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Questions and Answers
Questions and Answers
How do hormones primarily influence the activity of target cells?
How do hormones primarily influence the activity of target cells?
- By initiating an inflammatory response within the cell.
- By disrupting the cell's membrane integrity.
- By directly altering the cell's DNA structure.
- By binding to specific receptors on or within the cell. (correct)
What is the defining characteristic of a 'target cell' in the context of hormone action?
What is the defining characteristic of a 'target cell' in the context of hormone action?
- Its proximity to the endocrine gland releasing the hormone.
- Its ability to phagocytose and neutralize excess hormones.
- The presence of specific receptors for a particular hormone. (correct)
- Its role in producing the hormone itself.
How do steroid hormones differ from nonsteroid hormones in their mechanism of action?
How do steroid hormones differ from nonsteroid hormones in their mechanism of action?
- Steroid hormones activate secondary messengers, while nonsteroid hormones directly alter gene expression.
- Steroid hormones directly influence gene expression within the nucleus, while nonsteroid hormones typically use secondary messengers. (correct)
- Steroid hormones are fast-acting, while nonsteroid hormones have prolonged effects.
- Steroid hormones bind to surface receptors, while nonsteroid hormones enter the cell.
What property of steroid hormones allows them to easily cross cell membranes?
What property of steroid hormones allows them to easily cross cell membranes?
After a steroid hormone binds to its receptor, what is the next immediate step in its mechanism of action?
After a steroid hormone binds to its receptor, what is the next immediate step in its mechanism of action?
How does the binding of a hormone-receptor complex to DNA ultimately affect the cell?
How does the binding of a hormone-receptor complex to DNA ultimately affect the cell?
Why do steroid hormones typically have a slower, but more sustained effect compared to nonsteroid hormones?
Why do steroid hormones typically have a slower, but more sustained effect compared to nonsteroid hormones?
What is the primary reason nonsteroid hormones cannot pass through the cell membrane?
What is the primary reason nonsteroid hormones cannot pass through the cell membrane?
What is the immediate effect of a nonsteroid hormone binding to its receptor on the cell surface?
What is the immediate effect of a nonsteroid hormone binding to its receptor on the cell surface?
Why are secondary messengers important in the action of nonsteroid hormones?
Why are secondary messengers important in the action of nonsteroid hormones?
Which of the following is a common secondary messenger involved in nonsteroid hormone action?
Which of the following is a common secondary messenger involved in nonsteroid hormone action?
What is the role of the circulatory system in the function of the endocrine system?
What is the role of the circulatory system in the function of the endocrine system?
Which of the following is a function of the hypothalamus regarding the endocrine system?
Which of the following is a function of the hypothalamus regarding the endocrine system?
What role does the pineal gland play in regulating body functions?
What role does the pineal gland play in regulating body functions?
What is the primary effect of aldosterone, a hormone produced by the adrenal glands?
What is the primary effect of aldosterone, a hormone produced by the adrenal glands?
How does cortisol, secreted by the adrenal glands, affect the body's response to infection?
How does cortisol, secreted by the adrenal glands, affect the body's response to infection?
What is the immediate hormonal response initiated by the adrenal glands during times of stress or danger?
What is the immediate hormonal response initiated by the adrenal glands during times of stress or danger?
What is the difference between the roles of insulin and glucagon, both produced by the pancreas?
What is the difference between the roles of insulin and glucagon, both produced by the pancreas?
A malfunction of the pancreas that results in the insufficient production or ineffective use of insulin leads to which disease?
A malfunction of the pancreas that results in the insufficient production or ineffective use of insulin leads to which disease?
What is the primary function of thyroxine (T4), produced by the thyroid gland?
What is the primary function of thyroxine (T4), produced by the thyroid gland?
Why is iodine essential for normal thyroid function?
Why is iodine essential for normal thyroid function?
How does calcitonin, another hormone produced by the thyroid gland, affect calcium levels in the blood?
How does calcitonin, another hormone produced by the thyroid gland, affect calcium levels in the blood?
What is the principal function of parathyroid hormone (PTH) released by the parathyroid glands?
What is the principal function of parathyroid hormone (PTH) released by the parathyroid glands?
Which group of hormones is primarily secreted by the ovaries in females?
Which group of hormones is primarily secreted by the ovaries in females?
What hormone do the testes produce?
What hormone do the testes produce?
Which is the primary role of the thymus gland during childhood?
Which is the primary role of the thymus gland during childhood?
How are the hormones in the endocrine system regulated to maintain homeostasis?
