Endocrine System Overview Quiz
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Questions and Answers

Endocrine _______ – the body’s second great controlling system which influences metabolic activities of cells by means of hormones.

system

Results of endocrine system stimulation are ______________ than that of the nervous system

slower

Most of the hormone producing cells of the endocrine system is arranged in a _________ fashion with many branched extensions.

networked

The pancreas and gonads _____________ hormones and exocrine products

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

Hormones –__________ biological chemicals produced by endocrine glands in very small amounts and then released into the bloodstream and carried to the various cells of the body.

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

It is considered the counterpart of the hormone ______

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

______ is also produced by the Arcuate nucleus of the hypothalamus where it stimulates Growth Hormone release from the anterior pituitary

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

______ arise from all three germ layers

<p>Endocrine glands</p> Signup and view all the answers

Most ______ show structural changes with age, but hormone production may or may not be effected

<p>Endocrine organs</p> Signup and view all the answers

GH levels decline with age and this accounts for muscle ______

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

Estrogen is also made by ______ cells, which is the primary site of estrogen for menopausal women and for men as well.

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

There are ______ forms of estrogen at work throughout a woman’s life.

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

E2: Estradiol- the predominant form of estrogen in ______ females.

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

Estradiol is ______ for estrogenic effects a woman experiences throughout life.

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

Estradiol is also considered the most powerful form because it causes cellular proliferation and is about ______ more potent than the other two estrogens.

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

Confers female ______

<p>secondary sexual characteristics</p> Signup and view all the answers

Stimulates brain/cognitive function such as memory, mood, stamina, ambition, ______

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

Estrogen’s emergence at puberty causes epiphyseal plate closure in ______

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

Promotes ______ of body tissues

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

Functions as a pre-curser for other steroid hormones such as the ______ hormones

<p>adrenal cortical</p> Signup and view all the answers

Both glucagon and epinephrine (adrenaline) cause the ______________________________________

<p>same physiological effect</p> Signup and view all the answers

___________- when one hormone opposed the action of another

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

Speed of inactivation and removal _______________

<p>from the bloodstream</p> Signup and view all the answers

Liver enzyme _____________

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

Vary only __________________________________

<p>within specific ranges</p> Signup and view all the answers

Humoral stimuli – secretion of hormones in direct response to changing blood levels ____________________________

<p>of certain ions or nutrients</p> Signup and view all the answers

Preganglionic sympathetic nervous system (SNS) fibers stimulate the adrenal medulla to secrete catecholamines (________________________________)

<p>such as epinephrine and norepinephrine</p> Signup and view all the answers

Hormonal stimuli – release of hormones in response to hormones produced by other ______________________

<p>endocrine glands</p> Signup and view all the answers

Hormones are measured in _________ (ngs-Parts per billion)

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

Hormones regulate the metabolic ____________________

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

Adrenaline has a lag time of __________ seconds or less

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

Hormones of the menstrual and ovulatory cycles can take days or __________ to have an effect

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

Hormones tend to have _____________ effects in the body

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

Steroid hormones and thyroid hormone diffuse easily into their target cells due to their lipid nature. They bind and activate a specific intracellular _____________

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

Hormones alter cell activity by one of two mechanisms: Regulatory ____ proteins

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

The hormone-receptor complex travels to the nucleus and binds a DNA-associated ___________________________

<p>response element</p> Signup and view all the answers

Target cell activation depends upon ___________________

<p>blood levels of the hormone</p> Signup and view all the answers

Multiple hormones may act on the same target at ___________ ________________

<p>different times</p> Signup and view all the answers

The nervous system can override normal endocrine controls for example, control of blood glucose levels normally the endocrine system maintains ______________.

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

Under stress, the body needs more glucose, and the hypothalamus and the sympathetic nervous system are activated to supply ample ______________.

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

The major endocrine glands include the pineal gland, hypothalamus, and ______________.

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

In females, LH works with FSH to cause maturation of ______________.

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

POMC is a prohormone, or a _____________ to the other hormones produced by the anterior pituitary.

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

Thyroid stimulating hormone (TSH) stimulates the normal development and secretory activity of the ______________.

<p>thyroid gland</p> Signup and view all the answers

ADH helps to avoid dehydration or water overload by preventing urine ______________.

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

Alcohol inhibits ADH release and causes copious urine ______________.

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

Calcitonin targets the skeleton where it inhibits osteoclast activity and thus bone ______________.

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

Cortisol helps the body resist stress by keeping blood sugar levels ______________.

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

Glucagon promotes glycogenolysis, the breakdown of glycogen to ______________.

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

Insulin enhances transport of glucose into body cells and lowers blood ______________.

