Test: Adrenal, Thymus & Pineal Gland - NEET MCQ

Addison's disease is caused due to hyposecretion of steroid hormones from adrenal glands. The steroid hormones are cortisol and aldosterone which are secreted from adrenal cortex.
Cretinism is the retarded mental and physical development due to hyposecretion of thyroid hormones.
Dwarfism is the retarded physical development due to hyposecretion of growth hormone during period of skeletal growth.
Sterility is the inability of an individual to produce offspring.
So, the correct answer is 'Addison's disease'.

Topic in NCERT: Adrenal gland

Line in NCERT: "underproduction of hormones by the adrenal cortex alters carbohydrate metabolism causing acute weakness and fatigue leading to a disease called addison's disease."

Epinephrine is secreted from the adrenal medulla and increases heart rate.

- Adrenal medulla: Epinephrine is produced in the adrenal medulla, which is part of the adrenal glands located on top of the kidneys.
- Function: It acts as a hormone and a neurotransmitter, stimulating the "fight or flight" response in the body.
- Heart rate: Epinephrine increases heart rate by binding to beta-adrenergic receptors in the heart, leading to increased cardiac output.
- Overall impact: This physiological response prepares the body for physical activity or stress.

Topic in NCERT: Adrenal gland

Line in NCERT: "the adrenal medulla secretes two hormones called adrenaline or epinephrine and noradrenaline or norepinephrine. these hormones increase alertness, pupilary dilation, piloerection, sweating, heart beat, strength of heart contraction, rate of respiration."

The correct answer is B: Immunology.

- The thymus is a crucial organ in the immune system of humans.
- It is primarily responsible for the maturation and differentiation of T-lymphocytes or T cells, which are essential for the immune response.
- T cells play a critical role in recognizing and attacking pathogens such as bacteria, viruses, and other harmful substances in the body.
- The thymus helps in training T cells to distinguish between self and non-self antigens, thus preventing autoimmune reactions.
- Overall, the thymus is vital for the development and regulation of the body's immune responses.

Topic in NCERT: Thymus

Line in NCERT: "the thymus plays a major role in the development of the immune system. this gland secretes the peptide hormones called thymosins. thymosins play a major role in the differentiation of t-lymphocytes, which provide cell-mediated immunity."

- The correct answer is B: Steroids.
- Steroids are the hormones produced by the adrenal cortex and gonads (sex hormones).
- Steroids are a type of organic compound with a characteristic molecular structure containing four rings of carbon atoms.
- These hormones play crucial roles in various physiological processes in the body, including metabolism, immune response, and sexual characteristics.
- Examples of steroid hormones include cortisol, aldosterone, estrogen, and testosterone.
- Understanding the chemical nature of these hormones helps in grasping their functions in the body.

Topic in NCERT: Hormones

Line in NCERT: "hormones can be divided into groups: (ii) steroids (e.g., cortisol, testosterone, estradiol and progesterone)"

Melatonin is a hormone produced by the Pineal gland. Here's a detailed explanation:

- The Pineal gland, located in the brain, is responsible for producing and releasing melatonin.
- Melatonin plays a crucial role in regulating the sleep-wake cycle, also known as the circadian rhythm.
- This hormone helps to signal to the body when it's time to sleep and when to wake up.
- Production of melatonin is influenced by light exposure, with levels rising in the evening to promote sleepiness and dropping in the morning to encourage wakefulness.

Topic in NCERT: The pineal gland

Line in NCERT: "the pineal gland secretes a hormone called melatonin."

Epinephrine and norepinephrine together known as Catecholamine.

Epinephrine and norepinephrine are two neurotransmitters that also serve as hormones , and they belong to a class of compounds known as Catecholamines. 

However, Epinephrines works on both alpha and beta receptors and norepinephrine only works on alpha receptors.

Topic in NCERT: Adrenal gland

Line in NCERT: "the adrenal medulla secretes two hormones called adrenaline or epinephrine and noradrenaline or norepinephrine. these are commonly called as catecholamines."

• The hypothalamus is the basal part of the diencephalon of the forebrain.
• It contains a hormone of stimulating and inhibiting the pituitary.
• The pituitary gland is also located at the base part of the brain region just below the hypothalamus and joined together whereas the pineal gland is present in the very deep region where two halves of the brain join together.
• This area is present in the middle of the brain known as the epithalamus.
• It secretes melatonin which functions during the darkness and sends information of night.

