Adrenaline is a neurotransmitter that directly acts on the S A node.
The hormone adrenaline (epinephrine) is secreted by adrenal medulla. This was first hormone to be isolated in crystalline form. This hormone is primarily responsible for the alarming reactions. It increases the heart rate, breathing blood glucose level.

Correct Option: A

Adrenaline is a neurotransmitter that directly acts on the S A node.
The hormone adrenaline (epinephrine) is secreted by adrenal medulla. This was first hormone to be isolated in crystalline form. This hormone is primarily responsible for the alarming reactions. It increases the heart rate, breathing blood glucose level.

Deficiency of thyroxine causes cretinism in infants and myxoedema in adults. Excess of adrenaline does not cause any disorder. Acromegaly is caused by over secretion of STH or somatotrophic hormone (Growth hormone).

Correct Option: A

Deficiency of thyroxine causes cretinism in infants and myxoedema in adults. Excess of adrenaline does not cause any disorder. Acromegaly is caused by over secretion of STH or somatotrophic hormone (Growth hormone).

Iodine is an element used by thyroid gland for the synthesis of thyroid hormones. Thus radioactive isotope Iodine -131 is used as radioactive material for detection of thyroid cancer.

Correct Option: A

Iodine is an element used by thyroid gland for the synthesis of thyroid hormones. Thus radioactive isotope Iodine -131 is used as radioactive material for detection of thyroid cancer.

Melatonin is secreted by pineal gland present between the cerebral hemispheres. Melatonin concentration in blood follows a diurnal cycle, it rises in the evening and drops at noon. Melatonin lightens skin colour in certain animals and regulates working of gonads.

Correct Option: D

Melatonin is secreted by pineal gland present between the cerebral hemispheres. Melatonin concentration in blood follows a diurnal cycle, it rises in the evening and drops at noon. Melatonin lightens skin colour in certain animals and regulates working of gonads.

Parathyroid gland secretes parathormone which regulates Ca²⁺ level in blood. Anterior lobe of pituitary secretes the following hormones growth hormone, ACTH, TSH, FSH, LH. Posterior pituitary secretes vasopressin and oxytocin. The intermediate lobe (pars intermedium) of the pitutary gland secretes MSH which causes dispersal of pigment granules in the pigment cells which give colour to the skin.

Correct Option: B

Parathyroid gland secretes parathormone which regulates Ca²⁺ level in blood. Anterior lobe of pituitary secretes the following hormones growth hormone, ACTH, TSH, FSH, LH. Posterior pituitary secretes vasopressin and oxytocin. The intermediate lobe (pars intermedium) of the pitutary gland secretes MSH which causes dispersal of pigment granules in the pigment cells which give colour to the skin.