Tireóide e Paratireóides: Sistema Endócrino

Anatomia e etc. com Natalia Reinecke

1 May 201811:18

Summary

TLDRThis educational video delves into the anatomy and function of the thyroid gland, a vital endocrine organ located below the larynx, shaped like a butterfly. It explains the production of thyroid hormones T3 and T4, which regulate metabolism, and calcitonin, which helps control calcium levels. The video also touches on conditions like goiter and hypothyroidism, emphasizing the importance of iodine for hormone synthesis. It further discusses the parathyroid glands' role in calcium regulation through the hormone parathyroid hormone, contrasting its effects with calcitonin.

Takeaways

😀 The thyroid gland is an endocrine gland located below the larynx, shaped like a butterfly or bow tie, with two lobes on either side of the trachea.
🔬 The thyroid produces hormones T3 (triiodothyronine) and T4 (thyroxine), which contain iodine in their composition and are essential for metabolism.
📈 Iodine is crucial for thyroid hormone production; a deficiency can lead to goiter, or an enlarged thyroid, due to increased TSH levels.
🌐 TSH (thyroid-stimulating hormone), produced by the pituitary gland, stimulates the thyroid to produce T3 and T4, illustrating a feedback mechanism in hormone regulation.
🚫 Hypothyroidism occurs when the thyroid does not produce enough hormones, leading to symptoms like weight gain, fatigue, and sensitivity to cold.
♨️ Hyperthyroidism is the opposite, where the thyroid produces too much hormone, causing symptoms like weight loss, irritability, and intolerance to heat.
🩺 Both hypothyroidism and hyperthyroidism can be diagnosed through blood tests that measure levels of thyroid hormones and TSH.
🦴 Calcitonin, another hormone produced by the thyroid, helps regulate calcium levels in the blood by reducing calcium reabsorption in bones and kidneys.
🔄 The parathyroid glands, located near the thyroid, produce parathyroid hormone (PTH) that works in opposition to calcitonin, increasing blood calcium levels.
💊 Iodized salt is used to prevent iodine deficiency, ensuring adequate thyroid hormone production and highlighting the importance of iodine in public health.

Q & A

What is the location of the thyroid gland?
-The thyroid gland is located below the larynx, just below the thyroid cartilage, which is also known as the Adam's apple.
What is the shape of the thyroid gland?
-The thyroid gland has a shape similar to a butterfly or a tie, with two lateral lobes connected by a central part called the isthmus.
What hormones are produced by the thyroid gland?
-The thyroid gland produces the hormones thyroxine (T4), triiodothyronine (T3), and calcitonin.
Why is iodine important for the thyroid gland?
-Iodine is essential for the production of T3 and T4 hormones by the thyroid gland. A deficiency in iodine can lead to an enlargement of the thyroid gland known as goiter.
What is the role of TSH in the thyroid gland function?
-TSH, or Thyroid Stimulating Hormone, is produced by the pituitary gland and stimulates the thyroid gland to produce T3 and T4 hormones.
What is the purpose of the parathyroid glands located near the thyroid gland?
-The parathyroid glands produce parathyroid hormone (PTH), which works alongside calcitonin to regulate calcium levels in the blood, with PTH increasing calcium levels in opposition to calcitonin.
What is the effect of insufficient iodine on the thyroid gland?
-Insufficient iodine can lead to an increase in TSH production, potentially causing hypertrophy of the thyroid gland and a condition known as endemic goiter.
What are the symptoms of hypothyroidism?
-Symptoms of hypothyroidism include decreased basal metabolic rate, weight gain, fatigue, increased sensitivity to cold, and facial and peripheral edema.
What are the symptoms of hyperthyroidism?
-Symptoms of hyperthyroidism include increased basal metabolic rate, weight loss, irritability, sleep problems, intolerance to heat, and increased blood pressure.
How does calcitonin help regulate calcium levels in the body?
-Calcitonin decreases calcium levels in the blood by reducing bone resorption and stimulating osteoclast activity, as well as by reducing calcium reabsorption in the kidneys.
How does parathyroid hormone (PTH) affect calcium levels in the blood?
-Parathyroid hormone increases calcium levels in the blood by stimulating bone resorption and calcium release from bones, as well as by promoting calcium reabsorption in the kidneys.

Outlines

00:00

🦋 Introduction to the Thyroid Gland

The video begins by introducing the topic of the thyroid gland, emphasizing its importance and inviting viewers to subscribe for more anatomy-related content. The speaker mentions the availability of anatomy-themed t-shirts and provides a link for interested viewers. The thyroid gland is described as an endocrine gland located below the larynx, identifiable by the thyroid cartilage, commonly known as the Adam's apple. The gland's butterfly-like shape, with two lobes connected by a central isthmus, is highlighted. The hormones produced by the thyroid gland, T3 (triiodothyronine) and T4 (thyroxine), are introduced, noting their iodine content and the gland's requirement for iodine and specific amino acids for hormone synthesis. The role of TSH (thyroid-stimulating hormone) from the pituitary gland in stimulating the thyroid gland is also discussed, along with the concept of negative feedback and the impact of iodine deficiency on thyroid size and function.

