Photo AI
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
How his body maintained his temperature at 37 °C
Answer
To maintain his temperature at 37 °C despite being in a cool environment, the man's body underwent several physiological processes.
- Thermoregulation:
- The receptors in the skin detected the drop in temperature caused by the cool room.
- These receptors sent impulses to the hypothalamus of the brain, which is the body's thermostat.
- In response to the low temperature, the hypothalamus triggered a vasoconstriction reflex, leading to the narrowing of blood vessels in the skin. This process reduced blood flow to the skin, thus retaining heat.
- Additionally, less blood flow meant that less heat was lost to the environment.
- The body also decreased the activity of sweat glands, resulting in less sweat being released. With less sweat evaporating from the skin, there was further reduction in heat loss.
- Collectively, these mechanisms helped maintain the body’s internal temperature close to the normal range of 37 °C.
Step 2
How his co-worker heard his cries for help
Answer
The co-worker heard the man's cries due to the following process:
- Hearing Process:
- When the man cried out, the sound waves produced traveled through the air.
- The pinna of the ear trapped these sound waves and directed them into the auditory canal.
- As the sound waves reached the tympanic membrane (eardrum), they caused it to vibrate.
- This vibration was transmitted to the ossicles (small bones in the middle ear) including the malleus, incus, and stapes.
- The stapes then transmitted the vibrations to the oval window, creating pressure waves in the fluid of the inner ear (endolymph).
- These pressure waves stimulated the Organ of Corti, converting mechanical vibrations into neural impulses.
- Finally, these impulses were sent via the auditory nerve to the brain, where they were interpreted as sound, allowing the co-worker to hear the cries for help.