Chapter 3: compartmentation Flashcards
What are cells?
Basic functional units of living organisms, and an individual cell can carry out all the processes of life
What are the three major body cavities?
-Cranial cavity (skull)
-thoracic cavity (thorax)
-abdominopelvic cavity
What are the three major body cavities separated by and lined with?
-separated from one another by bones and tissues, and they are lined with tissue membranes
What does the cranial cavity (cranium) contain?
Contains the brain
What is the thoracic cavity bounded by and what does it contain?
-bounded by the spine and ribs on top and sides, with the muscular diaphragm forming the floor
-Contains the heart, which is enclosed in a membranous pericardial sac, and two lungs which are enclosed in separate pleural sacs
Describe the abdominopelvic cavity
- Abdomen and pelvis form one continuous cavity –> abdominopelvic cavity
- tissue lining called peritoneum lines the abdomen and surrounds the organs within it (stomach, intestines, liver, pancreas, gallbladder, and spleen)
- the kidneys lie outside the abdominal cavity, between the peritoneum and the muscles and bones of the back, just above the waistline
-The pelvis contains reproductive organs, the urinary bladder, and the terminal portion of the large intestine
What is a lumen?
The interior of any hollow organ
What are the fluid compartments of the body?
two main fluid compartments:
-extracellular fluid (ECF) outside the cells
-intracellular fluid (ICF) within the cells
-The ECF subdivides further into plasma, the fluid portion of the blood, and interstitial fluid, which surrounds most cells of the body
What are the general functions of the cell membrane:
-physical isolation
-Regulation of exchange with the environment
-Communication between the cell and its environment
-structural support
What shape does the phospholipid cell membrane make?
– when placed in an aqueous solution phospholipids orient themselves so that the polar heads of the molecules interact with the water molecules while the nonpolar fatty acid tails “hide” by putting the polar heads between themselves and the water this can be seen in three structures:
–>form bilayer, micelles, or liposomes
describe phospholipid bilayer, micelles, and liposomes
-phospholipid bilayer forms a sheet
-micelles are small droplets with a single layer of phospholipids arranged so that the interior of the micelle is filled with hydrophobic fatty acid tails –> important in the digestion and absorption of fats in the digestive tract
-liposomes are larger spheres with bilayer phospholipid walls. This arrangement leaves a hollow centre with an aqueous core that can be filled with water-soluble molecules.
What are the main types of lipids that make up cell membranes?
-phospholipids, sphingolipids, and cholesterol
What makes up phospholipids?
-a glycerol backbone with two fatty acid chains extending to one side and a phosphate group extending to the other
-The glycerol-phosphate head of the molecule is polar and thus hydrophilic
-the fatty acid “tail” is nonpolar and thus hydrophobic
what makes up sphingolipids?
-have fatty acid tails, but their head may be either phospholipids or glycolipids. Sphingolipids are slightly longer than phospholipids
describe cholesterol’s role in the cell membrane?
-cholesterol molecules are mostly hydrophobic
- insert themselves between the hydrophilic heads of phospholipids
-cholesterol helps make membranes impermeable to small water-soluble molecules and keeps membranes flexible over a wide range of temperatures
