Biol 322 final
Hydrostatic skeletal systems – answer mevhanical advantage for cylindrical hydrostats
wall tension for internally pressurized containers
importance of collagenous connective tissue
pliable skeletons - answer time-dependent properties (mesoglea)
stiffening gel matrices with spicules
hydrostatic skeletons criteria - answer fluid maintained at constant volume
container for fluid must be deformable
container for fluid is wrapped in muscle and connective tissue
fluid in a deformable container that is wrapped in muscle transmits force of muscle
contraction
conventional hydrostats - answer tube feet of echinoderms
lophophoral tentacles of bryozoans
errantid annelid: coelomic compartments
sea anemone GVC
muscular hydrostats – answer arms of cephalopod: no hard elements to transmit force
solid muscle
the foot of gastropods
force transmission platyhelmintes - answer have no coelomic compartments
any deformable compressible material at constant volume can transmit force
parenchymal cells turbellarians
octopus histological transverse section through arm - answersolid mass of muscle and
connective tisssue to transmit force of muscle contraction
skeletons that facilitate movment options stiff levers or hydrostats - answertransmit
force created by muscle shortening (to do work against environment)
re extend antagonistic muscles
exploit mechanical advantage (force or displacement amplification)
mechanical advantage for cylindical hydrostats - answercyllinders with different volumes
have different lengths and diameters
non-linear relationship of length and diameter
V= pir^2L
length and radius non-linear
as a cylinder of constant volume changes shape there is a non-linear relationship
between its diameter and length
,squid tentacles longer than its 8 arms: how to extend - answertentacles for prey
capture: shoot out tentacles to grab prey
tentacles longer but both solid muscle
need to contract any muscles that reduce c.s. diameter upon shortening
cross section of muscles tentacle - answercircular, radial and transverse muscle
contraction: all 3 could dec diameter of the tentacle
how to shorten tentacles (or arms) - answercontract any muscle that reduces length
longitudinal muscles
resting dimensions of squid arm - answerchange in diameter of 1 unit results in change
in length of 10 units
resting dimensions squid tentacle - answerchange in diameter 1 unit causes length
change 25 units
tentacle muscles myofilament arrangement - answerlongitudinal muscles: circular
muscle, transverse muscle, radial msucles
need long effective working extension
better to have oblique
need short muscle fibres for speed (not force) connected in series
annelida maldanidae bamboo worms - answerpush against sides of their tube hard to
pull out of tube
very long metameres for annelid
able to do a lot of force
wall tension for internally pressurized containers - answercircumferential tensile stress
and axial tensile stress
circumferential tensile stress= 2 x axial tensile stress
Circumferential tensile stress = (internal pressure x radius of cylinder)/ wall thickness
consider an annelid perastaltic body movements - answercircular and longitudinal
muscle contraction down length of worm
wall has different pressure depending on area
need appropriate wall enforcemnt
pressure in cylinder examples - answera fat sausage will split before a thin one
need more pressure in bike tires than car tires for them to have good tension
sea anemone - answerthick stalk and narrow tentacles
wall of tentacles much thinner than wall of stalk, tentacles need more pressure to inflate
,echinoderm tube feet inflation - answercircumferential tensile stress = 2x axial tensile
stress
if you forced water in it would baloon out not forward
internally pressurized cylinders - answerneed to prevent ruptures
need to control/ limit shape change
importance of collagenous connective tissue
need a latticework of helical fibres (collagen)
wall reinforcemnt: crossed lattice of fibres - answerJ shaped stress strain plot
role of collagenous connective - answerallow modest increase in circumference
limit extreme increase in circumference
mesoglea time dependent properties - answerat first doesn't extend, over time
increases extension
after time increases extension
sea anemone mesoglea - answerxanthogrammica short and stubby
metridium suspension feeders, many fine tentacles
will bed toward current to get better suspension feeding
need more mesoglea to extend
single material can serve variety of functions on different time scales
pliable skeletons stiffening with spicules - answerstiffen dependent on spicule density
stiffening dependent on spicule size
anisometric spicules
mesoglea: spicules stiffen mesoglea - answerway lower strain in stress strain plot in
alcyonarian mesoglea (spicules present)
sea cucumbers spicules - answermicroscopic ossicles embedded in the connective
tissue dermis
