Topic 1: Milieu Interieur. Compartments, Changes of Water Compartments Flashcards
What should be mentioned in this topic?
- Milieu Interieur
- Homeostasis
- Compartments
- Changes of Water Compartments
- Transport process through the membranes
- Intracellular Compartment
Milieu Interieur:
Cells of the living organism can only work in constant environment. This environment is called the “milieu interieur”, coined by Claude Bernard. The living organism does not live in an outer environment but in its own fluid environment.
Homeostasis:
It is the maintenance of a constant internal environment. This maintenance is important in both unicellular and multicellular components of the organism.
Isovolemia: Isotonia: Isoionia: Isohydria:
Isovolemia: Constant volume Isotonia: Constant osmotic pressure Isoionia: Constant ion composition Isohydria: Constant pH
Water
Water is the most important component in the body. It acts as a solvent, medium for reactions, a source of osmotic forces and maintains compartment and form.
Compartments, Changes of Water Compartments
The body is divided into anatomical spaces and compartments. They are separated by barriers: - Cell Membrane -Permeable for water without restriction -Selective for every other substance - Capillary Wall -Retains colloids -Permeable for all other substances
Transport process through the membranes:
Part of the membrane determining transport: - Lipid double layer - Complex proteins -Receptors -Enzymes -Carriers -Channels Types of Transport - Passive Transport -Simple Diffusion -Facilitated Diffusion - Active Transport -From direct energy source -From indirect energy source
Total body water:
Extracellular Compartment (EC 33%) and Intracellular Compartment (IC 66%)
EC subcompartments:
The EC is divided into subcompartments: - Intravascular - Interstitial - Transcellular -Separated from the other compartments of the body by epthelial cell layers. - Synovial fluid -Aqueous humour -Glandular discharges -Content of the urinary bladder -Gastrointestinal tract -(Rumen)
Intravascular compartment:
Plasma water: 45/bwkg Blood cells: 35 ml/bwkg
Interstitium:
About 250/bwkg Soft tissues: 120-250 ml/bwkg Fibrous connective tissue: 45 ml/bwkg Bone tissue: 45 ml/bwkg
Intracellular Compartment:
The intracellular compartment is considered to be uniform. In spite of the fact that it consists of a great number of small compartments
What is the water content of different tissues?
Blood 90% Liver, muscle, brain 70-75% Bone 25% Fat 10%
Barriers separating compartments:
- Cell membrane -Capillary wall
Distribution in the EC space:
On measuring the EC compartment by the dilution principle, distribution of the indicator has at least two phases: -Quickly equilibrating space :substance flow is fast, it equilibrates within the 0.5 -1 hour – blood plasma, – interstitium of soft tissues, – lymph -Slowly equilibrating space: completely uniform distribution develops only 8-10 hours later – bone – transcellular space
Compartments : picture
