Endocrine System - Human Physiology PDF

The Endocrine System Human Physiology Calvin Teahan The Endocrine System  Works alongside of the nervous system to form the control systems of the body.  The nervous system = very fast, direct system to turn on specific glands and muscles throughout the body.  The endocrine sys...

The Endocrine System Human Physiology Calvin Teahan The Endocrine System  Works alongside of the nervous system to form the control systems of the body.  The nervous system = very fast, direct system to turn on specific glands and muscles throughout the body.  The endocrine system = slower acting, widespread, long lasting effects.  Hormones are distributed by glands through the bloodstream The Endocrine System  Endocrinology = study of hormones  Work at a distance rather than mechanically attaching directly  Composed of amino acids The Endocrine System 1. Endocrine: at a distance 2. Paracrine: work closely 3. Autocrine: work at a small distance (small cell) The Endocrine System The Endocrine System  A system of glands that involve the release of hormones.  By regulating the functions of organs in the body, these glands help to maintain the body’s homeostasis  Instrumental in  Regulating metabolism,  Growth and Development,  Puberty,  Tissue function,  Internal environment (temperature, water balance,)  Plays a part in determining mood Function  Information signal system much like the nervous system.  Nervous system uses nerves to conduct information  Endocrine system mainly uses blood vessels as information channels.  Glands located in many regions of the body, e.g. brain  Glands release specific chemical messengers called hormones into the bloodstream Hormones  Distributed through the body via the bloodstream.  Pass through cells or along the plasma membranes of cells until they encounter a receptor for that particular hormone. Hormones can only affect target cells that have the appropriate receptors  Many hormones are classified as tropic hormones: A hormone that is able to trigger the release of another hormone in another gland. Major hormones and systems  Top down organization of endocrine system.  Hypothalamus produces releasing factors that stimulate production of anterior pituitary hormone which act on peripheral endocrine gland to stimulate release of third hormone Hypothalamus  Control Centre  Involved in nervous and endocrine system  Stimulates the pituitary and also releases: Posterior 1. ADH (Fluid Regulation) 2. Oxytocin (Uterus Contraction ) Pituitary Gland Located in the front of the brain Controls  Growth  Other gland functions  Water level in blood  Lactation  Reproduction  Ovulation & menstrual cycle  Reduces sensitivity to pain Pituitary Gland  Master Gland  Other endocrine glands depend on the pituitary to function 1. Thyroid gland: Metabolism 2. Parathyroid: Calcium 3. Adrenal: Fluid balance / Stress 4. Gonads: Sex Hormones Which hormones does the pituitary gland make? The anterior lobe of your pituitary gland makes and releases the following hormones:  Adrenocorticotropic hormone (ACTH or corticotrophin): ACTH plays a role in how your body responds to stress. It stimulates your adrenal glands to produce cortisol (the “stress hormone”), which has many functions, including regulating metabolism, maintaining blood pressure, regulating blood glucose (blood sugar) levels and reducing inflammation, among others.  Follicle-stimulating hormone (FSH): FSH stimulates sperm production in people assigned male at birth. FSH stimulates the ovaries to produce estrogen and plays a role in egg development in people assigned female at birth. This is known as a gonadotrophic hormone.  Thyroid-stimulating hormone (TSH): TSH stimulates your thyroid to produce thyroid hormones that manage your metabolism, energy levels and your nervous system. Which hormones does the pituitary gland make? The anterior lobe of your pituitary gland makes and releases the following hormones:  Growth hormone (GH): In children, growth hormone stimulates growth. In other words, it helps children grow taller. In adults, growth hormone helps maintain healthy muscles and bones and impacts fat distribution. GH also impacts your metabolism (how your body turns the food you eat into energy).  Luteinizing hormone (LH): LH stimulates ovulation in people assigned female at birth and testosterone production in people assigned male at birth. LH is also known as a gonadotrophic hormone because of the role it plays in controlling the function of the ovaries and testes, known as the gonads.  Prolactin: Prolactin stimulates breast milk production (lactation) after giving birth. It can affect fertility and sexual functions in adults. Which hormones does the pituitary gland make? The posterior lobe of your pituitary gland stores and releases the following hormones, but your hypothalamus makes them:  Antidiuretic hormone (ADH, or vasopressin): This hormone regulates the water balance and sodium levels in your body.  