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Endocrine and Lymphatic/ Immune Systems. Endocrine System – works with the Nervous System to coordinate and integrate the activity of body cells. Endocrinology. Endo = inside or within Crine = Secrete Ology = study of Hormon – to excite
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Endocrine System – works with the Nervous System to coordinate and integrate the activity of body cells
Endocrinology • Endo = inside or within • Crine = Secrete • Ology = study of • Hormon – to excite • Definition = Study of hormones and how they work in the body • Hormone – a mediator molecule that gets released in one part of the body but regulates the activity of cells in other parts of the body
Functions • Work with Nervous System to coordinate body functions • Maintain homeostasis within the body
Hormone Facts • Two types of glands in the body • Exocrine • Secretes products to outside of body • Endocrine • Ductless glands and make hormones • Secrete products inside the body • Organs • Hypothalamus, thymus, pancreas, ovaries, testes, kidneys, stomach, liver, small intestine, skin, heart, adipose tissue, placenta
Hormone Travels • Circulating Hormones – True Hormones • Affect specific target cells • Stay in the blood stream • Local Hormones - Pseudohormones • Act on neighboring cells • Do not enter the blood stream • Paracrine – act locally, but affect cell types other than those releasing them • Somatostatin – secreted by the pancreas – stops the release of insulin • Autocrine – chemicals that exert their effects on the same cells that secrete them • Prostaglandins - released by smooth muscle cells to make the smooth muscles contract
Chemical Classes of Hormones • Lipid-soluble hormones • Dissolve in fats • Water-soluble hormones • Dissolve in water
Lipid-Soluble Hormones • Steroids • Derived from cholesterol • Cortisol, Estrogen, Testosterone, Aldosterone, Androgens, Calcitriol, Progesterone • Thyroid Hormones • T3 and T4 • Nitric Oxide • Hormone and neurotransmitter
Water-Soluble Hormones • Amines – made by modifying amino acids • Epinephrine and norepinephrine, melatonin, histamine, serotonin • Peptide Hormones – chains of amino acids • Antidiuretic hormone, oxytocin, HGH, Thyroid-stimulating hormone, adrenocorticotropic hormone, FSH, LH, Prolactin, melanocyte-stimulating hormone, insulin, glucagon, somatostatin, parathyroid hormone, calcitonin, gastrin, secretin, cholecystokinin, erythropoietin, leptin • Protein Hormones – more complex chains of amino acids – subtype of peptide hormones • Eicosanoid – derived from a 20-carbon fatty acid • Prostaglandins • Leukotriens
How Hormones work • Lipid-Soluble – diffuse through the lipid bilayer of the plasma membrane and bind to receptors within target cells • Water-Soluble – cannot diffuse through the membrane • Bind to Integral Proteins on the membrane surface
Control of Hormone Secretion • Hormones are secreted in short bursts • Regulated by • Signals from NS • Hypothalamus signals the Pituitary Gland to make and realease hormones • Chemical changes in the blood • Other hormones
Hypothalamus and Pituitary Gland • Hypothalamus is the “Master” of the Pituitary Gland • Major link between the NS and ES • Secretes 9 hormones • Pituitary Gland • Secretes 7 hormones • Two Lobes: Anterior and Posterior • Rests in the Sella Turcica • Hypothalamus and Pituitary Gland are connected by the INFUNDIBULUM
Anterior Pituitary Hormones • Human Growth Hormone (HGH) • Most plentiful Ant. Pituitary Hormone • Gigantism – too much HGH – typically reach 8ft • Pituitary Dwarfism – too little HGH – 4ft. or under, body is properly proportioned • Thyroid-Stimulating Hormone • Stimulates Thyroid gland to make and secrete Thyroid Hormone which has 2 forms: T3 and T4 m • Invtrsdrd nsdsl mrysnoliv tsyr snf nofy hrsy ptofuvyion • Released in response from TRH hormone of the Hypothalamus
Thyroid Problems • Hypothyroidism • Underactive thyroid gland • Adults - Myxedema – low metabolism, cold, constipation, thick/ dry skin, puffy eyes, edema, lethargy and mental sluggishness • If myxedema is from a lack of Iodine, the thyroid gland can enlarge and protrude and become an endemic goiter • Why salt is now IODIZED; Goiter Belt • Infants – Cretinism – mental retardation, disproportionate body size, thick tongue and neck – might be a genetic defect of fetal thyroid or a lack of iodine in mother’s diet • Can be prevented by hormone replacement therapy if diagnosed early enough • Most states test newborns to check for hypothyroidism at birth
Thyroid Problems • Hyperthyroidism – overactive thyroid • Grave’s Disease – believed to be autoimmune because people who have this disease have abnormal antibodies that mimic TSH and will stimulate the release of TH • Increased metabolism, sweating, irregular/ rapid heart beat, nervousness, weight loss • Signs – enlarged thyroid (goiter), exophthalmos • Treatment – Thyroidectomy or treatment with Radioactive Iodine which will destroy most of the active thyroid cells
