Test: Pancreas, Kidney, Skin, Glands & Pheromones - NEET MCQ

Glucagon is a hormone that plays a crucial role in regulating blood sugar levels.

It is primarily secreted by the islets of Langerhans in the pancreas. Here are some key points about glucagon:

• It helps to increase blood glucose levels when they are too low.
• Glucagon stimulates the liver to convert stored glycogen into glucose.
• It also promotes the production of glucose from non-carbohydrate sources.
• This hormone works in tandem with insulin, which lowers blood sugar levels.

Understanding the function of glucagon is essential for grasping how the body maintains homeostasis in blood sugar levels.

The hormone responsible for converting glucose into glycogen is produced by the pancreas.

This process is vital for regulating blood sugar levels. Here are some key points:

• The pancreas secretes insulin, a hormone that facilitates the uptake of glucose by cells.
• Once inside the liver, glucose is transformed into glycogen for storage.
• When blood sugar levels drop, glycogen can be converted back into glucose, ensuring a steady energy supply.

In summary, the pancreas plays a crucial role in managing energy by producing insulin, which helps maintain healthy blood sugar levels.

Estrogen is a crucial hormone primarily secreted by the:

• Ovaries: The main site of estrogen production in females.
• Liver: Plays a role in the metabolism of hormones but does not produce significant amounts of estrogen.
• Spleen: Not involved in estrogen secretion.
• Pituitary: Regulates hormone release but does not produce estrogen itself.

In summary, while several organs are involved in hormone activity, the ovaries are the primary source of estrogen in the body.

Androgens are male sex hormones that play a crucial role in various body functions. They are primarily secreted by:

• Testes: The main source of androgens in males.
• Ovaries: In females, androgens are also produced, although in smaller amounts.
• Adrenal glands: These glands, located above the kidneys, produce androgens in both sexes.

In summary, the primary source of androgens is the testes, while the ovaries and adrenal glands contribute to androgen production as well.

Ovulation in mammals is primarily regulated by hormones. The key hormones involved are:

• Follicle-Stimulating Hormone (FSH): Responsible for the growth and maturation of ovarian follicles.
• Luteinising Hormone (LH): Triggers ovulation and supports the formation of the corpus luteum.

These hormones work together to ensure proper reproductive function. FSH stimulates the ovaries to produce follicles, and when the follicles are ready, a surge in LH leads to ovulation, releasing an egg.

This hormonal interplay is essential for the reproductive cycle in mammals, influencing fertility and the timing of ovulation.

The pancreas is a unique gland in the body, functioning as both an endocrine and an exocrine gland. Here are the key features:

• Endocrine Function: The pancreas produces hormones, such as insulin and glucagon, which regulate blood sugar levels. These hormones are secreted directly into the bloodstream.
• Exocrine Function: It also produces digestive enzymes, which are released into the small intestine to aid in the digestion of food.
• This dual functionality makes the pancreas essential for both metabolic processes and digestive health.

In summary, the pancreas plays a critical role in maintaining the body's overall health by managing blood sugar levels and assisting in digestion.

The Islets of Langerhans are small clusters of cells located within the pancreas. They play a crucial role in regulating blood sugar levels by producing and secreting insulin. Here are some key points about them:

• The Islets are composed of different types of cells, including beta cells, which are responsible for insulin production.
• Insulin is a hormone that helps control blood glucose levels by facilitating the uptake of glucose into cells.
• When blood sugar levels rise, such as after eating, the Islets release insulin to help lower blood sugar levels.
• Inadequate insulin production can lead to health conditions like diabetes.

Overall, the Islets of Langerhans are essential for maintaining healthy blood sugar levels and overall metabolic function.

Oversecretion of glucagon can lead to various health issues. Here are some of the effects:

• Tetany: This condition involves muscle spasms and cramps due to low calcium levels.
• Diabetes insipidus: Characterised by excessive thirst and urination, this condition occurs when the body cannot properly regulate water.
• Acromegaly: This is a hormonal disorder that results from excess growth hormone, leading to enlarged bones and tissues.
• Glycosuria: This condition involves the presence of glucose in urine, often indicating issues with blood sugar regulation.

