Question

A person exposed to cold environment does't show

• A. Shivering
• B. Vasoconstriction of peripheral vessels
• C. Increased secretion of Thyroid and Adrenal medulla
• D. Increased heart beat and volume per stroke

Answer 1

The correct option is D Increased heart beat and volume per stroke

• Peripheral vasoconstriction, decrease in blood flow, shivering, tiredness or urinating more than usual are some of the important physiological response exhibited by humans exposed to cold. Cold weather can increase our body's need for thyroid hormone and cause or exacerbate hypothyroid symptoms. Commonly, during colder months, our thyroid stimulating hormone (TSH) level will rise.
  
• Heat in our body is produced by muscular work and by chemical reactions.

• Thyroid and adrenal hormones and the sympathetic nervous system maintenance
  

and regulate the oxidative phosphorylation. It is noteworthy that animals

from which thyroid or adrenal glands are removed do not tolerate cold.

• Humans have two general types of responses to cold. Vasomotor responses reduce dry heat loss to the environment. Metabolic responses act to replace heat lost to the environment. Vasomotor Responses: Peripheral vasoconstriction is one important physiological response exhibited by humans exposed to cold. Blood flow decreases as the temperature becomes colder,
• Metabolic Responses: In addition to those mechanisms that limit heat loss, humans employ other means to defend body temperature. Metabolic heat production can increase in order to replace heat loss during cold exposure. Muscle is generally considered the source of the increased metabolic heat production. Besides generating external force, muscle contractions also result in the liberation of considerable heat.
  
• So the correct answer is 'Increased heartbeat and volume per stroke'.