The spinnerets have muscles, valves and tiny spigots that control the

Spider’s
abdomen
Spiders make silk in different
glands in their abdomens.
The silk starts as a liquid
made of long chains of
proteins.
This liquid flows
into pairs of
spinning
organs called
spinnerets.
Stomach
CUTAWAY
VIEW
Silk glands
Liquid
silk
Spiders make different silks
for different tasks. There are
seven known silk glands, each
of which produces a different silk.
Muscular
valve
Spinnerets
The spinnerets have muscles,
valves and tiny spigots that
control the direction, flow and
properties of the silk as it
comes out.
Silk fiber
The types are:
Silk for
anchoring
threads to
a surface
or joining
threads
Silk for
making the
nonsticky
scaffolding
lines
Silk for
wrapping
or
swathing
prey
SOURCES: Todd Blackledge, University of Akron;
University of Bristol, United Kingdom
Silk for
making the
core fibers
of sticky
“capture
threads”
Silk that
forms
gluey,
highly
adhesive
droplets on
capture
threads
Silk for
making
safety
lines and
lines for
major
framework
Silk for
making the
tough,
insulating
cover
around
egg sacs
JOHN MANGELS, WILLIAM NEFF | THE PLAIN DEALER