Thyroid Gland Anatomy and Physiology
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Questions and Answers

What complication may occur due to excessive thyroid tissue removal during thyroidectomy?

  • Hypoparathyroidism
  • Hypothyroidism (correct)
  • Thyrotoxic crisis
  • Bleeding due to slipped ligature

What serious condition can occur in a thyrotoxic patient who is not properly prepared for thyroid surgery?

  • Hypoparathyroidism
  • Thyrotoxic crisis (correct)
  • Respiratory obstruction
  • Laryngeal nerve paralysis

Which of the following is an emergency treatment for a patient suffering from bilateral recurrent laryngeal nerve paralysis after thyroid surgery?

  • O2 therapy and IV fluids
  • Calcium and vitamin D3 supplementation
  • Carbimazole administration
  • Emergency tracheostomy (correct)

Which medication is NOT typically used in the treatment of a thyrotoxic crisis?

<p>Levothyroxine (A)</p> Signup and view all the answers

What is the primary cause of hypoparathyroidism that may occur after thyroid surgery?

<p>Incidental removal of parathyroid glands (C)</p> Signup and view all the answers

What are the primary hormones secreted by the follicular cells of the thyroid gland?

<p>Tri-iodo-thyronine (T3) and Thyroxine (T4) (B)</p> Signup and view all the answers

Which hormone is considered the active and fast-acting component of thyroid function?

<p>Tri-iodo-thyronine (T3) (A)</p> Signup and view all the answers

What condition is defined as the enlargement of the thyroid gland?

<p>Goitre (C)</p> Signup and view all the answers

In which condition are thyroid hormone levels increased while TSH levels are low?

<p>Hyperthyroid goitre (B)</p> Signup and view all the answers

How can goitre be prevented according to the provided information?

<p>Using iodised salt and avoiding goitrogens (D)</p> Signup and view all the answers

Which type of goitre occurs due to physiological demands for thyroid hormones during puberty and pregnancy?

<p>Physiological goitre (B)</p> Signup and view all the answers

What is the influence of thyroid stimulating hormone (TSH) on the secretion of T3 and T4?

<p>High levels of T3 and T4 inhibit TSH secretion (A)</p> Signup and view all the answers

What is the commonest type of goitre according to classification based on shape?

<p>Diffuse goitre (C)</p> Signup and view all the answers

Which symptom is associated with hyperthyroidism?

<p>Exophthalmos (A)</p> Signup and view all the answers

What is the primary treatment for hypothyroidism?

<p>Thyroxine (Eltroxine) (A)</p> Signup and view all the answers

Which of the following is NOT an indication for thyroidectomy?

<p>Diffuse goitre (D)</p> Signup and view all the answers

What condition is characterized by bradycardia and hypotension?

<p>Hypothyroid goitre (D)</p> Signup and view all the answers

What diagnostic test assesses vocal cord mobility before thyroid surgery?

<p>Indirect laryngoscopy (B)</p> Signup and view all the answers

Which drug is commonly used to treat tachycardia in hyperthyroid patients?

<p>Propranolol (B)</p> Signup and view all the answers

Which type of thyroidectomy involves removing a lobe and connecting the two remaining lobes?

<p>Lobectomy with isthmectomy (C)</p> Signup and view all the answers

What is one of the preoperative assessments for thyroidectomy?

<p>Complete blood picture (C)</p> Signup and view all the answers

Flashcards

Thyroid Gland Anatomy

Butterfly-shaped endocrine gland in the neck, composed of two lobes connected by an isthmus.

Thyroid Hormone Secretion

Controlled by TSH (thyroid-stimulating hormone) from the pituitary gland, using negative feedback. T3 is fast-acting, T4 slow. Stored in colloid.

Goiter

Enlarged thyroid gland, often detected as a neck mass.

Classification of Goiter (Function)

Goiter can be classified by function including Physiological, Colloid, Hyperthyroid, Hypothyroid, and Neoplastic.

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Physiological Goiter

Goiter from increased demands for thyroid hormones during puberty and pregnancy

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Hyperthyroid Goiter

Goiter caused by excess thyroid hormones, and low TSH levels.

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Preventing Goiter

Iodized salt, milk, dairy, eggs, seafood, and avoiding goitrogens (e.g., cabbage), and drugs like sulphonamides are important.

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Hypothyroid Goiter

Goiter caused by decreased thyroid hormones, and high TSH levels.

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Hyperthyroidism symptoms

Symptoms include weight loss, anxiety, rapid heartbeat, heat intolerance, and bulging eyes.

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Hypothyroidism symptoms

Symptoms include weight gain, fatigue, cold intolerance, slow heart rate, and dry skin.

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Thyroid function tests

Tests like T3, T4, and TSH measure thyroid gland function.

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Thyroidectomy preparation

Pre-surgery steps involve physical exams, imaging (ultrasound), blood tests, and potentially X-rays to assess the thyroid and neck.

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Indications for thyroidectomy

Reasons for thyroid surgery includes: failed medication, goitre (nodules), suspicious lumps, pressure issues (breathing or swallowing issues), and cosmetic concerns.

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Types of thyroidectomy

Different procedures like lobectomy (part removal), subtotal (mostly removal), or near-total/total removal (full removal) vary in scope.

