Ch. 48 Animal Movement Flashcards
types of movement
1) locomotion
2) movement of one part of the animal’s body relative the entire body
locomotion
movement of entire organism under its own power
- generated by muscle contraction
modes of locomotion
1) walking
2) swimming
3) flying/gliding
4) running
*depends on build/body type
muscle fiber
a single muscle cell
- composed of long, slender cells
- contains myofibril
myofibril
long, slender structure composed of contractile proteins organized into repeating units (sacromeres) in vertebrate heart muscle & skeletal muscle
- may be striped or striated
sacromere
light & dark areas of myofibril
- made up of actin & myosin
- shorten = contracted myofibril
- relax = longer myofibril
actin
a globular protein that can be polymerized to form filaments
- part of the cytoskeleton
- THIN FILAMENTS in skeletal muscle cells
- make up sacromere
- moves
myosin
any one of a class of motor proteins that use the chemical energy of ATP to move along actin filaments in muscle contraction, cytokinesis & vesicle transport
- thick filments
- does not move
sliding-filament model
the hypothesis that thin (actin) filaments & thick (myosin) filaments slide past each other, shortening the sacromere
- shortening of all the sacromere in a myofibril results in contraction of the entire myofibril
- proposed by Hugh Huxley & Jean Hanson
thin filament
a filament composed of 2 coiled chains of ACTIN and associated regulatory proteins
- anchored @ Z disk of the sacromere
- contain troponin & tropomyosin
thick filament
a filament composed of bundles of the motor protein MYOSIN
- anchored to the center of the sacromere
Z disk
the structure that forms each end of a sacromere
- contains a protein that binds tightly to actin
- anchors thin filaments
- other end is free to interact w/ thick filament
troponin
a regulatory protein
- present in thin (actin) filaments
- moves tropomyosin off the myosin-binding sites on thin filaments
- triggers muscle contraction
- activated by high intracellular calcium
CALCIUM
tropomyosin
a regulatory protein present in thin (actin) filaments
- blocks myosin-binding sites on thin filaments in resting muscle
- prevents muscle contraction
Actin can only interact with myosin after ________ bind with troponin, the troponin-tropomyosin complex.
calcium ions
T tubule
any of the membraneous tubes that extend into the interior of muscle cells
- propagates action potentials throughout the cell
- triggers release of calcium from the sacroplasmic reticulum
- connected to endoplasmic reticulum (releases calcium)
model for actin-myosin interaction
1) ATP binds to myosin head; head releases from thin filament
2) ATP hydrolyzed; head pivots; binds to new actin subunit
3) P1 released; heat pivots; moves filament
4) ADP released
cycle ready to repeat
muscle relaxed
tropomyosin & troponin work together to block myosin binding sites on actin
contraction begins
when a calcium ion binds to troposin, the troponin-tropomyosin complex moves, exposing myosin binding sites
calcium ions connect to sites open for myosin to bind
acetylcholine (Ach)
a neurotransmitter
- released by nerve cells @ nt junctions
- triggers contraction of skeletal muscle cells
- slows rate of contraction in cardiac muscle cells
- may also be used as nt btwn neurons
- released from motor neuron
- deposited into the synaptic cleft btwn the motor neuron & muscle cell
- parasympathetic neurons
movement process
1) action potential triggers the release of Ach
2) Ach binds to receptors on the membrane of the muscle cell; this depolarizes the muscle cell, which can trigger action potentials in the fibers
3) action potential spreads into the interior of the fiber through invaginated tubules (T tubules) of the cell membrane
4) T tubules interacts w/ smooth endoplasmic reticulum (ER), a special smooth ER known as the sacroplasmic reticulum; a protein in this ER changes its shape & allows Ca+ ions to enter
5) the myosin binding sites on the actin are exposed to enable a contraction
types of muscle tissue
1) smooth
2) skeletal
3) cardiac
skeletal muscle
the muscle tissue attached to the bones of the vertebrate skeleton
- long, unbranched muscle fibers
