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38 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Conditions needed to be maintained in cells |
A suitable Temperature A suitable pH An aqeous enviroment that keeps substrates in solition Freedom from toxins and access inhibitors |
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What type of adaptations respond to stimulus (enviromental change) |
Phycological and behavioural |
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Why is too much carbon dioxide in the blood bad |
It lowers the pH of the blood |
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How does the body's internal enviroment change when their is too much carbon dioixde |
The reduced pH in the blood stimulates greater breathing to get rid of the carbon dioxide |
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Why do you need changing internal enviroments |
To expel unhelpful waste products |
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How does waste in tissue fluid stop not waste from being produced |
It builds up in the tissue fluid and on to the cells reducing their activities |
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What is the main way waste products are realeased |
Excretion |
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Good communication systems will |
Cover the whole body Enable cells to communicate with each other Enable specific communication Enable rapid communication Enable both short term and long term responses |
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The 2 types of communication system |
Neuronal system and Hormonal system |
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Key points of the neuronal system |
Interconnected network of neurons Signal through synaps junction The signal is very quick Rapid respose |
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Key points of hormonal system |
Blood transport it's signals Hormones are transported all round the body but only target cells get signaled Enabled longer term responses |
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Homeostasis controls |
Body temperature Body glucose concentration Blood salt concentration Water potential in blood Blood pressure Carbon dioxide concentration |
6 |
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Standered response pathway for homeostasis |
Stimulus - receptor - communication pathway (cell signaling) - effector (the cell/organ/tissue that brings about the response) - response |
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Negative Feedback |
A mechanism that reverse change bringing the system back to the optimum |
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Where is change in temperature detected |
The thermo-regulatory centre in the hypothalamus |
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Positive feedback |
The mechanism to increase change taking it away from the optimum |
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Examples of positive feedback |
During pregnancy cervix dilation which stimulates the pituitary gland to release oxytocin which streches the cervix more |
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Ectotherm |
An organism that relies I external scources of heat to maintain body temperature |
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Endothern |
An organism that uses heat from metabolic factions to maintain body temperature |
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If an ectotherm is to cool it will |
Move to a sunny area Lie on a warm surface Expose a large surface area to the sun |
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If an ectotherm is to warm it will
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Move out the sun Move underground Reduce the body surface exposed to the sun |
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Advantages of ectothermy
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Less of their food is used in respiration More energy is used for growth They need to find less food They can survive for long periods without food |
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Disadvantages of ectothermy
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Less active when cold
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What does the skin do if the body is too hot
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Sweat glands secrete sweat Hairs and feather lie flat to allow air flow Vasodilation of arterioles Blood is directed to the skin surface |
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What does the skin do if the body is too cold
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Less sweat secreted Hairs and feathers stand up to trap air which insulates the body Vasoconstriction of arterioles Blood is away from the skin surface |
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What does the gaseous exchange system do if the body is too cold
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Less panting, less heat lost |
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What does the gaseous exchange system do if the body is too hot
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Increased evaporation of water from lungs and airways using heat from the blood
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What does the liver do if the body is too hot
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Less respiration so less hear released
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What does the liver do if the body is too cold |
Increased respiration that means more energy from food is converted to heat
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What do the skeletal muscles do if the body is too hot
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Fewer contractions so less heat is released
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What do the skeletal muscles do if the body is too cold
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Spontaneous muscle contractions (shivering) release heat
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What do the blood vessels do if the body is too hot
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Dilate to direct the blood to the extremities
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What do the blood vessels do if the body is too cold
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Constrict to direct the blood away from the extremities (This is frostbite)
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Advantages of endothermy
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Maintain a fairly constant body temperature what ever the external temperature Remain active when temperatures are low Inhabit areas of cold climate |
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Disadvantages of endothermy
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A significant amount of energy is used to maintain temperature Need more food Less energy is used for growth May overheat in warm weather |
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What is the arrangment of the loop henle called |
The hairpin counter current multiplier system |
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Draw the hairpin counter current multiplier system |
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Draw the concentration changes in the title fluid |
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