Chapter 18: Endocrine Glands AP2 Chapter 18 1 Chapter 18 Outline - PowerPoint Presentation

Chapter 18: Endocrine Glands AP2 Chapter 18 1

Chapter 18 Outline Fxns of the Endocrine System Pituitary Gland & Hypothalamus Thyroid Gland Parathyroid Glands Adrenal GlandsPancreasHormonal regulation of nutrients Hormones of the reproductive systemHormones of the pineal bodyHormones of the ThymusHormones of the GI tractHormone-like SubstancesFX of aging on the endocrine system 2 AP2 Chapter 18

Understanding the Endocrine System ES’s regulation of body fxns:Anatomy of each gland & its location Hormones secreted by each gland Target tissues & their responses to the hormone Regulation of those hormones secretionConsequences & causes of hypersecretion/hyposecretion of the hormoneAP2 Chapter 183

I. Fxns of the Endocrine System (ES) AP2 Chapter 18 4

I. Fxns of the Endocrine System Metabolism & tissue maturation Ion regulation Water Balance Immune System regulation Heart rate & BP regulationControl of bld glucose & other nutrientsControl of reproductive fxnsUterine contractions & milk releaseAP2 Chapter 185 Main regulatory fxns of the ES

I. Fxns of the Endocrine System Main regulatory fxns of the ES Metabolism & tissue maturation Regulated rate of metabolism Influences the maturation of tissues (i.e. nervous system) Ion regulationRegulate blood pHNa, K, & Ca [ ] in bloodWater BalanceControlling solute [ ] in the bloodImmune System regulationControlling the prod’n of immune cells Heart rate & BP regulationHelps to prep the body for physical activity Control of bld glucose & other nutrients In the bld Control of reproductive fxns Controls the development & fxns of reproductive system in both males & females Uterine contractions & milk release During childbirth & after birth AP2 Chapter 18 6

II. Pituitary Gland & Hypothalamus AP2 Chapter 18 7

II. Pituitary Gland & Hypothalamus Hypothalamus :Major site where nervous system & ES interact Hypo regulates secretions of the Posterior Pituitary Hormones, sensory information that enters the CNS & emotions in turn influence the activity of the hypothalamusPituitary Gland:Secretes 9 major hormones that regulate numerous body fxns & secretory activities of other glandsDivided into 2 parts:Posterior PituitarySecretions = neurohormonesAnterior Pituitary3 regions:Pars tuberalisPars intermedia Pars distalisHormones from AP are not neurohormones AP2 Chapter 18 8 Figure 18.1 Pg. 610 Pg 611 Figure 18.2

II. Anterior Pituitary & Hypothalamus Anterior Pituitary Hypothalamohypophysial Portal System Extends from the hypothalamus to the AP so that neurohormones produced by the hypothalamus to stimulate or inhibit the cells of the APTHUS the hypothalamus controls the APAP2 Chapter 15: The Special Senses

Thyroid releasing hormone Growth hormone inhibiting hormone Hypothalamus Corticotropin releasing hormone Gonadotropin releasing hormone Prolactin releasing hormone Low Bld Glucose Stress High Bld Glucose Low Thyroid hormone level Anterior Pituitary Growth hormone releasing hormone Anterior Pituitary Anterior Pituitary Anterior Pituitary Anterior Pituitary High Thyroid hormone level Growth Hormone Thyroid Stimulating Hormone Adrenocorticotropic Hormone LH & FSH Prolactin

II. Posterior Pituitary & Hypothalamus Posterior Pituitary Neurohormones released from PP are not made by the PP. These hormones that are stored in the PP are originally made in the hypothalamus. The neurosecretory cells of the hypothalamus have axons that extend to the PP. Neurohomeones are prod’d in these neurosecretory cells and travel via vesicle toward the axon terminal. AT the axon terminal they are stored in secretory vesicles. The axon terminals are buried in the PP. Action potentials cause the release of the neurohormones from the axon terminal so that they can enter the blood stream.AP2 Chapter 15: The Special Senses

Thyroid releasing hormone Growth hormone inhibiting hormone Hypothalamus Posterior Pituitary Corticotropin releasing hormone Gonadotropin releasing hormone Prolactin releasing hormone Low Bld Glucose Stress High Bld Glucose Low Thyroid hormone level Anterior Pituitary Growth hormone releasing hormone Anterior Pituitary Anterior Pituitary Anterior Pituitary Anterior Pituitary High Thyroid hormone level Growth Hormone Thyroid Stimulating Hormone Adrenocorticotropic Hormone LH & FSH Prolactin Antidiuretic hormone Oxytocin

