𝑮𝒐𝒊𝒕𝒓𝒆 & 𝑻𝒉𝒚𝒓𝒐𝒕𝒐𝒙𝒊𝒄𝒐𝒔𝒊𝒔 Flashcards by Anita Ogbonnaya

Describe the complete feedback mechanism of thyroid hormone regulation

Hypothalamus releases TRH (+) → Anterior pituitary releases TSH (+) → Thyroid releases T3/T4 → T3/T4 provide negative feedback to both hypothalamus and anterior pituitary

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What is the clinical significance of RLN damage during thyroid surgery and its symptoms?

Critical during thyroid surgery due to nerve’s close anatomical relationship

RLN damage causes:
1) Hoarseness
2) Difficulty breathing
3) Difficulty swallowing
4) Loss of voice.

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Differentiate between toxic and non-toxic goitre

Non-toxic goitre: Enlarged but produces normal thyroid hormone levels.

Toxic goitre: Enlarged and produces excess hormone causing hyperthyroidism

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List the complete venous drainage pathway of the thyroid gland

Superior thyroid vein → Internal jugular vein

Middle thyroid vein → Internal jugular vein

Inferior thyroid vein → Brachiocephalic veins

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Compare and contrast Graves’ disease and Hashimoto’s thyroiditis

Both are autoimmune conditions.

Graves’ causes hyperthyroidism through stimulating antibodies

Hashimoto’s causes hypothyroidism through destructive antibodies

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What are the three types of thyroid carcinoma cells and their origins?

1) Papillary - from follicular cells

2) Medullary - from parafollicular cells

3) Follicular - from follicular cells

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Why is papillary thyroid cancer considered most significant clinically?

Most common type and more malignant, characteristically spreads to lungs, bones, and brain

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Explain the mechanism of goitre formation in iodine deficiency

Iodine deficiency → Hypothyroidism → Increased TSH → Thyroid cells undergo hypertrophy & hyperplasia to compensate → Goitre formation

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What are the key components of thyroid function assessment?

1) Serum T3
2) Serum T4
3) Serum TSH
4) Thyroid autoantibody level
5) Serum thyroglobulin
6) Fine needle aspiration
7) Thyroid imaging
8) Thyroid scintigraphy

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Describe the complete surgical anatomy of thyroid gland

Located in anterior neck (C5-T1)
Weighs 20-25g
Anterior to tracheal rings 2,3,4
Two lobes connected by isthmus
Pyramidal lobe may be present
Attached to hyoid bone by levator glandulae thyroideae

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What is the clinical significance of goitrogens and list examples

Goitrogens interfere with iodine uptake leading to hypothyroidism. Examples: cabbage, broccoli, kale, cassava. Important dietary consideration in iodine-deficient regions

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Explain De Quervain’s thyroiditis: cause, pathology, and significance

Granulomatous/ Giant cell thyroiditis usually caused by viral infection.
Important cause of transient thyroid dysfunction

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Compare different types of simple/non-toxic goitre and their clinical significance

Types: 1) Diffuse 2) Multi-nodular 3) Recurrent 4) Nodule. Important for surgical planning and malignancy risk assessment

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What is the embryological development of thyroid and its clinical relevance?

Develops from thyroglossal duct, first endocrine gland to develop. Clinical relevance: thyroglossal duct cysts, ectopic thyroid tissue

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List all physiological causes of goitre and their mechanism

Pregnancy
Puberty
Breast feeding

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Describe the complete blood supply of thyroid gland

Superior thyroid artery (external carotid), Inferior thyroid artery (thyrocervical trunk), Thyroid ima artery (occasionally present)

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What is Riedel’s thyroiditis and its clinical significance?

Chronic form of thyroiditis characterized by fibrosis and infiltration by IgG & secretory plasma cells. Can cause compressive symptoms

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Explain the transport mechanism of thyroid hormones in blood

T3 & T4 bound to: 1) Albumin 2) Globulin 3) Pre-albumin. Understanding important for interpreting thyroid function tests

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What are the histological features of thyroid follicles?

