A&P Ch 3 Flashcards
cellular form and function
cell shapes
squamous, cuboidal, columnar, polygonal, stellate, spheroid, discoid, fusiform, fibrous
squamous
best for diffusion, flat, squished
cuboidal
squarish looking. liver cells
columnar
taller than wide. inner lining of cells in the stomach
polygonal
irregular angular shapes with for, five or more sides
stellate
multiple pointed processes. starlike shape. nerve cells
spheroid
round to oval. eggs cells and white blood cells
discoid
disc shaped, red blood cells
fusiform
spindle shaped, elongated. thick middle and tapered ends. smooth muscle cells
fibrous
long, slender, threadlike. skeletal muscle cells, axons of nerve cells
cell size
limited due to the fact that surface area does not increase at the same rate as volume
cell surface
phosphate group, hydrophillic (cookie), hydrophobic fatty acid (inside of cookie), membrane protein, and intercellular space
phospholipid bilayer
hydrophilic portion, hydrophobic portion. permeable to little bit of H2O, O2/CO2, small lipids
hydrophilic portion
made of phosphate, found on the outside of the membrane.
hydrophobic portion
made up of fatty acids, found on the inside of the membrane.
cholesterol
regulates fluidity, moderates the effect of temperature. keeps membranes from melting.
membrane proteins
50% of the membrane by weight. 2% by number. have numerous functions
functions of membrane proteins
receptors, enzymes, channel proteins, carriers, second messenger systems, cell identity markers, cell adhesion molecules
second messenger system
g proteins
enzymes
brush border enzymes
channel proteins
Na+ channels. may be turned on by a ligand, a voltage change or a mechanical stress.
carriers
glucose transporters
cell identity markers
MHCs involved in immune system