Oxytocin: Your hypothalamus makes oxytocin, and your pituitary gland stores and releases it. In people assigned female at birth, oxytocin helps labor to progress during childbirth by sending signals to their uterus to contract. The Pituitary Gland Hypothalamus and Pituitary Gland Endocrine glands  Hypothalamus  Pituitary  Thyroid  Parathyroid  Pancreas  Adrenal  Gonads  The Endocrine system Endocrine Glands Thyroid/Parathyroid Glands The pituitary gland stimulates production of Thyroid Stimulating Hormone (TSH) which stimulated the thyroid gland to make thyroid hormone Located in front of the trachea Controls  Metabolic rate  Bone growth  Development of the brain and  Development of the nervous system Parathyroid (4 glands) Location - Lying on either side of the thyroid  help maintain normal calcium, magnesium and phosphate levels Thyroid/Parathyroid Glands Thyroid Gland Thyroid Gland Adrenal Glands Located on top of the kidneys  Regulates salt & water balance  Stimulates fight or flight response - Adrenaline  Increase in blood pressure and heart rate Adrenal Glands Adrenal Glands Adrenal Glands The cortex produces steroids 1. Cortisol: Stress 2. Aldosterone: Blood volume Medulla produce catecholamines Adrenaline: Fight or Flight Adrenal Glands Pancreas Located just between stomach and small intestine  Insulin secretion is directly controlled by level of blood glucose that passes through pancreas  Regulates blood glucose levels through production of insulin and glucagon The Pancreas Pancreas Gonads  Males: Testes, secrete testosterone, regulates body changes i.e facial hair growth, deepening of voice, muscle growth & strength Gonads  Female: Ovaries secrete estrogen & progesterone, controls sexual features, involved in pregnancy & menstrual cycle. Major endocrine glands Major endocrine glands Major endocrine glands Endocrine System Common diseases of the endocrine system  Type 1 Diabetes  Thyroid disease  Hyperthyroidism, overactive  Hypothyroidism, underactive  Growth  Obesity Diabetes  In this condition, the pancreas makes little or no insulin. Insulin is a hormone the body uses to allow sugar (glucose) to enter cells to produce energy.  Different factors, such as genetics and some viruses, may cause type 1 diabetes. Although type 1 diabetes usually appears during childhood or adolescence, it can develop in adults.  Even after a lot of research, type 1 diabetes has no cure. Treatment is directed toward managing the amount of sugar in the blood using insulin, diet and lifestyle to prevent complications. Diabetes  In this condition, the pancreas makes little or no insulin. Insulin is a hormone the body uses to allow sugar (glucose) to enter cells to produce energy.  Different factors, such as genetics and some viruses, may cause type 1 diabetes. Although type 1 diabetes usually appears during childhood or adolescence, it can develop in adults.  Even after a lot of research, type 1 diabetes has no cure. Treatment is directed toward managing the amount of sugar in the blood using insulin, diet and lifestyle to prevent complications. Diabetes Type 1 diabetes symptoms can appear suddenly and may include:  Feeling more thirsty than usual  Urinating a lot  Bed-wetting in children who have never wet the bed during the night  Feeling very hungry  Losing weight without trying  Feeling irritable or having other mood changes  Feeling tired and weak  Having blurry vision Diabetes The role of insulin  Once a large number of islet cells are destroyed, the body will produce little or no insulin. Insulin is a hormone that comes from a gland behind and below the stomach (pancreas).  The pancreas puts insulin into the bloodstream.  Insulin travels through the body, allowing sugar to enter the cells.  Insulin lowers the amount of sugar in the bloodstream.  As the blood sugar level drops, the pancreas puts less insulin into the bloodstream. Diabetes https:// www.youtube.com/watch? v=Txqe_CAD43c Hyperthyroidism  Hyperthyroidism, also called overactive thyroid, is a condition where your thyroid makes and releases high levels of thyroid hormone.  This condition can make your metabolism speed up. Symptoms of hyperthyroidism include a rapid heartbeat, weight loss, increased appetite and anxiety.  Hyperthyroidism can be treated with antithyroid drugs, radioactive iodine, beta blockers and surgery. Hypothyroidism  Hypothyroidism is a condition where there isn’t enough thyroid hormone in your bloodstream and your metabolism slows down.  Hypothyroidism happens when your thyroid doesn’t create and release enough thyroid hormone into your body. This makes your metabolism slow down, affecting you entire body. Also known as underactive thyroid disease, hypothyroidism is fairly common. A very serious condition, this can cause serious symptoms, including:  A low body temperature.  Anemia.  Heart failure.  Confusion.  Coma. In general, hypothyroidism is a very treatable condition. It can be managed with regular medications and follow-up appointments with your healthcare provider.