- striated appearance
- voluntary control
- multinucleate cells
- contains myofibril
- longer than smooth & cardiac muscles
- stimulated by somatic motor neurons
- neuron damage will result in paralysis
(aka) striated muscle
cardiac muscle
the muscle tissue of the vertebrate heart
- responsible for pumping blood
- long, branched fibers
- fibers are electrically connected end to end via intercalated discs & initiate their own contractions
- involuntary control
- contains myofibril & sacromeres
- contracts upon depolarization of muscle cell
intercalated disc
a type of specialized connection between adjacent heart muscle cells that contain gap junctions
- allow electrical signals to pass btwn cells
- critical to flow of electrical signals from cell to cell
- critical for coordination of the heartbeat
gap junctions
a type of cell attachment structure
- directly connects to cytosolic components of adjacent animal cells
- protein-lined openings
- allows passage of water, ions & small molecules btwn cells
smooth muscle
unstriated muscle tissue that lines the intestine, blood vessels & some otro organs
- tapered, unbranched cells that can sustain long contractions
- involuntary control
- lacks myofibrils & sacromeres
- often organized into thin sheets
- contains single nucleus
- contains autonomic motor neurons
- connected to parasympathetic neurons
(ie) found in lungs, blood vessels, urinary bladder & reproductive system
Sympathetic neurons & the adrenal gland release nts that _______ muscle contraction in the digestive tract.
inhibit
parasympathetic neuron
release acetylcholine for stimulating contractions throughout digestive system
sympathetic neuron
release norepinephrine (inhibits muscle contraction of digestive tract)
adrenal glands
release epinephrine & adrenaline (inhibits muscle contraction)
norepinephrine
a catecholamine used as a nt
- sympathetic nervous system
- produced by adrenal medulla
- FCN: hormone that triggers rapid responses relating to fight-or-flight response
epinephrine
a catecholamine hormone
- produced/secreted by adrenal medulla
- triggers rapid responses related to fight-or-flight response
- sympathetic nervous system
- inhibits muscle contraction
(aka) adrenaline
skeletal muscle encloses the openings of 2 major systems:
1) digestive system - swallowing & defecation
2) urinary system - urination
types of skeletal muscle fiber
- based on mitochondria & function
1) slow muscle fiber
2) fast muscle fiber
3) intermediate muscle fiber
slow muscle fiber
type of skeletal muscle fiber
- red color (due to abundance of myoglobin)
- many mitochondria
- generates ATP by oxidative phosphorylation
- needs oxygen to move
- contracts slowly
- does not fatigue slowly
- high concentration of mitochondria (need steady stream of ATP)
(ie) needed for endurance in marathon running
(aka) slow oxidative fiber OR Type I
fast muscle fiber
type of skeletal muscle fiber
- white color
- generates ATP by glycolysis
- slow ATP oxidation
- contracts rapidly
- fatigues easily
- associated w/ fight-or-flight movement
- few mitochondria
- low myoglobin concentration
(ie) needed for explosive movement
(aka fast glycolytic fiber OR Type IIb
intermediate muscle fiber
type of skeletal muscle fiber
- pink color
- generates ATP by glycolysis (break glucose, produce pyruvate) & aerobic respiration
- oxidizes ATP @ fast or slow (intermediate) rate
- contractile properties that are intermediate btwn slow & fast fibers
- many mitochondria
- high myoglobin concentration
(aka) fast oxidative fiber
force of a muscle depends on
1) cross-sectional area of muscle cell
2) number of sacromeres lined up side by side
types of muscle fiber orientations
1) parallel - maximize length change
2) diagonal - maximize force
example of parallel muscle fiber
(maximizes length change)
sartorius muscle
example of diagonal muscle fiber
(maximizes force)
gastrocnemius
skeletal system function
1) protection from physical & biological intrusions
2) maintain of body posture
3) re-extension of shortened muscles
4) transfer of muscle fibers
different types of skeletal systems
1) exoskeleton
2) hydrostatic skeleton
3) endoskeleton
exoskeleton
a hard, hollow structures covering the outside of the body