Parathyroid Hormone • Controls calcium balance within the blood • Hyperparathyroidism • rare, usually happens because of a tumor – Ca gets leached from the bones – bones will soften and deform as their mineral salts are replaced by fibrous CT – high blood Ca can suppress the nervous system and cause kidney stoes
Parathyroid Hormone • Hypoparathyroidism • Usually after some type of parathyroid trauma or removal during thyroid surgery, extended lack of dietary Mg • Hypocalcemia – tetany (loss of sensation, muscle twitches, convulsions) • Untreated – symptoms progress to respiratory paralysis and death • Was how the Parathyroid gland was discovered
Anterior Pituitary Hormones • Follicle-Stimulating Hormone • Hypothalamus – Anterior Pituitary – Testes, Ovaries • Stimulates production of sperm and maturing of follicles (eggs) • Luteinizing Hormone • Controlled by the hypothalamus • Stimulates secretion of estrogen and progesterone and ovulation in females; in males it stimulates the release of testosterone
Anterior Pituitary Hormones • Prolactin • Hypothalamus secretes Releasing and Inhibiting Hormones to control Prolactin • Makes the body recognize a pregnancy • Stimulate milk production in women
Posterior Pituitary Hormones • Oxytocin • Enhances muscle contraction during childbirth • After childbirth – stimulates milk production and delivery of the placenta • Pitocin to induce labor – synthetic verson • Antidiuretic Hormone or Vasopressin • Diabetes Insipidus – excessive urine and intense thirst – results in fluid retention, headache, disorientation
Cushing’s Syndrome • Excessive Cortisol in the blood stream • Persistent hyperglycemia • Loss in muscle and bone protein • Water and salt retention • Swollen “moon” face • Redistribution of fat – buffalo hump • Ease in bruising
Hypoglycemia – low blood glucose • Stimulates the hypothalamus to release GHRH (growth-hormone-relasing-hormone) and GHRH goes to the Anterior Pituitary • Anterior Pituitary is then stimulated to release HGH into the blood stream • HGH – stimulates the release of insulin-like growth factors that speed up the breakdown of liver glycogen into glucose • As a result, blood glucose rises to the normal level (90mg/100mL of blood plasma) • An increase in blood glucose above the normal level inhibits (stops) the release of GHRH NEGATIVE FEEDBACK
Hyperglycemia – abnormally high blood glucose • Stimulates the hypothalamus to secrete GHIH (Growth-hormone-inhibiting-hormone) while inhibiting the release of GHRH • GHIH travels to the Anterior Pituitary and prevents it from releasing Growth Hormone • Low levels of GH in the blood stream and IGFs slows down the breakdown of glycogen in the liver and glucose is released into the bloodstream more SLOWLY • Blood glucose falls to its normal level • A decrease in the blood glucose below the normal level inhibits the release of GHIH NEGATIVE FEEDBACK
Congenital Adrenal Hyperplasia • Genetic disorder in which a person lacks the enzymes needed to make Cortisol • If there is low or no cortisol, another hormone (ACTH) stimulates enlargement of the adrenal glands • Causes Virilism • Females – masculinization – growth of a beard, deep voice, body hair similar to male, growth of clitoris to resemble a penis, loss of breasts • Males – same as females – over-masculinization
Addison’s Disease • Cause – ACTH is blocked from it’s receptors • Symptoms – lethargy, anorexia, nausea, vomiting, weight loss, hypoglycemia, weakness, bronzed appearance to skin • Treatment – hormone replacement and increasing sodium in diet • JFK had this
Diabetes • Diabetes Mellitus(mell = honey sweetened) • Inability to produce insulin • 4th leading cause of death in the US • Causes glucosuria (excessive glucose in the urine) • Key defining symptoms • Polyuria – excessive urine production due to an inability of the kidneys to resabsorb water • Polydipsia – excessive thirst • Polyphagia – excessive eating • Genetic and Environmental components • 2 types – Type I and Type II
Type I Diabetes – Insulin-dependent Diabetes Mellitus • Insulin level is low because the person’s immune system destroys the pancreatic beta cells that make the insulin • People with this must have daily doses of insulin to prevent death • Develops in people younger than age 20 • If not treated properly can lead to blindness and kidney disease
Type II Diabetes – Non-insulin-dependent Diabetes Mellitus • Most common, 90% of all cases of diabetes • Typically found in obese people over age 35 • Can be controlled through diet, exercise and weight loss • Can be temporary • No shortage of insulin, rather the target cells become less sensitive to it
Gestational Diabetes • Occurs in pregnant women who may or may not have had diabetes before the pregnancy • Pregnancy hormones block mom’s insulin receptors from being able to absorb insulin • Glucose can’t get absorbed properly so it is transferred to the baby • Baby grows more than it should – can lead to marcosomia (fat baby) • Concerns for during and after birth • Goes away immediately after giving birth