Chapter 9 - Muscles and Locomotion Flashcards
1
Q
basic internal framework of the vertebrate body
A
musculoskeletal system
2
Q
muscles and bones work in close coordination to produce
A
voluntary movement
3
Q
in addition to working together, bone and muscle perform many
A
independent functions
4
Q
physical support and locomotion are hte functions of the animal
A
skeletal system
5
Q
force is generated by
A
muscular system
6
Q
protozoans and primitive algae may move by
(unicellular locomotion)
A
beating cilia or flagella
7
Q
cilia and flagella of all eukaryotic cells possess same basic structure
each contains
A
a cylindrical stalk of eleven microtubules - nine paired microtubules arrounged in a circle with two single microtubules in the center
8
Q
flagella achieve movement by means of a
A
power stroke
9
Q
power stroke
A
means of movement for flagella
thrusting movement generated by sliding action of microtubules
10
Q
recovery stroke
A
return of cilium or flagellum to original position
11
Q
pseudopodia
A
locomotion of amoeba
advancing cell membrane extends forward, allowing cell to move
12
Q
invertebrate locomotion
hydrostatic skeletons
flatworms
A
e.g. planaria
muscles within body wall of advanced flatworms arranged in two antagonistic layers
longitudinal and circular
13
Q
the muscles of the flatworm contract against the restistance of the
A
incompressible fluid within the animal’s tissues
14
Q
hydrostatic skeleton of flatworm
A
hydrostatic fluid against which muscles contract
15
Q
contraction of the circular layer of muscles causes
(flatworm locomotion)
A
incompressible interstitial fluid to flow longitudinally, lengthening the animal
16
Q
contraction of the longitudinal layer of muscles
flatworm locomotion
A
shortens the flatworm
17
Q
hydrostatic skeleton in which each segment of animal can expand or contract independently operates the same in
A
flatworms and annelids
18
Q
annelids
earthworms advance by axn of muscles on a
(invertebrate locomotion)
A
hydrostatic skeleton
19
Q
setae
A
bristles in the lower part of each segment of the earthworm
anchor the earthworm temporarily in the earth
20
Q
as bristles in the lower part of each segment of the earthworm anchor the worm to the earth, _____ push ahead
A
muscles
21
Q
exoskeleton
(invertebrate locomotion)
A
hard skeleton that covers all muscles and organs of some invertebrates
22
Q
exoskeletons found primarily in
A
arthropods
e.g. insects
23
Q
insect exoskeleton
composition
A
chitin
composed of noncellular material secreted by epidermis
24
Q
advantage vs. disadvantage of exoskeleton
A
offer protection
but
growth limitations
25
molting
to overcome limitations on growth imposed by exoskeleton
periodic molting and deposition of new skeleton are necessary tp permit body growth
26
endoskeleton
framework within all vertebrate organisms
muscles attached to bones, permitting movement
27
in addition to permitting movement, endoskeleton also
provide protection by surrounding delicate vital organs in bone
28
example of protective function of endoskeleton
rib cage protects thoracic organs (heart and lungs)
skule protects brain
vertebrate colum protects spinal cord
29
two major components of skeleton
cartilage
bone
30
cartilage
connective tissue
softer, more flexible than bone
31
cartilage retained in adults in places where
firmness and flexibility are needed
32
human adult cartilage components
external ear
nose
walls of larynx, trachea
skeletal joints
33
bone
mineralized connective
has ability to withstand physical stress
34
bone tissue is ideally designed for body support
hard and strong
elastic and lightweight
35
two types of bone
compact bone
spongy bone
36
compact bone
dense bone
naked eye cannot see cavities
37
osteons
fxn
(Haversian systems)
(compact bone)
bony matrix deposited in structural units - osteons
38
osteon
structure
central microscopic channel - Haversian canal
surrounded by concentric circles of bony matrix (calcium phosphate) - lamellae
39
Haversian canal
central microscopic channel of osteon
40
lamellae
concentric circles of bony matrix (calcium phosphate) surrounding Haversian canal
41
