Which one of the following statement is correct? 
Endocrine system, like the nervous system, is meant for internal communication and regulation of the animal body. These two systems operate in a coordinated way on many occasions. Many important functions of the endocrine system are infact, under the control of nervous system. Therefore, the two systems are often collectively called as neuroendocrine system.
Which part of ovary in mammals acts as an endocrine gland after ovulation ? 
Graafian follicle – the ovarian medulla contains many rounded or oval bodies, called ovarian, or grafian follicles, at various stages of development. Each follicle contains a large ovum surrounded by many layers of follicle cells.
A person is having problems with calcium and phosphorus metabolism in his body. Which one of following glands may not be functioning properly ? 
Parathyroid disorders : It causes the lowering of blood calcium level. This increases the excitability of nerves and muscles causing cramps and convulsions.
Feeling the tremors of an earthquake a scared resident of seventh floor of a multistored building starts climbing down the stairs rapidly. Which hormone initiated this action ? 
It is commonly called as ‘emergency hormone’ or 3F – hormone (For fear, fight & flight). Its secretion is regulated by SNS, and not by pituitary as in case of adrenal cortex. It stimulates sweating, heart beat and breathing rate. It causes the dilation of coronary artery (supplying blood to the heart muscles), bronchioles (for increasing inspiratory volume) and pupil (for better vision).
The blood calcium level is lowered by the deficiency of 
A peptide hormone secreted by the parathyroid gland in response to low levels of calcium in the blood. It acts to maintain normal blood levels of calcium by increasing the number of osteoclasts, which break down the bone matrix and release calcium into the blood. It also increases the reabsorption of calcium and magnesium ions in the kideny tubules, so that their concentration is maintained in the blood.
Which one of the following pairs of organs includes only the endocrine glands? 
Parathyroid and adrenal are the endocrine glands. Adrenal glands are the pairs of endocrine glands situated immediately above the kidneys. Hence they are also known as suprarenal glands. Parathyroid glands are the two pairs of endocrine glands -situated behind or embedded within, the thyroid gland in higher vertebrates. They produce parathyroid hormone, which controls the amount of calcium in the blood.
A health disorder that results from the deficiency of thyroxine in adults and characterised by (i) a low metabolic rate, (ii) increase in body weight and (iii) tendency to retain water in tissues is: 
Myxoedema is caused by deficiency of thyroid hormone or thyroxine in adults. It is characterised by increase in body weight, puffy appearance, low metabolic rate, and tendency to retain water in tissues.
Injury to adrenal cortex is not likely to affect the secretion of which one of the following? 
Adrenal gland has two parts-cortex and medulla. The medulla is stimulated by sympathetic nervous tissue to produce adrenaline and non-adrenaline while the cortex is stimulated by pituitary hormone to release cortisol, aldosterone and estrogens. Thus injury to adrenal cortex is not likely to affect the secretion of adrenaline
Low Ca++ in the body fluid may be the cause of:
Tetany is caused by reduction in the calcium level due to underactive parathyroid hormone.
Which one of the following pairs is incorrectly matched? 
Glucagon is secreted by a-cells of the islets of Langerhans in the pancreas. It increases the concentration of glucose in the blood by stimulating the breakdown of glycogen.
Toxic agents present in food which interfere with thyroxine synthesis lead to the development of: 
Goitre is caused by deficiency of iodine in diet. Iodine is needed for the synthesis of thyroxine. Toxic agents present in food interfere with thyroxine synthesis and lead to goitre.
Match the source gland with respective hormone as well as the function correctly. 
Posterior pituitary releases vasopressin which stimulates reabsorption of water in the distal tubules in nephron.
Given below is an incomplete table about certain hormones, their source glands and one major effect of each on the body in humans. Identify the correct option for the three blanks A, B and C. 
Anterior pituitary secrets growth hormone. Ovary secrets oestrogen hormone. Alpha cells of islets of langerhans secrets glucagon.
The 24 hour (diurnal) rhythm of our body such as the sleep-wake cycle is regulated by the hormone : [2011M]
Melatonin is a hormone that regulates the 24 hour rhythm of our body such as the sleep-wake cycle etc. Melatonin is produced by pineal gland in the brain, which is responsible for operation and regulation of the biological clock in mammals.
Which one of the following pairs of hormones are the examples of those that can easily pass through the cell membrane of the target cell and bind to a receptor inside it (Mostly in the nucleus) 
Cor tisol and testosterone are steroid hormones which are lipid soluble and easily pass through the cell membrane of a target cell and bind to specific intracellular receptor.
What is correct to say about the hormone action in humans 
Glucagon is secreted by α cells of islets of langerhans and stimulate glycogenolysis i.e. breakdown of glycogen into glucose Thymosin hormone secreted from thymus gland stimulates the development of certain kinds of white blood cells involved in producing immunity. It also hostens attainment of sexual maturity.
F2 generation in a Mendelian cross showed that both genotypic and phenotypic ratios are same as 1 : 2 : 1. It represents a case of : 
Incomplete dominance is a type of intermediate inheritance in which one allele is not completely dominant over its paired allele. In this, the third phenotype is observed in heterozygous condition. In monohybrid cross with incomplete dominance, the phenotypic and genotypic ratio is 1:2:1, where one part is with dominant phenotype, 2 parts are with intermediate phenotype and 1 part is with recessive phenotype. For example, a snapdragon flower shows red (dominant), white (recessive) and pink (intermediate) flowers.
Thus, the correct answer is 'Monohybrid cross with incomplete dominance.'
Which of the following statements is correct in relation to the endocrine system? [NEET 2013]
Hormones are non-nutrient chemicals which act as intercellular messengers and are produced in trace amounts.
Gastrointestinal tracts secretes four major peptide hormones – gastrin, secretin, cholecystokinin (CCK) and gastric inhibitory peptide (GIP) while juxtaglomerular cells of kidney secretes erythropoietin, a peptide hormone. Releasing and inhibitory hormones are produced by hypothalamus. Neurohypophysis or posterior pituitary is under direct neural regulation of the hypothalamus.
A pregnant female deliver a baby who suffers from stunted growth, mental retardation/low intelligence quotient and abnormal skin. This is the result of : [NEET 2013]
Iodine is essential for the normal rate of hormone synthesis in the thyroid. Deficiency of iodine in our diet results in hypothyroidism and enlargement of the thyroid gland, commonly called goitre.
Hypothyroidism during pregnancy causes defective development and maturation of the growing baby leading to stunted growth (cretinism), mental retardation, low intelligence quotient, abnormal skin, deaf-mutism, etc.
Select the answer which correctly matches the endocrine gland with the hormone it secrets and its function/deficiency symptom: [NEET 2013]
Which of the following represents the action of insulin? [NEET Kar. 2013]
Insulin is a pe ptide hor mone, which plays a major role in the regulation of glucose homeostasis. Insulin acts mainly on hepatocytes and adipocytes (cells of adipose tissue), and enhances cellular glucose uptake and utilization. Insulin also stimulates conversion of glucose to glycogen (glycogenesis) in the target cells.
Norepinephrine : [NEET Kar. 2013]
(1) Is released by sympathetic fibres
(2) Is released by parasympathetic fibres
(3) Increases the heart rate
(4) Decreases blood pressure
Which of the above said statements are correct?
Norepinephrine is released by sympathetic fibres i.e, rapidly secreted in response to stress of any kind and during emergency situations. It increases the heart beat, the strength of heart contraction and the rate of respiration.