Growth hormone releasing hormone Growth hormone inhibiting hormone Thyroid releasing hormone Corticotropin releasing hormone Gonadotropin releasing hormone Prolactin releasing hormone Hypothalamus Posterior Pituitary Low Bld Glucose Stress High Bld Glucose High Thyroid hormone level Low Thyroid hormone level Anterior Pituitary Anterior Pituitary Anterior Pituitary Anterior Pituitary Anterior Pituitary Growth Hormone Thyroid Stimulating Hormone Adrenocorticotropic Hormone LH & FSH Prolactin Antidiuretic hormone Oxytocin Target: Kidney Target: Uterus & Mammary Glands Response: Increased water reabsorption & less urine prod’n Response: Female: Increased uterine contraction and increased milk expulsion from the mammary glands

II. Anterior Pituitary Gland Hormones are proteins, glycoproteins, or polypeptides labeled Tropic Hormones Transported via the cardiovascular systemHalf life of these hormones is minutesBind to membrane bound receptors on target tissues Most hormones are secreted by their own separate cell types . AP2 Chapter 15: The Special Senses

Growth hormone releasing hormone Growth hormone inhibiting hormone Thyroid releasing hormone Corticotropin releasing hormone Gonadotropin releasing hormone Prolactin releasing hormone Hypothalamus Posterior Pituitary Low Bld Glucose Stress High Bld Glucose High Thyroid hormone level Low Thyroid hormone level Anterior Pituitary Anterior Pituitary Anterior Pituitary Anterior Pituitary Anterior Pituitary Growth Hormone Thyroid Stimulating Hormone Adrenocorticotropic Hormone LH & FSH Prolactin Target Tissue: Most tissues Target Tissue: Thyroid tissue Target Tissue: Adrenal cortex Target Tissue: Gonads Target Tissue: Mammary glands Ovaries Response: Stimulates the growth of most tissues Important in the regulation of nutrient levels Regulation of metabolism Increases movement of AA into the cells Increases lipolysis Increases FA release from Adipocytes Increased glucose synthesis in the liver Response: Stimulates synthesis and secretion of thyroid hormones from the thyroid Response: Increased hormone secretion from the adrenal cortex Response: Stimulate formation of gametes (sperm/egg) Control prod’n of reproductive hormones (Ovaries: estrogen & progesterone) (Testis: testosterone) Response: Female: milk prod’n in mammary glands and ovaries increase progesterone secretion Males: Unknown fxn Antidiuretic hormone Oxytocin Target: Kidney Target: Uterus & Mammary Glands Response: Increased water reabsorption & less urine prod’n Response: Female: Increased uterine contraction and increased milk expulsion from the mammary glands

Growth hormone releasing hormone Growth hormone inhibiting hormone Thyroid releasing hormone Corticotropin releasing hormone Gonadotropin releasing hormone Prolactin releasing hormone Hypothalamus Posterior Pituitary Low Bld Glucose Stress High Bld Glucose High Thyroid hormone level Low Thyroid hormone level Anterior Pituitary Anterior Pituitary Anterior Pituitary Anterior Pituitary Anterior Pituitary Growth Hormone Thyroid Stimulating Hormone Adrenocorticotropic Hormone LH & FSH Prolactin Target Tissue: Most tissues Target Tissue: Thyroid tissue Target Tissue: Adrenal cortex Target Tissue: Gonads Other related substances Lipotropins b -endorphins Melanocyte stimulting hormone Target Tissue: Fat tissue Target Tissue: Brain- rest unknown Target Tissue: Melanocytes Response: Increased fat brkdwn Response: Painkiller in the brain, Inhibition of GnRH Response: Increased melanin prod’n  Darker skin Antidiuretic hormone Oxytocin Target: Kidney Target: Uterus & Mammary Glands

III. Thyroid Gland AP2 Chapter 18 17

III. Thyroid Gland Location: Lateral upper portion of the trachea just inferior to the larynxOne of the largest endocrine glands @ ~ 20g Highly Vascular with numerous follicles whose centers are filled w/proteins called Thyroglobin (Prod’d by follicular cells)Follicles store large amounts of thyroid hormones as part of thyroglobin (T3 & T4)Parafollicular cells prod calcitonin AP2 Chapter 1818 Pg 620 Figure 18.8

