Week 18 / Endocrine system 1 Flashcards
Q: What does the endocrine system consist of?
A: The endocrine system consists of specialised ductless glands and neurosecretory cells scattered throughout the body.
Q: What do endocrine glands/cells secrete?
A: Endocrine glands/cells secrete biologically active chemical messengers called hormones.
Q: How are hormones carried through the body?
A: Hormones are carried in the bloodstream to interact with distant target cells.
Q: What is the result of hormone interaction with target cells?
A: The interaction leads to a specific target cell response, which can affect metabolism, growth, or reproduction.
Q: What are some of the major glands in the endocrine system? [6]
the pituitary gland,
thyroid gland,
pineal gland,
hypothalamus,
adrenal gland,
pancreas, ovary, and testis.
Q: What is the function of the pituitary gland in the endocrine system?
Q: What hormones does the thyroid gland produce?
Q: What is the function of the pineal gland?
Q: What role does the hypothalamus play in the endocrine system?
Q: What does the adrenal gland produce? [3]
Q: What is the role of the pancreas in the endocrine system?
Q: What hormones do the ovaries produce?
Q: What hormones are produced by the testes?
A: The pituitary gland secretes hormones that regulate various functions, including growth, metabolism, and reproduction.
A: The thyroid gland produces hormones such as thyroxine (T4) and triiodothyronine (T3), which regulate metabolism.
A: The pineal gland produces melatonin, which helps regulate sleep-wake cycles.
A: The hypothalamus controls the pituitary gland and regulates hormone secretion that affects body temperature, hunger, and emotional responses.
A: The adrenal glands produce hormones like cortisol, adrenaline, and aldosterone, which help manage stress, metabolism, and blood pressure.
A: The pancreas produces insulin and glucagon, which regulate blood sugar levels.
A: The ovaries produce estrogen and progesterone, which regulate the female reproductive system.
A: The testes produce testosterone, which regulates male reproductive functions and secondary sexual characteristics.
Q: What is one of the main functions of the endocrine system?
A: The endocrine system is one of the body’s two major regulatory systems, responsible for regulating, integrating, coordinating, and controlling important cellular, organ, and body functions.
Q: How does the endocrine system help with cellular metabolism and balance?
A: The endocrine system regulates cellular metabolism and helps maintain water and electrolyte balance.
Q: What role does the endocrine system play in growth and reproduction?
A: The endocrine system regulates cell growth, development, and reproduction.
Q: How does the endocrine system assist with stress?
A: The endocrine system helps the body cope with stressful situations by making adaptive changes.
Q: How does the endocrine system affect the circulatory and digestive systems?
A: The endocrine system controls and integrates the circulatory and digestive systems.
Q: What are the major chemical classifications of hormones in the endocrine system?
A: The major chemical classifications of hormones are amines & amino acid derivatives, polypeptides, proteins & glycoproteins, and steroids.
Q: Can you name some examples of amines and amino acid derivative hormones?
A: Examples of amines and amino acid derivative hormones include norepinephrine (NA), adrenaline (AD), dopamine (DA), melatonin, T3, and T4.
Q: What are some examples of polypeptides, proteins, and glycoprotein hormones?
A: Examples include thyrotropin-releasing hormone (TRH), antidiuretic hormone (ADH), growth hormone (GH), follicle-stimulating hormone (FSH), and insulin.
Q: What are steroids in terms of hormone classification?
Q: Can you name some examples of steroid hormones?
A: Steroids are hormones derived from cholesterol
A: Examples of steroid hormones include cortisol, testosterone, estradiol, and progesterone.
Q: What is the difference between hydrophilic and lipophilic hormones?
A: Hydrophilic hormones are water-soluble (e.g., polypeptides, proteins), while lipophilic hormones are fat-soluble (e.g., steroid hormones).
Q: What is the vesicle-mediated pathway in hormone synthesis?
A: In the vesicle-mediated pathway, hormones are synthesized in the rough endoplasmic reticulum (rER) and packaged in secretory vesicles. This pathway is used for polypeptide/protein hormones.
Q: How are steroid hormones synthesized and released?
A: Steroid hormones are synthesized in the smooth endoplasmic reticulum (sER) and are directly released without the use of vesicles.
Q: How are peptide hormones and amines transported in the bloodstream?
A: Peptide hormones and amines are transported in the bloodstream in their free and unbound form.
Q: How are steroid and thyroid hormones transported in the bloodstream?
A: Steroid and thyroid hormones are transported in the bloodstream bound to carrier proteins.
Q: How is the timing or pattern of hormone secretion often regulated?
A: Hormone secretion can be regulated in a pulsatile or cyclical pattern.
Q: What is negative-feedback control in hormonal secretion?
Q: What is the role of end-product inhibition in negative-feedback control?
A: Negative-feedback control is a mechanism where the end-product of a process inhibits its own production, helping to maintain balance in the system.
