Tag: endocrine system and chemical co-ordination

Questions Related to endocrine system and chemical co-ordination

How many of these hormones are lipid soluble?
Progesterone, Estrogen, Epinephrine, Cortisol, Norepinephrine, Thyroxine, Prolactin, Aldosterone.

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

  1. Three

  2. Five

  3. Eight

  4. Four

Show answer
Correct Option: A
Explanation:
Dissolve in fats rather than in water. These are usually formed from cholesterol. Therefore fat-soluble hormones can pass through cell membranes.
Sex hormones or gonadal steroids are examples of the lipid-soluble hormone, like, Testosterone, Progesterone & Oestrogen. Other steroids, including Glucocorticoids such as cortisone &Mineralocorticoids such as Aldosterone, are the types of lipid-soluble hormones.
So the correct option is ' Three '.

The given table enlists various hormones and their chemical nature. Select the option which completes the table.

Hormone Chemical composition
(i) Peptide
Testosterone (ii)
Thyroxine (iii)
(iv) Amino-acid derivative
zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. (i)-Cortisol, (ii)-Steroid, (iii)-Polypeptide, (iv)-Estradiol

  2. (i)-Oxytocin, (ii)-Protein, (iii)-Iodothyronin, (iv)-Epinephrine

  3. (i)-Cortical, (ii)-Protein, (iii)-Amine, (iv)-Estradiol

  4. (i)-Oxytocin, (ii)-Steroid, (iii)-Iodothyronine, (iv)-Epinephrine

Show answer
Correct Option: D
Explanation:

(i) Peptides: These hormones are further of two types: Short peptide and long peptide.

Short peptide: The hormones oxytocin and vasopressin from the posterior lobe of the pituitary gland.
Long peptide: The hormones insulin and glucagon from the pancreas.
(ii) Steroid: The hormones from adrenal cortex, testes, ovaries and placenta are steroids. So, testosterone is a steroid.
(iii) Amino acid derivative: The hormones epinephrine and norepinephrine from the adrenal medulla and thyroxine from the thyroid gland are derived from the amino acid tyrosine.
So, the correct answer is '(i)- Oxytocin, (ii)- Steroid, (iii)- Iodothyronine, (iv)- Epinephrine'.

GnRH of hypothalamus stimulates

zoology endocrine system and chemical co-ordination hypothalamus nervous and endocrine system in humans coordination in human beings- chemical control

  1. Ovulation and maintenance of corpus luteum

  2. Secretion of androgen and development of mammary gland

  3. Contraction of uterus during parturition

  4. Ejection of milk

Show answer
Correct Option: A
Explanation:

GnRH of hypothalamus stimulates the synthesis and secretion of the two gonadotropin hormones, namely luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary gland. FSH is responsible for the ovulation. It stimulates the growth of ovarian follicle and growth of eggs in the ovaries. It is also responsible for the pubertal development. Corpus luteum is formed and maintained by the LH. 

Thus, the correct answer is 'Ovulation and maintenance of corpus luteum.'

When a young child's body temperature drops, hypothalamus produces _____________ hormone.

zoology endocrine system and chemical co-ordination hypothalamus nervous and endocrine system in humans coordination in human beings- chemical control

  1. GH

  2. TSH

  3. TRH

  4. Both A and B

Show answer
Correct Option: C
Explanation:
  • The hypothalamus is the basal part of the diencephalon, forebrain.
  • When a young child's body temperature drops, the hypothalamus produces TRH( thyrotropin-releasing hormone)hormone.
  • Thyroid-releasing hormone (TRH) from the hypothalamus stimulates TSH(Thyroid stimulating hormone) from the pituitary, which stimulates thyroid hormone release from the thyroid gland.
  • Thyroid hormone causes an increase in BMR(Basal metabolic cate) and increases in BMR results in an increase in body temperature to normal.
  • Hence When a young child's body temperature drops, the hypothalamus produces TRH( thyrotropin-releasing hormone)hormone.
  • So, the correct answer is 'TRH'.

Gonadotropin releasing hormone is transferred to anterior pituitary by

zoology endocrine system and chemical co-ordination hypothalamus nervous and endocrine system in humans coordination in human beings- chemical control

  1. left coronary artery

  2. hypophysial portal artery

  3. axons of neurosecretory cells

  4. nuclei of hypothalamus

Show answer
Correct Option: B
Explanation:

Gonadotropin-releasing hormone is a hormone responsible for releasing FSH and LH  from anterior pituitary gland. It is transferred to the anterior pituitary gland by the hypophysial portal artery. 

