Endocrine System Quiz

<p>It inhibits the secretion of growth hormone (A)</p> Signup and view all the answers

<p>Luteinizing hormone (LH) (A)</p> Signup and view all the answers

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

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

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

<p>To act as chemical signals for distant target sites (A)</p> Signup and view all the answers

<p>Insulin regulating blood sugar levels (A)</p> Signup and view all the answers

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

<p>They release hormones directly into the bloodstream. (C)</p> Signup and view all the answers

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

<p>Specific hormones must bind to their receptors. (C)</p> Signup and view all the answers

<p>In the cytoplasm or nucleus. (A)</p> Signup and view all the answers

<p>Steroid hormones. (C)</p> Signup and view all the answers

<p>They activate or repress gene expression. (D)</p> Signup and view all the answers

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

<p>By binding to extracellular receptors. (D)</p> Signup and view all the answers

<p>Facilitating digestion in the stomach. (B)</p> Signup and view all the answers

<p>They are derived from cholesterol. (C)</p> Signup and view all the answers

<p>It regulates the release of hormones from the pituitary gland. (D)</p> Signup and view all the answers

<p>To communicate and transport neurohormones from the hypothalamus to the anterior pituitary. (A)</p> Signup and view all the answers

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

<p>Breast development and milk production. (D)</p> Signup and view all the answers

<p>It increases basal metabolism rate (BMR). (A)</p> Signup and view all the answers

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

<p>Growth hormone (GH) (B)</p> Signup and view all the answers

<p>Both positive and negative feedback. (A)</p> Signup and view all the answers

<p>It lowers blood calcium levels. (B)</p> Signup and view all the answers

<p>Sella turcica. (C)</p> Signup and view all the answers

<p>T4 has a long half-life compared to T3. (A)</p> Signup and view all the answers

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

<p>Damage to the central nervous system (CNS). (A)</p> Signup and view all the answers

<p>They release calcitonin. (A)</p> Signup and view all the answers

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

<p>By enzymatic modification in target cells. (A)</p> Signup and view all the answers

<p>It stimulates the uptake of calcium from the intestine. (C)</p> Signup and view all the answers

<p>It decreases calcium levels. (C)</p> Signup and view all the answers

<p>Both corticosteroids and catecholamines. (A)</p> Signup and view all the answers

<p>A decline in blood volume or blood pressure. (B)</p> Signup and view all the answers

<p>On the principal cells of the cortical distal tubules and collecting duct. (B)</p> Signup and view all the answers

<p>Retention of sodium and water along with secretion of potassium. (B)</p> Signup and view all the answers

<p>Aldosterone binds to a cytoplasmic receptor. (D)</p> Signup and view all the answers

<p>Decreased calcium levels due to reduced parathyroid hormone. (B)</p> Signup and view all the answers

Hormones interact with target cells by binding to specific receptors located on the cell surface, in the cytoplasm, or in the nucleus. These receptors are programmed to recognize and bind to specific hormones, triggering a chain of events.

The effect of a hormone on a target cell depends on the cell's programmed response to the hormone. Different cell types may respond differently to the same hormone.

Hormones trigger specific cellular responses by activating or repressing genes within the target cell. This process involves hormone-receptor complexes binding to DNA in the nucleus, acting as transcription factors.

Peptide hormones are chains of amino acids synthesized on ribosomes of the ER of endocrine cells. They are water-soluble and bind to receptors on the cell surface.

Amino acid derivatives are hormones derived from tyrosine or tryptophan. Examples include catecholamines (epinephrine, norepinephrine, dopamine) and thyroid hormones (T4, T3).

Steroid hormones are lipids derived from cholesterol produced by the gonads, adrenal cortex, and kidneys. They are fat-soluble and bind to intracellular receptors.

Hormones that are lipid-soluble (nonpolar) are called lipophilic. They are fat-soluble and bind to intracellular receptors. Examples include steroid hormones and thyroid hormones.

Hormones that are water-soluble (polar) are called hydrophilic. They bind to extracellular receptors, such as those found on the cell surface. Most other hormones (except steroid and thyroid) are hydrophilic.

The anterior pituitary gland produces a diverse range of hormones that regulate key functions related to growth, puberty, stress response, and metabolism.