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

Thyroid hormone affects metabolism and helps in developing ___________ and reproductive capabilities.

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

Aldosterone helps regulate electrolyte ___________ of extracellular fluids.

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

The adrenal glands act as _____________ and release hormones in response to stress.

<p>endocrine organs</p> Signup and view all the answers

Flashcards

Endocrine System

The body's second major control system that influences cell metabolism through hormones. Its effects are generally slower than the nervous system.

Hormone-Producing Cells

Specialized cells within the endocrine system, arranged in a network with many extensions, maximizing contact with nearby capillaries for hormone release.

Hormones

Chemical messengers produced in small amounts by endocrine glands and released into the bloodstream to target specific cells throughout the body.

Hormone Concentration

A state where hormones are present in different concentrations or levels, causing them to perform different functions.

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Endocrine Glands

Endocrine glands, such as the pituitary, thyroid, parathyroid, adrenal, pineal, and thymus, all release hormones into the bloodstream.

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Hormonal lag time

The time it takes for a hormone to exert its effect after being released.

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Hormones and Metabolism

Hormones regulate metabolic processes in the body, influencing how cells use energy and build components.

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Second Messenger System

A type of hormonal action involving a series of intracellular molecules that relay a signal from the hormone to the cell's interior.

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Second Messenger

A molecule inside a cell that transmits a signal from the hormone to the cell interior, triggering a specific response.

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Steroid Hormones

Lipid-based hormones, including estrogen, testosterone, and cortisol, that bind to intracellular receptors and influence gene expression.

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Target Cells

The cells in the body that respond to a specific hormone, possessing receptors that bind to that hormone.

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Up-regulation

The process of a target cell increasing the number or sensitivity of its receptors in response to a specific hormone.

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Down-regulation

The process of a target cell decreasing the number or sensitivity of its receptors in response to a specific hormone.

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Synergism

A situation where two or more hormones work together to produce a greater effect than they would individually.

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Permissiveness

A situation where one hormone cannot exert its full effects without the presence of another hormone, even though they may target the same cells.

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Antagonism

A mechanism where one hormone opposes or counteracts the action of another hormone. For example, insulin lowers blood glucose levels, while glucagon raises them.

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Hormone Concentrations in Blood

The rate at which a hormone is released from a gland and the speed at which it is removed from the blood.

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Degrading Enzymes

Enzymes found in the liver, kidneys, and other tissues that break down hormones, leading to their inactivation and removal from the bloodstream.

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Humoral Stimuli

Secretion of hormones in response to changes in the levels of substances in the blood.

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Neural Stimuli

Hormone release triggered by nerve impulses.

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Hormonal Stimuli

Hormone release initiated by hormones produced by other glands.

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Nervous System Modulation

The nervous system's ability to adjust and regulate the activity of endocrine glands. It allows quick responses to changing demands.

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Control of Hormone Synthesis and Release

The process of maintaining stable hormone levels, usually achieved through negative feedback systems. The body releases hormones when needed and stops when sufficient levels are reached.

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What is the hormone that counters Leptin?

It's the hormone responsible for promoting hunger and food intake. It is secreted by the stomach.

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What type of hormone are steroid hormones?

A type of hormone derived from cholesterol and fat.

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How does the endocrine system change with age?

Age related changes in the endocrine system affect the production of growth hormone, thyroid hormone, and parathyroid hormone.

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What is muscle atrophy?

This is the loss of muscle mass as you age.

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What are ovaries?

These are the female sex organs responsible for producing eggs and hormones.

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Estradiol (E2)

The primary form of estrogen in reproductive-age females.

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Estriol (E3)

The dominant form of estrogen during pregnancy.

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Esterone (E1)

The primary form of estrogen produced during menopause.

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Estrogen

A hormone involved in the maturation of female reproductive organs and the development of secondary sexual characteristics.

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Progesterone

This hormone balances the effects of estrogen, plays a role in pregnancy, and helps mature the uterine lining.

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Testosterone

The male sex hormone responsible for development of male reproductive organs, secondary sexual characteristics, and sperm production.

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Testosterone in Males

A hormone that initiates maturation of male reproductive organs and causes the appearance of secondary sexual characteristics, like facial hair and muscle growth.

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Melatonin

A hormone produced by the pineal gland, involved in regulating sleep-wake cycles and other rhythmic variations in the body.

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Thymosin

A hormone produced by the thymus gland, essential for the development of T lymphocytes, which are crucial components of the immune system.

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Atrial Natriuretic Peptide (ANP)

A hormone produced by the heart, primarily involved in reducing blood pressure, blood volume, and sodium concentration.

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Nervous System Override

The nervous system can override normal endocrine controls, like regulating blood glucose levels during stress.

