Podcast
Questions and Answers
Which symptom is NOT associated with hyperthyroidism?
Which symptom is NOT associated with hyperthyroidism?
What effect does calcitonin have on calcium levels in the blood?
What effect does calcitonin have on calcium levels in the blood?
How does parathyroid hormone (PTH) primarily function to increase blood calcium levels?
How does parathyroid hormone (PTH) primarily function to increase blood calcium levels?
What is the primary role of calcitonin?
What is the primary role of calcitonin?
Signup and view all the answers
Which condition is characterized by high parathyroid hormone levels?
Which condition is characterized by high parathyroid hormone levels?
Signup and view all the answers
What is a likely symptom of hypoparathyroidism?
What is a likely symptom of hypoparathyroidism?
Signup and view all the answers
Which of the following actions contributes to the effect of PTH?
Which of the following actions contributes to the effect of PTH?
Signup and view all the answers
What distinguishes Grave’s Disease from other types of hyperthyroidism?
What distinguishes Grave’s Disease from other types of hyperthyroidism?
Signup and view all the answers
What stimulates the pineal gland to increase melatonin secretion at night?
What stimulates the pineal gland to increase melatonin secretion at night?
Signup and view all the answers
Which hormone is secreted by the testis and is vital for the development of secondary male characteristics?
Which hormone is secreted by the testis and is vital for the development of secondary male characteristics?
Signup and view all the answers
What role does atrial natriuretic peptide (ANP) play in the body?
What role does atrial natriuretic peptide (ANP) play in the body?
Signup and view all the answers
Which hormone does the gastrointestinal tract secrete to aid in digestion?
Which hormone does the gastrointestinal tract secrete to aid in digestion?
Signup and view all the answers
What is the primary function of erythropoietin (EPO) secreted by the kidneys?
What is the primary function of erythropoietin (EPO) secreted by the kidneys?
Signup and view all the answers
Which hormone secreted by the thymus gland is essential for immune system development?
Which hormone secreted by the thymus gland is essential for immune system development?
Signup and view all the answers
What is a significant effect of estrogen on female physical development?
What is a significant effect of estrogen on female physical development?
Signup and view all the answers
What two hormones does the liver secrete related to growth and metabolism?
What two hormones does the liver secrete related to growth and metabolism?
Signup and view all the answers
What effect does low blood pressure have on aldosterone secretion?
What effect does low blood pressure have on aldosterone secretion?
Signup and view all the answers
Which hormone is secreted by the adrenal medulla?
Which hormone is secreted by the adrenal medulla?
Signup and view all the answers
What is a common symptom of Addison’s disease?
What is a common symptom of Addison’s disease?
Signup and view all the answers
How does cortisol affect energy usage in the body?
How does cortisol affect energy usage in the body?
Signup and view all the answers
What condition is characterized by increased levels of cortisol and leads to rapid weight gain?
What condition is characterized by increased levels of cortisol and leads to rapid weight gain?
Signup and view all the answers
What triggers the reduction of melatonin secretion in the morning?
What triggers the reduction of melatonin secretion in the morning?
Signup and view all the answers
Which symptom is associated with Cushing Syndrome?
Which symptom is associated with Cushing Syndrome?
Signup and view all the answers
What is the primary role of aldosterone in the body?
What is the primary role of aldosterone in the body?
Signup and view all the answers
What is the primary function of glucagon in the body?
What is the primary function of glucagon in the body?
Signup and view all the answers
What stimulates the secretion of insulin?
What stimulates the secretion of insulin?
Signup and view all the answers
Which process does insulin NOT facilitate?
Which process does insulin NOT facilitate?
Signup and view all the answers
What is the role of glycogenolysis in relation to glucagon?
What is the role of glycogenolysis in relation to glucagon?
Signup and view all the answers
Which statement about Type 1 diabetes is correct?
Which statement about Type 1 diabetes is correct?
Signup and view all the answers
Which hormone's secretion is primarily affected by hypoglycemia?
