All questions of February Week 3 for NEET Exam

The correct answer is oxytocin because oxytocin stimulates contraction of the myoepithelial cells surrounding the alveoli which already holds milk . the increased pressure causes milk to flow through the duct system and be released through the nipple .

Melatonin is the only known hormone synthesized by the pineal gland and is released in response to darkness hence the name, “hormone of darkness” [

A node is a point along the medium of no displacement. The point is not displaced because destructive interference occurs at this point.

Explanation:
Pituitary dwarfism, also known as growth hormone deficiency, is a condition characterized by inadequate production or secretion of growth hormone by the pituitary gland. This deficiency results in stunted growth and development.

Causes of Pituitary Dwarfism:
Pituitary dwarfism can occur due to various reasons, including:

1. Genetic mutations: In some cases, pituitary dwarfism is caused by genetic mutations that affect the production or function of growth hormone.

2. Pituitary gland abnormalities: Certain conditions, such as tumors or damage to the pituitary gland, can disrupt the production and release of growth hormone.

3. Hypothalamic abnormalities: The hypothalamus plays a crucial role in regulating the secretion of growth hormone. Abnormalities in the hypothalamus can lead to pituitary dwarfism.

Effect on Intelligence:
Contrary to the other options mentioned in the question, individuals with pituitary dwarfism typically do not experience mental retardation. Intelligence is not directly affected by growth hormone deficiency. Therefore, option C, which states "mental retardation," is incorrect.

Effects on Growth:
Pituitary dwarfism primarily affects physical growth. The condition leads to stunted growth, resulting in individuals being shorter than average. This is due to the inhibited growth of long bones, which are responsible for height.

Effects on Intelligence:
Individuals with pituitary dwarfism generally have normal intelligence. The condition primarily affects physical growth, not cognitive development. Therefore, option A, which states "normal intelligence," is correct.

Conclusion:
In summary, individuals with pituitary dwarfism do not experience mental retardation but have normal intelligence. The condition mainly affects physical growth, leading to stunted growth and inhibited growth of long bones.

Answer:

Introduction:
Glucose is a simple sugar that is normally filtered by the kidneys and reabsorbed back into the bloodstream. However, in certain medical conditions, glucose is lost in the urine. One such condition is diabetes mellitus. Let's discuss why glucose is lost in the urine of patients suffering from diabetes mellitus.

Explanation:
Diabetes mellitus is a metabolic disorder characterized by high blood sugar levels due to either insufficient insulin production or the body's inability to use insulin effectively. In this condition, glucose cannot enter the cells and remains in the bloodstream, leading to hyperglycemia.

Role of Kidneys:
The kidneys play a crucial role in maintaining glucose homeostasis. They filter the blood, reabsorb essential substances, and excrete waste products in the form of urine. Normally, almost all of the filtered glucose is reabsorbed back into the bloodstream by the renal tubules.

Effect of Diabetes Mellitus:
In diabetes mellitus, the high levels of glucose in the blood exceed the renal threshold for glucose reabsorption. The renal threshold is the blood glucose concentration at which glucose starts to be excreted in the urine. In healthy individuals, the renal threshold for glucose is approximately 180-200 mg/dL.

Key Point 1: Renal Threshold for Glucose:
In diabetes mellitus, the blood glucose levels are consistently high, exceeding the renal threshold. As a result, glucose is not entirely reabsorbed by the renal tubules, and some amount of glucose is lost in the urine.

Key Point 2: Polyuria:
The presence of excess glucose in the urine leads to an osmotic diuresis, causing increased urine production (polyuria). This occurs because glucose in the urine attracts water molecules, resulting in increased fluid loss.

Key Point 3: Glycosuria:
The presence of glucose in the urine is called glycosuria. It is a hallmark feature of diabetes mellitus and can be detected through a urine test.

Conclusion:
In summary, glucose will be lost in the urine of patients suffering from diabetes mellitus due to the high blood glucose levels exceeding the renal threshold for glucose reabsorption. This condition leads to polyuria and glycosuria, which are characteristic features of diabetes mellitus.

