Principles Of Physiology Flashcards
Physiology
The study of the function of living things, describing how processes in the body occur
What are the different types of tissues? And what to they do?
- epithelial tissue : protection, secretion and absorption
- connective tissue : structural support
- muscle tissue : movement
- nervous tissue : communication, co-ordination and control
External environment
The surrounding environment in which the organism lives
Internal environment
The fluid that surrounds the cell
Extracellular fluid
The fluid outside the cell, plasma and interstitial fluid
Plasma : fluid portion of the blood
Interstitial fluid : surrounds and bathes cells
Intracellular fluid
Fluid contained within body cells
Homeostasis
The maintenance of a stable internal environment
Factors that are homeostatically maintained
- nutrient molecules - energy production
- waste products - might be toxic
- O2 & CO2
- pH - nerve cells and enzymes
- water, salts, electrolytes: cell volume, rhythmic beating of the heart (K+)
- temperature - enzymes
- volume & pressure - plasma
How does the circulatory system contribute to homeostasis
- transport system
- carries materials from one part of the body to the other
- transports nutrients, O2, CO2, wastes, electrolytes & hormones
- exchanges with ALL other systems
- thus contributes to homeostasis
Honeostasis
intrinsic?
Intrinsic/local
Intrinsic = within
Inherent in an organ, for example exercising skeletal muscle - vasodilation of the blood vessels
Homeostasis
Extrinsic
Extrinsic/systemic
Extrinsic = Outside of
Mediated by nervous and endocrine systems
Initiated outside of an organ to alter its activity for example blood pressure - nervous system acts in heart and blood vessels
It has a coordinated regulation to achieve common goal
Negative feedback
Drives variable in the opposite direction of initial change
Corrects the situation
Shuts itself off
Positive feedback
Variable continues to move in the direction of the initial change
Reinforces it in the same direction
Eg release of OxyContin during pregnancy
Metabolic rate (MR)
Rate at which energy expended by the body per unit of time
Basal metabolic rate (BMR)
Index of metabolism under standardised conditions
Minimal waking rate of internal energy expenditure
