BIOL 122 Chapter 18 The Endocrine System
BIOL 122 Chapter 18 The Endocrine System BIOL 122
Popular in Human Anatomy & Physiology II
Popular in Biology
This 6 page Class Notes was uploaded by Bridget Notetaker on Thursday February 4, 2016. The Class Notes belongs to BIOL 122 at University of Southern Indiana taught by Dr. Pilcher in Spring 2016. Since its upload, it has received 21 views. For similar materials see Human Anatomy & Physiology II in Biology at University of Southern Indiana.
Reviews for BIOL 122 Chapter 18 The Endocrine System
Eugh...this class is soo hard! I'm so glad that you'll be posting notes for this class
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/04/16
Chapter 18: The Endocrine System Thursday, January 28, 20112:38 AM Anatomy of the pituitary Infundibulum -‐stalk of pituitary Pituitary gland in sella turcica Another name for pituitary gland is hypophysis Posterior pituitary (neurohypophysis) Nervous tissue Anterior lobe (adenohypophysis) Glandular tissue Hypothalamic -‐pituitary relationship Hypothalamus connects with anterior pituitary via two capillary beds Anterior pituitary Hypothalamohypophysial portal system Capillary networks and hypophysial portal vessels Portal system: two capillary beds Posterior pituitary: Hypothalamophypophysial tract Posterio-rpituitary hormones Posterior pituitary secretes neurohormones produced in hypothalamus and stored in axon terminals within posterior pituitary -‐Stimuli within the nervous system cause hypothalamic neurons to either increase or decrease their action potential frequency -‐Action potentials are conducted by axons of the hypothalamic neurons through the hypothalamohypophysial tract to the posterior pituitary -‐In the posterior pituitary gland, action potentials cause the release of neurohormones from axon terminals into the circulatory system -‐the neurohormones pass through the circulatory system and influence the activity of their target tissues Oxytocin Target: smooth muscle of uterus (uterine contraction), breast tissue (mammary gland smooth muscle cells) Functions: role in labor and milk let down Antidiuretic hormone (ADH) Reduces amount of urine you produce Target: kidney tubules Function: regulates amount of water released in urine (mammary gland smooth muscle cells) Functions: role in labor and milk let down Antidiuretic hormone (ADH) Reduces amount of urine you produce Target: kidney tubules Function: regulates amount of water released in urine Target: blood vessels Function: influences blood pressure by changing degree of constriction of blood vessels Hyposecretion -‐-‐> diabetes insipidus Increased urinary output because of not enough ADH Less ADH -‐-‐> reduced "ant-‐i" effect on urine production = more urine made Effects: high urine output (diabetes insipidus), thirst due to water loss, influence on blood pressure Hypersecretion -‐-‐> "syndrome of inappropriate ADH secretion" (SIADH) Too much ADH -‐> greater "ant-‐i" effect on urine production = less urine made Effects: fluid retenti-‐-‐> brain edema, influence on blood pressure Anterior pituitary hormones Tropins (tropic hormones) TSH-‐thyroid stimulating hormone ACTH-‐adrenocorticotropic hormone FSH-‐follicle stimulating hormone Other (nontropic) hormones GH-‐growth hormone PRL-‐prolactin Growth hormone (GH) (somatotropin) Target: body cells Actions geared toward growth Increased proteins synthesis (necessary for growth) Increased lipolysis (conserves glucose) Action via insulin: like growth factors (somatotomedins) Increased amino acid upt-e> increased protein synthesis Increased bone and cartilage growth Secretion regulated by Growth hormone -‐releasing hormone (GHRH from hypothalamus) Growth hormone -‐inhibiting hormone (somatostatin) (GHIH from hypothalamus) Hypersecretion of GH Gigantism Acromegaly Hyposecretion of GH Pituitary dwarfism hypothalamus) Hypersecretion of GH Gigantism Acromegaly Hyposecretion of GH Pituitary dwarfism Prolactin (PRL) Target: mammary glands Actions: milk production Regulation: Prolactin -‐inhibiting hormone (PIH) (dopamine) from hypothalamus Prolactin -‐releasing hormone (PRH) from hypothalamus Thyroid-‐stimulating hormone (TSH) (thyrotropin) Target: thyroid gland Actions for TSH: Normal development of thyroid Production and secretion of thyroid hormones (T3 and T4), from thyroid Regulation: thyrotropin -‐releasing hormone (TRH from