Endocrine System Hormones Quiz

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Questions and Answers

Which of the following hormones is released in an episodic pattern?

Prolactin

Thyroid Stimulating Hormone (TSH)

Growth Hormone (correct)

Cortisol

What is the primary role of the hypothalamus in the endocrine system?

Integrating information and controlling pituitary gland activity (correct)

Directly producing and releasing all major hormones

Regulating body temperature and sleep cycles

Acting as a relay station for all sensory information

Which hormone is responsible for stimulating the adrenal gland to produce cortisol?

GHRH

GnRH

CRH (correct)

TRH

Which of the following is NOT a characteristic of negative feedback regulation in hormone secretion?

Involves the production of more hormones in response to a stimulus (B) Signup and view all the answers

What is the primary mechanism by which estrogen regulates its own production?

Positive feedback (C) Signup and view all the answers

Which of the following is a characteristic of a primary endocrine disorder?

Over-secretion from a target gland (B) Signup and view all the answers

What is the main structural similarity between TSH, LH, and FSH?

They all have the same alpha subunit (C) Signup and view all the answers

Which of the following is an example of product regulation in hormone secretion?

Insulin secretion in response to high blood glucose levels (D) Signup and view all the answers

What is the most likely consequence of long-term hydrocortisone therapy?

Suppression of the HPA axis (D) Signup and view all the answers

Which of the following is a key difference between male and female hormone secretion?

Males have a higher ratio of androgens to estrogens than females (A) Signup and view all the answers

Which of the following hormones is NOT primarily responsible for secondary sex characteristics in both males and females?

Growth hormone (C) Signup and view all the answers

What is the main function of somatostatin in the endocrine system?

Inhibiting growth hormone and TSH secretion (A) Signup and view all the answers

Which of the following is NOT a component of the HPG axis?

Adrenal gland (D) Signup and view all the answers

Which of the following hormones is DIRECTLY responsible for stimulating follicle maturation in females?

FSH (C) Signup and view all the answers

Which of the following best describes the mechanism by which the hypothalamus regulates the pituitary gland?

Producing hormones that regulate pituitary hormone secretion (A) Signup and view all the answers

Which of the following is NOT a type of hormone regulation described in the provided content?

Hormonal feedback (B) Signup and view all the answers

Which hormone acts on the testes to produce testosterone?

LH (D) Signup and view all the answers

Which of the following hormones are produced by the anterior pituitary?

ACTH, FSH, LH, GH (D) Signup and view all the answers

Which cell type in the testes is responsible for producing androgens?

Leydig cells (A) Signup and view all the answers

What is the primary function of the hypothalamus in hormone secretion?

To regulate and control the release of hormones from the pituitary gland. (A) Signup and view all the answers

What is the primary androgen produced by the testes?

Testosterone (A) Signup and view all the answers

What is the role of Sertoli cells in sperm development?

Binding testosterone and increasing its concentration around developing sperm (C) Signup and view all the answers

Which of the following is a characteristic of hydrophilic hormones?

They are stored in secretory granules. (A) Signup and view all the answers

What is the key enzyme involved in the conversion of androgens to estrogens in granulosa cells?

P450 aromatase (C) Signup and view all the answers

What is the most abundant protein in blood, which binds to various steroids and thyroid hormones?

Albumin (C) Signup and view all the answers

Which of the following hormonal mechanisms utilizes secondary signaling molecules?

LH and ACTH signaling through G protein-coupled receptors (GPCRs). (A) Signup and view all the answers

What is the role of testosterone during fetal development in males?

Development of internal male organs like the epididymis and seminiferous tubules (A) Signup and view all the answers

Which hormone is primarily responsible for the cyclical pattern of hormone secretion in females?

Estradiol (B) Signup and view all the answers

What is the primary function of the adrenal medulla?

Production of catecholamines such as epinephrine and norepinephrine. (A) Signup and view all the answers

Which of the following is an example of a circadian secretion pattern?

Cortisol levels peaking in the morning. (B) Signup and view all the answers

What is the role of DHT during puberty in males?

Growth of external male organs and male pattern hair growth (A) Signup and view all the answers

What is the effect of the negative feedback mechanism of testosterone on hormone secretion?

Decreased testosterone secretion (A) Signup and view all the answers

What is the significance of the blood-brain barrier in hormonal regulation?

