Homeostasis W1 Flashcards
(30 cards)
What is homeostasis?
Maintenance of a constant and “normal” internal environment
What is homeostasis like during steady state?
Physiological variable is unchanging
Balance between demands placed on body and body’s response to those demands
What causes mean pressure to remain constant even though arterial pressure oscillates over time?
Baroreflex responses and kidney function
How does exercise influence metabolism?
Increases adipose tissue lipolysis and FFA mobilisation
Increases liver glucose output (glycogenolysis and gluconeogenesis)
How does exercise influence skin?
Increases sweat rate
Effects:
Fluid homeostasis
Cardiovascular function
Temperature regulation
Metabolism
How does exercise influence oxygen transport?
Increases whole body oxygen uptake
Increases heart rate and cardiac output
Increases ventilation
Increases arterial PO2
How does exercise influence skeletal muscle?
Increases ATP turnover
Increases glycogenolysis, Glucose uptake, Lipolysis, FFA uptake
Increases O2 utilisation, CO2 and heat production
Increases blood flow and capillary recruitment
In the biological control system, what are the key components?
Control centre
Sensor/receptor
Effector
In the biological control system, what does the control centre do?
Assess input and initiates response
In the biological control system, what does the effector do?
Changes internal environment back to normal
In the biological control system, what does the sensor/receptor do?
Detects changes in the variable
What are biological control systems?
Series of interconnected components that maintain physical or chemical parameters at a near constant value
What is negative feedback?
Response reverses the initial disturbance in homeostasis
What is positive feedback system?
Biological response increases the original stimulus
What is gain (sensitivity of the response)?
Degree of which a control system maintains homeostasis
What are examples of homeostatic control?
Regulation of body temperature
Regulation of blood glucose
Regulation of cellular homeostasis
How does exercise disrupt homeostasis?
Changes pH, PCO2 and temperature in cells
What is the major test for homeostatic control?
Exercise
What is adaptation?
Change in structure/function
What is acclimation?
Adaptation to environmental stresses
Improves function of existing system (homeostatic)
What is exercise-induced hormesis?
A process in which a low-to-moderate dose of potentially harmful stress results in beneficial adaptive response on the cell or organ system
What is cell signalling?
Communication between cells using chemical messengers
Coordinates cellular activities
What are the 5 different cell signalling pathways?
Intracrine
Juxtracrine
Autocrine
Paracrine
Endocrine
What is intracrine signalling?
Cell messengers inside cell triggers response
