YEAR 2 PHYSIOLOGY Flashcards
What is human physiology
The science of how humans’ function in an integrated way and is the basis for many biological and clinical sciences
what is exercise physiology
The branch of the biological sciences that is concerned with the way that the body responds to exercise and training
what is homeostasis
- Maintenance of a constant and normal internal environment
- All variables of physiological mechanisms must operate within a narrow range of values
what is steady state exercise
- Physiological variable (HR) is unchanging but not necessarily normal, plateau on graph
- Balance between demands placed on body and the body’s response to those demands
- Eg; HR, Body temp, Arterial BP
at rest what does arterial blood pressure do
fluctuates
at rest what does mean blood pressure do
stays constant due to baroreflex responses and kidney function
what are intracellular control systems
- protein breakdown and synthesis
- energy production
- maintenance of stored nutrients
what are organ systems
- pulmonary and circulatory systems
- replenish oxygen and remove carbon dioxide
in a biological control system what is a sensor for
detects change in a variable
in a biological control system what is a control centre for
asses input and initiates the response
in a biological control system what is an effector for
changes internal environment back to normal
what is negative feedback
- Acts to reduce an effect. When a change occurs in a system it opposes that change and restores the controlled variable back to its usual value
- Eg; respiratory systems control of CO2 conc in extracellular fluid
1. Increase in extracellular CO2 triggers a receptor
2. Sends info to respiratory control centre
3. Respiratory muscles are activated to increase breathing
4. CO2 conc returns to normal
Most control systems work via negative feedback
what is positive feedback
- Acts to increase an effect. When a change occurs, it becomes amplified
- Eg; childbirth
1. Initiation of childbirth stimulates receptors in cervix and sends message to brain to release oxytocin from pituitary gland
2. Oxytocin promotes increased uterine contractions
what is gain
sensitivity of the response
- Degree to which a control system maintains homeostasis
- Pulmonary and cardiovascular systems have large gains (thus more capable of maintaining homeostasis)
what happens to homeostasis at exercise
- Exercise disrupts homeostasis by changes in pH, PO2, PCO2 and temperature in cells
- Inability to maintain steady state = fatigue and end of exercise
what is adaptation
o Changes in structure and function of cell or organ system
o Results in improved ability to maintain homeostasis
o Many adaptive changes occur within cells
what is acclimatisation
o Adaptation to environmental stresses (e.g. heat or hypoxic stress)
o Results in improved function of existing homeostatic system
what is exercise enduced hormesis
process in which a low to moderate dose of a potentially harmful stress (for example a chemical agent or environmental stress) results in a beneficial adaptive response on the cell or organ system.
what is the function of cell signalling
-communication between cells using chemical messengers
-coordinates cellular activities
-important for maintaining homeostasis
five different cell signalling pathways exist in cells
what is intracrine signalling
Chemical messengers inside cell triggers response
what is juxtacrine signalling
chemical messengers passed between 2 CONNECTED cells
what is autocrine signalling
chemical messengers acts on that same cell
what is paracrine signalling
chemical messengers acts on nearby cells
what is endocrine signalling
chemical messengers (that is hormones) released into blood. (affects cells with specific receptor to the hormone)