Tag: coordination in human beings- chemical control

Questions Related to coordination in human beings- chemical control

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

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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. 

Specific part of hypothalamus, responsible for physiological sweat secretion is

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

  1. Supra-optic nucleus

  2. Para ventriculus nucleus

  3. Pars distalis

  4. Median eminence

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Correct Option: B

The primary target of the hormones of hypothalamus is 

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

  1. Pineal gland

  2. Thymus

  3. Pituitary

  4. Testis

Show answer
Correct Option: C
Explanation:
A. Pineal gland is a small, rounded and reddish brown gland present at the dorsal side of forebrain. This gland secretes melatonin and serotonin hormones.
B. Thymus gland is associated with the development of immune system and present on the dorsal side of heart.
C. Pituitary gland is the master gland that regulates the activity of other endocrine glands and secretes many hormones like growth hormone, follicle stimulating hormone, thyroid stimulating hormone etc.
D. Testis are the primary sex organs in males that secrete the hormone testosterone.
The hormones secreted by hypothalamus reach the pituitary gland through circulatory system and regulate the functions of anterior part of pituitary gland. Hence, the primary target of hormones of hypothalamus is pituitary gland.
So, the correct answer is 'Pituitary'.

The releasing hormones are produced by

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

  1. Testis

  2. Pancreas

  3. Pituitary

  4. Hypothalamus

Show answer
Correct Option: D
Explanation:
A. Testis are the primary sex organs in males that secrete the hormone testosterone.
B. Pancreas is a heterocrine gland as it acts both as endocrine and exocrine gland. It secretes insulin hormone into blood and act as endocrine gland and when it secretes digestive enzymes and juice through pancreatic duct, it acts as exocrine gland.
C. Pituitary gland is the master gland that regulates the activity of other endocrine glands and secretes many hormones like growth hormone, follicle stimulating hormone, thyroid stimulating hormone etc.
D. Hypothalamus is present in the forebrain. This gland secretes hormones that regulate the synthesis and secretion of hormones of pituitary gland. Two types of hormones are produced by hypothalamus, releasing hormones that stimulate the secretion of pituitary hormones and inhibiting hormones that inhibit the secretion of pituitary hormones.
So, the correct answer is 'Hypothalamus'.

Pituitary gland is under the control of

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

  1. Thyroid gland

  2. Adrenal gland

  3. Adrenal medulla

  4. Hypothalamus

Show answer
Correct Option: D
Explanation:
A. Thyroid gland is situated between the trachea and larynx in the neck and secretes thyroxine hormone which increases oxygen consumption by metabolically active tissues.
B. Adrenal gland is present on upper side of kidneys and has two parts, adrenal cortex which secrete glucocorticoids, mineralocorticoids and sexocorticoids and adrenal medulla which secrete adrenaline and nor-adrenaline hormone.
C. Adrenal medulla is part of adrenal gland and secretes adrenaline and nor-adrenaline hormones.
D. Hypothalamus is present in the forebrain. This gland secretes hormones that regulate the synthesis and secretion of hormones of pituitary gland. 
So, the correct answer is 'Hypothalamus'.

Which centre is stimulated during increase in body temperature

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

  1. Anterior hypothalamus

  2. Posterior hypothalamus

  3. Limbic system

  4. Red nucleus

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Correct Option: A

Hypothalamus controls the production of which of the following pituitary hormones?

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

  1. ACTH (corticotropin), GH (growth hormone) and ADH (vasopressin)

  2. FSH and progesterone

  3. TSH (thyrotropin) and cortisol

  4. LH (luteinising hormone), ACTH (corticotropin) and TSH (thyrotropin)

Show answer
Correct Option: D
Explanation:

  • ACTH (Adrenocorticotropic hormone) is secreted from anterior lobe of pituitary gland. It increases the flow of blood to adrenal cortex and also increases the concentration of cholesterol and steroids. This result in increased output of steroid hormone cortisol from adrenal cortex.
  • GH (Growth hormone) is secreted from anterior lobe of pituitary gland and stimulates body growth and carbohydrate, protein, fat metabolism.
  •  ADH (Anti diuretic hormone )or Vasopressin is secreted from the posterior part of pituitary gland. This hormone increases reabsorption of water in kidneys and this results in decreased rate of urine production.
  • Follicle stimulating hormone (FSH) is secreted from the anterior part of pituitary gland. It stimulates the growth of ovarian follicles in females and seminiferous tubules in males.
  • Progesterone is a steroid female sex hormone which is also known as pregnancy hormone. It maintains the inner lining of uterus which aids in implantation of embryo in the uterus. 
  • TSH (Thyroid stimulating hormone) is secreted from anterior lobe of pituitary gland and stimulates the function and growth of thyroid gland.
  • Cortisol is a glucocorticoid hormone secreted from adrenal cortex and regulates carbohydrate metabolism , storage of glycogen and increased reabsorption of sodium and water from the renal tubules.
  • Luteinizing hormone or LH is secreted from anterior lobe of pituitary gland and stimulates growth of ovarian follicles in females. In males this hormone is called interstitial cell stimulating hormone or ICSH and affects the Leydig cells of testes.
Hence, LH, ACTH and TSH are secreted from pituitary gland.
So, the correct answer is 'LH (luteinising hormone), ACTH (corticotropin) and TSH (thyrotropin)'.