- FCN: body support, protection & muscle attachment
- prominent in arthropods
- limited range of movement
- must be shed for internal parts to grow
(ie) crayfish
hydrostatic skeleton
a system of body support involving a body wall in tension surrounding a fluid or soft tissue under compression
- use pressure of internal body fluids to support the body
(ie) jellyfish & anemone
endoskeleton
bony and/or cartilaginous structures w/in the body that provide support
- composed of the connective tissues cartilage & bone
(ie) bony skeleton of vertebrates, like humans
(ie) spicules of sponges
(ie) plates of echinoderms, like starfish
muscular hydrosat
a hydrostat that is dominated by muscle tissue
types of muscle in earthworm (hydrostat)
- antagonistic muscle
1) longitudinal
2) circumferential
how hydrostats move
1) muscles contract, making segments narrow
2) muscle contraction squeezes internal fluid, increasing the internal pressure
3) pressure pushes outward, extending the relaxed longitudinal muscles
4) longitudinal muscles contract & circumferential muscles relax
peristalic wave
alternating relaxation & contraction of the 2 muscle layers in a hydrostat
antagonistic muscle group
a set of 2 or more muscles that reextend one another by transmitting their forces via the skeleton
(ie) muscles in earthworm
cartilage
a type of vertebrate connective tissue that consists of relatively few cells scattered in a stiff matrix of polysaccharides & protein fibers
- provides structural support
- made up of cells scattered in rubbery gelatinous matrix
- decreases friction btwn bones
bone
a type of vertebrate connective tissue
consisting of living cells & blood vessels w/in a hard extracellular matrix composed of calcium phosphate (CaPO4) & small amounts of calcium carbonate (CaCO3) & protein fibers
- cells in a hard extracellular matrix of calcium phosphate
articulation
a movable point of contact between 2 rigid components of a skeleton, such as between bones of vertebrate endoskeleton or between segments of cuticle in an arthropod exoskeleton
- places where bones meet
(ie) joint
joint
a place where 2 components (bones, cartilages, etc) of a skeleton meet
- may be movable (articulated joint) or immovable (skull sutures)
types of joints
1) movable - articulated joint
2) immovable - skull sutures
tendon
a band of tough, fibrous connective tissue
- connects muscle to bone
- dense
- elastic/rubber band like
ligament
connective tissue that joins bones of an endoskeleton together
- connects bone to bone
flexor
a muscle that swings 2 bones closer together
- decreases joint angle, as in the flexing of a limb or the spine
(ie) hamstring
extensor
a muscle that pulls 2 bones farther apart from each other
- increases angle of the joint, as in the extension of a limb or the spine
(ie) quadriceps
apodeme
any of the chitinous ingrowths of the exoskeleton to which muscles attach
- transduce small shortening of muscles
- increases joint angle
*think leatherparts of a knight’s armor
pennate
feather-like arrangement of muscle fibers
- causes a limited range of movement, esp. in organsims w/ exoskeletons
- increases cross-sectional area
- small width/length change
molting
a method of body growth
- used by ecysozoans
- shedding of an external protective cuticle or skeleton
- expansion of the soft body
- growth of a new external layer
(ie) grasshoppers molt
biomechanic
a field of biology that applies the principles of physics & engineering to analyze the mechanical structure & fcn of organisms
examples of forces involved in location depending on animal’s environment
1) land - gravitational & inertial forces dominate
2) water - drag forces
3) air - need adaptations to make animal lightweight, counters gravity & minimize drag
rate of oxygen consumption is a measure of _______
cost of locomotion
surface are to volume ratio is ________ (proportionally/inversely) related to size
inversely
weight is __________ (proportionally/inversely) related to volume
proportionally
the ability of the leg bones to support weight is ________ (proportionally/inversely) related to the cross-sectional area
proportionally
An aquatic organism with high inertia will move _______ (faster/slower)
faster