How are the hormones in the endocrine system regulated to maintain homeostasis?
What is the function of Antidiuretic hormone (ADH)?
What is the function of Antidiuretic hormone (ADH)?
Which of the following is NOT secreted by Anterior Pituitary Hormone?
Which of the following is NOT secreted by Anterior Pituitary Hormone?
Which of the following is involved in rhythmic activities, such as daily sleep-wake cycles?
Which of the following is involved in rhythmic activities, such as daily sleep-wake cycles?
Which of the following does the adrenal glands NOT control?
Which of the following does the adrenal glands NOT control?
Which of the following regulated the level of glucose in the blood?
Which of the following regulated the level of glucose in the blood?
Which hormone increases the rate of cellular metabolism?
Which hormone increases the rate of cellular metabolism?
Which hormone decreases the amount of calcium in the blood?
Which hormone decreases the amount of calcium in the blood?
Which hormone increases the amount of calcium present within the blood?
Which hormone increases the amount of calcium present within the blood?
What hormone is required for the development of female secondary sex characteristics and for the development of eggs?
What hormone is required for the development of female secondary sex characteristics and for the development of eggs?
Which hormone is responsible for sperm production?
Which hormone is responsible for sperm production?
Which of the following stimulate T cell development and proper immune response?
Which of the following stimulate T cell development and proper immune response?
Which gland releases thymosin?
Which gland releases thymosin?
Questions and Answers
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Flashcards
Flashcards
Endocrine System
Endocrine System
Glands that release hormones which travel through the blood and control cells, tissues, and organs.
Hormones
Hormones
Chemicals that act by binding to receptors on cell membranes or within cells, triggering a response.
Target cells
Target cells
Cells that have receptors for a particular hormone.
Steroid Hormones
Steroid Hormones
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Nonsteroid Hormones
Nonsteroid Hormones
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Oxytocin
Oxytocin
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ADH (Antidiuretic Hormone)
ADH (Antidiuretic Hormone)
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Hypothalamus
Hypothalamus
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Pineal Gland
Pineal Gland
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Melatonin
Melatonin
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Adrenal Glands
Adrenal Glands
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Aldosterone
Aldosterone
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Cortisol
Cortisol
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Adrenaline
Adrenaline
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Insulin
Insulin
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Glucagon
Glucagon
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Diabetes
Diabetes
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Thyroid gland
Thyroid gland
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Thyroxine (T4)
Thyroxine (T4)
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Calcitonin
Calcitonin
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Parathyroid Glands
Parathyroid Glands
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Parathyroid hormone (PTH)
Parathyroid hormone (PTH)
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Estrogens
Estrogens
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Testosterone
Testosterone
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Thymus
Thymus
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Negative feedback
Negative feedback
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Pituitary Gland
Pituitary Gland
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Growth hormone (GH)
Growth hormone (GH)
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Prolactin (PRL)
Prolactin (PRL)
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Follicle Stimulating Hormone (FSH)
Follicle Stimulating Hormone (FSH)
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Luteinizing hormone (LH)
Luteinizing hormone (LH)
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Flashcards
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Study Notes
Study Notes
The Endocrine System
- The endocrine system consists of glands releasing hormones.
- Hormones travel in the blood, controlling cells, tissues, and organs.
- Hormones bind to specific chemical receptors on cell membranes or within cells.
- Cells with receptors for a hormone are called target cells.
- A hormone has no effect on cells lacking its specific receptors.
Hormone Action
- Hormones affect cells differently and fall into two general groups.
- These groups are steroid hormones and nonsteroid hormones.
Steroid Hormones
- Steroid hormones are derived from cholesterol, a lipid, and easily cross cell membranes.
- Examples of steroid hormones include estrogen and progesterone.
- A steroid hormone enters a cell by directly passing through the cell membrane.
- Once inside, it binds to a steroid receptor protein, forming a hormone-receptor complex.
- The hormone-receptor complex enters the cell nucleus.
- In the nucleus, it binds to regions of DNA that control gene expression.
- This binding starts the transcription of specific genes to messenger RNA (mRNA).
- The mRNA then directs protein synthesis in the cytoplasm.
- Steroid hormones have a slower but longer-lasting response due to changes in gene expression.
Nonsteroid Hormones
- Nonsteroid hormones include proteins, small peptides, and modified amino acids.
- Examples of nonsteroid hormones include insulin and glucagon.
- A nonsteroid hormone binds to receptors on the cell membrane.
- Nonsteroid hormones cannot generally pass through the cell membrane.