It stimulates the thyroid gland to release thyroid hormones, which are vital in regulating metabolism.

It's responsible for the release of corticosteroids from the adrenal glands, which are vital for managing stress and other bodily functions.

It regulates the production of testosterone in men and plays a key role in ovulation in females.

It governs the release of FSH and LH from the anterior pituitary, essential for sex hormone production and reproductive function.

Hormones that dissolve in fats and pass through cell membranes to bind to receptors inside the target cell.

The process of maintaining a stable internal environment in an organism.

A mechanism where a change in a regulated variable triggers a response that counteracts the initial change, restoring the variable to its set point.

A mechanism where a change in a regulated variable triggers a response that amplifies the original change, pushing the variable further away from its set point.

Hormones released by neurons directly into the bloodstream, acting as messengers to distant target cells.

Hormones that are produced in one cell and act on nearby cells.

Hormones that are produced in a cell and act on the same cell that produced it.

The primary endocrine organs produce hormones directly, while secondary endocrine organs produce hormones as a secondary function.

The hypothalamus, located in the brain, regulates the secretion of hormones from the pituitary gland by releasing its own hormones.

The pituitary gland is a small gland located at the base of the brain, considered the 'master gland' because it controls the function of other endocrine glands.

The anterior pituitary gland is responsible for producing and releasing various hormones, including growth hormone (GH), thyroid-stimulating hormone (TSH), and prolactin (PRL).

The posterior pituitary gland doesn't produce hormones, but it stores and releases two hormones: antidiuretic hormone (ADH) and oxytocin. These hormones are produced in the hypothalamus.

The hypophyseal portal system is a network of blood vessels that connect the hypothalamus to the anterior pituitary. This system allows the hypothalamus to regulate the release of hormones from the anterior pituitary.

The hypothalamus controls the release of anterior pituitary hormones by releasing its own hormones, which act as 'on' or 'off' switches for the anterior pituitary.

Positive feedback loops amplify a response, leading to increased secretion of a particular hormone. Negative feedback loops dampen a response, causing a decrease in hormone secretion.

Hormones travel through the bloodstream to reach target cells. Once they reach their targets, they bind to specific receptors, triggering a chain of events that ultimately leads to a specific cellular response.

A condition caused by insufficient production of antidiuretic hormone (ADH), leading to excessive water loss in urine and dehydration.

Growth hormone (GH) excess during childhood, resulting in abnormally tall stature.

Excess growth hormone (GH) secretion in adulthood, causing enlargement of hands, feet, and facial features.

The thyroid gland is located in the anterior neck, inferior to the larynx.

The thyroid gland produces hormones, primarily T3 and T4 which contain tyrosine and iodine.

Thyroid hormone T3 is considered more potent than T4, and is responsible for most of its biological effects.

Production of T3 and T4 requires iodine and the interaction of follicle cells and colloid lumen.

Calcitonin, secreted by parafollicular cells, lowers blood calcium levels by influencing bone and kidney activity.

A steroid hormone produced by the adrenal cortex, aldosterone plays a crucial role in regulating blood volume and blood pressure by promoting sodium reabsorption and potassium secretion in the kidneys.

Aldosterone primarily impacts the principal cells of the distal tubules and collecting duct in the kidneys. It increases sodium reabsorption and water reabsorption while promoting potassium secretion.

Aldosterone secretion is triggered by a decline in blood volume or blood pressure, often due to events like severe hemorrhage. This mechanism helps restore blood pressure and volume to normal levels.

Aldosterone combines with a cytoplasmic receptor within the target cells. This hormone-receptor complex initiates transcription in the nucleus, leading to the production of new proteins responsible for sodium and potassium transport.

The net effect of aldosterone action is to retain sodium and water in the body while excreting potassium. This helps maintain blood pressure and volume by adjusting electrolyte balance.

Parathyroid hormone (PTH) is a vital hormone that plays a key role in regulating calcium levels in the body. It is secreted by the parathyroid glands, four tiny glands located near the thyroid gland.

PTH increases calcium levels in the blood by stimulating the release of calcium from bones, increasing calcium absorption in the intestines, and reducing calcium excretion in the kidneys.

PTH has the opposite effect on calcium compared to calcitonin, which lowers calcium levels in the blood. They work in a balanced way to ensure proper calcium homeostasis.