bony matrix is composed of
calcium phosphate
42
spongy bone
less dense than compact bone
43
spongy bone
structure
interconnecting lattice of bony spicules (trabeculae)
cavities in between spicules filled with yellow and/or red bone marrow
44
yellow bone marrow
found in cavities between spicules of spongy bone
inactive
infiltrated by adipose tissue
45
red bone marrow
fills cavities between spicules of spongy bone
involved in blood cell formation
46
osteocytes
two types
cells found in bone tissue
osteoclasts
osteoblasts
47
osteoblasts
synthesize and secrete organic constituents of bone matrix
once surrounded by matrix, mature into osteocytes
48
osteoclasts
large multinucleated cells
bone resorption
49
osteoBLASTS vs osteoCLASTS
build bone
vs
destroy bone
50
two mechanisms for bone formation
1. endochondrial ossification
2. intramembraneous ossification
51
endochondral ossification
existing cartilage replaced by bone
long bones arise primarily via endochondral ossification
52
intramembraneous ossification
messenchymal (embryonic, undifferentiated) connective tissue is transformed into, and replaced by, bone
53
axial skeleton
basic famework of the body
skull, vertebral column, rib cage
54
appendicular skeleton
attaches to axial skeleton
bones of appendages, pectoral, pelvic girdles
55
sutures, immovable joints
hold bones of skull together
56
movable joints
hold together bones that move relative to one another
57
ligaments
support and strengthen movable joints
bone-to-bone connectors
58
tendons
attach skeletal muscle to bones
bend skeleton at movable joints
59
origin
point of attachment of a muscle to a stationary bone
(proximal end in limb muscles)
60
insertion
point of attachment of muscle to bone that moves
(distal end in limb muscles)
61
extension
straightening of a joint
62
flexion
bending of a joint
63
muscle tissue
bundles of specialized contractile fibers held together by connective tissue
64
three morphologically and functionally distinct types of muscle in mammals
skeletal muscle
smooth muscle
cardiac muscle
65
skeletal muscle
voluntary movements
innervated by somatic nervous system
66
the skeletal muscle is composed of muscle fibers, which are made up of
multinucleated cells
67
multinucleated cell is created by the fusion of
several mononucleated embryonic cells
68
myofibrils
filaments embedded in the muscle fibers
69
sarcomeres
contractile units which make up the myofibrils
70
sarcoplasmic reticulum
evelopes myofibrils
modified endoplasmic reticulum
stores calcium ions
71
sarcoplasm
cytoplasm of a muscle fiber
72
sarcolemma
muscle cell membrane
73
the sarcolemma is capable of
propagating an action potential
74
the sarcolemma is connected to
system of transverse tubules (T system) oriented perpindicularly to the myofibrils
75
T system (transverse tubules)
channels for ion flow throughout muscle fibers
can propagate action potential
76
because of the high energy requirements of contraction, ______ are abundant in muscle cells
mitochondria
77
mitochondria in muscle cells
very abundant
distributed along myofibrils
78
striations
light and dark bands of skeletal muscle
79
skeletal muscle is aka
striated muscle
80
two components of muscle cell that can propagate an action potential
sarcolemma
t system (transverse tubules)
81
sarcomere
structure
thin and thick filaments
82
the thin filaments of sarcomere are
chains of actin molecules
83
the thick filaments of the sarcomere are
organized bundles of myosin molecules
84
sarcomere
organization
Z line
M line
I band
H zone
A band
85
Z lines
# define boundaries of a single sarcomere
anchors thin filaments
86
M line
runs down center of sarcomere
87
I band
region containing thin filaments only
88
A band
spans entire length of thick filaments
and any overlapping portions of thin filaments
89
during contraction of the sarcomere
A band NOT reduced in size
H zone, I abnd are reduced in size
90
H zone
region containing thick filaments only
(pg 117)
91
muscle contraction is stimulated by
a message from the somatic nervous system
sent via a motor neuron
92
neuromuscular junction
