chapter 11

© 2009 Delmar, Cengage Learning

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– 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– 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

chapter 11

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