sea anemone anisometric spicules - answeranisometric spicules strongest when
tension is parallel
preferentially stiffen the stalk longitudinally
dual anchor crawling - answerpush and pull alternately against 2 anchors
1. penetration anchor (push against)
2. terminal anchor (pull_
leech and caterpillar looping - answersuckers in leech
anterior sucker on substrate, body pulls: terminal anchor
posterior sucker attches, pushes against (penetration anchor)
caterpillar does same looping
, Dual anchor crawling/ burrowing by annelids peristalsis - answerfat metameres and
setae as anchors
thin metameres skinny, fat areas are the peentration anchor and the terminal anchor
will change area of each over the course of the movement
terminal anchor is sometimes the everted pharynx (blood worms)
bloodworms move - answerbulbous swelling at tip of pharynx is the terminal anchor
more to burrowing than just body mrphology - answermaterial properties of sediment
important
fine muddy sediment is cohesive, elastic solid that can be fractured
coarse sandy are non-cohesive and do not behave as an elastic solid that can be
fractured
sediment particles move relative to each other
muddy sediments - answerelastic solid: a material under tension that deforms and when
its released it springs back to shape
crack in sediment from applying tension
stress is concentrated at the tip of crack
crack can be easily propagated at its tip
burrowing annelid - answermud with organic particles act as cohesive solid held
together by water molecules
fracturing at the fattened head acts as a wedge to go through
dual anchor burrowing annelids peristalsis - answerterminal anchor as wedge to
introduce cracks into sediment
anterior expansion is both the terminal anchor and the fracture wedge
bivalve burrowing in coarse sand - answerdual anchor burrowing and fluidization of
sediment
hinge ligamnet opens shell valves, 2 valves as penetration anchors
foot penetrates down and pushes against the shell
adductor muscles contract and 2 shell valves come together
foot expands to become terminal anchor
water forced out and fluidizes the surrounding sand
bivalve burrowing 1. shell valves gape - answerpenetration achor
adductor not contracted
foot pushes against shell anchor to extand into sand
displacement of easily moved sand grains, no fracturing
bivalve burrowing 2. adductor muscles contract - answerwater forced out, fluidizes the
sediment
narrows the shell profile
Hydrostatic skeletal systems – answer mevhanical advantage for cylindrical hydrostats
wall tension for internally pressurized containers
importance of collagenous connective tissue
pliable skeletons - answer time-dependent properties (mesoglea)
stiffening gel matrices with spicules
hydrostatic skeletons criteria - answer fluid maintained at constant volume
container for fluid must be deformable
container for fluid is wrapped in muscle and connective tissue
fluid in a deformable container that is wrapped in muscle transmits force of muscle
contraction
conventional hydrostats - answer tube feet of echinoderms
lophophoral tentacles of bryozoans
errantid annelid: coelomic compartments
sea anemone GVC
muscular hydrostats – answer arms of cephalopod: no hard elements to transmit force
solid muscle
the foot of gastropods
force transmission platyhelmintes - answer have no coelomic compartments
any deformable compressible material at constant volume can transmit force
parenchymal cells turbellarians
octopus histological transverse section through arm - answersolid mass of muscle and
connective tisssue to transmit force of muscle contraction
skeletons that facilitate movment options stiff levers or hydrostats - answertransmit
force created by muscle shortening (to do work against environment)
re extend antagonistic muscles
exploit mechanical advantage (force or displacement amplification)
mechanical advantage for cylindical hydrostats - answercyllinders with different volumes
have different lengths and diameters
non-linear relationship of length and diameter
V= pir^2L
length and radius non-linear
as a cylinder of constant volume changes shape there is a non-linear relationship
between its diameter and length
,squid tentacles longer than its 8 arms: how to extend - answertentacles for prey
capture: shoot out tentacles to grab prey
tentacles longer but both solid muscle
need to contract any muscles that reduce c.s. diameter upon shortening
cross section of muscles tentacle - answercircular, radial and transverse muscle
contraction: all 3 could dec diameter of the tentacle
how to shorten tentacles (or arms) - answercontract any muscle that reduces length
longitudinal muscles
resting dimensions of squid arm - answerchange in diameter of 1 unit results in change
in length of 10 units
resting dimensions squid tentacle - answerchange in diameter 1 unit causes length
change 25 units
