13.
Assume that a substance is more concentrated on one side of a membrane than
the other but that it cannot pass through the membrane. The process in which water
passes to the side of greater concentration is called
.
If, however, the substance can easily pass through the membrane, the process in
which the substance passes through the membrane to the area where it is less
concentrated is called
. If the substance needs assistance to pass through
the membrane, we call the process f
d
n.
Since the cell membrane allows only some types of substances to pass
through it, the cell membrane is
ble.
When energy is used to move a substance across a membrane to an area of
higher concentration, the process is called
e
t.
When a minute amount of tissue fluids is engulfed by the cell membrane, the
process is
cytosis. When larger particles are engulfed, the process is
cytosis.
14.
When the cell is in a resting state, the membrane potential is maintained by the
s
/p
pump. This membrane potential is called the
ing potential.
The s_______/p__________ pump actively transports 3 (positive)(negative) sodium
ions to the outside of the cell membrane and 2 potassium ions to the inside of the cell
membrane. This results in a
tive charge inside the cell and a
tive charge
outside the cell.
When a neuron or muscle fiber is stimulated, the resulting activity is called the
potential. This involves
tion and subsequent
tion. First,
sodium ions move into the cell by
n. This reverses the
y. Second,
potassium moves out of the cell by diffusion which causes
tion.
15.
A condition in which tissue mass increases without an increase in the number of
cells is called hyper
. When tissue mass increases due to an increase in
the number of cells, it is hyper
.
16.
The epithelial tissue lining a serous cavity secretes a
s fluid to act as a
_________t. The secretion of sebaceous glands is formed as portions of the cells are
______ghed off.
MD0007
2-19