Glucagon is a hormone that plays a crucial role in regulating blood sugar levels. It is primarily secreted by:

• Alpha cells of the islets of Langerhans in the pancreas.
• Unlike beta cells, which produce insulin, alpha cells are responsible for increasing blood sugar levels.
• Glucagon works by promoting the conversion of stored glycogen into glucose in the liver.
• This process helps to ensure that the body has a steady supply of energy, especially during fasting or between meals.

The adrenal cortex does not produce glucagon; its functions are related to stress response and metabolism.

Insulin is a vital hormone produced by the pancreas, and it plays a crucial role in regulating blood sugar levels. Its chemical nature is primarily classified as a:

• Protein - Insulin is made up of amino acids, which are the building blocks of proteins.
• Function - It helps cells absorb glucose, converting it into energy.
• Importance - Without insulin, the body cannot effectively manage blood sugar, leading to conditions such as diabetes.

In summary, insulin is best described as a protein hormone essential for metabolic processes.

When ovaries are removed from a pregnant woman in the fourth month of pregnancy, the effects can vary:

• Development of the embryo may become abnormal due to a lack of necessary hormones from the ovaries.

• There is a high likelihood that abortion will occur after some time because the embryo relies on hormonal support.

• In some cases, the embryo may develop normally until birth, but this is less common without ovarian function.

• Option D suggests none of the above, which is not accurate given the hormonal dependencies involved.

In conclusion, while it is theoretically possible for the embryo to continue developing normally until birth, the most probable outcome is a disruption in development or an eventual abortion.

Leydig cells are specialised cells found in the male reproductive system. They play a crucial role in the production of hormones, particularly:

• Testosterone: This is the primary male sex hormone, essential for the development of male characteristics and the production of sperm.
• Progesterone: Although primarily associated with female physiology, Leydig cells also produce small amounts of this hormone.

In summary, Leydig cells are vital for:

• Producing testosterone, which influences sexual development and function.
• Supporting the overall health and function of the male reproductive system.

The secretion of oestrogen is regulated by several hormones in the body. Here are the key players:

• Luteinising Hormone (LH): This hormone stimulates the ovaries to produce oestrogen.
• Follicle-Stimulating Hormone (FSH): FSH promotes the growth of ovarian follicles, which are essential for oestrogen production.
• Human Chorionic Gonadotropin (HCG): Primarily associated with pregnancy, HCG supports the continued production of oestrogen.
• Progesterone: While primarily known for its role in the menstrual cycle, progesterone can also influence oestrogen levels.

In summary, LH and FSH are the main hormones that directly control oestrogen secretion, while HCG and progesterone play supporting roles. Understanding these hormones helps clarify the complex regulation of oestrogen in the female reproductive system.

Immediate cause of induction of ovulation in human females is a significant surge in plasma levels of certain hormones. The hormone primarily responsible for triggering ovulation is:

• LH (Luteinising Hormone) - This hormone plays a crucial role in the final maturation of ovarian follicles and the subsequent release of an egg.
• Other hormones such as FSH (Follicle-Stimulating Hormone), Estradiol, and Progesterone are involved in the menstrual cycle but do not directly induce ovulation.

During the ovulation phase, the surge in LH levels indicates that the ovary is ready to release an egg, marking a key point in the reproductive cycle.

Alpha cells are located in the periphery of the islet, whereas beta cells are predominantly found in the centre of the islet. This arrangement plays a crucial role in the function of the pancreas.

• Alpha cells produce glucagon, a hormone that raises blood sugar levels.
• Beta cells produce insulin, which lowers blood sugar levels.
• The spatial distribution of these cells is essential for maintaining glucose homeostasis.

Understanding this layout helps in comprehending how the pancreas regulates blood sugar and the implications for conditions like diabetes.

Stimulation of uterine contraction during childbirth is primarily caused by the hormone oxytocin. This hormone plays a crucial role in the following ways:

• Enhances contractions: Oxytocin increases the strength and frequency of uterine contractions.
• Facilitates labour: It helps to progress the stages of labour, making childbirth more effective.
• Triggers natural release: It is naturally released by the body as childbirth approaches.

Other hormones involved in childbirth include:

• Adrenaline: While it can affect the stress response, it is not a primary driver of uterine contractions.
• Progesterone: This hormone maintains pregnancy and inhibits contractions during the early stages.
• Prolactin: Mainly known for its role in milk production, it does not significantly impact uterine contractions.

