endocrine
77 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which two major systems control body homeostasis?

The nervous system and the endocrine system

What is the primary function of the endocrine glands?

To secrete hormones directly into the surrounding extracellular fluid.

What are hormones?

Signaling molecules or chemical messengers that transport information from one set of cells to another.

What is the difference between endocrine, paracrine, and autocrine functions?

<p>Endocrine functions occur when a hormone acts on a distant target cell, paracrine when a hormone acts on a neighboring cell of a different type, and autocrine when a hormone acts on the producer cell itself.</p> Signup and view all the answers

Which of the following are examples of peptide or protein hormones?

<p>Growth Hormone</p> Signup and view all the answers

Steroid hormones are stored in secretory granules within the endocrine gland.

<p>False</p> Signup and view all the answers

What are two major sites for hormone degradation and elimination in the body?

<p>Kidney</p> Signup and view all the answers

What is the primary event that initiates a hormone response?

<p>Binding of a hormone to its specific target-cell receptor.</p> Signup and view all the answers

What is the function of adenyl cyclase in the cAMP second messenger system?

<p>Adenyl cyclase catalyzes the conversion of adenosine triphosphate (ATP) to cAMP, which acts as the hormone's intracellular messenger.</p> Signup and view all the answers

Hormone receptor number remains constant throughout the lifespan of a cell.

<p>False</p> Signup and view all the answers

What are the three main control mechanisms for hormone secretion?

<p>Neural controls</p> Signup and view all the answers

What is the role of the hypothalamus in regulating pituitary gland secretion?

<p>The hypothalamus collects and integrates information from throughout the body and releases neurohormones that control the synthesis and secretion of specific anterior pituitary hormones.</p> Signup and view all the answers

What are the six major peptide hormones secreted by the anterior pituitary lobe?

<p>Thyrotropin-releasing hormone (TRH), Corticotropin-releasing hormone (CRH), Growth hormone-releasing hormone (GHRH), Growth hormone inhibitory hormone (GHIH), Gonadotropin-releasing hormone (GnRH), and Prolactin-inhibiting factor (PIF).</p> Signup and view all the answers

What is the key function of growth hormone (GH)?

<p>GH promotes skeletal development and body growth, stimulates insulin-like growth factor-1 (IGF-1),and inhibits the action of insulin on carbohydrate and fat metabolism.</p> Signup and view all the answers

What is the difference between dwarfism and gigantism?

<p>Dwarfism is a condition of short stature caused by deficient GH production in childhood, while gigantism is the result of excessive GH production before puberty, leading to abnormally tall stature.</p> Signup and view all the answers

What are some common clinical features of acromegaly?

<p>Enlarged hands and feet, prominent prognathic mandible, soft-tissue overgrowth, visceromegaly, hypertension, osteoarthritis, glucose intolerance, peripheral neuropathy, skeletal muscle weakness, headaches, and visual field defects.</p> Signup and view all the answers

What are the two major peptide hormones secreted by the posterior pituitary lobe?

<p>Antidiuretic hormone (ADH) and oxytocin.</p> Signup and view all the answers

What is the primary function of ADH?

<p>ADH regulates water excretion and reabsorption in the kidneys, playing a major role in maintaining serum osmolarity and blood volume.</p> Signup and view all the answers

Which of the following events can stimulate ADH release?

<p>Pain</p> Signup and view all the answers

What is the defining characteristic of diabetes insipidus?

<p>The inability to produce a concentrated urine due to a lack of ADH or impaired responsiveness to ADH, resulting in excessive production of dilute urine (polyuria).</p> Signup and view all the answers

Desmopressin is a selective V2 agonist, making it a preferred treatment option for central diabetes insipidus.

<p>True</p> Signup and view all the answers

What is the defining characteristic of SIADH?

<p>High circulating vasopressin levels relative to plasma osmolarity and serum sodium concentration, resulting in water retention despite hyponatremia and plasma hypotonicity.</p> Signup and view all the answers

Which of the following events can stimulate PTH secretion?

<p>Hyperphosphatemia</p> Signup and view all the answers

What is the main function of calcitonin?