It prevents most hormones from directly accessing the brain. (A) Signup and view all the answers

What is the key difference between the hormonal control of reproduction in males and females?

Females have a cyclical pattern of hormone secretion, while males have a relatively constant pattern (C) Signup and view all the answers

Which of the following is NOT a factor that can stimulate hormone secretion?

Dietary fiber (B) Signup and view all the answers

What are the main cell types found in the seminiferous tubules?

Sertoli cells and developing sperm cells (B) Signup and view all the answers

What is the function of the adrenal glomerulosa layer?

Secretion of aldosterone (C) Signup and view all the answers

Which of the following statements accurately describes the action of steroid hormones within the cell?

They enter the nucleus and directly bind to DNA, influencing gene expression. (B) Signup and view all the answers

How do steroid hormones primarily exert their effects?

By binding to receptors and altering gene expression (A) Signup and view all the answers

What is the role of aromatase in steroid hormone action?

Converting testosterone to estradiol (D) Signup and view all the answers

Which of the following hormones is primarily secreted in an episodic pattern?

Growth hormone (D) Signup and view all the answers

What is the primary function of the parathyroid hormone (PTH)?

Regulation of blood calcium levels (D) Signup and view all the answers

What is the effect of five alpha reductase deficiency?

Underveloped external genitalia until puberty (B) Signup and view all the answers

Which of the following is NOT a function of testosterone in adults?

Closure of the epiphyses in bones (C) Signup and view all the answers

Which of the following is an example of paracrine hormone secretion?

Testosterone stimulating sperm production in the testes. (A) Signup and view all the answers

Which of the following statements is TRUE regarding the hormonal control of reproduction?

LH and FSH act directly on the hypothalamus (A) Signup and view all the answers

Which of the following is an example of a hormone that can cross the blood-brain barrier?

Cortisol (A) Signup and view all the answers

What is the primary function of the adrenal reticularis layer?

Synthesis of androgens (A) Signup and view all the answers

Which of the following hormones is primarily responsible for stimulating the conversion of androgens to estrogens in the granulosa cells of the follicle?

FSH (C) Signup and view all the answers

During which phase of the menstrual cycle does the corpus luteum form?

Luteal phase (B) Signup and view all the answers

Which of the following statements accurately describes the role of estrogen in the follicular phase?

Estrogen stimulates the production of FSH receptors on granulosa cells. (C) Signup and view all the answers

What is the main function of the thecal cells in the ovary?

Producing androgens (A) Signup and view all the answers

Which hormone exhibits a surge or peak during ovulation?

LH (C) Signup and view all the answers

What hormone is responsible for stimulating the development of the granulosa cells in the ovary?

FSH (D) Signup and view all the answers

Which of the following statements about the luteal phase is TRUE?

The corpus luteum produces both progesterone and estrogen. (C) Signup and view all the answers

What is the primary function of the primordial follicle?

Being the starting point for follicle development (A) Signup and view all the answers

What is the main reason for the variability in the length of the menstrual cycle?

Variations in the length of the follicular phase (B) Signup and view all the answers

Which of the following hormones is NOT produced by the ovary?

FSH (B) Signup and view all the answers

How does estrogen influence the development of the dominant follicle?

Estrogen stimulates the production of FSH receptors on granulosa cells, leading to positive feedback. (D) Signup and view all the answers

What is the primary function of inhibin in the ovary?

Inhibiting the production of FSH (A) Signup and view all the answers

Which of the following events is NOT directly associated with the luteal phase of the menstrual cycle?

Surge in LH levels (D) Signup and view all the answers

Which of the following statements accurately reflects the relationship between the pituitary gland and ovarian function?

The pituitary gland releases LH and FSH, which regulate ovarian function. (C) Signup and view all the answers

During the follicular phase, which hormone has the strongest positive feedback effect on the follicle?

Estrogen (B) Signup and view all the answers

What is the main difference between LH and FSH?

LH acts primarily on the thecal cells, while FSH acts primarily on the granulosa cells. (B) Signup and view all the answers

A patient presents with fatigue, cold intolerance, and weight gain. Their TSH levels are high, and free T4 levels are low. What is the most likely diagnosis?

Definite hypothyroidism (A) Signup and view all the answers

Which of the following conditions can affect thyroid function tests (TFTs) and potentially lead to misinterpretation?

Acquired pituitary dysfunction (C) Signup and view all the answers

What is the primary cause of hypothyroidism worldwide?