III. Thyroid Gland Thyroid Hormones 10% of thyroid product AP2 Chapter 18 19 A.k.a. Thyroxine90% of thyroid product 2 types Triiodothyronine [T 3 ] Tetraiodothyronine [T 4 ] XS thyroid hormone is stored w/in the follicles TSH causes the release of T 3 & T 4 from follicles Major component of T 3 & T 4 is iodine wh /is why it is so important to have in your diet. These are also lipid soluble hormones 70-75% in blood must be bound to transport protein called: Thyroxine-binding protein Creates a large reservoir of T 3 & T 4 . 33-44% of the T 3 is converted into T 4 in the tissues b/c T 3 is major hormone that interacts with target & is several times more potent. Rapidly metabolized and excreted in urine or bile

Thyroid Gland Follicular Cells Parafollicular Cells Thyroid Hormone T 3 & T 4 Target tissue: Most cells in the body Response: Essential for the normal process of growth and maturation Increase metabolic rate: Increase breakdown of sugar, fat, and protein Increase Na/K pump activity Alter the # and activity of mitochondria Calcitonin Target tissue: Bone Decreases osteoclast activity Lengthens life of osteoblast Response: Increases bone deposition Decreases the amount of calcium and phosphate in the blood.

IV. Parathyroid Glands AP2 Chapter 18 21

IV. Parathyroid Glands 4 small units embedded in the back of the thyroid 2 cell TypesChief CellsOxyphils AP2 Chapter 18 22 Figure 18.11

Parathyroid Gland Chief Cells Oxyphils Parathyroid Hormone Target tissue: Bone, Kidney, Small Intestine Response: Increased bone breakdown by osteoclasts Increased reabsorption of calcium in the kidneys & small intestine Increased vitamin D synthesis Increased Blood Calcium levels UNKNOWN

V. Adrenal Glands AP2 Chapter 18 24

V. Adrenal Glands Located above the kidney surrounded by abundant adipose tissue & CT capsule w/an abundant blood supply. 2 major regionsCortex Outer edge 3 layers Zona glumerulosa (outer)Zona fasiculata (middle)Zona reticularis (inner)MedullaInner coreAP2 Chapter 1825 Each of the regions & layers is fxnally & structurally specialized

Adrenal Gland Adrenal Medulla Adrenal Cortex Epinephrine & Norepinephrine Target tissue: Heart Blood vessels Liver Fat cells Response: Preparation for physical activity Increased cardiac output Increased blood flow to skeletal muscle and heart Vasoconstriction of blood vessels to visceral organs Increased release of glucose and fatty acids Zona Glumerulosa Zona Reticularis Zona Fasiculata

V. Adrenal Glands Adrenal Cortex 3 types of steroid hormones are prod’d here All have similar structure to steroids & are derived from cholesterolB/c they are lipid solubleThey are not stored in the cell but synthesized as neededTransported in the blood via transport proteinsMetabolized in the liver & excreted in bile & urineBind to intracellular receptors to stimulate the synthesis of specific proteins responsible for prod’ing cellular responsesAP2 Chapter 1827

V. Adrenal Glands Adrenal Cortex Hormones are made as needed not stored Zona Glomerulosa MineralcorticoidsZona FaciculataGlucocorticoidsZona ReticularisAdrenal AndrogensAP2 Chapter 1828 Hormones are made as needed not stored

Adrenal Gland Adrenal Medulla Adrenal Cortex Epinephrine & Norepinephrine Target tissue: Heart, Blood vessels, Liver & Fat cells Response: Preparation for physical activity Increased cardiac output Increased blood flow to skeletal muscle and heart Vasoconstriction of blood vessels to visceral organs Increased release of glucose and fatty acids Zona Glumerulosa Zona Reticularis Zona Fasiculata Mineralcorticoids Glucocorticoids Adrenal Androgens Target tissue: Most Tissue Target tissue: Kidney Target tissue: Many Tissues Response: Increase in fat and protein breakdown Increase in glucose prod’n Inhibition of immune response and decreased inflammation Response: Increased Na+, K+, and H+ excretion by the kidney Enhanced water reabsoption Response: Males : Minor importance Females : development of secondary sex characteristics

VI. Pancreas AP2 Chapter 18 30

VI. Pancreas Lies btwn the greater curvature if the stomach & duodenum (beginning of the small intestine) Head: lies close to the duodenumBody: extends toward spleen Fxns as both an endocrine and exocrine gland Exocrine: Acini cells prod pancreatic juice & a duct which carries the pancreatic juice into the small intestine31Pg 634Fig 18.16 Endo crine : Pancreatic islets secrete hormones into the circulatory system

VI. Pancreas Pancreatic Islets Alpha (a) cells Secrete glucagon Small peptide hormone 20% of cellsBeta (b) cellsSecrete insulinSmall protein w/2 polypeptide chains75% of cellsDelta (d) cellsSecrete somatostatinSmall polypeptide hormoneRemaining 5% of cellsAP2 Chapter 1832

