Study Guide: Understanding and Responding to Jellyfish Stings

Quiz: Jellyfish Stings

Instructions: Answer the following ten questions in 2-3 complete sentences each, based on the information provided in the source context.

1. What is a jellyfish sting, and what is the specific biological mechanism that causes it?
2. Differentiate between the local and systemic symptoms that can occur after a jellyfish sting.
3. List and briefly explain three factors that determine the severity of a jellyfish sting.
4. What are the critical first-aid steps that should be performed immediately after a person is stung by a jellyfish?
5. Explain why using fresh water to rinse a jellyfish sting is strongly advised against.
6. Identify two common but incorrect “remedies” for jellyfish stings and explain why they are ineffective or harmful.
7. Under what circumstances does a jellyfish sting become a medical emergency requiring immediate professional help?
8. Can a jellyfish that has washed ashore and appears to be dead still pose a threat? Explain your reasoning.
9. According to the provided text, what is an effective method for alleviating the pain associated with a jellyfish sting?
10. Describe the typical appearance of a mark left by a jellyfish sting and state whether these marks are usually permanent.

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Answer Key

1. A jellyfish sting is a biochemical reaction that occurs when the stinging cells on a jellyfish’s tentacles inject venom into the skin. This mechanism involves microscopic stinging capsules called nematocysts, which are located on the tentacles and are used for defense or hunting. When triggered by contact, each nematocyst fires a tiny, needle-like tube that penetrates the skin and delivers the venom.
2. Local symptoms are reactions that occur directly at the site of the sting and include immediate, severe pain (burning or throbbing), redness, swelling, intense itching, and visible track marks on the skin. Systemic symptoms are rarer reactions that affect the entire body, such as nausea, vomiting, headache, muscle spasms, difficulty breathing, heart palpitations, and, in the most severe cases, loss of consciousness.
3. The severity of a sting is determined by several factors. First, the species of jellyfish is critical, as some, like the Box Jellyfish, have extremely potent and potentially fatal venom. Second, the size of the contact area matters; more tentacles touching a larger skin surface results in more venom being injected. Third, the individual’s sensitivity, including their allergic predisposition or immune system response, can significantly intensify the reaction.
4. The first-aid priorities are to ensure the person’s safety by removing them from the water and then to stop the venom’s spread. Any visible tentacle fragments must be carefully removed from the skin using gloves to avoid further stings. The affected area should then be rinsed thoroughly with salt water or sea water.
5. Using fresh water is dangerous because it can trigger any remaining nematocysts on the skin to fire. The change in osmotic pressure caused by fresh water causes the stinging cells to rupture and release more venom into the person’s system. Therefore, only salt water should be used for rinsing the affected area.
6. Two incorrect remedies are using urine or ammonia and rubbing or scraping the area. There is no scientific evidence that urine or ammonia neutralizes the venom; in fact, they can trigger more venom release and increase the risk of infection. Rubbing or scraping the skin is also harmful because this physical pressure can cause unfired nematocysts to discharge their venom, worsening the sting.
7. A jellyfish sting requires immediate medical attention if systemic symptoms appear, such as difficulty breathing, chest pain, dizziness, or loss of consciousness. Medical help is also essential if a child or elderly person is stung, if the sting is on the face, eyes, or throat, or if the sting covers a large area of the body. Worsening or non-improving symptoms are also a clear sign to seek professional care.
8. Yes, a dead jellyfish can still be dangerous. The nematocysts on its tentacles can remain active and capable of firing and injecting venom even after the jellyfish has died. For this reason, it is crucial to avoid touching any jellyfish, whether it is in the water or washed up on the shore.
9. An effective method for alleviating pain is the application of heat. Immersing the affected area in hot water (around 45-50°C) or applying a hot compress can help reduce pain and itching. The heat works by breaking down the protein structure of the venom, thereby reducing its effect.
10. A mark from a jellyfish sting often appears as linear, whip-like, or grid-like red or purplish lines on the skin that trace the path of the tentacle contact. These marks are generally not permanent. In most mild-to-moderate cases, the marks and associated redness begin to fade in a few days and typically disappear completely within one to two weeks.