Tag: zoology

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

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

  1. GH

  2. TSH

  3. TRH

  4. Both A and B
Reveal answer Fill a bubble to check yourself
C Correct answer
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'.
Multiple choice zoology endocrine system and chemical co-ordination hypothalamus nervous and endocrine system in humans coordination in human beings- chemical control

Gonadotropin releasing hormone is transferred to anterior pituitary by

  1. left coronary artery

  2. hypophysial portal artery

  3. axons of neurosecretory cells

  4. nuclei of hypothalamus
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.

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

Gonadotropin releasing hormone is formed by

  1. Adenohypophysis

  2. Pars intermedia

  3. Neurohypophysis

  4. Hypothalamus
Reveal answer Fill a bubble to check yourself
D Correct answer
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'.
Multiple choice zoology endocrine system and chemical co-ordination hypothalamus nervous and endocrine system in humans 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 

  1. Cerebrum

  2. Hypothalamus

  3. Cerebellum

  4. Medulla oblongata
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

Hormones of hypothalamus are known as

  1. Regulatory hormones

  2. Growth hormones

  3. Trophic hormones

  4. Angiotensin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The hormones produced by the hypothalamus are called regulatory hormones (releasing or inhibiting hormones) because they control the secretion of hormones from the anterior pituitary.

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

Thermoregulatory centre of the human body is

  1. Pituitary

  2. Skin

  3. Hypothalamus

  4. Thyroid
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

The thermoregulatory centre in higher animals is found in

  1. Pituitary

  2. Medulla

  3. Thalamus

  4. Hypothalamus
Reveal answer Fill a bubble to check yourself
D Correct answer
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. 

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

Specific part of hypothalamus, responsible for physiological sweat secretion is

  1. Supra-optic nucleus

  2. Para ventriculus nucleus

  3. Pars distalis

  4. Median eminence
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The paraventricular nucleus of the hypothalamus is involved in various autonomic functions, including the regulation of physiological responses like sweat secretion.

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

The primary target of the hormones of hypothalamus is 

  1. Pineal gland

  2. Thymus

  3. Pituitary

  4. Testis
Reveal answer Fill a bubble to check yourself
C Correct answer
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'.
Multiple choice zoology endocrine system and chemical co-ordination hypothalamus nervous and endocrine system in humans coordination in human beings- chemical control

The releasing hormones are produced by

  1. Testis

  2. Pancreas

  3. Pituitary

  4. Hypothalamus
Reveal answer Fill a bubble to check yourself
D Correct answer
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'.