Presentation on theme: "What do the following have in common?"— Presentation transcript:
1What do the following have in common? The TitanicThe London undergroundA tri-athleteA London Marathon RunnerFour asylum-seekersPensioners Raymond and Doreen Elsom
2Look at the following slides and discuss why the people died?
3Titanic – 1,502 died – WHY?It was 2:20 am on Monday 15th April The Titanic had collided with an iceberg at 11:40 pm on 14th April and had floundered 3.5 hours later. About 650 passengers were lowered in lifeboats capable of holding 1178; the remaining passengers entered the sea as the Titanic sank. Hundreds of people thrashed about in water that was less than -2 degrees, well below freezing point. It was 4:10am before another ship arrived to collect the survivors. Only 705 of the 2207 survived died.Many of the passengers had life jackets and there was a lot of debris to hang onto. It was a calm and still night. Why did they die?
4People die on underground trains all over the world during the hot summer months – WHY?
5An elderly couple died in bed after forgetting to switch their electric hob off in the kitchen. No fire broke out, there was no evidence of fire damage. Just two dead bodies WHY?
6After the London Flora Marathon. Why did this man collapse?
7Why is this tri-athlete more likely to get hyperthermia when wet?
8Four asylum-seekers die in a tragedy Four asylum-seekers die in a tragedy. Police have discovered the bodies of four suspected asylum-seekers in a container. The four, all young men are believed to be have been Romanian. The bodies were found in a container load of tiles bound for the UK. The grim discovery was made when police noticed seals had been broken on the container and investigated. WHY did they die?
9** Explain the concept of negative feedback HomeostasisObjectives:*Define homeostasis** Explain the concept of negative feedback*** Explain the control of blood glucose concentration in terms of negative feedback
10Homeostasis is maintaining a nearly constant conditions in the body. Why nearly constant?Why this is necessary?Clue: metabolism, enzymesWho has the overall control of body processes?What things need controlling?
11Homeostasis makes sure our body has the correct levels of; pH and ionsTemperatureWaterOxygenCarbon dioxideBlood sugar(glucose)
12What happens if you are in your living room and experience either of these two situations? Brain stimulates the production of more heat in the muscles by shivering and by increasing respiration rate in the liver. It also stimulates the body to conserve more heat by decreasing sweat production by the sweat glands. Most body heat is generated in the deep organs like liver and brainBrain stimulates the body to sweat more to release more heat.
13Nice comfortable temperature Negative FeedbackHow does your heating work?Too hotTemp. increases during the dayHeating is switched off by thermostat.Nice comfortable temperatureHeating is switched on by thermostatTemp. drops at nightToo coldThis is NEGATIVE FEEDBACKWhat should we be controlled using negative feedback?
14Draw a negative feedback diagram of controlling temperature in an oven Thermostat switches heater offTemp fallsOven gets hotReqd oven temperatureReqd oven temperatureTemp risesThermostat switches heater onOven gets cold
15blood sugar levels in our bodies. Copy this down into your booksThe PancreasInsulin controlsGlucose is a sugar needed by cells for piraRestion.It is important that the concentration of glucose in the blood is kept at a constant level.blood sugar levels in our bodies.
16Changing glucose levels After a meal the level of glucose in our bodies [increases/decreases]?After exercise the levels of glucose in our bodies [increases/decreases]?Why do you think this happens?I think this happens because
21Insulin and glucagon(the hormones) Stimulate liver cells to change glucose to glycogen or vice versa. Both made in pancreas. They are not enzymes so they stimulate changes to blood glucose level but do not convert one to another. The enzymes in the liver and muscle help do the conversion.