Iodine deficiency (B) Signup and view all the answers

A patient has normal T4 and T3 levels, but a low TSH level. What is the most likely diagnosis?

Subclinical hyperthyroidism (B) Signup and view all the answers

What is the biological function of T3 compared to T4?

T4 is more abundant but T3 is biologically more active (D) Signup and view all the answers

Which of the following is NOT considered a symptom of hypothyroidism?

Intolerance to heat (B) Signup and view all the answers

What is the most common cause of hyperthyroidism?

Grave's disease (A) Signup and view all the answers

What is the main difference between primary and secondary hypothyroidism?

Secondary hypothyroidism results from pituitary dysfunction, while primary is caused by thyroid gland failure (B) Signup and view all the answers

Which of the following is NOT a common treatment goal for hyperthyroidism?

Reduce TSH levels (A) Signup and view all the answers

Which statement accurately describes the role of thyroid hormone in the cardiovascular system?

Thyroid hormone increases beta receptors, potentially leading to atrial fibrillation (C) Signup and view all the answers

Which of the following is NOT a common symptom of hyperthyroidism?

Fatigue (C) Signup and view all the answers

What is the half-life of free T4?

6-7 days (A) Signup and view all the answers

What is the primary function of the hypothalamus in the regulation of thyroid hormone production?

Stimulates the pituitary gland to produce TSH (C) Signup and view all the answers

Which of the following is NOT a secondary cause of hypothyroidism?

Hashimoto's thyroiditis (D) Signup and view all the answers

What is the most common treatment for hyperthyroidism that involves the use of radioactive iodine?

Radioactive iodine therapy (A) Signup and view all the answers

Which of the following hormones is NOT derived from an amino acid?

Cortisol (A) Signup and view all the answers

What is the main function of the endocrine system?

To regulate and coordinate biological processes (D) Signup and view all the answers

Which type of hormone signaling involves the release of a hormone that acts on the same cell that secreted it?

Autocrine (C) Signup and view all the answers

Which hormone is produced by the adrenal gland and is involved in the 'fight-or-flight' response?

Epinephrine (D) Signup and view all the answers

Which of the following gland pairs DOES NOT produce hormones that regulate blood glucose levels?

Hypothalamus and Pituitary Gland (B) Signup and view all the answers

Which of these hormones is responsible for stimulating growth in bone and muscle?

Growth Hormone (A) Signup and view all the answers

Why are steroid hormones generally slower-acting than amino acid derived hormones?

Steroid hormones influence gene expression and protein synthesis, which takes time. (D) Signup and view all the answers

What is a potential consequence of endocrine dysfunction?

Disruption of critical biological processes, like reproduction and metabolism (A) Signup and view all the answers

What primarily stimulates the development of multiple follicles during the early follicular phase?

High FSH levels (C) Signup and view all the answers

What effect does high estradiol levels have during the early follicular phase?

Suppresses FSH production (B) Signup and view all the answers

Which hormone is primarily produced by the corpus luteum after ovulation?

Progestin (B) Signup and view all the answers

During the luteal phase, which hormones are typically at low levels?

FSH and LH (A) Signup and view all the answers

What role does the dominant follicle play in the mid-cycle surge of LH?

It produces high levels of estradiol (A) Signup and view all the answers

What occurs to smaller follicles as a result of increased estrogen levels?

They regress due to decreased FSH (C) Signup and view all the answers

What is the effect of progesterone on the endometrial glands during the luteal phase?

Stimulates secretion from these glands (C) Signup and view all the answers

What initiates the cycle of follicular growth after menstruation?

Regression of the corpus luteum (A) Signup and view all the answers

How does the presence of progesterone impact LH and FSH during the luteal phase?

Leads to slow pulses (D) Signup and view all the answers

What characterizes the proliferative phase of the menstrual cycle from the uterine perspective?

Growth-promoting effects due to estrogen (A) Signup and view all the answers

What leads to the breakdown of the endometrial lining at the end of the luteal phase?

Loss of estrogen and progesterone (D) Signup and view all the answers

What is a significant effect of the follicles in the early follicular phase?

Production of estradiol leading to FSH regulation (A) Signup and view all the answers

What occurs during menstruation?

Sloughing off of the endometrial lining, blood supply, and glands (D) Signup and view all the answers

What hormone is dominant during the luteal phase?