<p>Calcitonin lowers serum ionized calcium levels primarily by inhibiting bone osteoclasts, shifting the balance towards osteoblasts and bone deposition.</p> Signup and view all the answers

What are the common causes of hypoparathyroidism?

<p>Inadvertent surgical removal of the parathyroid glands or damage to their blood supply during parathyroid surgery, thyroid surgery, or radical neck dissection, as well as hereditary hypoparathyroidism, parathyroid gland injury from irradiation or trauma, amyloidosis, chronic severe magnesium deficiency, and acute hypermagnesemia.</p> Signup and view all the answers

Which of the following are classic clinical signs of hypoparathyroidism?

<p>Chvostek sign</p> Signup and view all the answers

What are the three most common etiologies of primary hyperparathyroidism?

<p>Parathyroid cancer</p> Signup and view all the answers

Secondary hyperparathyroidism is usually associated with hypercalcemia.

<p>False</p> Signup and view all the answers

What are the four cell types found in the islets of Langerhans?

<p>Alpha (a) cells, Beta (ẞ) cells, Delta (8) cells, and PP (pancreatic polypeptide) cells.</p> Signup and view all the answers

What hormone is produced by the beta (ẞ) cells of the islets of Langerhans?

<p>Insulin.</p> Signup and view all the answers

What hormone is produced by the alpha (a) cells of the islets of Langerhans?

<p>Glucagon.</p> Signup and view all the answers

What is the function of somatostatin?

<p>Somatostatin is a hormone that inhibits the secretion of both insulin and glucagon, and it is also a potent inhibitor of growth hormone (GH) release.</p> Signup and view all the answers

What is the primary role of insulin in glucose metabolism?

<p>Insulin promotes the uptake of glucose into insulin-responsive tissues to meet energy needs, facilitates the storage of excess glucose as glycogen in the liver and skeletal muscle, inhibits the breakdown of stored triglyceride into glycerol and free fatty acids, and increases the uptake of amino acids into muscle for protein synthesis.</p> Signup and view all the answers

What are the four main criteria for diagnosing diabetes?

<p>A1C ≥ 6.5%, Fasting Plasma Glucose (FPG) ≥ 126 mg/dL, 2-hr Plasma Glucose ≥ 200 mg/dL during an oral glucose tolerance test, and Random Plasma Glucose ≥ 200 mg/dL.</p> Signup and view all the answers

What is the defining characteristic of Type 1 Diabetes Mellitus?

<p>An absolute deficiency or lack of insulin, requiring exogenous insulin therapy for survival.</p> Signup and view all the answers

What are some defining features of Type 2 Diabetes Mellitus?

<p>Excessive hepatic glucose production</p> Signup and view all the answers

What is the defining characteristic of diabetic ketoacidosis (DKA)?

<p>Hyperglycemia, ketonemia, and acidemia, triggered by an acute hyperglycemic event, most commonly seen in patients with Type 1 Diabetes.</p> Signup and view all the answers

What is the defining characteristic of hyperglycemic hyperosmolar state (HHS)?

<p>A life-threatening condition characterized by severe hyperglycemia and hyperosmolarity, typically seen in patients with Type 2 diabetes, but can also occur in patients without a history of diabetes.</p> Signup and view all the answers

What are the three layers of the adrenal cortex?

<p>Zona glomerulosa, zona fasciculata, and zona reticularis.</p> Signup and view all the answers

What is the main function of aldosterone?

<p>Aldosterone is a mineralocorticoid hormone that regulates sodium and potassium ion concentrations and total body fluid balance, primarily by promoting sodium reabsorption and potassium excretion in the kidneys.</p> Signup and view all the answers

What are some common symptoms of primary aldosteronism?

<p>Hypertension, hypokalemia, and metabolic alkalosis.</p> Signup and view all the answers

What is the key function of cortisol?

<p>Cortisol is a glucocorticoid hormone involved in carbohydrate, fat, and protein metabolism, playing a critical role in the body's response to stress, and mediating the effects of catecholamines.</p> Signup and view all the answers

Cortisol can be synthesized and released in response to both physical and mental stress.

<p>True</p> Signup and view all the answers

What is a common clinical sign of Cushing syndrome?

