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Pineal Gland

Q: Name the hormones secreted by the following endocrine glands and specify one function:1. Thyroid2. Pituitary 3. Pancreas

Thyroid: Thyroxin hormone is secreted; regulates carbohydrate, protein, and fat metabolism so as to provide best balance for growth.Pituitary: Human Growth Hormone, Regulates growth and development, deficiency leads to dwarfism, gigantism if excessive production takes place.Pancreas: Secretes insulin, regulates blood sugar levels.

Q: Which of the following is not present in pancreatic juice?

Pancreatic juice is secreted by the pancreas, which contains a variety of enzymes, including trypsinogen, chymotrypsinogen, elastase, carboxypeptidase, pancreatic lipase and amylase. Pepsin in not present in pancreatic juice. It is secreted by the peptic cells of the stomach.

Q: Select the incorrect statement

LH is a Luteinizing hormone produced by the gonadotropic cells in the anterior pituitary gland. It plays an important role in puberty, menstruation, and fertility. It triggers ovulation and development of the corpus luteum. In male, LH triggers the secretion of androgen called as testosterone from the Leydig cells. FSH is follicle-stimulating hormone produced by gonadotropic cells in the anterior pituitary gland. It helps in regulation of development, growth, pubertal maturation and reproductive processes of the body. It stimulates the Sertoli cells of the testicles and helps in spermatogenesis, production of sperm. During the follicular phase, the LH and FSH increase gradually. They stimulate follicular development and estrogen secretion by follicular cells.Thus, the correct answer is 'LH and FSH decrease gradually during the follicular phase.'

Q: Which of the following causes an increase in sodium reabsorption in distal convoluted tubule?

Correct Option: AExplanation:Aldosterone is secreted from the adrenal cortex. The main function of aldosterone is to serve as a stimulant of the renal absorption of sodium ions and water. This leads to the increment of the blood volume. When the aldosterone level is reduced, it helps to increase the sodium secretion by Distal Convoluted Tubules.

Q: Match the following hormones with the respective disease.(a) Insulin(i) Addison's disease(b) Thyroxin(ii) Diabetes insipidus(c ) Corticoids(iii) Acromegaly(d) Growth Hormone(iv) Goitre(v) Diabetes mellitusSelect the correct option.

∙∙ Insulin deficiency leads to diabetes mellitus∙∙ Hypersecretion or hyposecretion of thyroxine can be associated with enlargement of thyroid gland called goitre.∙∙ Deficiency of corticoids (Glucocorticoid ++ mineralocorticoid) leads to Addison's disease∙∙ Growth hormone hypersecretion in adults leads to Acromegaly.So, the correct answer is '(a)-(v), (b)-(iv), (c)-(i), (d)-(iii)'

Q: What is meant by control and co-ordination?

Control is the power of restraining and regulation by which something can be started, slowed down or stopped. Co-ordination is the working together of various agents of the body of an organism in a proper manner to produce an appropriate reaction to a stimulus is called coordination. For example, the nervous system and endocrine system act in a coordinated manner for the proper regulation of body activities.

Q: Which of the following hormones is not secreted by anterior pituitary?

Hypothalamus secretes oxytocin and ADH (vasopressin) that is stored and released by neurohypophysis. Therefore, it is not secreted by anterior pituitary.So, the correct answer is 'Oxytocin'

Q: Which is the largest endocrine gland in the human body?

The thyroid gland is the largest endocrine gland in the body. It is located in the neck, below the larynx, and in front of the trachea.It secretes thyroid hormone, which regulates important metabolic processes connected to our heart rate, body temperature, and energy levels.So, the correct answer is option A.

Q: The posterior lobe of pituitary gland is not a 'true' endocrine gland because:

Oxytocin and vasopressin hormones are produced by the hypothalamus but stored and are released into the bloodstream via the posterior pituitary. That's the reason why it is not a true endocrine gland. Endocrine glands are the ductless glands that secrete and release hormones in the blood directly. Therefore, the correct answer is option D.

Q: Which one of the following pairs correctly matches a hormone with a disease resulting from its deficiency : -

Gigantism is a rare condition of accelerated growth and increased height as a result of too much growth hormone secretion during childhood or adolescence. It is almost always the result of a growth hormone-secreting pituitary tumour. Congenital hypothyroidism (under activity of the thyroid gland at birth), which results in growth retardation, developmental delay, and other abnormal features. Cretinism can be due to a deficiency of iodine in the mother's diet during pregnancy.Hypoparathyroidism is decreased function of the parathyroid glands with underproduction of parathyroid hormone. This can lead to low levels of calcium in the blood, often causing cramping and twitching of muscles or tetany (involuntary muscle contraction) and several other symptoms.Diabetes mellitus occurs due to insulin resistance or insulin deficiency and subsequent high blood glucose levels. Diabetes Insipidus, on the other hand, develops as a result of the stilted production of a hormone in the brain, which is released to stop the kidneys producing so much urine in order to retain water.So, the correct answer is 'Parathyroid hormone Tetany'.

Biology

definition

Pineal gland- Origin, location and structure

Pineal gland is also called as pineal body or epiphysis or the third eye.
Origin

Develops from the Ectoderm of the embryo

Location

It is located behind the third cerebral ventricle on the dorsal side of the fore brain

Structure

It has a pine-cone like structure and consists of pineal cells and supporting glial cells.
It lower vertebrates it has an eye-like structure and acts as a light receptor (hence the name third eye)

definition

Hormones of the pineal gland

The Pineal gland produces only one hormone called the melatonin. The functions of melatonin are as follows

Both melatonin and its precursor called serotonin are synthesized in the pineal gland
Tryptamine (an alkaloid substance) is the precursor for both melatonin and serotonin.
Melatonin plays an important role in the diurnal rhythm (e.g. sleep-wake cycle) of the body.
Melatonin causes a sense of drowsiness (sleepiness) in the brain at night time, which affects the modulation of sleep patterns.
Melatonin also influences metabolism, pigmentation, menstrual cycle and immunity.