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A man was accidentally locked in a cool room in which the temperature was 8 °C - NSC Life Sciences - Question 4 - 2017 - Paper 1
Question 4
A man was accidentally locked in a cool room in which the temperature was 8 °C. He was only released after six hours when a co-worker heard his cries for help. Desc... show full transcript
Worked Solution & Example Answer:A man was accidentally locked in a cool room in which the temperature was 8 °C - NSC Life Sciences - Question 4 - 2017 - Paper 1
Step 1
Describe how his body maintained his temperature at 37 °C
Answer
The human body maintains its temperature through a process called thermoregulation. When exposed to the cold environment of 8 °C, receptors in the skin detect the drop in temperature and send impulses to the hypothalamus of the brain.
Upon receiving this information, the hypothalamus triggers several physiological responses to help maintain the core body temperature at 37 °C:
- Vasoconstriction: Blood vessels in the skin constrict, reducing blood flow to the skin and leading to less heat loss.
- Reduced sweat production: The sweat glands become less active, resulting in less sweat being released onto the skin, minimizing evaporative cooling.
- Decreased heat loss: With less blood near the skin's surface, the body reduces heat loss through the skin, thereby maintaining the core temperature during the prolonged cold exposure.
Step 2
How his co-worker heard his cries for help
Answer
When the man cried for help, the sound waves produced by his voice traveled through the air. The process of hearing involves several key steps:
- Pinna Function: The pinna, or outer ear, traps the sound waves and directs them into the auditory canal.
- Vibration of the Tympanic Membrane: The sound waves cause the tympanic membrane (eardrum) to vibrate, which is crucial for sound transmission.
- Transmission via Ossicles: The vibrations are transmitted to the small bones in the middle ear known as ossicles (malleus, incus, stapes), which amplify the vibrations.
- Oval Window: The vibrations then cause the oval window to vibrate, creating pressure waves in the inner ear.
- Signal to the Brain: This stimulates the Organ of Corti, which converts the vibrations into an impulse. The impulse travels via the auditory nerve to the cerebrum, where the sound is interpreted. Thus, through this sequence, the co-worker was able to hear the cries for help.