ENDOCRINE SYSTEM Endocrine
Function Help regulate internal functions Use chemical messengers Recall: Endocrine vs. Exocrine glands Nervous System vs Endocrine System
Target Specificity Lock n Key action Hormone-Receptor Complex Hormone Receptor
ENDOCRINE GLANDS & HORMONES Glands
Hypothalamus Functions both as an Endocrine Gland and nervous tissue. Location Hormones Tropic Hormones
Pituitary Gland Two Parts: Anterior and Posterior Anterior Pituitary Gland (APG) Growth Hormone (GH) Prolactin Thyroid Stimulating Hormone (TSH) Adrenocorticotropic Hormone (ACTH) Follicle-Stimulating Hormone (FSH) Luteinizing Hormone (LH)
Pituitary Cont d Posterior Pituitary (PPG) Oxytocin (OT) Antidiuretic Hormone (ADH) Hypothalamic control: APG: stimulated by hormones from hypothalamus PPG: modified axons
Fig. 17.4 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Anterior Posterior Third ventricle of brain Floor of hypothalamus Pineal gland Nuclei of hypothalamus: Paraventricular nucleus Supraoptic nucleus Cerebral aqueduct Mammillary body Optic chiasm Adenohypophysis: Pars tuberalis Anterior lobe Neurohypophysis: Median eminence Hypothalamo hypophyseal tract Stalk (infundibulum) Axons to primary capillaries Neuron cell body Posterior lobe Oxytocin (a) Antidiuretic hormone Superior hypophyseal artery Hypothalamic hormones Gonadotropin-releasing hormone Thyrotropin-releasing hormone Corticotropin-releasing hormone Prolactin-inhibiting hormone Growth hormone releasing hormone Somatostatin Hypophyseal portal system: Primary capillaries Portal venules Secondary capillaries Anterior lobe hormones Follicle-stimulating hormone Luteinizing hormone Thyroid-stimulating hormone (thyrotropin) Adrenocorticotropic hormone Prolactin Growth hormone Anterior lobe Posterior lobe (b)
Thyroid Follicles: Produce Hormones Hormones Thyroxine (T4) Triiodothryonine (T3) Both used iodine and have nonspecific target cells Calorigenic effect Colloid: Stores Hormones, jelly-like structure Parafollicular Cells: Cells found between follicles produce Calcitonin Calcitonin
Fig. 17.9 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Superior thyroid artery and vein Thyroid cartilage Follicular cells Thyroid gland Isthmus Colloid of thyroglobulin C (parafollicular) cells Follicle Inferior thyroid vein Trachea (a) (b) b: Robert Calentine/Visuals Unlimited
Fig. 17.7 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. TRH 1-6 Negative feedback inhibition + 5-4 Target organs 2 + TSH Thyroid hormone + 3 + Stimulatory effect Inhibitory effect
Parathyroid Gland Location Parathyroid Hormone (PTH)
Adrenal Glands Sits on top of each Kidney Receives a lot of Blood from Renal Artery 2 sections: Medulla: Inner layer Cortex: Outer layer, has sub-layers or zones.
Adrenal Cortex Aldosterone Produced in outer zone Regulates Electrolytes Cortisol Produced in middle zone Regulates metabolism and glucose Androgens Produced in inner zone Sex steroids
Adrenal medulla Produces and releases epinephrine and noreprinephrine. Functions: Gluconeogenesis Glycogenolysis Increased cardiac function Increased blood flow to muscles Increased pulmonary ventilation
Pancreas Exocrine and Endocrine Gland Acinar Cells produce pancreatic juices Islet cells produce hormones Beta Cells Produce insulin Lowers Blood Glucose levels and stores glucose in cells Alpha Cells Produce glucagon Increase Blood Glucose levels by releasing glucose into blood stream Antagonistic Effect