Progesterone (C) Signup and view all the answers

What is the primary function of the placenta during pregnancy?

Facilitating nutrient exchange (B) Signup and view all the answers

Which structure is formed from the remnants of the follicle after ovulation?

Corpus luteum (A) Signup and view all the answers

What type of cervical mucus is typically present during the follicular phase?

Clear and thin (C) Signup and view all the answers

What hormone secreted by the placenta is critical for maintaining early pregnancy?

Human Chorionic Gonadotropin (hCG) (A) Signup and view all the answers

Which change occurs in the uterus during the luteal phase?

Glandular secretion and nutrient preparation (D) Signup and view all the answers

What occurs around 8 to 12 weeks of gestation concerning placental hormone production?

The placenta begins to produce its own estrogen and progesterone (C) Signup and view all the answers

Which of the following is NOT a function of trophoblast cells?

Ovum development (A) Signup and view all the answers

What is the primary role of placental lactogen (hPL) during pregnancy?

Influencing glucose metabolism (B) Signup and view all the answers

How does progesterone affect uterine contractility during pregnancy?

Decreases contractility (D) Signup and view all the answers

What physiological change occurs in the cardiovascular system during pregnancy?

Increased cardiac output (B) Signup and view all the answers

Which structure does the embryo embed into during the luteal phase?

Endometrium (B) Signup and view all the answers

What type of cellular change occurs in the follicular phase of the menstrual cycle?

Proliferative changes (B) Signup and view all the answers

What role does estrogen play in the uterine changes during pregnancy?

Facilitates proliferation of the endometrial layer (D) Signup and view all the answers

Which hormone is primarily responsible for the growth of the endometrial lining during the early cycle?

Estrogen (C) Signup and view all the answers

What is the main role of progesterone during the luteal phase?

Secrete nutrients for a fertilized embryo (D) Signup and view all the answers

What occurs during the transition to the follicular phase at the end of the cycle?

Sloughing off of the endometrial lining (A) Signup and view all the answers

Which of the following is a consequence of reduced estrogen after menopause?

Vaginal dryness and atrophy of estrogen-dependent tissues (A) Signup and view all the answers

What happens to the levels of LH and FSH after menopause due to decreased estrogen?

They increase due to reduced feedback (D) Signup and view all the answers

At what point in the menstrual cycle does ovulation occur?

At the end of the follicular phase (B) Signup and view all the answers

Which event characterizes the follicular/proliferative phase of the menstrual cycle?

High estrogen production affecting the reproductive tract (A) Signup and view all the answers

What is one function of estrogen outside the reproductive tract?

Lower blood pressure through vasodilation (A) Signup and view all the answers

Which statement about estrogen's role at puberty is correct?

It stimulates the growth of the uterus and breasts. (D) Signup and view all the answers

During menopause, which change occurs regarding androgen production?

The adrenal gland begins to produce androgens. (B) Signup and view all the answers

Which phase follows directly after ovulation?

Luteal Phase (D) Signup and view all the answers

How does estrogen affect the brain?

It inhibits GnRH, LH, and FSH release. (B) Signup and view all the answers

What is a characteristic effect of progesterone during the luteal phase?

Promotes thick cervical mucus that prevents sperm penetration (D) Signup and view all the answers

What event occurs during the proliferative phase of the uterine cycle?

Regrowth of the endometrial lining (C) Signup and view all the answers

What is the primary reason for the increase in cardiac output during pregnancy?

To supply blood to the placenta and kidneys. (D) Signup and view all the answers

How does blood pressure typically change during normal pregnancy?

It decreases despite increased blood volume. (C) Signup and view all the answers

What role does cortisol play in gestational insulin resistance?

It contributes to increased insulin resistance. (C) Signup and view all the answers

What initiates the positive feedback loop during labor?

Uterine contractions causing cervical stretch. (A) Signup and view all the answers

What causes gestational diabetes?

Severe insulin resistance in the mother. (C) Signup and view all the answers

What is the role of estrogen in labor initiation?

It increases oxytocin receptor activity. (B) Signup and view all the answers

Why is lactation not a reliable method of birth control?

Prolactin response to stimulation decreases over time. (C) Signup and view all the answers

What is one of the key physiological effects during mid to late pregnancy?

Enhanced fat deposition for energy storage. (D) Signup and view all the answers

What initiates the secretion of oxytocin during labor?

