Chapter 35

Chapter 35: The Endocrine System

Organs and Structures of the Endocrine System

• Pituitary Gland

  • Anterior and Posterior glands

• Thyroid Gland

• Parathyroid Glands

• Adrenal Glands

• Pancreas

  • Beta cells release insulin.

  • The pancreas only houses the insulin.

• Ovaries and Testes

• Pineal Gland

• Thymus Gland

• Heart

Effects of Hormones from the Pituitary Gland

• GH (Growth Hormone)

• TSH (Thyroid-Stimulating Hormone)

• ACTH (Adrenocorticotropic Hormone)

• PAL

• FSH (Follicle-Stimulating Hormone)

• LH (Luteinizing Hormone)

• Oxytocin

  • Effects include uterine contractions and milk ejection during lactation.

• ADH (Antidiuretic Hormone)

  • Promotes kidney water reabsorption.

Functions of the Endocrine System

• Alters chemical reactions and controls the rates of chemical activities within cells.

• Changes the permeability of cell membranes, selecting substances that can be transported.

• Activates specific mechanisms in cells, essential for cellular growth and reproduction.

• Controls metabolism, growth rate, physical development, sexual function, and reproduction.

Functions of Major Endocrine Glands

Effects of the Pituitary Hormones

• Posterior Pituitary Gland

  • Does not produce hormones; stores and releases oxytocin and ADH produced by the hypothalamus.

• Anterior Pituitary

  • Produces hormones secreted into the bloodstream due to releasing hormones from the hypothalamus.

Effects of Thyroid Hormones

• Secretes thyroxine (T4), triiodothyronine (T3), and calcitonin.

  • Activates heat production, stimulates synthesis and degradation of proteins and lipids.

  • Regulates carbohydrate metabolism and response to catecholamines (epinephrine and norepinephrine).

Effects of Epinephrine

• Released in response to stress and physical activity.

• Increases heart rate, glucose levels in blood, and cardiac muscle contraction while diverting blood from non-essential functions.

Functions of Other Endocrine Glands

Parathyroid Glands

• Produce parathyroid hormone (PTH) which regulates plasma calcium levels.

• Calcitonin from the thyroid balances the action of PTH.

Adrenal Glands

• Adrenal Medulla

  • Secretes epinephrine and norepinephrine (catecholamines) in response to sympathetic nervous stimulation.

• Adrenal Cortex

  • Secretes corticosteroids (including cortisol, aldosterone).

Effects of Aging on the Endocrine System

• Pituitary gland often decreases in size.

• Thyroid may become nodular or lumpy; hormonal fluctuations are common.

• Increased blood glucose levels and decreased levels of thyroid hormones and insulin.

• Metabolism declines with age, affecting stress handling and inflammatory responses.

Hormonal Functions of the Pancreas

• Produces insulin (from beta cells) and glucagon (from alpha cells).

• Insulin is crucial for cellular uptake of glucose.

• Glucagon stimulates conversion of glycogen to glucose in the liver.

Endocrine System Disorders

• Causes of Disorders

  • Primary dysfunction: hypersecretion or hyposecretion due to tumors or inflammation.

  • Secondary dysfunction: medications, trauma, or hormone therapy.

    • Can lead to temporary or permanent disturbances.

Preventing Goiter

• Goiter can be prevented with adequate iodine intake.

Diagnostics

• Thyroid Panel

  • Patients should avoid aspirin and birth control 2 days prior.

• Parathyroid Function Tests

  • Serum calcium & phosphate levels.

• Adrenal Gland Function

  • Electrolyte panels, glucose levels, and hormone levels.

• Diabetes Mellitus Diagnosis

  • Random blood glucose > 200 mg/dL or fasting glucose ≥ 126 mg/dL.

  • Glucose tolerance tests and HbA1C tests for monitoring.

Nursing Management of Endocrine Disorders

• Conduct thorough focused assessments and evaluations.

• Establish nursing diagnoses and community care approaches.

• General Nursing Goals

  • Prevention of injury, maintenance of fluid/electrolyte balance, hormone balance, reduction of stress, and effective coping mechanisms.

  • Promote self-care and tolerate physical activity.

  • Improve mental-emotional status and integration of body image.