Which hormone's secretion is primarily affected by hypoglycemia?
Signup and view all the answers
What is the result of lipolysis in relation to glucagon action?
What is the result of lipolysis in relation to glucagon action?
Signup and view all the answers
What distinguishes Type 2 diabetes from Type 1 diabetes?
What distinguishes Type 2 diabetes from Type 1 diabetes?
Signup and view all the answers
What are the two primary hormones produced by the thyroid gland?
What are the two primary hormones produced by the thyroid gland?
Signup and view all the answers
What is the role of Calcitonin in the body?
What is the role of Calcitonin in the body?
Signup and view all the answers
Which hormone is responsible for stimulating the thyroid gland to secrete T3 and T4?
Which hormone is responsible for stimulating the thyroid gland to secrete T3 and T4?
Signup and view all the answers
What characterizes hyperthyroidism?
What characterizes hyperthyroidism?
Signup and view all the answers
Which type of hormone feedback mechanism regulates T3 and T4 levels in the body?
Which type of hormone feedback mechanism regulates T3 and T4 levels in the body?
Signup and view all the answers
What condition is characterized by swollen eyelids and cold intolerance?
What condition is characterized by swollen eyelids and cold intolerance?
Signup and view all the answers
Which hormone requires iodine for its synthesis?
Which hormone requires iodine for its synthesis?
Signup and view all the answers
What is the primary effect of increased levels of T3 and T4 in the body?
What is the primary effect of increased levels of T3 and T4 in the body?
Signup and view all the answers
Study Notes
Endocrine System 2 (MD203)
- Lecture Aim: Basics of endocrine system and hormone action. Functions of thyroid, adrenal, pineal, and parathyroid glands. Role of pancreas in blood glucose regulation. Hormonal regulation via feedback mechanisms. Disorders of thyroid, adrenal cortex (Addison's, Cushing's), and parathyroid glands. Impacts of hyper/hypoglycemia and diabetes types. Clinical implications: Metabolic effects of growth hormone and calcium homeostasis.
The Thyroid Gland
- Located in front of the trachea below the larynx.
- Produces thyroxine (T4) and triiodothyronine (T3).
- These hormones are essential for physical growth, mental development, and reproductive system maturation.
- Calcitonin is released due to hypercalcemia to reduce calcium levels in the blood.
Thyroid Hormones
- Iodine is essential for hormone synthesis.
- Thyroxine (T4): 4 iodine atoms, less potent, long duration.
- Triiodothyronine (T3): 3 iodine atoms, more potent, short duration.
- T4 and T3 secretion is regulated by TSH (thyroid-stimulating hormone) secreted by the pituitary gland, stimulated by TRH (thyrotropin-releasing hormone).
- T3 and T4 levels are regulated by negative feedback; increasing levels decrease TSH and TRH production.
Disorders of Thyroid Hormones
-
Hypothyroidism: Characterized by low thyroid hormone levels.
- Cretinism (infants): Physical and mental retardation.
- Myxedema (adults): Swollen eyelids, facial puffiness, weight gain, cold intolerance, and slow heart rate.
-
Hyperthyroidism: Characterized by high thyroid hormone levels.
- Grave's Disease: Symptoms include exophthalmos (bulging eyes), weight loss, heat intolerance, tachycardia (fast heart rate), and CNS excitability.
- Goiter: Enlarged thyroid gland.
- Exophthalmos: Bulging eyes
Role of Calcitonin in Maintaining Calcium Homeostasis
- Calcitonin is released in response to hypercalcemia (high calcium levels).
- Its function is to stimulate urinary calcium excretion, inhibit calcium absorption in the intestines, and stimulate osteoblasts to deposit calcium in bones.
Parathyroid Gland
- Four parathyroid glands located on the back of the thyroid lobes.
- Produces parathyroid hormone (PTH).
- PTH secretion is stimulated by hypocalcemia (low calcium levels) in the blood.
- PTH increases blood calcium levels.