Cervical stretch caused by uterine contractions. (A) Signup and view all the answers

How does the fetal adrenal gland contribute to labor timing?

It increases DHEA production for estrogen synthesis. (C) Signup and view all the answers

What effect does progesterone generally have during most of pregnancy?

Maintains uterine quiescence. (D) Signup and view all the answers

What is the primary function of prolactin during lactation?

To promote glandular tissue growth in the breast. (B) Signup and view all the answers

Which hormone primarily stimulates myometrial contractions at labor?

Estrogen. (D) Signup and view all the answers

What happens to insulin levels during pregnancy?

They increase overall but with decreased effectiveness. (C) Signup and view all the answers

What mechanism is primarily involved in increasing calcium levels in the blood?

Stimulating calcium absorption in the intestines (D) Signup and view all the answers

Which hormone is secreted in response to high blood calcium levels to lower calcium concentration?

Calcitonin (A) Signup and view all the answers

How does parathyroid hormone promote calcium retention in the body?

By increasing renal calcium reabsorption (C) Signup and view all the answers

What is one of the primary symptoms of hypercalcemia?

Renal stones (B) Signup and view all the answers

Which of the following conditions is characterized by low bone mineral density?

Osteoporosis (A) Signup and view all the answers

What is a common cause of hypocalcemia?

Vitamin D deficiency (A) Signup and view all the answers

Which of the following hormones indirectly activates osteoclasts by binding to osteoblasts?

Parathyroid hormone (A) Signup and view all the answers

What is the primary action of glucagon in the liver?

Stimulates glycogenolysis (D) Signup and view all the answers

What role does vitamin D play in calcium homeostasis?

It enhances intestinal calcium absorption. (A) Signup and view all the answers

Which factor is known to inhibit glucagon secretion?

High glucose levels (B) Signup and view all the answers

What is a characteristic of insulin secretion in Type II diabetes during a meal?

Suppressed or absent first-phase insulin secretion (D) Signup and view all the answers

What is the significance of DXA scans in assessing bone health?

They predict the risk of vertebral fractures. (D) Signup and view all the answers

What is the role of cortisol during fasting?

Enhances gluconeogenesis and glycogenolysis (D) Signup and view all the answers

Which of the following statements is true regarding osteoporosis in men?

It can occur due to chronic illnesses and medications. (C) Signup and view all the answers

Which factor is primarily associated with Type II diabetes progression?

Genetic defects related to insulin receptor (A) Signup and view all the answers

What physiological mechanism does glucagon use to increase glucose output from the liver?

Activates protein kinase A (C) Signup and view all the answers

What distinguishes epinephrine's action from that of glucagon?

Acts on both liver and muscle for glycogenolysis (A) Signup and view all the answers

What is a common misconception regarding treatment requirements at the onset of Type II diabetes?

Insulin is not usually required at onset (D) Signup and view all the answers

How does rapid action of parathyroid hormone manifest within minutes?

Stimulating osteoblasts to release calcium (C) Signup and view all the answers

Which of the following substances stimulates glucagon secretion?

Amino acids from protein meals (A) Signup and view all the answers

What is one of the major differences between Type I and Type II diabetes in terms of patient symptoms at diagnosis?

Patients are usually very symptomatic in Type I (D) Signup and view all the answers

What factor significantly affects bone strength in post-menopausal women?

Estrogen deficiency (B) Signup and view all the answers

Which medication class can increase calcium excretion in urine?

Loop diuretics (D) Signup and view all the answers

During prolonged fasting, what sequential effect do glucagon and epinephrine have?

Enhance gluconeogenesis (B) Signup and view all the answers

Which population has been identified to show strong ethnic characteristics in relation to Type II diabetes?

Native Americans, African Americans, and Hispanics (D) Signup and view all the answers

What is a major effect of cortisol on adipose tissue?

Stimulates lipolysis (D) Signup and view all the answers

What is the function of calcitonin in calcium homeostasis?

Lowers blood calcium levels. (C) Signup and view all the answers

What is the probable reason for the increased risk of atherosclerosis in Type II diabetes?

Increased free fatty acids and dyslipidemia (A) Signup and view all the answers

What is a significant consequence of cortisol excess as seen in Cushing's syndrome?

Weight gain and truncal obesity (A) Signup and view all the answers

What is a significant sign indicating kidney dysfunction in an older patient with Type II diabetes?

