Endocrine System Overview Quiz

Endocrine System Overview

• Affects nearly every cell, organ, and body function
• Closely linked with the nervous and immune systems
• Hormone regulation is controlled by negative feedback mechanisms

Hormones

• Steroids: act inside the cell
• Peptides/proteins: act on cell surfaces
• Amines
• Fatty acid derivatives

Major Hormone-Secreting Glands

• Hypothalamus
• Pineal gland
• Pituitary gland (anterior and posterior)
• Thyroid gland
• Parathyroid gland
• Thymus
• Adrenals
• Islets of Langerhans (in the pancreas)
• Testes
• Ovaries

Hypothalamus

• Controls pituitary hormone release
• Secretes hormones such as: Corticotropin-releasing hormone (CRH), Thyroid-releasing hormone (TRH), Growth hormone-releasing hormone (GHRH), Gonadotropin-releasing hormone (GnRH), Somatostatin

Pituitary Gland and its Hormones

• Anterior pituitary: Releases hormones like growth hormone (GH), adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin
• Posterior pituitary: Stores and releases hormones like antidiuretic hormone (ADH) and oxytocin

Thyroid Gland

• Synthesizes hormones T3 and T4, and calcitonin
• Iodine is essential for thyroid hormone function
• TRH from the hypothalamus and TSH from the anterior pituitary control thyroid hormone release
• Controls cellular metabolic activity
• T3 is more potent and rapid-acting than T4
• Calcitonin regulates calcium levels

Thyroid Gland Functions

• Homeostatic regulation of growth and development
• Energy metabolism
• Electrolyte balance

Thyroid Diagnostic Tests

• Thyroid-stimulating hormone (TSH)
• Serum-free T4
• T3 and T4
• T3 resin uptake
• Thyroid antibodies
• Radioactive iodine uptake
• Fine-needle aspiration biopsy
• Thyroid scan, radio scan, or scintiscan
• Serum thyroglobulin

Thyroid Disorders

• Congenital hypothyroidism (formerly cretinism)
• Hypothyroidism:
  • Myxedema (severe hypothyroidism)
• Hyperthyroidism:
  • Thyroid storm (uncontrolled hyperthyroidism)
• Thyroiditis (inflammation of the thyroid)
• Thyroid cancer

Hypothyroidism

• Causes: autoimmune thyroiditis (Hashimoto's disease)
• Affects women more frequently than men
• Manifestations: often nonspecific initially, fatigue, hair/skin/nail changes, numbness/tingling, menstrual disturbances, subnormal temperature/pulse, weight gain, subdued emotions, slow speech, enlarged tongue/hands/feet, personality/cognitive changes, cardiac/respiratory complications, and myxedema

Myxedema

• Severe hypothyroidism
• Characteristics: bradycardia, hypothermia, delayed deep tendon reflexes, pitting edema, enlarged tongue, disorientation, seizures, and coma

Myxedema Management

• Pharmacological support (levothyroxine)
• Electrolyte supplementation
• Glucose supplementation
• Monitoring TSH levels, electrolytes, and glucose
• Monitor vital signs, urine output, and weight
• Warming fluids if hypothermic

Medical Management of Hypothyroidism

• Synthetic levothyroxine replacement therapy
• Medication interactions (e.g., reducing hypnotic/sedative dosages)
• Supporting cardiac and respiratory function
• Preventing complications

Hyperthyroidism

• Second most prevalent endocrine disorder
• Excessive output of thyroid hormone
• Graves' disease (most common cause)
• Affects women more than men
• Manifestations: thyrotoxicosis, nervousness, palpitations, rapid pulse, poor heat tolerance, tremors, flushed/warm/soft skin, exophthalmos, increased appetite/dietary intake, weight loss, elevated systolic BP, cardiac dysrhythmias, and heart failure

Goiter

• Enlarged thyroid gland
• Causes: iodine deficiency, inflammation, or overstimulation

Exophthalmos

• Bulging eyes
• Common in Graves' disease

Thyroid Storm

• Uncontrolled hyperthyroidism
• Life-threatening, develops quickly
• 10% mortality rate in elderly
• Triggered by major stressors or radioactive iodine treatments
• Symptoms: fever, tachycardia, systolic hypertension, GI symptoms, agitation/anxiety/tremors, restlessness/confusion/psychosis, and seizures/coma

Thyroid Storm Collaborative Care

• Decrease body temperature (remove excess clothing, hypothermia blanket)
• Humidified oxygen
• Intravenous fluids with glucose
• Medications (iodine etc)

Additional Thyroid Disorders

• Thyroiditis (acute, subacute, or chronic)
• Thyroid tumors (endemics, nodular goiter, and thyroid cancer)

Thyroidectomy

• Treatment of choice for thyroid cancer
• May involve modified or radical neck dissection and radioactive iodine.
• Preoperative goals: reduce stress and anxiety to prevent thyroid storm.
• Preoperative teaching: dietary guidance, avoiding stimulants, explaining tests and procedures.

Postoperative Care

• Monitor respirations and airway
• Monitor dressings for bleeding, hematoma
• Assess pain, provide pain relief
• Semi-Fowler's position, support head
• Assess voice, discourage talking
• Monitor for hypocalcemia (potential parathyroid gland injury)

Review Questions (Specific Examples)

• Question 1: The anterior pituitary gland stimulates T3 & T4 release
• Question 2: Iodine is not produced by the thyroid gland
• Question 3: A patient with hyperthyroidism will have a decreased TSH level
• Question 4: Levothyroxine should be taken on an empty stomach
• Question 5: Autoantibodies activating TSH receptors cause goiter in Graves' disease
• Question 6: Thyroidectomy is the treatment of choice for thyroid cancer
• Question 7: Blood pressure of 94/62 mmHg is not a symptom of thyroid storm
• Question 8: Coronary artery disease is a possible complication of hypothyroidism

Test your knowledge on the endocrine system with this comprehensive quiz. Explore various hormones, their functions, and the major hormone-secreting glands. Understand the intricate connections between the endocrine, nervous, and immune systems.