<p>Central obesity with thin extremities, florid complexion, moon facies, purplish striae, muscle weakness, and easy bruising.</p> Signup and view all the answers

What are the names of the three major categories of adrenal hormones?

<p>Mineralocorticoids, glucocorticoids, and androgens.</p> Signup and view all the answers

Primary adrenal insufficiency is characterized by a deficiency of all adrenal hormones.

<p>True</p> Signup and view all the answers

Secondary adrenal insufficiency results from inadequate ACTH production, while primary adrenal insufficiency results from destruction of the adrenal glands.

<p>True</p> Signup and view all the answers

What are the most common symptoms of acute adrenal crisis?

<p>Severe weakness, nausea, hypotension, fever, and decreasing mental status.</p> Signup and view all the answers

What is the primary function of the adrenal medulla?

<p>To secrete the catecholamines epinephrine and norepinephrine.</p> Signup and view all the answers

What are the two main metabolic pathways for catecholamines?

<p>Catechol-O-methyltransferase (COMT) and Monoamine oxidase (MAO).</p> Signup and view all the answers

What is the most common cause of pheochromocytomas?

<p>Chromaffin cells in the adrenal medulla.</p> Signup and view all the answers

What is the classical triad of symptoms for pheochromocytoma?

<p>Paroxysmal diaphoresis, tachycardia, and headache in the hypertensive patient.</p> Signup and view all the answers

What are some common clinical manifestations of pheochromocytoma?

<p>Epigastric pain</p> Signup and view all the answers

Most patients with pheochromocytoma will present with hypertension.

<p>True</p> Signup and view all the answers

Preoperative management of patients with pheochromocytoma is primarily focused on a-adrenergic blockade.

<p>True</p> Signup and view all the answers

What are some important things to consider during the perioperative management of a patient with pheochromocytoma?

<p>Cardiovascular instability, volume depletion, arrhythmias, hyperglycemia, hypoglycemia, and the potential for malignant hyperthermia during surgery.</p> Signup and view all the answers

What are some common clinical manifestations of hypothyroidism?

<p>Paresthesias</p> Signup and view all the answers

The most common cause of hypothyroidism is Hashimoto thyroiditis.

<p>True</p> Signup and view all the answers

What are some important considerations for perioperative anesthetic management of a patient with hypothyroidism?

<p>Evaluate the airway closely, monitor for exaggerated central nervous system depression with anesthetic agents, titrate muscle relaxants carefully, consider decreased hepatic metabolism and renal elimination when dosing medications, maintain normothermia, monitor ventilation closely, monitor for depressed myocardial function, and consider possible reduction in plasma volume when calculating fluid replacement.</p> Signup and view all the answers

What is the defining characteristic of myxedema coma?

<p>A rare and life-threatening syndrome that reflects severe manifestations of untreated or insufficiently treated hypothyroidism.</p> Signup and view all the answers

The thyroid gland is located anterior to the trachea between the cricoid cartilage and the suprasternal notch.

<p>True</p> Signup and view all the answers

What are the two main thyroid hormones produced by the thyroid gland?

<p>Triiodothyronine (T3) and thyroxine (T4).</p> Signup and view all the answers

What is the primary effect of thyroid hormones on cellular metabolism?

<p>To increase cellular metabolic activity, heat production, and oxygen consumption.</p> Signup and view all the answers

TSH release is stimulated by high circulating levels of T3 and T4.

<p>False</p> Signup and view all the answers

What are the most common causes of hyperthyroidism?

<p>Graves' disease, toxic nodular hyperthyroidism, and thyroiditis.</p> Signup and view all the answers

Graves' disease typically affects women more often than men.

<p>True</p> Signup and view all the answers

What are some common clinical features of hyperthyroidism?

<p>Enlarged thyroid gland, tachycardia, hand tremor, muscle weakness, weight loss, anxiety, fatigue, increased thermogenesis and oxygen consumption, Graves' ophthalmopathy, and thyroid dermopathy.</p> Signup and view all the answers

What are the three primary treatment options for thyrotoxicosis?

<p>Radioactive iodine therapy, surgery, and antithyroid drug therapy.</p> Signup and view all the answers

Total thyroidectomy is the preferred treatment for Graves' disease.