05:01

🌡 Hormonal Functions and Thyroid Disorders

This section delves into the functions of the thyroid hormones T3 and T4, explaining their role in increasing the basal metabolic rate of cells, protein synthesis, nervous system maturation, and cellular respiration. The video contrasts the effects of hypothyroidism, where the thyroid gland does not produce enough hormones, leading to symptoms like weight gain, fatigue, and cold intolerance, with hyperthyroidism, where overproduction of thyroid hormones results in weight loss, irritability, and heat intolerance. The importance of measuring both thyroid hormones and TSH for diagnosing thyroid disorders is emphasized. The video also introduces calcitonin, another hormone produced by the thyroid gland, which helps regulate blood calcium levels by reducing calcium reabsorption in bones and kidneys. The balance between calcitonin and parathyroid hormone, produced by the parathyroid glands, is discussed, with the latter increasing blood calcium levels.

10:01

🔄 Hormonal Balance and Thyroid Health

The final paragraph summarizes the functions of T3 and T4 hormones, reiterating their role in metabolism and the potential for thyroid disorders such as goiter and both hypothyroidism and hyperthyroidism. The video concludes with a brief mention of calcitonin's role in reducing blood calcium levels, contrasting it with the actions of parathyroid hormone, which increases blood calcium levels. The speaker encourages viewers to like the video for support and expresses hope that the content was understood, signing off with an invitation to the next lesson.

Mindmap

Keywords

💡Thyroid gland

The thyroid gland is an endocrine gland located below the larynx, described in the video as resembling a butterfly or bow tie due to its shape. It plays a crucial role in the body's metabolism by producing hormones. The video discusses the gland's location, structure, and function, emphasizing its importance in regulating various bodily processes.

💡Parathyroid glands

Parathyroid glands are small endocrine glands attached to the posterior surface of the thyroid gland. Although small, they are essential for calcium regulation in the body. The video explains that these glands produce parathyroid hormone, which works in opposition to calcitonin to maintain calcium balance.

💡Hormones

Hormones are chemical messengers produced by glands in the endocrine system. The video discusses three key hormones related to the thyroid and parathyroid glands: thyroxine (T4), triiodothyronine (T3), and calcitonin. It explains how these hormones regulate metabolism and calcium levels, respectively.

💡Iodine

Iodine is a crucial element for the production of thyroid hormones. The video highlights the importance of iodine in the diet, as it is necessary for the synthesis of T3 and T4. It also mentions the historical use of iodized salt to prevent iodine deficiency disorders such as goiter.

💡TSH (Thyroid-Stimulating Hormone)

TSH, produced by the pituitary gland, is an essential hormone that stimulates the thyroid gland to produce T3 and T4. The video explains the feedback mechanism involving TSH and how it can lead to conditions like goiter if the thyroid gland does not receive enough iodine.

💡Metabolism

Metabolism refers to the chemical processes that occur within a living organism to maintain life. The video discusses how thyroid hormones, T3 and T4, increase the basal metabolic rate, affecting protein synthesis, respiration rate, and overall energy expenditure.

💡Goiter

Goiter is a condition characterized by the enlargement of the thyroid gland, often due to iodine deficiency. The video describes how excessive TSH production can lead to goiter, which is a visible swelling at the front of the neck.

💡Hypothyroidism

Hypothyroidism is a condition where the thyroid gland does not produce enough hormones, leading to a slowed metabolism. The video outlines symptoms such as weight gain, fatigue, and cold intolerance that can result from hypothyroidism.

💡Hyperthyroidism

Hyperthyroidism is the opposite of hypothyroidism, where the thyroid gland produces excessive amounts of hormones, leading to an increased metabolic rate. The video mentions symptoms like weight loss, irritability, and heat intolerance associated with this condition.

💡Calcitonin

Calcitonin is a hormone produced by the thyroid gland that helps regulate calcium levels in the blood. The video explains how calcitonin reduces calcium levels by acting on bones and kidneys, contrasting its function with that of parathyroid hormone.

💡Parathyroid hormone (PTH)

Parathyroid hormone, produced by the parathyroid glands, is essential for calcium homeostasis. The video contrasts its action with calcitonin, noting that PTH increases blood calcium levels by promoting bone resorption and renal calcium reabsorption.

Highlights

Introduction to the thyroid gland and its location below the larynx.

Description of the thyroid cartilage and its relation to the 'Adam's apple'.

Explanation of the thyroid gland's butterfly or bow tie shape.

Mention of the two lobes of the thyroid gland and their position relative to the trachea.

Discussion on the hormones produced by the thyroid: T4, T3, and calcitonin.

Importance of iodine in the production of thyroid hormones.

Role of the amino acid tyrosine in the synthesis of T3 and T4.

The stimulation of thyroid hormone secretion by TSH from the pituitary gland.

Negative feedback loop involving iodine, TSH, and thyroid hormone production.

Impact of iodine deficiency on thyroid function and the development of goiter.

Function of T3 and T4 hormones in increasing the basal metabolic rate of cells.

Effects of hypothyroidism, including symptoms and causes.

Effects of hyperthyroidism, including symptoms and causes.

Role of calcitonin in regulating blood calcium levels.

Introduction to the parathyroid glands and their location on the posterior side of the thyroid.

Function of parathyroid hormone (PTH) in increasing blood calcium levels.

Balance between calcitonin and parathyroid hormone in calcium regulation.

Summary of thyroid gland functions and the impact of its hormones on metabolism and calcium levels.

Encouragement for viewers to like the video and look forward to the next lesson.