Temperature Regulation Flashcards
How is thermoregulation brought about?
By homeostatic control
What is the ectotherm?
Animal which is unable to regulate its body temperature by physiological means
What is an endotherm?
An animal which is able to maintain its body temperature at a relatively constant level independent of the temperature of the external environment, they have a high metabolic rate to generate heat energy
What is physiological homeostasis?
The maintenance of the bodies internal environment within certain tolerable limits despite changes in the bodys external environment, this regulation is brought about by negative feedback control and requires energy
What is the principle of negative feedback control?
When some factor affecting the bodies internal environment deviates from its normal optimum level (norm) this change in the factor is detected by receptors which send out nerve or hormonal messages which Are received by effecters
The affecters then bring about certain responses which counteract the original deviation from the norm and return the system to set point, this corrective mechanism is called negative feedback control
What is the role of the hypothalamus?
Part of the brain that is the body’s temperature monitoring centre which acts as a thermostat
It is sensitive to nerve impulses that it receives from heat and cold receptors in the skin
Has the ability to send appropriate nerve impulses to effectors which triggers corrective feedback mechanisms
Name mechanisms to prevent overheating
Vasodilation
Increase in the rate of sweating
Mechanisms to prevent overcooling
Vasoconstriction
Decreased rate of sweating
Contraction of erector muscles
What is an example of homeostatic control of body temperature?
Erector muscle contracting to make hair erect on arms
Features of conformers
State of their internal environment is directly dependent upon the abiotic factors in its external environment
The animals metabolic costs are low since it does not employ energy consuming physiological mechanisms
Narrow range of ecological niches so they are less adaptable to environmental change
Features of regulators
Employ physiological means to control the inner steady-state
Generate energy by metabolism but have to expend energy on physiological mechanisms
able to exploit a wide a range of ecological niches
More adaptable to environmental change
