Tag: endocrine system and chemical co-ordination

Questions Related to endocrine system and chemical co-ordination

The LH surge is essentially a signal sent from the brain to the ovary,which indicates

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. Onset of implantation

  2. An egg is mature

  3. Fertilization

  4. None of the above

Show answer
Correct Option: B
Explanation:

  • The LH surge causes the initiation of the process of ovulation. 
  • After ovulation, the follicle is transformed into the corpus luteum, which is stimulated by LH.
  •  It occurs roughly 36 hours before ovulation which indicates egg has matured and is ready for fertilisation. Hence, The LH surge is essentially a signal sent from the brain to the ovary, which indicates An egg is mature.
So, the correct answer is 'An egg is mature'.

Which hormone is antagonistic to calcitonin?

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. TSH

  2. Parathyroid

  3. Thyroxine

  4. None of the above

Show answer
Correct Option: B
Explanation:

  • Parathyroid hormone (PTH) is essential for the physiologic maintenance of mineral homeostasis. 
  • PTH regulates the mineral transport in bone and kidney and through its secondary actions on mineral transport in the intestine. 
  • Calcitonin, in many ways, acts as a physiologic antagonist to PTH. Hence,  Parathyroid hormone is antagonistic to calcitonin
So, the correct answer is 'Parathyroid'.

The cells which produces erythropoietin

zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

  1. Juxtaglomerular cells

  2. Hepatic cells

  3. Glandular cells

  4. None of the above

Show answer
Correct Option: A
Explanation:
  • Erythropoietin is produced by interstitial fibroblasts in the kidney in close association with the peritubular capillary and proximal convoluted tubulin the cell named juxtaglomerular cells. 
  •  It is also produced in perisinusoidal cells in the liver. Hence, The cells which produce erythropoietin Juxtaglomerular cells.
    • So, the correct answer is 'Juxtaglomerular cells'.

Hormones can be differentiated from neurotransmitters on the basis of the fact that

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. Hormones modify cellular activity

  2. Hormones are secreted into the bloodstream

  3. Hormones produce a change in animal behavior

  4. Hormones attach to receptors on the cell surface

  5. Hormones are released in response to external stimuli

Show answer
Correct Option: B
Explanation:
Neurotransmitters are the chemical messenger that is released from an axon terminal of a neuron in response to an action potential. Whereas a hormone is a long distance chemical mediator that is secreted by an endocrine gland into the blood which is transported to target cells. Thus, the correct answer is option B.

The genes, which are confined to differential region of Y chromosome

only, are called

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. Mutant

  2. Autosomal

  3. Holandric

  4. Completely sex-linked

Show answer
Correct Option: C
Explanation:

The genes present on the differential part of Y chromosome are passed directly from father to son and are called as Holandric genes.

Which of the following is a feature of endocrine glands?

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. Secrete vitamins

  2. Cease functioning after adolescence

  3. Begin functioning in adolescence

  4. Have ducts

  5. Ductless glands

Show answer
Correct Option: E
Explanation:

  • Endocrine glands are glands of the endocrine system that secrete their products, hormones, directly into the blood(ductless) rather than through a duct.
  •  The major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus and adrenal glands. Hence, Ductless gland is a feature of endocrine glands.
So, the correct answer is 'Ductless glands'.

Which of the following hormones is derived from a single amino acid?

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. Thyroxine

  2. Oxytocin

  3. Estradiol

  4. Epinephrine

Show answer
Correct Option: D
Explanation:

Hormones can be classified based on their chemical nature like amino acid derivative hormones, peptide hormones, iodothyronines and steroid hormones. Hormones like epinephrine, norepinephrine, thyroxine are derived from amino acids. Epinephrine and norepinephrine are released by renal medulla. These are derived from single amino acid tyrosine. Thyroxine is released by thyroid gland. It is also derived from tyrosine amino acid by the addition of iodine.

Thus, the correct answer is 'Epinephrine.'

How many of these hormones are lipid soluble? FSH, LH, Iodothyronine, Epinephrine, Aldosterone, Progesterone.

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. Two

  2. Three

  3. Four

  4. One

Show answer
Correct Option: A
Explanation:
Lipid soluble hormones are the hormones that can be dissolved in fats rather than in water. They are usually formed from cholesterol and lipids, therefore fat-soluble hormones can pass through cell membrane. Examples of lipid soluble hormones are progesterone and aldosterone.
So the correct answer is 'Two'.

Correct hormonal sequence in the rate of man is 

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. Oestrogen, Fs, progesterone

  2. Oestrogen, progesterone, FSH

  3. FSH, progesterone, oestrogen

  4. FSH, oestrogen , progesterone

Show answer
Correct Option: D
Explanation:

The secretion of gonadotropin s (LH & FSH) increase gradually during the follicular phase and stimulates follicular development as well as secretion of oestrogens and progesterone. 


So the correct option is " FSH, oestrogen, progesterone". 

Which of the following is TRUE regarding atrial natriuretic factor (ANF)?

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. When blood pressure is increased, ANF is secreted which causes dilation of the blood vessels

  2. ANF is a peptide hormone

  3. ANF is secreted by the atrial wall of the heart

  4. All of the above

Show answer
Correct Option: D
Explanation:

When the blood pressure is increased it results in excess of blood flow to the Heart. When the blood flow to the heart is increased it leads to the stretching of the atrial wall and the release of ANF (Atrial natriuretic polypeptide) from the atrial walls. The ANF is a polypeptide hormone which causes the vasodilation (dilation of blood vessels) and thereby decrease the blood pressure. Hence ANF is a peptide hormone which is secreted by the atrial wall of the heart when blood pressure is increased and causes dilation of the blood vessels which results in the decrease of the blood pressure.

So, the correct option is 'All the above'.