Progesterone is a vital hormone produced in the female body. It plays a crucial role in various physiological processes, particularly in relation to reproduction. The main sources of progesterone include:

• Placenta: This organ, which develops during pregnancy, produces progesterone to help maintain the pregnancy and support fetal development.
• Corpus luteum: This temporary endocrine structure forms in the ovaries after ovulation and secretes progesterone to prepare the uterus for potential implantation of a fertilised egg.

Both the placenta and the corpus luteum are essential for the production of progesterone, highlighting their importance in reproductive health.

Insulin Production in the Body

Insulin is a crucial hormone produced by the pancreas, specifically by certain types of cells. The primary cells responsible for insulin production are:

• Beta cells: These are the main producers of insulin, releasing it in response to rising blood sugar levels.
• Alpha cells: While these cells primarily produce glucagon, they play a role in overall hormone regulation in the pancreas.
• Delta cells: These cells produce somatostatin, which helps regulate the function of other pancreatic cells.
• F cells: Their exact role is less understood, but they are believed to have a role in the overall hormonal balance.

The predominant source of insulin is the beta cells, making them essential for maintaining blood sugar levels and overall metabolic health.

The adrenal cortex consists of three distinct layers.

• Zona glomerulosa: This is the outermost layer, responsible for producing hormones like aldosterone, which helps regulate blood pressure and electrolyte balance.
• Zona fasciculata: The middle layer, which secretes glucocorticoids such as cortisol, playing a vital role in metabolism and stress response.
• Zona reticularis: The innermost layer, which produces androgens, contributing to the development of male characteristics and influencing libido.

The zona glomerulosa is essential for maintaining health, as it directly affects fluid balance and blood pressure regulation.

HCG (Human Chorionic Gonadotropin) is a hormone that is commonly associated with pregnancy. Its presence in a female's urine can indicate:

• Pregnancy: The most common reason for detecting HCG in urine. It is produced shortly after a fertilised egg attaches to the uterus.
• Addison's disease: Rarely, elevated HCG levels may be seen in this adrenal insufficiency condition, but it is not a primary indicator.
• Gynaecomastia: This condition typically relates to male hormone imbalances and is not directly linked to HCG presence.
• Virilism: This refers to the development of male characteristics in females, which may be associated with hormonal imbalances, but HCG is not a defining factor.

In summary, the primary confirmation of HCG in urine is indicative of pregnancy, while other conditions have minimal or no direct association.

Injection of insulin into an animal increases the glucose levels in various areas of the body. Here are the key points:

• Insulin primarily functions to facilitate the uptake of glucose by cells.
• This leads to a decrease in the concentration of glucose in the bloodstream.
• As a result, the glucose level within cells rises, enabling them to use glucose for energy.
• The overall effect is a controlled increase in cellular glucose levels, which is crucial for metabolism.

In summary, the injection of insulin is vital for managing glucose levels effectively, particularly within cells.

Epinephrine, commonly known as adrenaline, is a hormone that is released rapidly during stressful situations, such as when someone is being chased by a dog. This hormone plays a crucial role in the body's 'fight or flight' response. Here are some key points about epinephrine:

• Quick Release: Epinephrine is released swiftly from the adrenal glands in response to stress.
• Increases Heart Rate: It elevates heart rate and blood pressure, preparing the body for immediate action.
• Boosts Energy: It increases the availability of energy by breaking down glycogen into glucose.
• Enhances Alertness: Epinephrine sharpens focus and awareness, which can be vital in dangerous situations.

Other hormones mentioned, such as somatostatin, somatotropin, and prolactin, do not respond as quickly to immediate stressors and are associated with different physiological functions:

• Somatostatin: Primarily regulates hormone secretion and slows down bodily processes.
• Somatotropin: Also known as growth hormone, it is involved in growth and metabolism.
• Prolactin: Mainly related to milk production and reproductive functions.

In conclusion, during a stressful encounter like being chased by a dog, epinephrine is the hormone that acts rapidly to prepare the body for action.

Glucagon is a hormone that has an anti-insulin effect, meaning it works to increase blood sugar levels. Here are some key points about glucagon:

• Produced by: The alpha cells of the pancreas.
• Function: Stimulates the liver to convert stored glycogen into glucose, releasing it into the bloodstream.
• Opposes insulin: While insulin lowers blood sugar levels, glucagon raises them, making it crucial for maintaining glucose balance in the body.
• Role in fasting: During periods of fasting, glucagon helps to provide energy by ensuring that glucose is available for use.