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Endocrine System's Role in Blood Glucose

The endocrine system normally maintains stable blood glucose levels.

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Stress and Glucose Demand

Under stress, the body needs more glucose to fuel the fight-or-flight response.

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Hypothalamus and Sympathetic Response

The hypothalamus and sympathetic nervous system provide ample glucose during stress by mobilizing energy reserves.

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Posterior Pituitary Function

The posterior lobe of the pituitary (neurohypophysis) receives, stores, and releases hormones produced by the hypothalamus, acting as a neuroendocrine organ.

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ADH Synthesis

The supraoptic nucleus of the hypothalamus synthesizes ADH (antidiuretic hormone) and vasopressin.

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Oxytocin Synthesis

The paraventricular nucleus of the hypothalamus synthesizes oxytocin.

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Anterior Pituitary Function

The anterior lobe of the pituitary (adenohypophysis) is composed of glandular tissue and synthesizes and secretes various hormones.

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Posterior Pituitary-Hypothalamus Connection

The posterior pituitary has a direct neural connection with the hypothalamus through the hypothalamic-hypophyseal tract.

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Anterior Pituitary-Hypothalamus Connection

The anterior pituitary does not have a direct neural connection with the hypothalamus but is connected through the hypophyseal portal system, a vascular pathway.

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Adenohypophysis Hormones

The six hormones of the adenohypophysis are abbreviated as GH, TSH, ACTH, FSH, LH, and PRL.

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POMC as Prohormone

Pro-opiomelanocortin (POMC) is a prohormone in the anterior pituitary, a precursor to other hormones like ACTH and beta-endorphin.

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Releasing Hormones

Releasing hormones stimulate the synthesis and release of hormones from the anterior pituitary, always ending with 'RH'.

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Inhibiting Hormones

Inhibiting hormones shut off the synthesis and release of hormones from the anterior pituitary, always ending with 'IH'.

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Growth Hormone Function

Growth hormone (GH) stimulates most cells, targeting bone and muscle growth, promoting protein synthesis, and encouraging fat use for energy.

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Study Notes

Endocrine System Overview

  • The endocrine system is the body's second major controlling system, influencing cell metabolism through hormones.
  • Endocrine system effects are generally slower than nervous system responses.
  • Endocrine organs are small, scattered throughout the body, and often arranged in a branched, capillary-adjacent fashion to maximize hormone release.
  • Within = endo; to secrete = crine

Endocrine Glands

  • Major endocrine glands include the pituitary, thyroid, parathyroid, adrenal, pineal, and thymus.
  • Pancreas and gonads produce both hormones and exocrine products.
  • Hypothalamus regulates neural functions and hormone release.
  • Other hormone-producing tissues include cells in the digestive tract, stomach, kidneys, heart, and brain.

Hormones

  • Hormones are biological chemicals, produced in small amounts by endocrine glands, released into the bloodstream, and transported to target cells.
  • Hormone means "to excite or arouse."
  • Hormones regulate and coordinate many bodily functions, interacting in complex ways.
  • Hormone function varies with its concentration. A hormone can have a totally different effect at a different level. This is why hormone levels are tightly regulated.
  • Hormones are measured in nanograms (ng – parts per billion) and picograms (pg – parts per trillion).
  • Hormones regulate metabolic activities, with lag times ranging from seconds to days and weeks.
  • Hormones typically have widespread, long-lasting effects.
  • Hormones are classified as amino acid-based or steroids.
  • Steroids are biologically active lipids with local hormone-like effects
  • Eicosanoids are a class of lipid hormones including leukotrienes, prostaglandins, and thromboxane.

Hormone Action

  • Hormone action involves altering cell activity through:
    • Second messenger systems (amino acid-based hormones) involving proteins like G proteins and enzymes like adenylate cyclase to produce cAMP.
    • Direct activation (steroid hormones) involving binding to intracellular receptors that move into the nucleus to affect DNA transcription and protein synthesis.

Hormone-Target Cell Specificity

  • Hormones affect only cells with specific receptors.
  • Receptors can be located on the plasma membrane or inside the cell.
  • Hormone activity depends on blood levels, receptor number, and receptor affinity.
  • Up-regulation increases receptor sensitivity; down-regulation decreases it.
  • Multiple hormones can interact with the same cells (synergism, antagonism). Some hormones require the presence of another to have a full effect.