the hypothalamus Adrenocorticotropic hormone (ACTH) Corticotropin Target: adrenal cortex Actions: Causes release of corticosteroids from adrenal cortex Glucocorticoids such as cortisol Mineralocorticoids such as aldosterone Gonadocorticoids (androgens) Regulation: corticotropin -‐releasing hormone (CRH from hypothalamus) Gonadotropins Follicl-‐stimulating hormone (FSH) Luteinizing hormone (LH) Target: gonads Actions: gamete (sperm, egg) production, stimulates production of sex hormones (estrogen, progesterone, testosterone) Regulation: gonadotropin-‐releasing hormone (GnRH from hypothalamus) Thyroid gland Thyroid hormone (TH) Triiodothyronine (T3) and thyroxine (T4) (tetraiodothyronine) Precursor (thyroglobulin) produced by follicular cells and stored in colloid Active form is T3 Most is secreted as T4 and converted to T3 at the target cells Transported bound to thyrnbinding globulin Triiodothyronine (T3) and thyroxine (T4) (tetraiodothyronine) Precursor (thyroglobulin) produced by follicular cells and stored in colloid Active form is T3 Most is secreted as T4 and converted to T3 at the target cells Transported bound to thyrnbinding globulin Target: most cells of the body Actions: basal metabolic rate, body temperature, blood pressure, tissue growth and development Regulation: TRH from hypothalamus TSH from anterior pituitary gland Negative feedback: TH inhibits TRH and TSH secretion Imbalances: Hypothyroidism Hyperthyroidism Goiter Enlarged thyroid gland Calcitonin From parafollicular cells Stimulus for release: elevated blood calcium levels Actions: inhibits osteoclasts, stimulates calcium uptake into bone matrix Parathyroid glands Parathyroid hormone (PTH) Action: Regulation of blood calcium levels Stimulus for release: decreased blood calcium levels PTH effects Stimulates osteoclasts in bone Increases calcium reabsorption (conservation) by kidneys Increases calcium absorption from intestines Adrenal glands Adrenal medulla Adrenal cortex Adrenal cortex Mineralocorticoids: Aldosterone Actions Control of sodium and potassium handling by kidney Sodium and water retained (reabsorbed) Potassium excreted/secreted Indirect influence on blood pressure Control of secretion High blood potassium levels Low blood volume or BP (via reninangiotension system) Sodium and water retained (reabsorbed) Potassium excreted/secreted Indirect influence on blood pressure Control of secretion High blood potassium levels Low blood volume or BP (via reninangiotension system) Glucocorticoids: Cortisol Actions Energy metabolism (glucose, proteins, amino acids, fats) Role in stress response Suppression of immune system; ainfammatory effects Control of secretion ACTH (with negative feedback by cortisol) Gonadocorticoids: androgen Actions Converted to testosterone Minimal role in reproductive system (amounts are small relative to gonadal hormones) Hair distribution Sex drive Post-‐menopausal estrogen Control not well understood Stimulation by ACTH, but questionable negative feedback Adrenal medulla Catecholamines: norepinephrine, epinephrine Stimulus for release: sympathetic nervous system (preganglionic fibers) Target cells: those within adrenergic receptors Action/response: figh -tr-‐flight response Pancreas Pancreatic islets: endocrine portion of pancreas Alpha and beta cells Pancreatic islets Glucagon (from alpha cells) Stimulus for release: Drop in blood glucose Neural: sympathetic nervous system Action: increase in blood glucose Target organ is primarily the liver Glycogenolysis Gluconeogenisis Release of glucose from liver Insulin (from beta cells) Stimulus for release Increase blood sugar Gluconeogenisis Release of glucose from liver Insulin (from beta cells) Stimulus for release Increase blood sugar Parasympathetic nervous stimulation Action Lowers blood glucose Stimulates glucose entry into cells Inhibits gluconeogenisis and glycoenolysis Stimulates glycogenisis and fat storage Amino acid and fatty acid uptake (used for protein synthesis and fat storage) Imbalances Hypoglycemia Hypersecretion of insulin (hyperinsulinemia) Diabetes mellitus Hypoactivity or hyposecretion of insulin Hyperglycemia Polyuria, polydipsia, polyphagia Type 1 Type 2 Other endocrine glands Gonads Estrogen, progesterone Testosterone Pineal gland Melatonin Thymus gland Thymopoietins, thymulin, thymosins
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'