Understanding glucagon's role is essential for grasping how the body regulates blood sugar levels and maintains overall metabolic balance.

Addison's disease is a condition caused by a deficiency of hormones produced by the adrenal cortex. This condition affects the body's ability to respond to stress and maintain various physiological functions.

• The adrenal cortex produces essential hormones, including cortisol and aldosterone.
• A lack of these hormones can lead to symptoms such as:
• Fatigue and weakness
• Weight loss
• Low blood pressure
• Darkening of the skin
• It is important to diagnose Addison's disease early to manage symptoms effectively.

Treatment typically involves hormone replacement therapy to restore the levels of adrenal hormones in the body.

The adrenal medulla is responsible for the secretion of catecholamines, which are important hormones involved in the body's response to stress.

• Catecholamines include adrenaline and noradrenaline.
• These hormones prepare the body for a quick response in situations of danger.
• They increase heart rate, blood pressure, and energy supplies.
• The adrenal medulla is part of the adrenal glands, located on top of each kidney.

In summary, the adrenal medulla plays a crucial role in the body's fight-or-flight response by secreting catecholamines.

Assertion: Diabetes insipidus is characterised by excessive urination and a strong thirst for water.

Reason: The anti-diuretic hormone is secreted by the posterior lobe of the pituitary gland.

• Both the Assertion and Reason are true.
• The Reason is a correct explanation of the Assertion.

In summary:

• Diabetes insipidus leads to significant fluid loss due to poor regulation of water retention.
• The anti-diuretic hormone plays a crucial role in controlling water balance in the body.
• When this hormone is insufficiently produced, it results in increased urination and thirst.

Progesterone is a hormone that plays a vital role in the reproductive system. It is mainly produced by:

• Corpus Luteum: This structure forms in the ovary after ovulation and is the primary source of progesterone during the menstrual cycle.
• Ovarian Follicles: These are the sacs in the ovaries that contain developing eggs. They produce progesterone at various stages of the menstrual cycle.
• Stromal Tissues: These tissues support the ovarian follicles and can contribute small amounts of progesterone.
• Seminiferous Tubules: Although primarily involved in sperm production, these structures do not secrete progesterone.

In summary, the main source of progesterone is the corpus luteum, particularly during the latter half of the menstrual cycle, which is crucial for preparing the uterus for potential pregnancy.

Estrogen secretion is primarily regulated by specific hormones. The main controllers are:

• Follicle-Stimulating Hormone (FSH): This hormone plays a crucial role in the development of ovarian follicles, which are essential for estrogen production.
• Luteinising Hormone (LH): LH triggers ovulation and also supports the production of estrogen from the ovaries.
• Progesterone: Although primarily associated with the menstrual cycle and pregnancy, progesterone also influences estrogen levels indirectly.
• Gonadotropin Hormone (GTH): This hormone can affect the secretion of both FSH and LH, thus playing a role in estrogen regulation.

In summary, FSH and LH are the primary hormones directly controlling estrogen secretion, while progesterone and GTH also contribute to its regulation.

Glucagon plays a crucial role in regulating blood sugar levels, primarily through the following processes:

• Glycogenolysis: This is the breakdown of glycogen into glucose, which increases blood sugar levels.
• Gluconeogenesis: This process involves creating glucose from non-carbohydrate sources, further raising blood sugar levels.

However, it is important to note that glucagon does not:

• Increase cellular glucose uptake: Unlike insulin, which promotes the uptake of glucose by cells, glucagon does not facilitate this process.
• Decrease cellular glucose uptake: Glucagon's primary function is to elevate blood sugar, not to reduce it.

Glycosuria and Ketonuria are significant indicators of certain medical conditions. They refer to the presence of glucose and ketones in the urine, respectively.

• Glycosuria: This occurs when glucose is excreted in the urine, often indicating that blood sugar levels are elevated. It is most commonly associated with Diabetes mellitus.
• Ketonuria: The presence of ketones suggests that the body is using fat for energy instead of glucose. This can occur in uncontrolled diabetes or during periods of fasting.

Both conditions are typically used to diagnose and manage diabetes, as they provide insight into the body's metabolic state. Regular testing for these substances can help in monitoring the effectiveness of diabetes management strategies.