Thyroid Hormones and Related Disorders

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Questions and Answers

Describe the roles of T3 and T4 hormones in the body.

T3 and T4 hormones increase energy production and protein synthesis, regulate metabolic rate, and support the functioning of vital organs.

What role does TSH play in the secretion of thyroid hormones?

TSH, produced by the anterior pituitary, stimulates the thyroid gland to increase the secretion of T3 and T4 hormones.

What is the primary function of calcitonin and when is it most important?

Calcitonin helps maintain normal blood levels of calcium and phosphate and is especially vital during childhood for bone growth.

Explain how the hypothalamus regulates the production of thyroid hormones.

The hypothalamus secretes TRH in response to a decrease in metabolic rate, which then prompts the anterior pituitary to release TSH, ultimately stimulating the thyroid gland. Signup and view all the answers

Where is the thyroid gland located and what are its structural components?

The thyroid gland is located on the front and sides of the trachea just below the larynx, consisting of two lobes connected by an isthmus. Signup and view all the answers

What hormone is produced by the parathyroid glands and what is its primary function?

The hormone is parathyroid hormone (PTH), and its primary function is to maintain normal blood levels of calcium. Signup and view all the answers

How does parathyroid hormone (PTH) respond to low and high blood calcium levels?

PTH secretion is stimulated by hypocalcemia and inhibited by hypercalcemia. Signup and view all the answers

What is a goiter and what can cause its development?

A goiter is an enlarged thyroid gland, often caused by iodine deficiency or goitrogens. Signup and view all the answers

List two disorders associated with thyroid gland dysfunction.

Two disorders are hyperthyroidism and hypothyroidism. Signup and view all the answers

What are the systemic manifestations of thyroiditis?

Systemic manifestations of thyroiditis include fever, chills, sweats, and fatigue. Signup and view all the answers

Identify a common dietary cause of goiter and explain its significance.

A common dietary cause of goiter is a lack of iodine, which is essential for thyroid hormone production. Signup and view all the answers

Name one thyroid inhibitor and give an example of a food that contains thyroid-inhibiting substances.

One thyroid inhibitor is Methimazole, and an example of a food is broccoli. Signup and view all the answers

What symptoms might occur if the thyroid enlarges rapidly?

It may compress structures in the neck, affecting breathing and changing the voice. Signup and view all the answers

What phase can occur in Hashimoto’s thyroiditis due to antibody destruction of thyroid tissue?

A transient phase of hyperthyroidism can occur due to leaking thyroid hormones from damaged tissues. Signup and view all the answers

During which timeframe is silent thyroiditis typically observed in postpartum women?

It is usually seen in the first 6 months after delivery. Signup and view all the answers

What are the expected T4 and T3 hormone levels in Hashimoto’s thyroiditis?

T4 and T3 levels are usually low while TSH levels are high. Signup and view all the answers

What types of treatments may be employed for bacterial thyroiditis?

Specific antibiotics or surgical drainage may be used as treatment. Signup and view all the answers

What medications can be used to relieve symptoms in subacute and acute thyroiditis?

NSAIDs like aspirin or naproxen, and corticosteroids such as prednisone can relieve symptoms. Signup and view all the answers

What cardiovascular symptoms may be addressed with propranolol or atenolol in hyperthyroid patients?

These medications can relieve symptoms like increased heart rate. Signup and view all the answers

What is the risk for a patient with Hashimoto’s thyroiditis concerning other diseases?

They are at risk for other autoimmune diseases such as Addison’s disease and pernicious anemia. Signup and view all the answers

What is the recommended therapy for a patient who is hypothyroid?

Thyroid hormone therapy is recommended for hypothyroid patients. Signup and view all the answers

What nursing interventions can help a patient manage fatigue during self-care activities?

Encourage participation in self-care as tolerated and provide assistance when the patient is fatigued. Signup and view all the answers

How can a nurse help maintain a patient's normal body temperature?

By providing extra layers of clothing or blankets and avoiding external heat sources such as heating pads. Signup and view all the answers

What dietary advice should be given to a patient suffering from constipation?

Encourage increased fluid intake and consumption of foods high in fiber. Signup and view all the answers

What is an essential component of managing lifelong thyroid replacement therapy?

Patients must understand the rationale for their therapy and recognize signs of over- and underdose. Signup and view all the answers

Describe an important factor in improving a patient's breathing pattern.