<p>False</p> Signup and view all the answers

What are some common complications associated with thyroid surgery?

<p>Damage to the recurrent laryngeal nerve (RLN), hypoparathyroidism (hypocalcemia), and neck hematoma.</p> Signup and view all the answers

What are some key anesthesia implications for patients with hyperthyroidism?

<p>Titrate muscle relaxants carefully.</p> Signup and view all the answers

What is thyroid storm?

<p>Thyroid storm is a rare but life-threatening medical emergency that represents a severe exacerbation of thyrotoxicosis.</p> Signup and view all the answers

What are some defining clinical features of thyroid storm?

<p>High fever, tachycardia, tremor, dysrhythmias, nausea and vomiting, hypertension, and potential heart failure.</p> Signup and view all the answers

What is the most common cause of hypothyroidism?

<p>Hashimoto thyroiditis.</p> Signup and view all the answers

Myxedema coma is a life-threatening condition that can develop quickly in patients with hypothyroidism.

<p>True</p> Signup and view all the answers

What are the key aspects of managing a patient with myxedema coma?

<p>Hemodynamic and ventilatory support, intravenous administration of levothyroxine, supplemental cortisol, and meticulous fluid replacement.</p> Signup and view all the answers

The presence of pheochromocytomas is always associated with a family history of endocrine disorders.

<p>False</p> Signup and view all the answers

Study Notes

The Endocrine System and Anesthesia

  • Body homeostasis is regulated by the nervous and endocrine systems, which communicate and organize the body's response to internal and external changes.
  • Endocrine glands secrete hormones directly into the extracellular fluid, regulating behavior, growth, metabolism, fluids, electrolytes, development, and reproduction.
  • Major endocrine glands include the pituitary, thyroid, parathyroid, adrenal, pancreas, ovaries, testes, and placenta.

Hormones

  • Hormones are chemical messengers transporting information between cells.
  • Released in minute quantities from endocrine glands into body fluids.
  • Types of hormones: proteins/peptides, tyrosine amino acid derivatives, steroids

Hormone Transmission

  • Endocrine: Hormone signals travel through the bloodstream to distant target cells.
  • Paracrine: Hormone signals act on neighboring cells of a different type.
  • Autocrine: Secreted hormone acts on the producer cell itself.

Hormone Receptors

  • Hormone receptors display high specificity and affinity for their specific hormone ligand.
  • Location directs hormones to target organs/cells.
  • Receptors are located on cell membranes, in the cytoplasm, or in the nucleus.
  • Membrane receptors activate intracellular pathways.
  • Intracellular receptors affect DNA and gene transcription/translation, leading to protein synthesis.

Hormone Receptor Activation

  • Membrane receptors trigger intracellular signals (second messengers) such as cAMP.
  • cAMP is generated through adenyl cyclase activation.
  • Other second messengers include calcium, diacylglycerol, inositol triphosphate, and cyclic guanosine monophosphate.
  • Thyroid and steroid hormones interact with intracellular receptors to influence gene expressions.

Hormone Secretion Regulation

  • Neural controls: Stimulate or suppress hormone secretion, such as pain, emotions, smell etc.
  • Biorhythms: Govern by genetically encoded oscillations (circadian, weekly, seasonal).
  • Feedback mechanisms: Negative feedback limits hormone production after appropriate response.
  • Positive feedback: Hormone response initiating more hormone release (e.g., LH surge before ovulation).

Pituitary Gland

  • The pituitary gland (hypophysis) is the "master endocrine gland."
  • It secretes hormones with far-reaching effects on various functions (homeostatic, developmental, metabolic, reproductive).
  • Anterior pituitary: Composed of multiple cell types including somatotrophs (GH), gonadotrophs (LH/FSH), thyrotrophs (TSH), corticotrophs (ACTH), and lactotrophs (prolactin).
  • Posterior pituitary: Stores/releases hormones synthesized in the hypothalamus (ADH/vasopressin, oxytocin).

