Tag: role of hormones in coordination

Questions Related to role of hormones in coordination

Hormones are carried from endocrine system to target organs linked through

  1. Blood

  2. Lymph

  3. Both A and B

  4. None of these


Correct Option: A
Explanation:

Hormones secreted by the endocrine system have to be carried throughout to body by the circulating blood to act where ever required.

The endocrine system which of the following functions?

  1. The endocrine system is responsible for regulating gene expression.

  2. The endocrine system is responsible for regulating dominant genes.

  3. The endocrine system is responsible for releasing, monitoring and regulating hormones.

  4. The endocrine system is responsible for communication between sensory systems.


Correct Option: C
Explanation:

The endocrine system do not regulate gene expression nor controls the release of dominant genes. It is also not responsible for communication between sensory system but is responsible for releasing, monitoring and regulating hormones.

Steroid hormones regulate gene activity through

  1. Transcription

  2. Binding with specific DNA sites

  3. Removing the repressor molecules

  4. The formation of a receptor complex


Correct Option: A
Explanation:

Steroids, though actually enter the cell and interact with steroid receptor proteins to control gene expression. In steroid receptor proteins, the N-terminal region of the protein is required to activate transcription. Negative and positive autoregulatory feedback loops serve to limit or augment hormonal responses, respectively. Autoregulation of the mRNAs encode oestrogen, progesterone, androgen, and glucocorticoid receptors by the steroid hormones in reproductive tissues. These post-transcriptional mRNA effects cause steroid hormones to impact the expression of a large population of genes. 

A ........................... mechanism regulates the action of hormones.

  1. Feed back

  2. Cascade

  3. Both A and B

  4. All of the above


Correct Option: A
Explanation:
Feedback mechanism is the mechanism of the body to maintain the levels of hormones in the body in the desired limits. An increase or decrease in the levels of the hormones triggers the feedback mechanism.
The body has two types of feedback mechanisms, positive and negative feedback mechanism.
Example:
Negative feedback mechanism: Whenever there is a change in the normal state, the messages are sent to ‘increase’ secretions if there is a fall below normal or to ‘decrease’ secretions if there is a rise above normal to restore the normal body state. Such a mechanism is called a negative feedback mechanism. The increase in the blood sugar level stimulates the secretion of insulin so that the sugar level is maintained. If the blood sugar level falls below normal, then it stimulates the secretion of glucagon. Glucagon stimulates the breakdown of glycogen to glucose, and thus, the normal sugar level is maintained.

So, the correct answer is 'Feed back'.

Cortisol is secreted by the adrenal cortex in response to stress. In addition to its function in a stress response, it functions in negative feedback by

  1. Inhibiting hypothalamus to secrete corticotropin releasing hormone or CRH

  2. Inhibiting anterior pituitary's ability to respond to CRH

  3. Inhibiting the epinephrine

  4. Both A and B


Correct Option: D
Explanation:
  • One distinctive feature of hormones whose secretion is regulated through the hypothalamus and pituitary is that they regulate their own secretion through negative feedback inhibition. 
  •  for example, cortisol binds to its receptor on cells in the hypothalamus and adenohypophysis, and has the effect of inhibiting secretion of tropic hormones: in this case, CRH (corticotropin releasing hormone) and ACTH (adrenocorticotropic hormone). 
  • Less tropic hormone secretion leads to less stimulation of cortisol secretion by cells of the zona fasciculata of the adrenal cortex. Hence, Cortisol is secreted by the adrenal cortex in response to stress. In addition to its function in a stress response, it functions in negative feedback by Inhibiting hypothalamus to secrete corticotropin-releasing hormone or CRH and  Inhibiting anterior pituitary's ability to respond to CRH. 
So, the correct answer is 'both A and B.

Epinephrine level in blood increases in response to stress. This hormone is known to affect the rate of glycolysis in different organs of the body. The rates of glycolysis in liver, heart and skeletal muscles in response to rise in blood epinephrine (in comparison to non-stress condition) is expected to be

  1. Unaffected in liver, low in heart, and high in skeletal muscles

  2. High in liver, low in heart, and low and skeletal muscles

  3. Unaffected in liver, high in heart, and low in skeletal muscles

  4. Low in liver, high in heart, and high in skeletal muscles


Correct Option: D
Explanation:

Epinephrine is the hormone released in response to stress conditions. The rise in the hormone level in he blood causes an increase in ATP production for which the rates of glycolysis increases in the muscles (heart and skeletal muscles). The synthesis of glucose by gluconeogenesis takes place in the liver and so, the rate of glycolysis is low. 

Thus, the correct answer is option D. 

Which illustrates feed back in development

  1. As tissue 'X' develops, it secretes enzyme to inhibit development of tissue 'Y'

  2. As tissue 'X' develops, it secretes something that induces tissue 'Y' to develop

  3. As tissue 'X' develops, it secretes something that slows down growth of tissue 'Y'

  4. Tissue 'X' secretes RNA which changes the development of tissue 'Y'.


Correct Option: A
Explanation:
The X and Y tissue system is observed in Crustaceans. The X organ produces hormones that control development, to prevent molting during development it releases an antiecdysis hormone, which stops the Y organ from secreting the molting hormone.
Therefore, the correct answer is' As tissue 'X' develops, it secretes enzyme to inhibit development of tissue 'Y'

Besides corticotropin releasing hormone(CRH) which other hormone also stimulate the release of adrenocorticotropic hormone(ACTH)?

  1. Glucagon

  2. Insulin

  3. Aldosterone

  4. Epinephrine


Correct Option: D
Explanation:

Epinephrine acts on nearly all body tissues and its actions vary by tissue type and tissue expression of adrenergic receptors. The  β adrenergic receptor binding helps in increasing the secretion of adrenocorticotropic hormone by the pituitary glands.

Blood sugar level is an example of _______

  1. Positive feed back mechanism

  2. Negative feedback mechanism

  3. Both A and B

  4. None of these


Correct Option: B
Explanation:

The body has a mechanism to maintain a normal state. Whenever there is change in thus state there are messages through the body systems to increase if there is a fall below the normal , or decrease if there is rise above the normal. This kind of ordering for the opposite. Is negative feedback to restore the normal state.

Hormonal secretions are controlled by

  1. Feedback mechanism

  2. Autosomal disorder

  3. Genetic disorder

  4. None


Correct Option: A
Explanation:

'Too much, slow down or too little, speed up' -this is the feedback mechanism. the body has a mechanism to maintain a normal state. Whenever there is a change in this state there are messages through the body systems to increase if there is a fall below the normal, or decrease if there is rise above the normal.  This kind of ordering for the opposite Is negative feedback to restore the normal state. examples of positive feedback mechanisms are very few. One example is that of uterine contractions during childbirth. The normal state of the uterus is uncontracted, one contraction instead of commanding to come to normal gives a message to continue further (positive feedback till the delivery is completed).

So, the correct answer is 'Feedback mechanism'.