Cells-Homeostasis

Homeostasis

Understand organisms maintain a dynamic equilibrium in their internal environment as possible to live.

Temperature taking: Under the armpit, in the anus

Core temperature

Cold-blooded: Ectotherms/ Poikilotherm

The temperature of their body is dependent on the surrounding temperature.

Explanation:

*They can regulate their temperature through their behaviour. They just cannot maintain a constant temperature like the warm-blooded animals.

Eg: When the sunrays are shining, the lizard will turn itself 90 degree to the sunrays. It will heat up the lizard’s body and increases its metabolism, making it more active. When it is too hot, they will turn themselves away from the sun.

Warm-blooded: Endotherms/ Homoiotherms

They are able to maintain a constant body temperature. Temperature will fluctuate at a constant temperature. (37-degree celcius)

Explanation: They are able to regulate their own temperature internally.

Example: A camel in a hot dessert is able to raise its body temperature higher, closer to the surrounding temperature. This is to reduce heat gain.

*Steeper the gradient, the greater the transfer, less steep, less transfer

Heat:

Radiation, conduction, convection

Question: How do you regulate your temperature, water and sugar in your body?

Temperature: 

(If your skin temperature drops below 37-degree celcius, these actions will be carried out to conserve heat.)

•   Vasoconstriction to decrease the flow of heat to the skin.

•   Cessation of sweating.

•   Shivering to increase heat production in the muscles.

•   Secretion of norepinephrine, epinephrine, and thyroxine to increase heat production

•   In lower animals, the erection of the hairs and fur to increase insulation.

Source: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heatreg.html 

Water: The kidneys maintain our body's water balance by controlling the water concentration of blood plasma. The kidneys also control salt levels and the excretion of urea. Water that is not put back into the blood is excreted in our urine.

Source: http://www.bbc.co.uk/schools/gcsebitesize/science/add_ocr_pre_2011/homeostasis/waterbalrev1.shtml

Glucose:

1. Too much glucose in blood

2. Pancreas produces insulin that enters blood

3. Insulin allows glucose to be absorbed by body cells 

4. Blood glucose reduced

Source: http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel/responses_to_environment/homeostasisrev6.shtml 

•   Protein: One of the best ways to stabilise blood sugar levels is by including high-quality protein with each meal. The best sources include lean red meat, fish, chicken, eggs, legumes, nuts, seeds and tofu.

•   Chromium: Chromium helps normalise blood sugar levels and enhance insulin production. Sources include broccoli, wholegrain cereals, nuts, mushrooms and soy beans.

•   Reducing sugar: Reduce your consumption of sugary processed foods such as chocolates, cakes, biscuits, sugary breakfast cereal and soft drinks. These foods give a sharp rise in blood sugar levels.

•   Fibre: Fibre helps to stabilise blood sugar levels. It slows the absorption of glucose from food, which reduces the sharp rise in blood sugar levels. Best sources include wholegrain breads and cereals, brown rice, legumes, fruit and vegetables. 

Source: http://www.bodyandsoul.com.au/nutrition/nutrition+tips/control+blood+sugar+levels+with+food,7489 

Physiological and Physical behaviour → lower the metabolic rate → decrease your temperature (regulating your temperature) → decrease use of your food (conserve energy and food)