- PTH works with calcitonin to maintain normal calcium levels in the blood.
Role of PTH in Maintaining Calcium Homeostasis
- PTH stimulates calcium reabsorption from the kidneys.
- PTH stimulates calcium absorption in the intestines.
- PTH stimulates osteoclasts to dissolve bones and release calcium into the blood.
Disorders of Parathyroid Hormones
- Hypoparathyroidism: Low PTH levels lead to low blood calcium, causing muscle cramping and convulsions.
- Hyperparathyroidism: High PTH levels lead to low bone density and calcium deposits in body tissues and organs, impairing their functioning. This can also cause kidney stones.
The Endocrine Pancreas
- Hormone-producing cells in the pancreas are called islets of Langerhans.
- Alpha cells produce glucagon.
- Beta cells produce insulin.
Glucagon
- Secreted in response to hypoglycemia (low blood sugar).
- Increases blood glucose levels by:
- Glycogenolysis (breakdown of glycogen into glucose).
- Gluconeogenesis (conversion of amino acids to glucose).
- Lipolysis (breakdown of fats into glycerol, which is converted to glucose).
Insulin
- Secreted in response to hyperglycemia (high blood sugar).
- Decreases blood glucose levels by:
- Transporting glucose from the blood into cells.
- Glycogenesis (conversion of glucose to glycogen for storage in liver and muscles).
Diabetes
- Type 1 Diabetes: The immune system attacks and destroys the insulin-producing beta cells in the pancreas (autoimmune disease), leading to an inability to produce insulin.
- Type 2 Diabetes: The pancreas produces insulin, but the body's cells do not respond properly to it (insulin resistance).
The Adrenal Gland
- Hormones secreted by the adrenal cortex:
- Aldosterone
- Cortisol
- Hormones secreted by the adrenal medulla:
- Epinephrine
- Norepinephrine
Aldosterone
- Secreted in response to low blood pressure (hypotension).
- Increases sodium and water retention, increasing blood pressure.
Cortisol
- Increases the use of fats and amino acids for energy but decreases glucose use.
- Has an anti-inflammatory effect.
- High levels of cortisol suppress the immune system and make the body susceptible to infections.
Disorders of Adrenal Cortex Hormones
-
Addison's Disease:
- Caused by decreased levels of cortisol and aldosterone due to adrenal cortex atrophy.
- Symptoms include hypoglycemia, low blood pressure, weight loss, and craving for salty food.
-
Cushing Syndrome:
- Caused by increased levels of cortisol and aldosterone due to pituitary gland tumor secreting high ACTH.
- Symptoms include moon-shaped face, buffalo hump, rapid weight gain, and hair loss.
The Pineal Gland
- Secretes melatonin, a sleep hormone.
- Melatonin secretion is regulated by light levels.
- High light (morning) inhibits melatonin secretion, promoting wakefulness.
- Low light (night) stimulates melatonin secretion, promoting sleep.
The Gonads (Testes and Ovaries)
-
Testes (Testosterone):
- Important for male reproductive system development and secondary male characteristics (deepened voice, body hair, increased muscle mass).
-
Ovaries (Estrogen):
- Important for female reproductive system development and secondary female characteristics (increased fat, breast development).
Organs with Secondary Endocrine Functions
- Heart (ANP): Releases atrial natriuretic peptide to reduce blood pressure.
- Kidneys (EPO): Release erythropoietin to maintain red blood cell homeostasis.
- Gastrointestinal tract (Gastrin): Secretes gastrin for digestion.
- Liver (IGF-1, Angiotensinogen): Releases Insulin-like growth factor-1 for body growth, and Angiotensinogen to increase blood pressure.
- Thymus (Thymosin): Releases thymosin to develop the immune system.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the fundamentals of the endocrine system focusing on hormone actions, particularly thyroid functions. Understand the roles of various glands, hormonal feedback mechanisms, and clinical implications related to metabolic disorders. Dive into the specifics of thyroid hormones and their impact on growth and development.