So, the correct option is 'Hypophysial portal artery'.

Gonadotropin releasing hormone is formed by

zoology endocrine system and chemical co-ordination hypothalamus nervous and endocrine system in humans coordination in human beings- chemical control

  1. Adenohypophysis

  2. Pars intermedia

  3. Neurohypophysis

  4. Hypothalamus

Show answer
Correct Option: D
Explanation:
A. Adenohypophysis is anterior pituitary which consists of pars distalis and pars intermedia. Pars distalis produces growth hormone (GH), thyroid stimulating hormone (TSH), adrenocorticotrophic hormone (ACTH), prolactin (PRL), follicle stimulating hormone (FSH) and luteinizing hormone (LH). Pars intermedia produces melanocyte stimulating hormone (MSH).
B. Pars intermedia is part of adenohypophysis which produce melanocyte stimulating hormone (MSH).
C. Neurohypophysis is posterior pituitary stores and releases two hormones oxytocin and vasopressin.
D. Hypothalamus secrete gonadotrophin releasing hormone (GnRH) and somatostatin hormone.
So, the correct answer is 'Hypothalamus'.

Thermostat is an instrument by which one can regulate the temperature of an oven, a heater or a refrigerator. Functionally a similar mechanism is located in the mammalian brain in the region of the 

zoology endocrine system and chemical co-ordination hypothalamus nervous and endocrine system in humans coordination in human beings- chemical control

  1. Cerebrum

  2. Hypothalamus

  3. Cerebellum

  4. Medulla oblongata

Show answer
Correct Option: B
Explanation:

Hypothalamus maintains the constant human body temperature by regulation of the diameter of blood vessels (constriction or dilation), shivering and sweating mechanisms. Option B is correct. Cerebrum serves to receive sensory inputs, to bring about integration before commanding voluntary motor responses, to coordinate the activities of other part of brain, and to carry out higher thought processes for learning, memory, language and speech.  This makes option A incorrect. Cerebellum serves to coordinate the voluntary movements of skeletal muscles as well as posture, balance and equilibrium. Option C is incorrect. Medulla oblongata consists of reflex centres that control heartbeat, blood vessel diameter and rhythm of breathing as well as other vital functions. Option D is incorrect.  Correct answer is B.

Hormones of hypothalamus are known as

zoology endocrine system and chemical co-ordination hypothalamus nervous and endocrine system in humans coordination in human beings- chemical control

  1. Regulatory hormones

  2. Growth hormones

  3. Trophic hormones

  4. Angiotensin

Show answer
Correct Option: A

Thermoregulatory centre of the human body is

zoology endocrine system and chemical co-ordination hypothalamus nervous and endocrine system in humans coordination in human beings- chemical control

  1. Pituitary

  2. Skin

  3. Hypothalamus

  4. Thyroid

Show answer
Correct Option: C
Explanation:

a) Hypothalamus maintains the constant human body temperature by regulation of the diameter of blood vessels (constriction to conserve heat during body temperature lower than normal or dilation to lose heat by increasing blood flow during body temperature higher than the normal range), shivering and sweating mechanisms.

b) Pituitary gland is associated with overall physical growth and development via its growth hormone as well as to instruct other endocrine glands to secrete their hormones via its tropic hormones. 
c) Thyroxine and triiodothyronine are thyroid hormones which target all tissues and stimulate metabolic rate. 
d) Sweat glands present in skin help dissipate the heat during summers by evaporation of water on the skin surface, thereby cooling the skin surface. Skin does not contain any thermoregulatory centres but only exhibit sweating as a mechanism of temperature regulation.
So, the correct answer is option C.

The thermoregulatory centre in higher animals is found in

zoology endocrine system and chemical co-ordination hypothalamus nervous and endocrine system in humans coordination in human beings- chemical control

  1. Pituitary

  2. Medulla

  3. Thalamus

  4. Hypothalamus

Show answer
Correct Option: D
Explanation:

Diencephalon consists of thalamus and hypothalamus. Thalamus serves as relay station for sensory impulses as well as integration centre for recognition of pain, temperature and hard touch. The thermostat centre for temperature control is present in hypothalamus. Hypothalamus maintains the constant human body temperature by regulation of the diameter of blood vessels (constriction or dilation), shivering and sweating mechanisms.