Presence of albumin in urine (B) Signup and view all the answers

Which of the following hormones has a slower effect due to its mechanism of action?

Cortisol (C) Signup and view all the answers

Which of these effects is NOT caused by glucagon?

Promotes amino acid uptake (C) Signup and view all the answers

Which hormone can positively influence glucagon secretion during exercise?

Epinephrine (B) Signup and view all the answers

What condition can arise from cortisol deficiency, as seen in Addison's disease?

Hyperpigmentation of the skin (D) Signup and view all the answers

What is the primary action of amylin in the body?

Inhibits glucagon secretion (D) Signup and view all the answers

How does insulin primarily affect fat tissue?

Promotes fatty acid synthesis (D) Signup and view all the answers

What is the role of GLUT-4 in skeletal muscle cells?

Facilitates glucose uptake (B) Signup and view all the answers

Which hormone released from beta cells is crucial for insulin secretion when glucose levels rise?

Amylin (D) Signup and view all the answers

What is the primary metabolic pathway that generates glucose from non-carbohydrate sources?

Gluconeogenesis (D) Signup and view all the answers

Which hormone primarily promotes the synthesis of glycogen in the liver?

Insulin (C) Signup and view all the answers

What effect does growth hormone (GH) have on insulin sensitivity?

Decreases insulin sensitivity (A) Signup and view all the answers

Which process describes the conversion of acetyl-CoA into fatty acids?

Lipogenesis (C) Signup and view all the answers

Which factor is known to stimulate insulin secretion?

Glucagon (B) Signup and view all the answers

What is the main activity of glucagon in the body?

Promotes glycogenolysis (D) Signup and view all the answers

Which hormone serves to inhibit glucagon secretion?

Amylin (A) Signup and view all the answers

What is the primary role of CCK in carbohydrate and lipid metabolism?

Alters insulin secretion (B) Signup and view all the answers

Which of the following factors inhibits growth hormone secretion?

Free fatty acids (C) Signup and view all the answers

Which of these hormones is considered catabolic and increases glucose levels?

Glucagon (D) Signup and view all the answers

What role does GIP (Gastric Inhibitory Peptide) play in insulin secretion?

Stimulates beta cell proliferation (D) Signup and view all the answers

How does insulin affect gluconeogenesis in the liver?

Stimulates glycogen synthesis (B) Signup and view all the answers

What is the function of GLUT4 transporters in the body?

Transport glucose into cells (C) Signup and view all the answers

What does insulin do to glucose concentration in the blood?

Decreases it (A) Signup and view all the answers

What is the effect of insulin on potassium levels in cells?

Increases potassium uptake (A) Signup and view all the answers

Which amino acid transporter is increased by insulin in skeletal muscle?

SNAT-2 (C) Signup and view all the answers

Which hormone is synthesized in the pancreas and promotes fat storage?

Insulin (D) Signup and view all the answers

What is a significant function of GLP-1 in relation to glucose regulation?

Enhances insulin secretion (A) Signup and view all the answers

What is the initial molecule synthesized before insulin is activated?

Proinsulin (A) Signup and view all the answers

What triggers the release of insulin from beta cells?

All of the above (D) Signup and view all the answers

Which hormone is known for its anabolic functions in protein synthesis?

Growth Hormone (B) Signup and view all the answers

Which organ does not respond to insulin by enhancing glycolysis and glycogen synthesis?

Lungs (C) Signup and view all the answers

Insulin actions involve various speeds. What action occurs rapidly after insulin binding?

GLUT4 transport (B) Signup and view all the answers

How does somatostatin affect insulin and glucagon secretion?

Inhibits both (C) Signup and view all the answers

What initiates the secretion of thyroid-stimulating hormone (TSH)?

Thyrotropin-releasing hormone (TRH) (A) Signup and view all the answers

Which substance inhibits iodide transport into the thyroid gland?

Lithium (D) Signup and view all the answers

What is the primary active form of thyroid hormone?

Triiodothyronine (T3) (A) Signup and view all the answers

How are T3 and T4 primarily transported in circulation?

Bound to thyroxine-binding globulin (TBG) (D) Signup and view all the answers

Which process occurs in the formation of triiodothyronine (T3)?

Combining one monoiodotyrosine (MIT) and one diiodotyrosine (DIT) (D) Signup and view all the answers

What effect does high levels of T3 have on the hypothalamus?