Pancreas Exocrine Gland Endocrine Gland Secretes enzymes onto the surface of the small intestine a -cells Pancreatic Islets d -cells b -cells Glucagon High Blood Glucose Low Blood Glucose Certain AA Sympathetic stimulation Liver Adipocytes Response: Rapid increase in glycogen breakdown & increase in blood glucose levels Increased glucose formation from AA and some fats Increased metabolism of FA’s resulting in increased ketones in the blood Response: Causes the breakdown of fats from adipocytes Target tissue:

Pancreas Exocrine Gland Endocrine Gland Secretes enzymes onto the surface of the small intestine a -cells Pancreatic Islets b -cells d -cells Glucagon Low blood glucose Somatostatin Increased Blood Glucose Certain AA GI-tract hormones Insulin Somatostatin Target tissue: Skeletal muscle Cardiac Muscle Cartilage Bone Fibroblasts Leukocytes Mammary glands Liver Adipocytes Nervous System Response: Increased glucose uptake Increased glycogen synthesis Increased uptake of certain AA’s Response: Increased glycogen synthesis Increased glycolysis Response: Increased glucose uptake Increased glycogen synthesis Increased fat synthesis Increased FA uptake Increased glycolysis Response: Increased glucose uptake in the satiety center

Pancreas Exocrine Gland Endocrine Gland Secretes enzymes onto the surface of the small intestine a -cells Pancreatic Islets b -cells d -cells Somatostatin Target tissue: a & b Cells of the pancreas Response: Inhibition of insulin and glucagon secretion

VII. Hormonal Regulation of Nutrients AP2 Chapter 18 36

VII. Hormonal Regulation of Nutrients AP2 Chapter 18 37 Pg 639

VII. Hormonal Regulation of Nutrients AP2 Chapter 18 38 Pg 640

VIII. Hormones of the Reproductive System AP2 Chapter 18 39

Reproductive System Male Testis Female Ovary Testosterone Response: Aids in spermatogenesis Development of the genitalia Maintenance of fxnal reproductive organs 2ndary sex characteristics Sexual Behavior Target tissue: Most cells Inhibin Target tissue: Anterior Pituitary Response: Inhibits FSH

Reproductive System Male Testis Female Ovaries Estrogen Response: Uterine and mammary gland development and fxn Maturation of genitalia 2ndary sex characteristics Sexual behavior Menstrual Cycle Target tissue: Most cells Progesterone Target tissue: Most cells Response: Uterine and mammary gland development and fxn Maturation of genitalia 2ndary sex characteristics Menstrual Cycle Inhibin Relaxin Target tissue: Anterior Pituitary Target tissue: Connective Tissue Response: Inhibits FSH Response: Increases flexibility of CT in pelvic area, especially in the symphysis pubis Female Placenta LH-Like Substance Response: Maintains pregnancy Female Placenta & Ovaries Increasing amounts of estrogen & progesterone Response: Necessary to maintain pregnancy

IX. Hormones of the Pineal Body AP2 Chapter 18 42

IX. Hormones of the Pineal Body 43 Pg 642 Fxn of PB in Humans is still actually unclear but when there are tumors 1. early sexual development or 2. retarded development of reproductive system

X. Thymus AP2 Chapter 18 44

Thymus Thymosin Response: Role in development and maturation of the immune system Target tissue: Immune Tissues

XI. Hormones of the GI-tract There are several & they relate to digestive fxns by influencing the activity of the stomach, intestine, liver, & pancreas AP2 Chapter 18 46

XII. Hormone like substances AP2 Chapter 18 47

XII. Hormone like Substances Autocrine chemical signals are released by cells the influence the same cell type which released them. Paracrine chemical signals are released from 1 cell type, diffuse short distance, & influence the activity of another cell type near by. Not secreted from discrete endocrine glands Have local FX rather than systemic FX Have fxns that are not understood adequately to explain their role in the bodyAP2 Chapter 1848

XII. Hormone like substances 49 Autocrine Paracrine Peptide growth hormones # of hormone like substances listed are minimal there are actually tons Chemical communication among cells in the body is complex, well developed, & necessary for maintenance of homeostasis Investigations increase knowledge of body fxns that can be used to develop techniques for treatment of pathologic conditions

XIII. FX of aging on Endocrine System Gradual decrease in secretion rate of most, but not all, hormones Some decreases are 2ndary to gradual decreases in physical activityGH Decreases w/ age but it is most drastic in people who do not exercise Melatonin Decreases and may help to explain the changes seen in sleeping pattern w/ageAP2 Chapter 1850