A: End-product inhibition is when the final product of a biochemical pathway inhibits the production of the hormone or substance, thereby controlling its levels.
Q: How do hormones produce their effects on target cells?
Q: What are target cell receptors linked to?
A: Hormones produce their effects by interacting with specific receptors on target cells.
A: Target cell receptors are linked to specific effector systems in the cell, which mediate the hormone’s effects.
Q: What are the two broad types of hormonal receptors?
Q: Can you name some types of cell surface receptors?
A: The two broad types of hormonal receptors are cell surface receptors and intracellular or nuclear receptors.
A: Types of cell surface receptors include receptor-ion channels and G-protein coupled receptors.
Q: What is the role of tyrosine kinase-linked receptors in hormonal signalling?
A: Tyrosine kinase-linked receptors are involved in signaling pathways that regulate cell growth and differentiation through the phosphorylation of tyrosine residues on target proteins.
Q: Where are intracellular or nuclear receptors located, and what is their function?
A: Intracellular or nuclear receptors are located inside the cell, either in the cytoplasm or nucleus, and they regulate gene expression by interacting with DNA in response to hormone binding.
Q: What are the three main causes of endocrine disorders?
A: Endocrine disorders may result from hyposecretion, hypersecretion, or abnormal target cell responsiveness.
Q: What is hyposecretion in endocrine disorders?
Q: What is hypersecretion in endocrine disorders?
A: Hyposecretion occurs when an endocrine gland secretes too little of its hormone. It can be classified as primary, secondary, or tertiary.
A: Hypersecretion occurs when an endocrine gland secretes too much of its hormone. It can also be classified as primary, secondary, or tertiary.
Q: What does “abnormal target cell responsiveness” refer to in endocrine disorders?
A: Abnormal target cell responsiveness occurs when target cells fail to respond appropriately to hormones, even when hormone levels are normal.
Q: What is receptor down-regulation in the context of endocrine disorders?
Q: What is receptor up-regulation in endocrine disorders?
A: Receptor down-regulation refers to a decrease in the number of receptors on target cells, reducing their sensitivity to a hormone.
A: Receptor up-regulation refers to an increase in the number of receptors on target cells, enhancing their sensitivity to a hormone
Q: What are the two broad anatomical divisions of the endocrine system?
Q: Which glands are part of the central endocrine glands?
Q: Which glands are part of the peripheral endocrine glands?
A: The two broad anatomical divisions are the central endocrine glands and the peripheral endocrine glands.
A: The central endocrine glands include the hypothalamus, pituitary gland, and pineal gland.
A: The peripheral endocrine glands include the thyroid glands, adrenal glands, endocrine pancreas, parathyroid glands, and the gonads (ovaries and testes).
Q: Where are the hypothalamus and pituitary gland located?
A: Both are located in the diencephalon of the brain.
Q: What is the primary function of the hypothalamus and pituitary gland?
A: They function cooperatively as “master regulators” of the endocrine system, controlling critical homeostatic and metabolic functions.
Q: How are the hypothalamus and anterior pituitary gland connected?
Q: How are the hypothalamus and posterior pituitary gland connected?
A: They are connected by blood flow via the hypophyseal portal system, allowing the hypothalamus to regulate the anterior pituitary.
A: They are connected via the hypothalamo-hypophyseal nerve tract, which allows direct neural communication.
Q: What is the primary role of the hypothalamus in the body?
Q: Why is the hypothalamus referred to as a neuroendocrine transducer?
Q: How does the hypothalamus control the secretion of pituitary hormones?
Q: What is the role of pituitary hormones regulated by the hypothalamus?
A: The hypothalamus acts as the brain’s coordinating center for endocrine, behavioral, and autonomic nervous system functions.
A: It serves as a bridge by receiving and integrating multiple brain signals, converting electrical signals into chemical messages.
A: The hypothalamus releases chemical messengers (hormones) that regulate the secretion of pituitary hormones.
A: Pituitary hormones control the activity of peripheral endocrine glands, influencing various physiological processes.
Q: What is the role of hypothalamic releasing hormones?
Q: Where are hypothalamic releasing hormones sent?
Q: What happens after the anterior pituitary releases tropic hormones?
Q: What is the primary function of tropic hormones?
A: Hypothalamic releasing hormones stimulate the anterior pituitary to release its stored tropic hormones.
A: They are sent to the anterior pituitary.
A: The tropic hormones enter systemic circulation and signal other endocrine organs to grow and secrete their hormones.
A: Tropic hormones regulate the activity of other endocrine glands in the body.
Q: Which hypothalamic hormones stimulate anterior pituitary secretions?
Q: Which hypothalamic hormones inhibit anterior pituitary secretions?
A: The stimulatory hormones are growth hormone-releasing hormone (GHRH), thyrotropin-releasing hormone (TRH), corticotropin-releasing hormone (CRH), and gonadotropin-releasing hormone (GnRH).