Monitoring respiratory rate, depth, pattern, and related vital signs is essential. Signup and view all the answers

What outcome indicates effective intervention for a patient with fatigue?

The patient reports a decreased level of fatigue and participates in self-care activities. Signup and view all the answers

How should a nurse protect a patient from cold exposure?

By ensuring they are kept warm and monitoring for drafts or cold environments. Signup and view all the answers

What should patients understand about the frequency of follow-up visits related to thyroid therapy?

Patients need to be aware of the necessity for periodic long-term follow-up visits to their physician. Signup and view all the answers

Which factors should be monitored to assess bowel function in a patient with constipation?

Fluid intake, dietary fiber consumption, and mobility levels should be monitored. Signup and view all the answers

Study Notes

Thyroid Gland Disorders

Learning Objectives: Anatomy and physiology of the thyroid gland, thyroid disorders, causes of disorders, multisystem effects, diagnostics, and management of disorders are covered.

Anatomy and Physiology of the Thyroid Gland

The thyroid gland is composed of two lobes connected by an isthmus.
It's located in the front and on the sides of the trachea, below the larynx.
The gland produces three hormones: T4 (thyroxine), T3(triiodothyronine), and calcitonin.
T4 and T3 are produced in the thyroid follicles, requiring iodine (T4 has four iodine atoms, T3 has three). They have identical functions.
Calcitonin is produced by parafollicular cells.

Thyroid Gland Hormones and Their Functions

T3 and T4: Increase energy production and protein synthesis; enhance metabolic rate, regulating energy, and heat production; essential regulators of metabolic rate, playing critical roles in multiple body systems like the heart, brain, muscles, and others; essential for growth, development, and reproduction.
Calcitonin: Regulates calcium and phosphate levels during childhood bone growth; maintains normal blood calcium and phosphate levels, crucial for strong bones.

Parathyroid Glands

Usually, four parathyroid glands are present, two on the back of each thyroid lobe.
Parathyroid hormone (PTH) has an antagonistic effect on calcitonin; its secretion is stimulated by low blood calcium levels (hypocalcemia) and inhibited by high blood calcium levels (hypercalcemia).
Functions of PTH: maintains healthy blood calcium levels and stimulates calcium/phosphate release from bones, increasing their blood levels.

Thyroid Disorders

Goiter: An enlarged thyroid gland. Often due to iodine deficiency. Cells may become overactive (hyperthyroidism), or underactive (hypothyroidism).
Thyroiditis: Inflammation of the thyroid gland, a frequent cause of goiter. It can be subacute (viral), acute (bacterial), or chronic (autoimmune). Symptoms may include localized or diffused pain, radiating to throat, ears or jaw; fever, chills, sweats and fatigue. Risk factors include female sex, family history, older age and white ethnicity.
Primary Hypothyroidism: Thyroid gland dysfunction.
Secondary Hypothyroidism: Impaired TSH secretion, originating from the pituitary gland.
Tertiary Hypothyroidism: Hypothalamus failure to release Thyroid-Releasing Hormone (TRH), resulting in decreased TSH release leading to diminished thyroid hormone secretion.
Causes of Hypothyroidism: Thyroidectomy, radiation treatment, Hashimoto's disease (chronic autoimmune), inflammatory diseases; hypothalamic failure, inborn thyroid errors, insufficient hormone replacement therapy for hyperthyroidism, pituitary dysfunction, iodine deficiency, drugs (lithium, amiodarone, etc.).
Causes of Hyperthyroidism: Family history, high iodine ingestion, trauma, toxic multinodular goiter, Graves' disease (genetic).

Multisystem Effects of Hypothyroidism

Neurological: Hand and foot paresthesia (numbness/tingling), lethargy, somnolence, confusion, slow speech, memory impairment.
Endocrine: Goiter.
Respiratory: Pleural effusion.
Gastrointestinal: Constipation.
Musculoskeletal: Muscle stiffness, weakness, fatigue.
Sensory: Periorbital edema (puffiness around the eyes).
Cardiovascular: Hypotension, bradycardia, dysrhythmias, enlarged heart, anemia.
Reproductive: Menorrhagia (female), infertility and decreased libido in females and males.
Integumentary: Hair loss, brittle nails, dry skin and non-pitting edema.
Metabolic: Hypothermia, anorexia, constipation, unexplained weight gain.
Myxedema: The face of a person with Myxedema appears puffy; the voice is hoarse and husky; progressive, myxedema coma includes stupor, hypoventilation, hypoglycemia.

