Endocrine System PDF

Endocrine System Learning Objectives Explore the structure form and function of the Endocrine System Compare the Endocrine and Nervous System Discuss the types of hormones found in the equine body  Explore the structure form and functio...

Endocrine System Learning Objectives Explore the structure form and function of the Endocrine System Compare the Endocrine and Nervous System Discuss the types of hormones found in the equine body  Explore the structure form and function of the endocrine system Endocrine Gland Function & Structure Secrete chemical called hormones. Secrete hormones directly into bloodstream. Have a rich supply of blood. Have no ducts (or tubes) so are termed ductless glands. Hormones - Organises energy usage, water and mineral balance, heart rate, blood pressure, growth, sexual development, reproduction, stress reactions. What are Hormones? Chemical messengers Produced by endocrine glands Travel in the blood Have specific effects on target organs Effective in low concentrations Explore the structure form and function of the endocrine system  Compare the endocrine and nervous system Endocrine vs Nervous Both systems communicate and control together They both: Transmit messages - triggered by a stimulus and producing a response Involve chemicals  Compare the endocrine and nervous system Endocrine vs Nervous They also have differences The endocrine system: Has slower hormonal responses More widespread hormonal responses Longer lasting hormonal responses  Explore the structure form and function of the endocrine system Gland Location There are 12 glands. Produce over 50 hormones. Located in - brain, neck, chest, intestines, thoracolumbar region, gonads.  Location of the Structures Involved Thyroid/Parathyroids Adrenal Thymus Hypothalamus Pituitary Gland Ovaries Pancreas Testes Hypothalamus Work directly with autonomic system to manage specific functions - heart rate, blood pressure, and body temperature. Releases hormones that direct other hormones or other glands to manage the other bodily functions - sleep, mood, muscle and bone growth. Main link between endocrine and nervous systems. Keeps the body balanced and in a stable state - homeostasis Pituitary Gland Located directly below the hypothalamus Regulates growth, metabolism, and reproduction. Production of hormones is stimulated by chemical messages sent from the hypothalamus to the pituitary. Pineal Gland Located within the brain. Receives information about the state of light-dark cycle from the environment. This information is transferred by the production and secretion of the hormone melatonin. Thyroid/Parathyroid Glands Thyroid Gland controls the speed of metabolism (metabolic rate). Secretes thyroxine into the bloodstream. Parathyroid Gland makes parathyroid hormone (PTH). Regulates the amount of calcium, phosphorus, and magnesium in the bones and blood. Adrenal Gland Regulate metabolism, immune system, blood pressure, stress, and behaviour. Produced during fight or flight response. Produces aldosterone which regulates sodium levels, water balance, and blood pressure. Produces gonadocorticoids which aid sperm production in stallions, and affects reproductive behaviour in both sexes. Pancreas Part of the digestive and endocrine systems. Produces enzymes to help digest food - digestive. Makes insulin hormone to help control blood sugar levels - endocrine. Ovaries Part of menstruation and conception. Produce eggs for fertilization. Make the hormones estrogen and progesterone. Testes Two small organs inside the scrotum. Produces sperm and testosterone hormone.  There are many hormones circulating through the body at any one time, but only cells that have the right receptor for that hormone will bind. Hormone Receptors Receptors for a specific hormones may be found on many different cells or they may be limited to specialised cells, e.g. Thyroid hormones creating metabolic activity throughout the body. Cells will respond to a hormone when they have a specific receptor for that hormone. The hormone will bind to the receptor protein, which will result in activation of that hormone and the associated effect on the body.  Discuss the types of hormones found in the equine body Hormone Types Hormones may be: Water-soluble peptides or proteins - e.g. insulin Water-insoluble steroids - e.g. oestrogen, testosterone, progesterone. Amino acid derivatives - e.g. thyroxine, adrenaline Water-Soluble Bind to a receptor protein on the plasma membrane of the cell Receptor stimulation leads to a change in cell activity, which sends feedback to the original hormone-producing cell. e.g Insulin. Water Insoluble Fat soluble molecules made of cholesterol. Testosterone, oestrogen, progesterone. Pass into a cell’s nucleus (through diffusion), bind to receptors, and triggers the cell to make proteins. Amino Acid Derivatives Derived from amino acids (the building blocks of protein). Hormones stored in endocrine cells until they are needed. Act by binding to protein receptors on the outside surface of the cell. The binding alerts a messenger molecule inside the cell that activates enzymes. e.g Adrenaline, thyroxine Homework Research the following endocrine problems/disorders: ➔ Pituitary Pars Intermedia Dysfunction (PPID) aka “Cushing Disease” ➔ Equine metabolic syndrome (EMS) ➔ Insulin resistance (IR) ➔ Hypothyroidism Use the table provided in hand out: description of the problem/disorder, possible causes, symptoms, how it can be managed.I suggest the BHS website a good place to start! Bring this along to next week’s class please :)