- The hormone's binding activates enzymes on the inner surface of the cell membrane.
- These enzymes release secondary messengers to relay the hormone's message within the cell.
- A common secondary messenger is cAMP (cyclic AMP), produced from ATP.
- Other secondary messengers: calcium ions, nucleotides, and fatty acids.
- Secondary messengers activate or inhibit a wide range of cell activities.
- Nonsteroid hormones have a faster but short-lived response time.
Endocrine System and Circulatory System
- The circulatory system transports hormones released by endocrine glands to cells, tissues, and organs.
Endocrine Glands and Their Hormones
- The hypothalamus makes hormones controlling the pituitary gland and stores hormones.
- The pituitary gland produces hormones regulating other endocrine glands and organs.
- The pineal gland releases melatonin, involved in rhythmic activities like sleep-wake cycles.
- The thyroid produces thyroxine, regulating metabolism throughout the body.
- The parathyroid glands release parathyroid hormone, which regulates calcium levels in the blood.
- The thymus (during childhood) releases thymosin, stimulating T cell development and immune response.
- The adrenal glands release hormones aiding the body's response to stress.
- The pancreas produces insulin to decrease blood glucose and glucagon to increase blood glucose.
- The ovaries produce estrogens and progesterone for female secondary sex characteristics and egg development.
- Progesterone prepares the uterus for a fertilized egg.
- The testes produce testosterone responsible for sperm production and male secondary sex characteristics.
Pituitary Gland
- The pituitary gland is a bean-sized structure at the brain's base.
- It produces hormones that regulate other endocrine glands and organs.
- It is divided into the anterior and posterior pituitary
Anterior Pituitary Hormones
- Thyroid Stimulating Hormone (TSH): acts on the thyroid gland
- Growth hormone (GH): stimulates protein synthesis and growth in cells
- Adrenocorticotropic Hormone (ACTH): acts on the adrenal gland
- Prolactin (PRL): stimulates milk production in nursing mothers
- Follicle Stimulating Hormone (FSH): stimulates egg production in ovaries and sperm production in testes
- Luteinizing hormone (LH): stimulates testes and ovaries
- Melanocyte Stimulating hormone (MSH): stimulates melanocytes in the skin to increase melanin production
Posterior Pituitary Hormones
- Oxytocin: stimulates uterine contractions during childbirth
- Antidiuretic hormone (ADH): acts on the kidney and stimulates the kidney to absorb water.
- Both antidiuretic hormone (ADH) and oxytocin are produced by the hypothalamus, not the pituitary gland.
- Antidiuretic hormone (ADH) and oxytocin are stored and released by the posterior pituitary gland
Hypothalamus
- The hypothalamus is located above the pituitary gland and links the central nervous system to the endocrine system.
- Its activities is influenced by hormone levels, blood substances, and sensory information from the central nervous system.
- The hypothalamus controls pituitary gland secretions.
Pineal Gland
- The Pineal Gland is a tiny endocrine gland in the brain's middle.
- Melatonin is produced here to regulate sleep.
- Darkness stimulates melatonin secretion and light inhibits it.
Adrenal Glands
- The adrenal glands sit atop the two kidneys.
- Aldosterone is vital for the reabsorption of sodium ions and regulates blood volume and pressure.
- Cortisol lowers the possibility of infection, decreases pain, reduces inflammation, and increases blood glucose.
- Adrenaline is released during stress/danger (fight or flight), by the sympathetic nervous system.
Pancreas
- Insulin decreases blood glucose, and glucagon increases blood glucose.
- Diabetes mellitus occurs when the body cannot produce or respond to insulin properly.
Thyroid Glands
- The thyroid gland is at the base of the neck, wrapping around the upper trachea.
- It produces two hormones: Thyroxine (T4) and Calcitonin.
- Thyroxine (T4) increases the rate of cellular metabolism and requires iodine.
- Calcitonin decreases the amount of calcium in the blood.
Parathyroid Glands
- Four parathyroid glands are located on the back of the thyroid.
- Parathyroid hormone (PTH) is produced in order to increase the amount of calcium in the blood.
Reproductive Glands
- In females, the ovaries produce eggs and estrogens.
- In males, the testes produce sperm and testosterone.
Thymus
- During childhood, the thymus releases thymosin.
- Thymosin stimulates T cell development and proper immune response.
Control of the Endocrine System
- The endocrine system is regulated by negative feedback mechanisms to maintain homeostasis.
- Hormones and their effects on other body systems are controlled similarly.
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