Anterior Pituitary Disorders

  • Hyposecretion: Caused by tumors or other destructive processes.
  • Hypersecretion: Caused primarily by benign adenomas.
  • Examples of syndromes: prolactin-secreting tumors (galactorrhea, amenorrhea); ACTH-secreting tumors (Cushing disease); growth hormone-secreting tumors (acromegaly or gigantism).

Growth Hormone

  • GH (somatotropin) stimulates skeletal development/growth, IGF-1 production, and has metabolic effects.
  • Secretion is regulated by hypothalamic hormones (GH-releasing, growth hormone inhibitory factor/somatostatin).
  • Hyposecretion: Dwarfism.
  • Hypersecretion: Acromegaly (adult), gigantism (childhood).

Antidiuretic Hormone (ADH)

  • ADH regulates water reabsorption in kidneys and serum osmolarity.
  • Released by osmotic receptors in hypothalamus in response to water deprivation, volume loss, or low BP.
  • Diabetes Insipidus: Insufficient ADH or impaired renal response to ADH results in polyuria, dehydration, and hypernatremia.
  • Excessive ADH (SIADH): Excessive ADH despite normal or low serum osmolarity results in hyponatremia and water retention.

Adrenal Gland

  • Adrenal cortex (outer): Secretes mineralocorticoids (aldosterone), glucocorticoids (cortisol), androgens.
  • Adrenal medulla (inner): Secretes catecholamines (epinephrine/norepinephrine).

Adrenal Gland Disorders

  • Hyperaldosteronism: Excessive aldosterone resulting in hypertension and hypokalemia (Conn's syndrome).
  • Cushing syndrome: Excess glucocorticoids resulting in characteristic physical changes (central obesity, moon face, buffalo hump), metabolic alterations (diabetes, osteoporosis) etc.
  • Adrenal insufficiency: Deficient hormone production.

Pancreas

  • Exocrine function: Secretes digestive enzymes and bicarbonate.
  • Islets of Langerhans (endocrine): Insulin (beta cells), glucagon (alpha cells), somatostatin (delta cells).

Glucose Homeostasis

  • Glucose is the primary body fuel; its concentration is tightly regulated.
  • Insulin promotes glucose storage (glycogenesis) and utilization in various tissues.
  • Glucagon promotes glycogen breakdown and glucose release in the liver.
  • Counterregulatory hormones (GH, cortisol, epinephrine) oppose the effects of insulin.
  • Hypoglycemia: Low blood glucose.
  • Hyperglycemia: High blood glucose.
  • Diabetes Mellitus: Characterized by impaired insulin secretion or function, leading to hyperglycemia. Two main types: Type 1 (absolute insulin deficiency) and Type 2 (impaired insulin secretion/resistance).
  • Diabetic ketoacidosis (DKA): Severe metabolic complication of type 1 diabetes, characterized by hyperglycemia, ketonemia, and acidosis.
  • Hyperglycemic hyperosmolar state (HHS): Severe metabolic complication of type 2 diabetes, characterized primarily by severe hyperglycemia and dehydration.

Thyroid Gland

  • The thyroid gland produces and releases T3/T4.
  • Synthesis involves iodide trapping, oxidation, organification, and coupling reactions.
  • T4 is converted to T3 for most of its functions. 
  • Hypothyroidism: Insufficient thyroid hormone resulting in a decreased metabolic rate, cold intolerance, weight gain.
  • Hyperthyroidism: Excessive thyroid hormone resulting in an increased metabolic rate, heat intolerance, weight loss, tachycardia.

Thyroid Disorders

  • Graves disease: Autoimmune disorder that results in hyperthyroidism.
  • Thyroid storm (Thyrotoxic crisis): Acute, life-threatening complication of uncontrolled hyperthyroidism associated with high fever, tachycardia, and other cardiovascular and neurologic symptoms.

Adrenal Medulla

  • Chromaffin cells synthesize/release catecholamines. 
  • Norepinephrine and epinephrine are the key hormones.

Adrenal Medulla Disorders

  • Pheochromocytoma: Tumor of the adrenal medulla leading to excessive catecholamine release, resulting in hypertension, tachycardia, and other symptoms.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Endocrine System & Anesthesia (Student Notes) PDF
Nagelhout - Nurse Anesthesia (2017) PDF

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser