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.
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
• 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)