Inhibits TRH production (D) Signup and view all the answers

In what location are thyroid hormones synthesized?

In the colloid of the thyroid follicle (B) Signup and view all the answers

What is the result of excess production of thyroxine-binding globulin (TBG)?

Decreased free hormone levels (B) Signup and view all the answers

Which enzyme is responsible for iodinating tyrosine in thyroid hormone synthesis?

Thyroid peroxidase (A) Signup and view all the answers

What physiological effect is primarily increased by thyroid hormones T3 and T4?

Increased basal metabolic rate (BMR) (A) Signup and view all the answers

What role does the pedrin transporter play in the thyroid gland?

Transport of iodide into colloid (D) Signup and view all the answers

What is the consequence of a lack of iodine in thyroid hormone synthesis?

Decreased synthesis of T3 and T4 (A) Signup and view all the answers

What is the primary biological activity of T3 compared to T4?

T3 is 10 times more potent than T4 (A) Signup and view all the answers

Which factor can lead to decreased levels of albumin and affect thyroid hormone binding?

Liver cirrhosis (C) Signup and view all the answers

What is reverse T3 (RT3)?

A byproduct of T4 metabolism (C) Signup and view all the answers

What is the primary effect of insulin in the fed state?

Promotion of glucose storage (B) Signup and view all the answers

Which hormone primarily helps in mobilizing stored fuel during the fasting state?

Glucagon (C) Signup and view all the answers

What triggers the secretion of growth hormone during fasting?

Low glucose levels (B) Signup and view all the answers

During extended fasting, what effect does cortisol have on the body?

Enhances epinephrine and glucagon effects (B) Signup and view all the answers

In a patient with diabetes, what is the significance of A1C levels over 6.5%?

Represents average glucose levels over the last few weeks (C) Signup and view all the answers

What is a key characteristic of Type I diabetes?

Autoimmune destruction of beta cells (D) Signup and view all the answers

Which of the following symptoms is NOT typically associated with Type I diabetes?

Obesity (A) Signup and view all the answers

What defines a fasting plasma glucose level indicating diabetes?

Over 126 mg/dL (B) Signup and view all the answers

In starvation, what happens to glucagon secretion?

It increases significantly (D) Signup and view all the answers

What is a common symptom in patients with Type II diabetes?

Gradual symptom development (A) Signup and view all the answers

What does a urine microalbumin level of 45 mg indicate in a diabetic patient?

Presence of protein in urine (D) Signup and view all the answers

What is the primary metabolic consequence of glucagon secretion during fasting?

Stimulation of gluconeogenesis (B) Signup and view all the answers

What is the primary role of ketones during prolonged starvation?

To serve as an alternative fuel source (D) Signup and view all the answers

Which of the following is NOT a modifiable factor directly influencing bone strength?

Genetic predisposition (B) Signup and view all the answers

What is the primary function of osteoclasts in bone remodeling?

Breaking down existing bone tissue (A) Signup and view all the answers

Which of the following is TRUE about the relationship between bone mineral density (BMD) and fracture risk?

A 10% increase in BMD results in a 1.5 to 3-fold decrease in fracture risk. (B) Signup and view all the answers

Which of the following cells is responsible for initiating the bone remodeling cycle?

Lining cells (D) Signup and view all the answers

Which of the following hormones directly promotes osteoclast formation and activity?

RANKL (C) Signup and view all the answers

What is the main function of osteoprotegerin (OPG) in bone remodeling?

Inhibiting osteoclast formation and bone resorption (A) Signup and view all the answers

Which of the following pathways for calcium absorption across intestinal epithelium is influenced by calcitriol?

Active pathway (C) Signup and view all the answers

Which of the following organs is NOT involved in calcium homeostasis?

Liver (C) Signup and view all the answers

What is the primary effect of parathyroid hormone (PTH) on calcium levels in the blood?

Increases plasma calcium levels (D) Signup and view all the answers

Which of the following is NOT a source of vitamin D?

Supplementation with vitamin C (D) Signup and view all the answers

Which of the following statements is TRUE regarding hypocalcemia?

Hypocalcemia can be caused by insufficient vitamin D levels. (B) Signup and view all the answers

Which type of bone is metabolically more active and is found in vertebrae and ends of long bones?

Trabecular bone (C) Signup and view all the answers

Which of the following statements accurately describes the roles of collagen and minerals in bone?

