Topic Five - Regulation of Systems Flashcards
What is homeostasis?
Homeostasis is a complex process that maintains the internal environment of an organism within set limits so that cells and systems can function properly.
What parameters affect the functioning of cells?
Parameters that affect the functioning of cells include temperature, pH (acidity level), blood sugar levels, sodium and potassium concentration, and fluid balance.
What is the stimulus-response model?
The stimulus-response model outlines how changes in the external and internal environment can influence an organism’s function.
What are the five components of the stimulus-response model?
The five components are stimulus, receptor, modulator, effector, and response.
What is a positive feedback system?
A positive feedback system occurs when the response increases the initial stimulus. It is rare in the body and doesn’t form part of homeostasis.
What is a negative feedback system?
A negative feedback system occurs when the response counters the stimulus. The response attempts to revert the system back to the set point – the value the body aims to maintain a given variable at. Homeostasis typically involves negative feedback loops.
What is cellular signaling?
Cellular signaling is the process of detecting a stimulus, transmitting a signal during cellular signaling, and producing a response.
What are the three steps of cellular signaling?
The three steps of cellular signaling are reception, transduction, and response.
What is the purpose of homeostasis?
Homeostasis maintains a constant internal environment in the body so cells can continue to function despite changes to the external environment.
What is the concept of feedback loops?
The concept of feedback loops is an important part of homeostasis, where negative feedback loops attempt to counter the stimulus and maintain the internal environment within set limits.
cellular signalling; Reception
The first step in cellular signaling.
The process of detecting a signal or stimulus by a cell receptor.
The signal can be mechanical, electrical, or chemical.
After reception, the signal is transmitted to the cell’s interior.
cellular signalling; Transduction
The second step in cellular signaling.
The process of transmitting a signal from the cell membrane to the interior of the cell.
The signal can be transmitted by molecules, ions, or other mechanisms.
Transduction can involve sending a signal between organisms, across the body, to a neighboring cell, or back to the original receptor cell.
cellular signalling; Response
The third and final step in cellular signaling.
The change in the function of a target cell, organ, or organism.
The response can be activation of an enzyme, secretion of a hormone, or contraction of a muscle, among other possibilities.
The response can be immediate or delayed.
What are the four main ways heat transfer can occur?
Heat can transfer through conduction, convection, radiation, and evaporation.
What is the difference between endotherms and ectotherms?
Endotherms (warm-blooded animals) are able to generate their heat energy internally using metabolic processes, while ectotherms (cold-blooded animals) produce very little metabolic energy and rely on environmental sources of heat to warm themselves.
What is thermoregulation?
Thermoregulation is the process by which an organism regulates its internal body temperature within a certain range, in order to maintain normal biological function.
What is the role of the hypothalamus in thermoregulation in humans?
The hypothalamus is the modulator in the thermoregulation process in humans. It sends messages to a variety of effector cells and tissues throughout the body, in response to the thermoreceptor’s detection of temperature changes.
What is the stimulus for thermoregulation in humans?
The stimulus for thermoregulation in humans is a change in core body temperature or the environmental temperature.
How does the human body respond to changes in temperature during thermoregulation?
The human body responds to changes in temperature by creating a response that causes a change in heat transfer, helping to maintain a core body temperature of 37°C.
What is negative feedback in thermoregulation in humans?
Negative feedback is the process by which the body responds to temperature changes and takes corrective action to maintain a stable internal body temperature.
What are the different factors that help to counter changes in environmental temperature during thermoregulation in humans?
Factors such as sweating, shivering, vasoconstriction, and vasodilation help to counter changes in environmental temperature during thermoregulation in humans. They all aim to either increase or decrease the heat generated/lost via the heat transfer principles of conduction, convection, evaporation, and radiation.
Convection
Definition: Convection is the transfer of heat through the movement of fluids (liquids or gases).
Example: Boiling water on a stove, where heat from the burner causes the water at the bottom of the pot to become hot and rise to the top, displacing the cooler water, which then sinks to the bottom and is heated.
Key points: Convection occurs in fluids (liquids and gases), and it involves the movement of the fluid itself as a means of heat transfer.
Conduction
Definition: Conduction is the transfer of heat through direct contact between two materials of different temperatures.
Example: Touching a hot pan on a stove, where the heat from the pan is transferred to your hand through direct contact.
Key points: Conduction occurs through direct contact between two materials, and it requires a temperature difference between them to occur.
Evaporation
Definition: Evaporation is the transfer of heat through the conversion of a liquid into a gas.
Example: Sweating, where heat from your body causes sweat to evaporate, taking heat away from your skin and cooling you down.
Key points: Evaporation requires a liquid to be present, and it involves the conversion of the liquid into a gas, which takes heat away from the source.
