Endocrine System Chapter 13

Basic Overview: Endocrine vs. Exocrine Paracrine – nearby cells Prostaglandins Autocrine – affect itself Function: Help Control Homeostasis Slower than Nervous System Negative Feedback Hormones – Chemical Messengers Released into blood Only affect target cells Specific proteins in membrane

Pituitary Gland Anterior Pituitary Posterior Pituitary Controlled by Hypothalamus Hormones (releasing hormones) Hypophoseal Portal Veins Growth Hormone, Prolactin, Thyroid Stimulating Hormone, Adrenocorticotropic Hormone Gonadotropins: Leutinizing Hormone, Follicle Stimulating Hormone Posterior Pituitary Neurosecretory Cells of Hypothalamus Anti-diuretic Hormone (vasopressin) – H2O conservation Oxytocin – Uterus contraction (labor)

Other Endocrine Glands Thyroid Metabolism (BMR) Thyroxine + Triiodothryonine Calcitonin Parathyroid Posterior side PTH – bone resorption Adrenal Top of the kidneys Medulla  Adrenaline (epinephrine) + Noradrenaline (norepinephrine) Fight or flight Cortex  Aldosterone + Cortisol

Other Endocrine Glands Pancreas: glucose glycogen Islets of Langherans Beta Cells  Insulin  lower blood sugar Alpha cells  glucagon  increase blood sugar Delta Cells  Somatostatin Pineal Gland Melatonin + circadian rythms Thymus  Immunity Shrinks after childhood Testes, ovaries + placenta Sex hormones – secondary sex characteristics Pregnancy test - hcg