Collagen provides flexibility and energy absorption, while minerals provide stiffness and strength. (A) Signup and view all the answers

Which of the following is NOT a characteristic of the bone remodeling process?

It is primarily regulated by hormones and cytokines. (C) Signup and view all the answers

Which of the following is an example of a hormone that inhibits parathyroid hormone (PTH) secretion?

Calcitonin (C) Signup and view all the answers

Study Notes

Diabetes Diagnosis Criteria

Fasting Plasma Glucose: Over 126 mg/dL (no calorie intake for at least 8 hours)
2-Hour Postprandial Glucose: Over 200 mg/dL (measured after OGTT or meal)
Random Plasma Glucose: Over 200 mg/dL (with symptoms: polyuria, polydipsia, polyphagia)
A1C (Glycated Hemoglobin): Over 6.5% (average glucose over the past few months)
- A1C is a percentage of glycated red blood cells.
- Higher glucose means more binding to red blood cells.
- A1C reflects average blood glucose in the previous few months.
- Estimated Average Glucose Level = (28.7 x A1C value) - 46.7.
Oral Glucose Tolerance Test (OGTT): Measures plasma glucose after a glucose challenge.
- Patients consume 75 grams of glucose dissolved in water.
- Fasting glucose is measured before the drink.
- Glucose levels are measured at various times (e.g., 30 min, 1 hr, 2 hrs)
- Normal Individual: Fasting <100 mg/dL, 2-hr <140 mg/dL, no value over 200 mg/dL.
- Pre-diabetes: Values between normal and diabetic levels.

Diabetes Classification

Type I Diabetes (IDDM): Insulin-Dependent Diabetes Mellitus (less than 10% of cases)
- Insulin deficiency due to autoimmune attack on pancreatic beta cells.
- Autoimmune disease, with T-cells as mediators.
- Autoantibodies (ICA, IAA, GAD, IA-2) are present.
- Often abrupt onset, often in younger patients (50% before 21).
- Lean body build is common.
- Untreated type 1 diabetes can lead to diabetic ketoacidosis.
- Low or absent insulin.
Type II Diabetes (NIDDM): Non-Insulin-Dependent Diabetes Mellitus (over 8% of US population; 30-50% undiagnosed)
- Insulin resistance, with gradual onset and less dramatic symptoms than type I.
- Often adult-onset; Increasing in children due to obesity.
- Overweight or obesity is a major factor.
- Insulin insensitivity is the main issue; initially managed with oral medications.
- Often undiagnosed for years; 30% need insulin eventually.
- Impaired glucose tolerance with elevated fasting glucose levels,
- Reduced insulin secretion with disease progression
- Reduced GLUT-2 transporter expression, suppressed first phase insulin secretion.
- Associated with obesity and metabolic syndrome (dyslipidemia, increased free fatty acids).
Gestational Diabetes: Glucose intolerance developing during pregnancy (diagnosed typically in the 3rd trimester)
Other Types: Drug-induced diabetes (e.g., glucocorticoids, thyroid hormone, diuretics)

Type I Diabetes (Patient Case 1)

22-year-old male with 497 blood glucose, lethargy, polyuria, polydipsia, decreased appetite, nausea, vomiting, abdominal pain, lean body build, daily alcohol use, and marijuana smoking.
Low carbon dioxide (18 mEq/L) and ketones in urine indicate likely ketoacidosis.

Type II Diabetes (Patient Case 2)

69-year-old male with 2-year history of type 2 diabetes, non-compliant with glyburide, BMI 31.3 (obese), fasting glucose 166, and A1C 8.1.
Urine microalbumin 45 mg (normal <30mg) indicates kidney dysfunction.

Important Differences Between Type I and Type II Diabetes

Feature	Type I Diabetes	Type II Diabetes
Onset	Abrupt	Gradual
Body Build	Lean	Obese or history of obese
Insulin Resistance	Absent	Present
Autoantibodies	Present	Rare
Symptomatic at Diagnosis	Very symptomatic	Often asymptomatic
Ketones Present	Usually present	Usually absent
Need for Insulin	Immediate	Not immediate, may require insulin
Complications	Diabetic ketoacidosis	Hyperosmolar hyperglycemic state (HHS)

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Description

Test your knowledge on the endocrine system with this quiz focused on hormones and their functions. Answer questions about hormone regulation, production, and the role of different glands in the body. Ideal for students of biology or anyone interested in human physiology.