hormones Released in response to luteinising hormone releasing hormone (LHRH) from the hypothalamus) Other pituitary gland hormones After puberty the Anterior Pituitary secretes 2 Gonadotrophin (sex hormones) in males and females: Follicle stimulating hormone (FSH) stimulates production of gametes & Luteinising hormone (LH) stimulates the ovaries to produce oestrogen / progesterone and the testes to secrete testosterone. Posterior Pituitary produces 2 hormones Oxytocin Promotes contraction of uterus Works with prolactin to produce breast milk Antidiuretic hormone (Vasopressin) Influences resorption of water by the kidney tubules resulting in concentration of urine Stimulates contraction of the muscular tissues of capillaries and arterioles raising blood pressure Take a break The thyroid gland Thyroid Gland Situated in the neck In front of larynx & trachea Secretes 3 hormones Thyroxine Triiodothyronine Calcitonin Iodine is essential for production of thyroid hormones  Function of Thyroxin and T3 Regulation of: Basal metabolic rate Female reproductive Motility of GI tract cycle & lactation Carbohydrate, protein Nervous & cardiovascular &lipid metabolism (peristalsis) systems (weight) Function of Calcitonin Regulation of blood calcium by reduction of blood calcium Storage of calcium in bones Excretion of calcium by kidneys It opposes the action of parathormone Release is stimulated by an increase in ionised calcium in the blood after a meal Parathyroid glands  4 glands embedded in thyroid gland, 2 per lobe  Produce the hormone parathormone AKA parathyroid hormone  Important in maintenance of plasma calcium level Parathormone Works with calcitonin to regulate blood calcium Parathormone raises blood calcium by influencing: Uptake by small intestine Amount resorbed by kidneys NB if there is not enough calcium in diet PTH can stimulate calcium to be taken from the skeletal system Parathormone & Calcitonin work together To maintain blood calcium level Calcium needed for : Muscle Nerve impulse Blood clotting contraction Transmission Take another break time Adrenal Glands Adrenal Glands Situated atop each kidney 4cm long, 3cm wide Adrenal Glands Consist of 2 parts Cortex – outer part Medulla – inner part Cortex essential to life Adrenal Gland video Video https://www.youtube.com/watch?v=4WJj8IE83oM Adrenal gland function Glucocorticoids (e.g. cortisol) Concerned with glucose metabolism, produced in response to stress Under stress e.g. shock or pain, hypothalamus induces anterior pituitary to release ACTH (adrenocorticotrophic hormone) ACTH causes adrenal cortex to release glucocorticoids Glucocorticoids Combat stress by:  blood sugar by  formation of new sugar amino acids converted to glucose by liver  Lipolysis (Fatty acids & glycerol converted to glucose for energy production) Breakdown of proteins to amino acids Promotion of sodium & water reabsorption from renal tubules Pathological & pharmacological quantities of glucocorticoids Have an anti-inflammatory action Suppress the immune system Suppress the response of tissues to injury Delay wound healing Cortisone is used as a medication What medical conditions might you take cortisone for? Why would this help the condition? What are the unwanted side effects of steroid medication? Aldosterone (a mineralocorticoid) Concerned with Electrolyte balance in the body Helps regulate blood volume and levels of sodium and potassium Stimulates reabsorption of sodium and water and the amount of potassium which is excreted Aldosterone is secreted when there are low blood sodium levels or when blood potassium increases Adrenal Medulla Produces 2 hormones adrenaline (epinephrine) & noradrenaline (Norepinephrine) Adrenaline concerned with fight or flight response What happens when you have a fright? Insert picture Effects of Adrenaline  metabolic rate  heart rate & blood pressure Dilates blood vessels of muscles, heart and brain Dilates pupils Dilates bronchioles Converts glycogen to glucose Constricts blood vessels in the skin Function of Noradrenaline Maintenance of blood Vasoconstriction pressure (except coronary arteries) Pause before moving onto the pancreatic islets Take a break time! Pancreatic Islets Hormones secreted by pancreatic islets Insulin and Glucagon are concerned with homeostasis of blood glucose levels Somatostatin inhibits the secretion of insulin and glucagon Insulin Glucagon Somatostatin  Pancreatic Islets Clusters of cells within pancreas Insulin Produce hormones – Glucagon Function of Insulin Regulation of blood glucose and other absorbed nutrients Insulin reduces blood glucose levels by: Stimulating uptake and use of glucose by muscle and connective tissue cells Insulin promotes the storage of glucose by increasing conversion of glucose to glycogen especially in the liver and skeletal muscles Function of Glucagon Glucagon increases blood glucose levels by:- Conversion of glycogen to glucose Gluconeogenesis (formation of new sugars from e.g. protein) Glucagon is secreted in response to a low blood glucose level. Hormones secreted by the ovaries and testis Hormones Hormones by secreted by ovaries testis Hormones produced by ovaries Oestrogen & progesterone Function Regulation of menstrual cycle Bring about sexual maturity Section through uterus The role of oestrogen Video www.youtube.com/watch?v=2_owp8kNMus Testes Produce Spermatozoa & the hormone Testosterone Testosterone & luteinising hormone (from antpituitary) Bring about sexual maturity in men Secondary sexual characteristics Regulation and effects of male hormone Video www.youtube.com/watch?v=Sr4recOxmNc Thymus Gland Situated in the chest behind the sternum, the thymus gland secretes the hormone THYMOSIN Thymosin THYMOSIN is needed for the development of T-lymphocytes for cell- mediated immunity THYMOSIN is actually responsible for the growth and maturation of the thymus and other lymph tissue As we reach adulthood and get older production of thymosin declines. The effectiveness of T-lymphocytes also declines Pineal Gland About 10 mm long Produces hormone MELATONIN Secretion suppressed by daylight Melatonin - function Co-ordination of circadian & daily rhythms(24 hour cycles) possibly influencing the hypothalamus. Inhibits the development of ovaries and testes before puberty. Prevents production /release of gonadotrophins before puberty. After puberty it begins to shrink and is often calcified by later life.  The End Of the beginning…. Video : endocrine system part 2 https://www.youtube.com/watch?v=K1y36Atqi-Y Test your knowledge – fill in the gaps P------- Gland situated below the hypothalamus T------ Gland is a butterfly shaped gland 4 p---------- glands embedded in the T------ Gland 2 adrenal glands lie one on each k----- The p--------- islets regulate blood sugar In the female there are 2 o------ Testes in the male secrete the hormone t----------- Pineal gland secretes m-------- Th----s gland plays an important part in i-------