Topic in NCERT: The hypothalamus

Line in NCERT: "the hypothalamus is the basal part of diencephalon, forebrain... the pineal gland is located on the dorsal side of forebrain."

The correct answer is C: Glucocorticoids.

- Glucocorticoids, produced by the adrenal cortex, regulate carbohydrate metabolism.
- These hormones, like cortisol, help in maintaining blood sugar levels by promoting gluconeogenesis (formation of glucose from non-carbohydrate sources) and inhibiting glucose uptake in peripheral tissues.
- They also play a role in suppressing the immune system and reducing inflammation.
- Glucocorticoids are essential for the body's response to stress and help in adapting to changing metabolic demands.

Topic in NCERT: Adrenal cortex hormones

Line in NCERT: "the corticoids, which are involved in carbohydrate metabolism are called glucocorticoids."

• The thymus is an endocrine gland that is located beneath the sternum and between the lungs.
• Thymosin is secreted from there, and T lymphocyte differentiation occurs there.
• Production of antibodies is encouraged.
• However, in elderly people, the thymus degenerates.

Topic in NCERT: Thymus

Line in NCERT: "thymus is degenerated in old individuals resulting in a decreased production of thymosins."

• Just above the kidneys are the adrenal glands. It is shaped like a pyramid.
• The thymus is situated between the lungs, the pituitary gland is situated at the base of the hypothalamus, and the thyroid gland is situated surrounding the trachea.

Topic in NCERT: Adrenal gland

Line in NCERT: "our body has one pair of adrenal glands, one at the anterior part of each kidney."

• The thymus gland is lobe-shaped. It functions as an essential lymphatic organ.
• Between the lungs and behind the sternum is where the thymus is situated. Thymosin, a peptide hormone, is released by it.
• The thymus gland supports the development of T-lymphocytes, sometimes referred to as T-cells, which are specialized white blood cells.
• The thymus gland receives lymphocytes from the bone marrow, which are white blood cells.
• The lymphocytes in the thymus mature into particular T-cells.
• Before entering circulation, T-cells are in the process of development.
• They travel to the lymph nodes, which are cellular collections, and other organs of the lymphatic system, where they support the immune system’s defense against disease and infection.

Topic in NCERT: Thymus

Line in NCERT: "the thymus gland is a lobular structure located between lungs behind sternum on the ventral side of aorta."

Middle lobe of pituitary secretes MSH(melanocyte stimulating hormone) that controls the synthesis of melanin granules in the chromatophores.

Topic in NCERT: The pituitary gland

Line in NCERT: "pars intermedia secretes only one hormone called melanocyte stimulating hormone (msh)."

Thymosin stimulates T-lymphocytes. Here's why:

- Thymosin is a hormone that plays a crucial role in the development and maturation of T-lymphocytes, which are a type of white blood cell essential for the immune system.
- T-lymphocytes are produced in the thymus gland, and thymosin aids in their differentiation and maturation process.
- This hormone helps in the regulation of the immune response by ensuring the proper functioning of T-lymphocytes in recognizing and fighting off pathogens.

Topic in NCERT: Thymus

Line in NCERT: "the thymus plays a major role in the development of the immune system. this gland secretes the peptide hormones called thymosins. thymosins play a major role in the differentiation of t-lymphocytes, which provide cell-mediated immunity."

Correct Answer: A. Option A is correct.

Explanation: Adrenal cortical hormones are indeed known as corticosteroids. Cortisol is a glucocorticoid, aldosterone is a mineralocorticoid, and the adrenal cortex does produce small amounts of androgenic steroids.

Topic in NCERT: Adrenal cortex hormones

Line in NCERT: "the adrenal cortex secretes many hormones, commonly called as corticoids. the corticoids, which are involved in carbohydrate metabolism are called glucocorticoids. in our body, cortisol is the main glucocorticoid. corticoids, which regulate the balance of water and electrolytes in our body are called mineralocorticoids. aldosterone is the main mineralocorticoid in our body."

The adrenal cortex consists of three layers: zona glomerulosa, zona fasciculata, and zona reticularis, each responsible for producing different hormones.

Topic in NCERT: Adrenal gland

Line in NCERT: "the adrenal cortex can be divided into three layers, called zona reticularis (inner layer), zona fasciculata (middle layer) and zona glomerulosa (outer layer)."