tentacle muscles myofilament arrangement - answerlongitudinal muscles: circular
muscle, transverse muscle, radial msucles
need long effective working extension
better to have oblique
need short muscle fibres for speed (not force) connected in series
annelida maldanidae bamboo worms - answerpush against sides of their tube hard to
pull out of tube
very long metameres for annelid
able to do a lot of force
wall tension for internally pressurized containers - answercircumferential tensile stress
and axial tensile stress
circumferential tensile stress= 2 x axial tensile stress
Circumferential tensile stress = (internal pressure x radius of cylinder)/ wall thickness
consider an annelid perastaltic body movements - answercircular and longitudinal
muscle contraction down length of worm
wall has different pressure depending on area
need appropriate wall enforcemnt
pressure in cylinder examples - answera fat sausage will split before a thin one
need more pressure in bike tires than car tires for them to have good tension
sea anemone - answerthick stalk and narrow tentacles
wall of tentacles much thinner than wall of stalk, tentacles need more pressure to inflate
,echinoderm tube feet inflation - answercircumferential tensile stress = 2x axial tensile
stress
if you forced water in it would baloon out not forward
internally pressurized cylinders - answerneed to prevent ruptures
need to control/ limit shape change
importance of collagenous connective tissue
need a latticework of helical fibres (collagen)
wall reinforcemnt: crossed lattice of fibres - answerJ shaped stress strain plot
role of collagenous connective - answerallow modest increase in circumference
limit extreme increase in circumference
mesoglea time dependent properties - answerat first doesn't extend, over time
increases extension
after time increases extension
sea anemone mesoglea - answerxanthogrammica short and stubby
metridium suspension feeders, many fine tentacles
will bed toward current to get better suspension feeding
need more mesoglea to extend
single material can serve variety of functions on different time scales
pliable skeletons stiffening with spicules - answerstiffen dependent on spicule density
stiffening dependent on spicule size
anisometric spicules
mesoglea: spicules stiffen mesoglea - answerway lower strain in stress strain plot in
alcyonarian mesoglea (spicules present)
sea cucumbers spicules - answermicroscopic ossicles embedded in the connective
tissue dermis
sea anemone anisometric spicules - answeranisometric spicules strongest when
tension is parallel
preferentially stiffen the stalk longitudinally
dual anchor crawling - answerpush and pull alternately against 2 anchors
1. penetration anchor (push against)
2. terminal anchor (pull_
leech and caterpillar looping - answersuckers in leech
anterior sucker on substrate, body pulls: terminal anchor
posterior sucker attches, pushes against (penetration anchor)
caterpillar does same looping
, Dual anchor crawling/ burrowing by annelids peristalsis - answerfat metameres and
setae as anchors
thin metameres skinny, fat areas are the peentration anchor and the terminal anchor
will change area of each over the course of the movement
terminal anchor is sometimes the everted pharynx (blood worms)
bloodworms move - answerbulbous swelling at tip of pharynx is the terminal anchor
more to burrowing than just body mrphology - answermaterial properties of sediment
important
fine muddy sediment is cohesive, elastic solid that can be fractured
coarse sandy are non-cohesive and do not behave as an elastic solid that can be
fractured
sediment particles move relative to each other
muddy sediments - answerelastic solid: a material under tension that deforms and when
its released it springs back to shape
crack in sediment from applying tension
stress is concentrated at the tip of crack
crack can be easily propagated at its tip
burrowing annelid - answermud with organic particles act as cohesive solid held
together by water molecules
fracturing at the fattened head acts as a wedge to go through
dual anchor burrowing annelids peristalsis - answerterminal anchor as wedge to
introduce cracks into sediment
anterior expansion is both the terminal anchor and the fracture wedge
bivalve burrowing in coarse sand - answerdual anchor burrowing and fluidization of
sediment
hinge ligamnet opens shell valves, 2 valves as penetration anchors
foot penetrates down and pushes against the shell
adductor muscles contract and 2 shell valves come together
foot expands to become terminal anchor
water forced out and fluidizes the surrounding sand
bivalve burrowing 1. shell valves gape - answerpenetration achor
adductor not contracted
foot pushes against shell anchor to extand into sand
displacement of easily moved sand grains, no fracturing
bivalve burrowing 2. adductor muscles contract - answerwater forced out, fluidizes the
sediment
narrows the shell profile