Thyroid follicles— Lined by Cuboidal cells

Follicular cells— Produce T3 & T4 and have basophilic cytoplasm

Para-follicular (C) cells— Secretes Calcitonin

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List risk factors for thyroid disease with clinical significance

1) Post partum state
2) Smoking
3) Stress
4) Lithium therapy
5) Iodine excess
6) Radiation exposure
7) Family history

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Describe the complete nerve supply of thyroid gland

Sympathetic: superior, middle & inferior cervical ganglia; Parasympathetic: vagus nerve (superior laryngeal & recurrent laryngeal)

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Compare the 3 inflammatory types of thyroiditis

Riedel’s: Fibrosis & infiltration by IgG & secretory plasma cells

De Quervain’s: Caused by viral infection

Hashimoto’s: autoimmune destruction of thyroid cells

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How do drugs like amiodarone and lithium affect thyroid function?

Amiodarone: contains iodine, can cause both hyper/hypothyroidism;

Lithium: inhibits hormone release, causes hypothyroidism

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What are the anatomical relations of thyroid gland?

Anterior: strap muscles; Lateral: carotid sheath; Posterior: trachea, esophagus, parathyroids; Superior: cricoid cartilage

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What is the significance of thyroid autoantibodies?

Indicate autoimmune thyroid disease, help diagnose Graves' disease and Hashimoto's thyroiditis, monitor treatment response

Explain the role of TSH in thyroid physiology

Stimulates: 1) Thyroid growth 2) Iodine uptake 3) Hormone synthesis 4) Hormone release. Key in diagnosis and monitoring

What is a total thyroidectomy?

The entire gland is removed.

In which conditions is total thyroidectomy performed?

It is done in follicular and medullary carcinoma.

What is a Hartley-Dunhill operation?

It involves the removal of one entire lateral lobe along with the isthmus and subtotal removal of the opposite lobe.

When is a Hartley-Dunhill operation performed?

It is done in non-toxic multinodular goitre.

What are some complications of thyroidectomy?

Bleeding Laryngeal edema Infection Wound dehiscence Hoarseness/voice changes Respiratory obstruction Parathyroid insufficiency Thyroid crisis Thyroid insufficiency.

What complication of thyroidectomy can cause breathing difficulties?

Laryngeal edema and respiratory obstruction.

Which complication of thyroidectomy affects calcium levels?

Parathyroid insufficiency.

What is thyroid crisis?

A life-threatening condition caused by excessive thyroid hormone release post-thyroidectomy.

What is wound dehiscence?

The reopening of a surgical wound after thyroidectomy.

How can thyroidectomy affect the voice?

It can cause hoarseness or voice changes due to nerve damage.

List and explain the WHO grading system for goiter

Grade 0: No visible/palpable goiter Grade 1: Palpable but not visible in normal neck position Grade 2: Visible goiter

What are the three key characteristics in thyroid swelling history that suggest malignancy?

1) Short duration with rapid growth— Malignancy 2) Sudden increase in size with pain — Haemorrhage 3) Long-standing swelling — Benign Condition

Compare and contrast the consistency findings in different thyroid conditions

Soft → Graves' disease & colloid goiter Firm → Adenoma & MNG Hard → Cancer

List all CNS symptoms of hyperthyroidism

Tremors, Preference to cold, Excitability, Irritability, Insomnia

What are the complete CVS manifestations of hyperthyroidism?

Palpitations, Precordial chest pain, Dyspnea on exertion

Describe the metabolic manifestations of hyperthyroidism

Weight loss with hyperphagia, Diarrhea, Amenorrhea

List and explain all eye signs in thyroid eye disease

1) Stellwag's: Absence of normal blinking 2) Von Graefe's: Upper lid lag 3) Joffrey's: Absence of forehead wrinkling 4) Möbius: Lack of convergence 5) Gifford: Difficulty everting upper lid 6) Naffziger's: Protruded eyes visible from behind

What are the key aspects to examine in thyroid inspection?

Site, Size & Shape (bilobar or butterfly), Surface (smooth/irregular/nodular), Skin over swelling, Surrounding skin, Movement with swallowing

Describe the proper technique for examining thyroid from behind the patient

1) Place hand on swelling & ask patient to swallow 2) Palpate each thyroid lobe for surface & consistency 3) Check mobility 4) Palpate each carotid pulse one after another

What are the three grades of thyroid eye disease and their features?