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Carbimazole (hyperthyroidism)

A medication used to reduce thyroid hormone levels.

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Propranolol (hyperthyroidism)

A medication used to treat rapid heart rate.

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Thyroidectomy complication: Bleeding

Bleeding after thyroidectomy can be caused by slipped ligatures.

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Thyroidectomy complication: Respiratory obstruction

Respiratory problems can occur due to a blood collection (hematoma) pressing on the airway (larynx).

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Thyroidectomy complication: Laryngeal nerve paralysis (unilateral)

Partial vocal cord paralysis (hoarseness) resulting from damage to a laryngeal nerve.

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Thyroidectomy complication: Hypothyroidism

Underactive thyroid after too much thyroid tissue is removed.

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Thyrotoxic crisis (thyroid storm)

Severe condition in a hyperthyroid patient poorly prepared for surgery; characterized by severe symptoms.

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Study Notes

Anatomy of the Thyroid Gland

  • Located in the front of the neck
  • Composed of two lobes connected by an isthmus
  • Resembles a butterfly
  • Attached to the larynx by the pretracheal fascia
  • Movable during swallowing

Thyroid Gland Cells

  • Follicular cells: Produce thyroid hormones (T3 and T4)
  • Parafollicular cells (C-cells): Produce calcitonin, which regulates calcium levels

Physiology of the Thyroid Gland

  • Hormone storage: T3 and T4 are stored in the gland as colloid
  • Hormone secretion: Hormones are secreted in response to body needs, regulated by thyroid-stimulating hormone (TSH)
  • TSH regulation: TSH secretion is controlled by a negative feedback mechanism; high thyroid hormone levels suppress TSH secretion, and vice versa
  • Hormone activity: T3 is fast-acting (hours), while T4 is slow-acting (days).
  • Hormone effects: Affect the nervous system, cardiovascular system, gastrointestinal system, and reproductive system

Goiter

  • Definition: Enlargement of the thyroid gland
  • Clinical detection: Palpable thyroid mass that moves with swallowing
  • Possible extension: Retrosternal extension is possible
  • Frequency: More common in females
  • Classifications:
    • Shape: Diffuse or nodular (multinodular or solitary)
    • Function: Physiological, colloid, hyperthyroid, hypothyroid, neoplastic

Physiological Goiter

  • Occurs due to increased physiological demands for thyroid hormones, often in puberty and pregnancy

Colloid Goiter

  • Results from iodine deficiency, leading to low thyroid hormone levels

Hyperthyroid Goiter

  • Characterized by increased thyroid hormone levels and low TSH levels

Hypothyroid Goiter

  • Results from decreased thyroid hormone levels and high TSH levels

Neoplastic Goiter

  • Includes benign and malignant thyroid tumors

Hyperthyroidism (Thyrotoxicosis)

  • Clinical features: Weight loss despite good appetite, anxiety, irritability, tremor, heat intolerance, sweating, cardiac arrhythmias, lid retraction, exophthalmos, and diarrhea.
  • Treatment: Antithyroid drugs (carbimazole), beta-blockers (propranolol), surgery, and radioactive iodine (alternatives to surgery)

Hypothyroidism (Myxedema)

  • Clinical features: Weight gain, slow speech, depression, tiredness, cold intolerance, bradycardia, dry skin, alopecia, and delayed puberty.
  • Treatment: Thyroid hormone replacement therapy (thyroxine)

Thyroid Crisis (Thyroid Storm)

  • Description: A life-threatening complication of hyperthyroidism
  • Potential triggers: Surgery, inadequate preparation for surgery
  • Clinical features: Anxiety, agitation, high fever, sweating, dehydration, diarrhea, cardiac arrhythmias, and hypertension.
  • Treatment: Supportive care (oxygen, intravenous fluids), antithyroid drugs, beta-blockers, hydrocortisone, and antipyretics (paracetamol).

Preoperative Preparation for Thyroidectomy

  • Clinical examination of the goiter
  • Evaluation of cervical lymph nodes
  • Thyroid function tests (T3, T4, TSH)
  • Indirect laryngoscopy to assess vocal cord mobility
  • Complete blood count, renal function tests, blood sugar, and blood groups
  • Chest X-ray and neck X-rays
  • ECG and echocardiography (if needed)
  • Fine-needle aspiration cytology (in suspected malignancy)

Indications for Thyroidectomy

  • Failure of medical treatment
  • Nodular goiter
  • Neoplastic goiter
  • Pressure symptoms (dyspnea, dysphagia)
  • Cosmesis (large size)

Types of Thyroidectomy

  • Lobectomy (with isthmectomy)
  • Subtotal thyroidectomy
  • Nearly total/total thyroidectomy

Potential Complications of Thyroidectomy

  • Bleeding due to slipped ligature
  • Respiratory obstruction due to tension hematoma
  • Laryngeal nerve paralysis (unilateral or bilateral)
  • Hypothyroidism
  • Hypoparathyroidism

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Related Documents

Thyroid Gland PDF

Description

Explore the essential features of the thyroid gland, including its anatomy, cellular structure, and physiological functions. Understand how hormones are produced and regulated, along with their effects on various body systems. This quiz covers key concepts associated with the thyroid gland.

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