Multisystem Effects of Hyperthyroidism

Neurological: Hand and eye tremors, nervousness, insomnia.
Sensory: Blurred vision, photophobia.
Cardiovascular: Hypertension, tachycardia, dysrhythmias, palpitations.
Reproductive: Amenorrhea, decreased fertility (female), impotence, decreased libido (male).
Integumentary: Fine, thin hair, flushed and moist skin.
Endocrine: Goiter.
Respiratory: Dyspnea.
Gastrointestinal: Nausea, vomiting, diarrhea, abdominal pain.
Musculoskeletal: Muscle wasting.
Metabolic: Hyperthermia, diaphoresis (excessive sweating), hunger, weight loss, fluid volume deficit.

Thyroid Diagnostics

Serum TSH, T3, T4 and free T4 levels are measured.
T3 resin uptake test and radioisotope thyroid uptake tests are performed.
Lab studies may show decreased serum T4, decreased blood glucose, decreased plasma osmolality, decreased TSH in pituitary/hypothalamic defects, increased TSH in thyroid defects, hyponatremia, hyperlipidemia, and lactic acidosis.

Thyroid Treatment

Hypothyroidism: Lifelong hormone replacement with synthetic levothyroxine sodium or liothyronine sodium (Liotrix). Symptoms are usually relieved within 2–3 days of starting treatment. Myxedema coma requires immediate I.V. corticosteroids, glucose, and levothyroxine sodium.
Hyperthyroidism: Antithyroid medications (methimazole, propylthiouracil) are usually used first; they block the production of thyroid hormones and usually provide improvement within two to four weeks. Beta-blockers may be used to control the effects of the sympathetic nervous system. Surgery (subtotal thyroidectomy) might be necessary in cases of a very large gland, or cases where the patient can't undergo other treatment, or if the patient has thyroid cancer. Radioactive iodine may also be an option depending on patient symptoms.

Nursing Responsibilities

Hypothyroidism/Hyperthyroidism: Assessing for complications, monitoring and managing patient symptoms, vital signs, educating patients and families on the importance and use of medication.
Thyroidectomy: Preoperative care, and postoperative care; management of hypothyroidism; providing health promotion about preventing hypothyroidism; and adequate iodine intake. Monitoring for increasing symptoms (including decreased level of consciousness, decreased vital signs, difficulties awakening or arousing). Respiratory support if needed, and close monitoring for other complications such as cardiac insufficiency. Avoiding unnecessary use of sedatives/analgesics.
Radioactive Iodine Therapy: Assess for allergies, dilute iodine sources appropriately, monitor for increased bleeding risk if anticoagulants are also administered.
Thyroid Storm/Crisis: Immediate treatment with antipyretics; maintain patent airway through suction and ventilatory support; careful administration of medications and fluids; monitoring of vital signs; environmental cooling (if necessary).

Nursing Diagnoses and Interventions (Specific examples)

Activity intolerance: Promoting independence in self-care; provide rest and exercise as tolerated; assist with self-care activities; encourage conversation and non-stressful activities; monitor patient response to increasing activities.
Risk for imbalanced body temperature: Provide extra layers of clothing or blankets, discourage use of heating pads/electric blankets; monitor body temperature and report decreases; protect from drafts.
Constipation: Encourage increased fluid intake within fluid restriction limits; provide high-fiber foods; instruct patients on high water content foods; monitor bowel function; encourage increased mobility within tolerance; sparingly encourage laxatives and enemas.
Deficient knowledge: Explain rationale for thyroid hormone replacement; describe the desired effects of medication and develop a schedule and checklist for self-administration; describe signs and symptoms of overdose/underdose; explain the need for long-term follow-up.
Ineffective breathing pattern: Monitor respiratory rate, depth, pattern, oxygen saturation, and arterial blood gases; encourage deep breathing and coughing; use incentive spirometry; administer medications (hypnotics/sedatives) carefully; maintain patent airway.
Other information regarding specific patient situations is addressed (e.g., myxedema, exophthalmos).

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Description

This quiz covers the roles and functions of T3, T4, TSH, and the parathyroid hormones, as well as the anatomy of the thyroid gland and various disorders related to thyroid dysfunction. Test your understanding of how these hormones interact and regulate bodily functions, along with the dietary factors influencing thyroid health.