Chapter 11 Endocrine System

Endocrine Glands Glands produce secretions Endocrine glands make hormones Hormones use the circulatory system to reach their target Do not confuse with exocrine glands which has secretions that go through a duct

Function of the Endocrine System Coordinate and integrate functions to maintain homeostasis Hypothalamus Neurotransmitters

Function of the Endocrine System Pituitary gland Negative feedback system Nervous control

Pituitary Gland About size of a grape Located at base of brain Connected to the hypothalamus Anterior lobe and posterior lobe Also known as the master gland

Anterior Lobe – Pituitary Growth hormone (GH) or somatotropin Prolactin hormone (PRL) Thyroid-stimulating hormone (TSH) Adrenocorticotropic hormone (ACTH)

Anterior Lobe – Pituitary Follicle-stimulating hormone (FSH) Luteinizing hormone (LH) Interstitial cell-stimulating hormone (ICSH)

Intermediate Lobe – Pituitary Few cells along borders of posterior and anterior lobes Melanocyte-stimulating hormone (MSH)

Posterior Lobe – Pituitary Vasopressin converts to antidiuretic hormone (ADH) in the bloodstream Oxytocin

Thyroid Glands Located in neck close to the cricoid cartilage (Adam’s apple) Regulates body metabolism Thyroxine (T4) Triiodothyronine (T3) Calcitonin

Parathyroid Glands Four glands size of grains of rice Attached to the posterior surface of the thyroid gland Maintains calcium-phosphorus balance Parathormone Parathormone and calcitonin Antagonistic effects

Thymus Gland Both an endocrine gland and lymphatic organ Located under the sternum Decreases in size with aging thymosin

Adrenal Glands Located on top of each kidney Have a cortex and a medulla ACTH from the pituitary gland stimulated activity of the cortex

Adrenal Cortex Mineralocorticoids Glucocorticoids Androgens Estrogens

Adrenal Medulla Epinephrine or adrenalin Norephinephrine Powerful cardiac stimulant Norephinephrine Responds to the sympathetic nervous system Fight-or-flight hormones

Gonads Also called sex glands Female Ovaries Male Testes

Gonads – Hormones Female Estrogen Progesterone Male Testosterone

Pancreas Located behind stomach Exocrine and endocrine functions Insulin Glucagon

Pineal Gland Located on the roof of the third ventricle in the brain Suprachiasmatic nucleus Melatonin

Other Hormones Prostaglandins Activity depends on which tissue secretes them Exact nature and function is being studied

Animation – Endocrine System Click Here to play Endocrine System animation

Effects of Aging Affects nearly every gland Blood levels of some hormones increase while others decrease Affects the homeostasis of the body

Endocrine System Disorders A number of factors can cause problems Disease of the gland Autoimmune causes Infections Dietary deficiencies Signs and symptoms usually do to hyper- or hypoactivity of the glands

Disorders – Pituitary Hyperfunction Hypofunction Diabetes insipidus Gigantism Acromegaly Hypofunction Dwarfism Diabetes insipidus

Disorders – Thyroid Diagnostic tests Hyperthyroidism Hypothyroidism Myxedema Cretinism

Disorders – Parathyroid Hyperparathyroidism Increased blood calcium Hypoparathyroidism Decreased blood calcium Tetany

Disorders – Adrenal Cortex Hyperfunction Cushing’s syndrome Hypofunction Addison’s disease

Steroid Abuse in Sports Androgenic anabolic steroids Risks of taking Males Females

Diabetes Mellitus Pancreatic disorder Decreased secretion of insulin from the islets of Langerhans cells or by the ineffective use of insulin Type I and Type II diabetes

Diabetes Mellitus Signs and symptoms Pathophysiology Hypo- and hyperglycemia Diagnostic tests Treatments