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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 its temperature at 37 °C
Answer
The man's body employs thermoregulation to maintain a stable internal temperature of 37 °C, even in a cool environment.
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Stimulus Detection: Receptors in the skin detect the cold temperature of 8 °C, sending signals to the hypothalamus in the brain.
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Impulse Transmission: The hypothalamus processes this information and sends impulses to the blood vessels in the skin.
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Vasoconstriction: The blood vessels constrict, reducing blood flow to the skin. This process minimizes heat loss from the body.
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Sweat Gland Activity: Less blood is sent to the sweat glands, making them less active and resulting in less sweat being produced.
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Evaporation Reduction: With less sweat on the skin, there is a decrease in evaporative cooling, assisting in maintaining body temperature.
These mechanisms work together to ensure that the man's core temperature does not drop significantly, despite the cold surroundings.
Step 2
how his co-worker heard his cries for help
Answer
His co-worker heard his cries for help through the following process:
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Sound Wave Capture: The sound waves generated by the man's voice were trapped by the pinna, the outer ear structure.
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Auditory Canal Direction: These sound waves were directed into the auditory canal (or external auditory meatus).
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Tympanic Membrane Vibration: The sound waves caused the tympanic membrane (eardrum) to vibrate, which is crucial for hearing.
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Transmission of Vibrations: Vibrations were then transmitted to the auditory ossicles (the malleus, incus, and stapes), which amplify the sound.
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Oval Window Movement: The movement of the oval window creates pressure waves in the cochlea (endolymph), further transmitting sound.
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Stimulation of Organ of Corti: These waves stimulate the Organ of Corti, converting them into electrical impulses.
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Signal Transmission: These impulses travel via the auditory nerve to the brain, where they are interpreted as sound, enabling the co-worker to hear the cries for help.