Mild: Lid retraction & widening of palpebral fissure; Moderate: Orbital fat deposition causing bulging & Joffrey's sign; Severe: Intra-orbital edema, raised IOP, diplopia, ophthalmoplegias

List all investigations required for thyroid swelling evaluation

1) Thyroid function test 2) X-ray 3) Ultrasound 4) CT scan 5) Fine needle aspiration cytology 6) Radioactive iodine scan

What are the complete indications for thyroidectomy?

1) Thyrotoxicosis therapy 2) Benign/malignant tumors 3) Cosmetic purpose 4) Establish definitive diagnosis 5) Pressure symptoms (dysphagia/respiratory distress)

Compare and contrast different types of thyroidectomy and their indications

Hemi-thyroidectomy: One lobe removed, for benign diseases; Sub-total: 8gm tissue retained, for toxic/non-toxic MNG; Near-total: Both lobes except small portion, for papillary carcinoma

What is the complete approach to examining upper and lower limb in thyroid disease?

Check: 1) Static hand tremor 2) Fine tremors 3) Pre-tibial myxedema 4) Ankle reflex

List the key features in thyroid swelling history that suggest benign condition

1) Long-standing swelling 2) Slow growth 3) No associated pain or compression symptoms

What are the causes of dyspnea in thyroid disease?

1) Malignant or retrosternal goiter 2) Thyrotoxicosis 3) Tracheal compression

Describe the ocular manifestations of hyperthyroidism

1) Double vision 2) Protruding eyeball 3) Eye muscle weakness 4) Lid retraction

What are the integumentary changes in hyperthyroidism?

Hair loss, Pruritus, Palmar erythema

List the symptoms of toxic goiter

Weight gain, Cold intolerance, Constipation, Slow thought & speech, Muscle fatigue, Hoarseness of voice

What is exophthalmos and its pathophysiology in Graves' disease?

Immune system mistakenly attacks muscles & fatty tissues around eyes causing them to swell, leading to eye protrusion

Compare the different types of goiter based on surface characteristics

Smooth: Adenoma, Puberty goiter, Graves' disease; Irregular: Thyroid Ca; Nodular: Multi-nodular goiter

What are the differential diagnoses for anterior neck swelling?

Thyroid mass, Thyroglossal cyst, Laryngocele, Dermoid cyst, Lymph nodes

List all preventive measures for thyroid disease

1) Prevent iodine deficiency 2) Avoid goitrogens (cabbage) 3) Avoid triggering drugs

What complications necessitate immediate thyroidectomy?

1) Tracheal obstruction 2) Hemorrhage in nodule 3) Severe compression symptoms

Describe the complete genito-urinary symptoms in thyroid disease

Oligomenorrhea/Amenorrhea, Occasional urinary frequency changes

What are the key points to note in skin examination over thyroid swelling?

Temperature, Tenderness, Surface characteristics, Skin attachment

List all treatments available for hyperthyroidism

Surgery, Radio-active iodine, Anti-thyroid medication, Beta-blockers

What are the characteristic features of movement with swallowing in thyroid swelling?

Movement restricted in malignancy, retrosternal goiter & large goiter; Free movement in benign conditions

Compare the different causes of thyroid enlargement based on consistency

Soft: Early Graves'; Firm: Established Graves'/MNG; Hard: Malignancy/Hashimoto's

What are the complete GI manifestations of thyroid disease?

Diarrhea in hyperthyroidism, Constipation in hypothyroidism, Weight changes, Appetite changes

What is the weight of the thyroid gland?

20-25g

What is the location of the thyroid?

Located in anterior neck (C5-T1)

Classify Goitre

* Non-toxic goitre * Toxic goitre *Neoplastic goitre *Inflammatory goitre *Rare

What are the types of neoplastic goitre?

*Papillary *Medullary *Follicular *Anaplastic

List 10 features of hyperthyroidism

CNS— Tremors, Heat intolerance, Sweating, Irritability CVS— Palpitations, Chest pain, Dyspnoea Metabolic— Weight loss with hyperphagia, Diarrhoea Eye— Double vision, protruding Eyeball Others— Amenorrhoea, Hair loss

𝑮𝒐𝒊𝒕𝒓𝒆 & 𝑻𝒉𝒚𝒓𝒐𝒕𝒐𝒙𝒊𝒄𝒐𝒔𝒊𝒔 Flashcards

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