A: The inhibitory hormones are somatostatin (growth hormone-inhibiting hormone, GHIH) and dopamine (prolactin-inhibiting hormone, PIH).
Q: What is the role of thyrotropin-releasing hormone (TRH)?
Q: What is the function of corticotropin-releasing hormone (CRH)?
Q: What is the role of gonadotropin-releasing hormone (GnRH)?
Q: What is the function of somatostatin (GHIH)?
Q: What is the role of dopamine (PIH)?
A: TRH stimulates the release of thyroid-stimulating hormone (TSH) from the anterior pituitary.
A: CRH stimulates the release of adrenocorticotropic hormone (ACTH) from the anterior pituitary.
A: GnRH stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary.
A: Somatostatin inhibits the release of growth hormone (GH) and thyroid-stimulating hormone (TSH) from the anterior pituitary.
A: Dopamine inhibits the release of prolactin from the anterior pituitary.
Q: What is the effect of thyrotropin-releasing hormone (TRH) on the anterior pituitary?
Q: What is the effect of corticotropin-releasing hormone (CRH) on the anterior pituitary?
Q: What is the effect of gonadotropin-releasing hormone (GnRH) on the anterior pituitary?
Q: What is the effect of growth hormone-releasing hormone (GHRH) on the anterior pituitary?
Q: What is the effect of somatostatin (GHIH) on the anterior pituitary?
Q: What is the effect of prolactin-releasing hormone (PRH) on the anterior pituitary?
Q: What is the effect of dopamine (prolactin-inhibiting hormone, PIH) on the anterior pituitary?
A: TRH stimulates the release of thyroid-stimulating hormone (TSH) and prolactin.
A: CRH stimulates the release of adrenocorticotropic hormone (ACTH).
A: GnRH stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
A: GHRH stimulates the release of growth hormone (GH).
A: Somatostatin inhibits the release of growth hormone (GH) and thyroid-stimulating hormone (TSH).
A: PRH stimulates the release of prolactin.
A: Dopamine inhibits the release of prolactin.
Q: Which hypothalamic hormones are transported and stored in the posterior pituitary?
Q: What is the function of vasopressin (ADH)?
Q: What is the role of oxytocin?
A: Vasopressin (antidiuretic hormone, ADH) and oxytocin.
A: Vasopressin helps regulate water balance in the body by increasing water reabsorption in the kidneys.
A: Oxytocin stimulates uterine contractions during childbirth and promotes milk ejection during breastfeeding.
Q: What is the pituitary gland also known as?
A: The pituitary gland is also known as the hypophysis.
Q: Why is the pituitary gland called the “Master Gland”?
A: It is called the “Master Gland” because it secretes hormones that control the function of many target glands and cells.
Q: What are the two distinct lobes of the pituitary gland?
A: The two lobes are the anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis).
Q: How many major hormones are secreted by the anterior pituitary?
A: The anterior pituitary secretes and releases six major hormones.
Q: What is the role of the posterior pituitary?
A: The posterior pituitary stores and releases two hormones: vasopressin (ADH) and oxytocin.
Q: What is the primary function of growth hormone (GH or somatotropin)?
A: Growth hormone regulates overall body growth and stimulates the growth of soft tissues and bone.
Q: How does GH promote tissue growth?
Q: What specific types of growth does GH promote in bones?
Q: How are the growth-promoting effects of GH mediated?
A: GH stimulates cell division (hyperplasia) and protein synthesis, leading to tissue hypertrophy.
A: GH promotes cartilage growth and bone growth in both length and thickness.
A: GH’s effects are mediated through the release of insulin-like growth factors (IGFs) or somatomedins, primarily by the liver.
Q: What is the role of growth hormone (GH) in intermediary metabolism?
A: GH plays an important role in intermediary metabolism, exerting largely anti-insulin effects.
Q: How does growth hormone affect lipolysis and fatty acids?
Q: How does growth hormone impact glucose metabolism?
Q: What factors modulate the secretion of growth hormone (GH)?
A: GH increases lipolysis, leading to the mobilization of free fatty acids (FFAs) for use as fuel.
A: GH inhibits peripheral cellular glucose uptake, increasing blood glucose levels and decreasing the use of glucose as fuel.
A: GH secretion is modulated by growth hormone-releasing hormone (GHRH) and somatostatin from the hypothalamus, as well as ghrelin from the gastric fundus.
Q: What are the growth-promoting actions of growth hormone (GH)?
Q: How does GH affect adipose tissue?
Q: What effect does growth hormone have on carbohydrate metabolism?
Q: How does growth hormone affect body growth?
A: GH promotes increased protein synthesis in the liver, growth in bone and cartilage, and increased lean muscle mass.
A: GH increases lipolysis, leading to increased free fatty acid (FFA) use and a decrease in adiposity (fat stores).
A: GH decreases glucose use by peripheral cells and increases blood glucose levels.
A: GH increases linear growth, especially in bone and cartilage, leading to increased size and function of body organs.