Understanding Diabetes Insipidus
Diabetes insipidus (DI) is a condition characterized by excessive thirst and the excretion of large amounts of dilute urine. The underlying cause of DI relates to the hormone vasopressin, also known as antidiuretic hormone (ADH).
Role of Vasopressin
- Production: Vasopressin is produced in the hypothalamus and released by the posterior pituitary gland.
- Function: Its primary role is to regulate water balance in the body by promoting water reabsorption in the kidneys.
Impact of Vasopressin Abnormality
- Deficiency: In cases of diabetes insipidus, there is either a deficiency of vasopressin or an insensitivity of the kidneys to this hormone.
- Symptoms: This leads to the kidneys being unable to retain water, resulting in excessive urination (polyuria) and thirst (polydipsia).
Types of Diabetes Insipidus
- Central Diabetes Insipidus: This type occurs due to insufficient production of vasopressin, often resulting from damage to the hypothalamus or pituitary gland.
- Nephrogenic Diabetes Insipidus: This type occurs when the kidneys fail to respond to vasopressin, often due to genetic factors or chronic kidney conditions.
Conclusion
In summary, an abnormality in the functioning of vasopressin is the primary cause of diabetes insipidus. The disruption in this hormone's activity leads to significant disturbances in water balance, resulting in the characteristic symptoms of the condition. Therefore, the correct answer to the question regarding the hormone related to diabetes insipidus is option 'B', vasopressin.

- Location of the pineal gland
The pineal gland is located on the dorsal side of the forebrain.
- Anatomy of the pineal gland
The pineal gland is a small, pine cone-shaped endocrine gland situated in the epithalamus, which is a part of the diencephalon of the brain. It is positioned near the center of the brain, between the two hemispheres, and is attached to the posterior end of the third ventricle.
- Function of the pineal gland
The pineal gland plays a crucial role in the regulation of various biological rhythms in the body, particularly the sleep-wake cycle. It produces and secretes the hormone melatonin, which helps in regulating sleep patterns and circadian rhythms. Additionally, the pineal gland is also involved in the regulation of reproductive hormones and immune function.
- Importance of the pineal gland
Despite its small size, the pineal gland is considered to be a vital part of the endocrine system and has been linked to various physiological processes in the body. Its functions extend beyond just regulating sleep patterns and circadian rhythms, making it an important gland for overall health and well-being.
In conclusion, the pineal gland is located on the dorsal side of the forebrain and plays a crucial role in regulating biological rhythms and hormone production in the body.

Hormones play a crucial role in regulating various physiological processes in the body. They are chemical messengers produced by specialized cells or glands and are secreted directly into the bloodstream. Hormones can be classified into different categories based on their chemical nature. In this question, we need to match the hormones (a-d) with their respective nature (i-iv).

Let's analyze each hormone and its nature:

a) Parathormone:
Parathormone, also known as parathyroid hormone (PTH), is produced by the parathyroid glands. It plays a vital role in regulating calcium and phosphate levels in the blood.

Nature:
Parathormone is a polypeptide hormone, which means it is composed of a chain of amino acids.

b) Oxytocin:
Oxytocin is a hormone produced by the hypothalamus and released by the posterior pituitary gland. It is commonly known as the "love hormone" and is involved in various reproductive and social behaviors, such as bonding, childbirth, and lactation.

Nature:
Oxytocin is a peptide hormone, which means it is composed of a shorter chain of amino acids.

c) Sex hormones:
Sex hormones include testosterone (produced by the testes in males) and estrogen and progesterone (produced by the ovaries in females). These hormones are responsible for the development of secondary sexual characteristics and play a crucial role in reproductive processes.

Nature:
Sex hormones are steroid hormones, which are derived from cholesterol and have a characteristic steroid structure.

d) Norepinephrine:
Norepinephrine, also known as noradrenaline, is a neurotransmitter and hormone produced by the adrenal glands and certain neurons in the brain. It is involved in the body's stress response and helps regulate blood pressure and heart rate.

Nature:
Norepinephrine is an amino acid derivative hormone, which means it is derived from the amino acid tyrosine.

Matching the hormones with their respective natures:

a) Parathormone - i) polypeptide
b) Oxytocin - iii) peptide
c) Sex hormones - iv) steroid
d) Norepinephrine - ii) amino acid derivative

Therefore, the correct match is:

a) Parathormone - i) polypeptide
b) Oxytocin - iii) peptide
c) Sex hormones - iv) steroid
d) Norepinephrine - ii) amino acid derivative

Jo lone pair double bond pe hota h vo participate nhi krta resonance mai ya aromaticity no maintain krne mai or easily available h protonation k liye

We'll use the three double bond symbol simply because it is also routinely used in the text. Keep in mind that if the hexagon contains neither the three double bonds nor the circle, the compound is not aromatic. It is simply cyclohexane and there are two hydrogens on each carbon atom.