Chapter 3- Compartmentation: Cells and Tissues
-Compartments separate biochemical processes that might otherwise conflict with one
another. Ex. Protein synthesis takes place in one subcellular compartment while protein
degradation is taking place in another.
-Barriers between compartments can make it difficult to move needed materials from one
compartment to another.
-Ex. Of intracellular compartment lysosome, pH so acidic that if lysosome ruptures, it
severely damages or kills the cell that contains it.
-Cell is the functional unit of most living organisms
Functional Compartments of the Body
-the major human body cavities are the cranial cavity (skull), thoracic cavity (throat), and
oCavities separated by bones and tissues, and are lined with tissue membranes
oCranial cavity; contains our brain the primary control center
oThoracic cavity; bounded by spine and ribs on top and sides, and muscular
diaphragm forming the floor. Surrounds the heart (enclosed in a membranous sac
and the 2 lungs), and in separate pleural sacs
oAbdominopelvic cavity; abdomen and pelvis. Peritoneum lines the abdomen and
surrounds the organ with it. Kidney lies outside the abdominal cavity, between
peritoneum, and the muscles of the bone and back, just above waist level. Pelvis
contains reproductive organs; urinary bladder, and terminal portion of large
-The Lumens of Some Organs Are Outside of the Body
oSome hallow organs (such as heart, lungs, blood vessels, and intestines) create
compartments within a body. The interior of a hollow organ is a lumen.
oFilled partially of fully with air or fluid. Ex. Lumen of blood vessels filled with a
fluid which is blood.
oIn some cases the lumen is an extension to the external environment, the lumen is
not truly part of the internal environment. Ex. A bacteria just lives and reproduces
in an intestine for example, it is not in the internal environment until the intestinal
wall is punctured by a disease or accident and the bacteria enters a causes a
-Functionally, the Body has Three Fluid Compartments
oThe body fluid compartments are the extracellular (ECF) fluid outside of the cells
and the intracellular fluid (ICF) inside the cells.
oThe ECF can be subdivided into interstitial fluid bathing the cells, lies between
circulatory system and the cells and plasma which the fluid portion of the blood
lies within the circulatory system and forms 1 extracellular compartment.
oICF and ECF separated by a barrier which is the cell membrane
-the word membrane used for both cell membranes (phospholipid-protein boundary layer)
and for epithelial tissues that line a cavity or separate 2 compartments