Hormone Concentrations and Control

  • Circulating hormone levels reflect the release rate and removal speed.
  • Removal mechanisms include degrading enzymes, the kidneys, and liver enzymes.
  • Hormone regulation is often via negative feedback systems, with levels tightly controlled within narrow ranges.
  • Hormone release is triggered by:
    • Humoral stimuli (e.g., blood calcium levels)
    • Neural stimuli (e.g., SNS to adrenal medulla)
    • Hormonal stimuli (e.g., hypothalamic hormones stimulating anterior pituitary

Major Endocrine Glands

  • Include the pituitary, thyroid, parathyroid, adrenal glands, pancreas, gonads, pineal gland, and thymus.

Pituitary Gland

  • Composed of anterior (adenohypophysis) and posterior (neurohypophysis) lobes.
  • Posterior pituitary stores ADH and oxytocin, synthesized in the hypothalamus.
  • Anterior pituitary produces and releases several hormones, including GH, TSH, ACTH, FSH, LH, and PRL.
  • Pituitary and hypothalamic hormones act in complex relationships.

Metabolic Actions of Growth Hormone (GH)

  • GH stimulates liver, bone, muscle, and cartilage to produce insulin-like growth factors (IGFs), promoting protein synthesis and fat use.
  • GH also directly promotes lipolysis and inhibits glucose uptake.

Thyroid-Stimulating Hormone (TSH)

  • TSH stimulates thyroid gland activity and is controlled by TRH from the hypothalamus.
  • Rising thyroid hormone levels inhibit TSH release (negative feedback).

Adrenocorticotropic Hormone (ACTH)

  • ACTH stimulates the adrenal cortex, regulated by CRH from the hypothalamus.
  • Stress, fever, and hypoglycemia can trigger ACTH release.

Gonadotropins (FSH and LH)

  • FSH and LH regulate gonadal function and are triggered by GnRH from the hypothalamus.

Prolactin (PRL)

  • PRL stimulates milk production in females and is regulated by PRH and PIH (dopamine) from the hypothalamus.

Posterior Pituitary Hormones

  • Posterior pituitary contains axons of hypothalamic neurons, releasing ADH and oxytocin.

Oxytocin

  • Oxytocin promotes uterine contraction and milk "let-down."

Antidiuretic Hormone (ADH)

  • ADH conserves water by increasing water reabsorption in the kidneys, regulated by osmoreceptors.

Thyroid Gland

  • Produces thyroid hormone (TH), consisting of T4 (thyroxine) and T3 (triiodothyronine).
  • TH regulates metabolism, growth, development, and homeostasis.

Calcitonin

  • Calcitonin lowers blood calcium levels by inhibiting osteoclast activity and stimulating calcium uptake into bone.

Parathyroid Glands

  • Produces parathyroid hormone (PTH), which increases blood calcium levels by stimulating osteoclasts, reabsorbing calcium, and promoting calcium absorption.

Adrenal Glands

  • Two glands (medulla and cortex) atop the kidneys.
  • Adrenal medulla secretes epinephrine and norepinephrine (catecholamines).
  • Adrenal cortex produces corticosteroids:
    • Mineralocorticoids (aldosterone) regulate electrolyte balance.
    • Glucocorticoids (cortisol) help resist stress.
    • Gonadocorticoids (androgens) affect sexual function.

Pancreas

  • Dual function gland producing both exocrine enzymes for digestion and endocrine hormones like:
    • Glucagon (alpha cells) raises blood glucose.
    • Insulin (beta cells) lowers blood glucose.
    • Somatostatin (delta cells) inhibits both glucagon and insulin release

Gonads (Female)

  • Ovaries produce estrogens (E1, E2, E3) and progesterone, crucial for female development, reproduction, and secondary sexual characteristics.
  • Estrogen maintains soft tissue, stimulates bone growth, and affects cognitive function.
  • Progesterone supports uterine lining and pregnancy.

Gonads (Male)

  • Testes produce testosterone, supporting male development, reproduction, and secondary sexual characteristics.

Pineal Gland

  • Secretes melatonin, affecting sleep-wake cycles and other biological rhythms.

Thymus Gland

  • Located in the thorax, produces thymopoietins and thymosins, important for immune function.

Other Hormone-Producing Structures

  • Heart (atrial natriuretic peptide), GI tract (digestive hormones), placenta, kidneys (erythropoietin), skin (cholecalciferol), adipose tissue (leptin) also produce hormones.
  • Ghrelin, produced in the stomach, stimulates hunger.

Developmental Aspects

  • Endocrine glands develop from all three germ layers.
  • Most endocrine glands show structural changes with age, sometimes affecting hormone production.
  • Hormone levels can change with age; there are various age-related concerns.

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Description

Test your knowledge of the endocrine system, its glands, and the hormones they produce. This quiz covers the major functions and components of the endocrine system, highlighting its role in metabolism and regulation. Prepare to dive into the details of this essential body system and its interconnectedness with other physiological processes.

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