link between nerve terminal (synaptic bouton) and sarcolemma of muscle fiber
93
synapse (synaptic cleft)
space between sarcolemma and nerve terminal
94
depolarization of motor neuron results in
release of neurotransmitters (acetylcholine) from nerve terminal
95
neurotransmitter diffuses across synaptic cleft and
binds to special receptor sites on sarcolemma
96
action potential is generated when
enough of receptors on sarcolemma are stimulated and permeability of sarcolemma is altered
97
once action potential is generated, it is conducted along the
sarcolemma and T system
98
after the action potential is conducted along the sarcolemma and T system, it is conducted into the
interior of the muscle fiber
99
conduction of action potential into interior of muscle fiber causes the
sarcoplasmic reticulum to release calcium ions
100
the sarcoplasmic reticulum releases calcium ions into the
sarcoplasm
101
once calcium ions are released into the sarcoplasm from the sarcoplasmic reticulum, they intiate the
contraction of the sarcomere
102
all-or-none response
and the threshold value
individual muscle fibers generally exhibit an all-or-none response
only a stimuls above a minimal value called the threshold value can elicit contraction
103
threshold value
minimal value above which a stimulus can elicit contraction
104
strenght of a contraction of a single muscle fiber cannot be
increased, regardless of strength of stimulus
105
although strength of contraction of single muscle fiber cannot be increased, regardless of the strength of the stimulus, the strength of contraction of the entire muscle can be increased by
recruiting more muscle fibers
106
simple twitch
definition
response of a single muscle fiber to a brief stimulus at or above threshold stimulus
107
simple twitch consists of
latent period
contraction period
relaxation period
108
latent period
| (simple twitch)
time between stimulation and onset of contraction
action potential spreads along sarcolemma and Ca2+ ions are released
109
contraction period caused by
| (simple twitch)
action potential spreads along sarcolemma and Ca2+ ions released
110
relaxation period
(absolute refractory period)
(simple twitch)
muscle is unresponsive to stimululs
111
temporal summation
fibers of a muscle are exposed to very frequent stimuli
muscle cannot fully relax
contractions begin to combine, becoming stronger and more prolonged
112
tetanus
contractions become continuous when stimuli are so frequent that muscle cannot relax
stronger than simple twitch of a single fiber
113
if tetanus is maintained
muscle will fatigue and contraction will weaken
114
tonus
state of partial contraction
muscles are never completely relaxed and maintain partially contracted state at all times
115
smooth muscle is responsible for
involuntary actions
116
smooth muscle is innervated by
autonomic nervous system
117
smooth muscle is found in the
digestive tract, bladder, uterus, blood vessel walls, etc
118
smooth muscles possess ____ nuceus
one centrally located
119
smooth muscles ________ skeletal muscles
lack the striations of
120
cardiac muscle fibers
compose muscle tissue of the heart
121
cardiac muscle possess characteristics of
both skeletal and smooth muscle
122
as in skeletal muscle, cardiac muscle has
actin and myosin filaments arranged in sarcomeres
123
this is what gives muscle a striated appearance
actin and myosin filaments arranged in sarcomere
124
like smooth muscle, cardiac muscle has
only one or two centrally located nuclei
125
primary source of energy for muscle contraction
ATP
126
where does ATP for muscle cells come from?
very little ATP stored in muscles
other forms of energy must be converted to ATP
127
creatine phosphate
(vertebrates and some invertebrates - echinoderms)
high-energy compound
temporarily stores energy for muscles
128
arginine phosphate
| (invertebrates)
high-energy compound
temp. stores energy for muscles
similar to creatine phosphate used in vertebrates and some invertebrates (echinoderms)
129
myoglobin
hemoglobin-like protein
found in muscle tissue
high oxygen affinity
maintains oxygen supply in muscles by binding oxygen tightly
130
