Lecture One: Body Fluid Comparments Flashcards
(40 cards)
What is protoplasm?
different substances that make up the cell
What do homeostatic responses of the body ensure?
- The internal fluid volume an composition remain fairly constant
- The preservation of the internal environment
- that cells are protected from insults that could compromise their survival
What are cells?
The basic unit of living organisms
Simplest structural units which complex multi cellular organisms can be divided into and still retain the functions characteristic of life
What is differentiation?
The process of transforming an unspecialised cell into a specialised cell
What happens during cell development?
Cells become specialised for the performance of a particular function
What can each cell perform?
Fundamental cellular processes
List some fundamental cellular processes
- movement across membranes
- energy production
- protein synthesis
- maintenance of cell volume etc
What are fundamental cellular processes essential for?
Maintaining the cell’s individual integrity and life
What does each cell simultaneously perform that, in concert with actions of other cells contributes to survival of the organism?
One or more specialised activities
How are cells classified? Give examples
Classified by the broad types of function they perform:
- muscle cells
- nerve cells
- epithelial cells
- connective tissue cells
What to specialised cells associate with other cells to form?
Tissues
What are organs composed of?
The 4 kinds of tissues arranged in various proportions and patterns
- sheets
- tubes
- layers
- bundles etc
What is an organ system?
Collections of organs that together perform an overall function
Homeostasis is mostly achieved by
Negative feed back mechanism which requires at least four elements
What is the homeostatic control mechanisms
- Where The activities of cells, tissues and organ systems
- are regulated and integrated with each other in such a way that
- any change in the extracellular fluid initiates a series of reactions that strive to
- minimise the change
Disruptions to homeostasis can arise from which two stimuli?
- Internal
2. External
Give an example of internal stimuli that disrupts homeostasis
Change in blood glucose levels
Change in pH
Give examples of external stimuli that disrupts homeostasis
Exercise
Physical insults like heat, lack of oxygen,
Psychological stresses like work stress, death in family
How does homeostasis occur at the level of single cells?
By the regulation of
- volume
- Concentration of electrolytes
What proportion of body weight does water account for?
60% for men, 50% for women
What main compartments is total body water distributed across?
Intracellular fluid 60%
and extracellular fluid 40%
What are the components of extracellular fluid?
Interstitial fluid (75%) Plasma volume (20%) Transcellular fluid (5%) Blood volume (PV/(1-hematocrit))
What are the components of a feed back system?
- Sensor:
System senses vital parameter e.g. Glucose - Ability to compare to reference:
Compares input signal with an internal reference and forms different signal - Sufficient gain:
System multiplies error signal by proportionality factor to produce some form of output signal e.g. Release of insulin - Effector mechanism:
Activated by output signal. This makes the responses.
This opposes the source of input and brings vital parameter closer to set point
(In the case of a negative feed back mechanism)
What are the fundamental importances of having an asymmetrical distribution of ions?
Ion gradients are responsible for
Setting the membrane potential
Generating electrical activity in nerve and muscle
Initiation of muscle contraction
Providing energy for uptake of nutrients and expulsion of waste products
Generation of intracellular signalling cascades
