Chapter 9- Muscles Flashcards
1
Q
the scientific study of muscles
A
myology
2
Q
function of muscular system
A
- Maintain posture and body position
- movement
- heat production
- guard orifices
- support visceral organs
3
Q
properties of muscles
A
- excitability
- contractility
- extensibility
- elasticity
4
Q
property of muscle — the ability to receive and respond to electrical or chemical stimuli
A
excitability
5
Q
property of muscle— the ability to shorten forcibly when stimulated
A
contractility
6
Q
property of muscle— ability to be stretched without damaging the tissue
A
extensibility
7
Q
property of muscle— ability to return to original shape after being stretched
A
elasticity
8
Q
composition of muscle
A
organs and consist of many tissues, arteries, veins, nerves, lymphatics, contractile muscle cells
9
Q
characteristics of muscle
A
- attaches to bone, skin or fascia
- striated with light and dark bands
- voluntary control
- long, thin and multi-nucleated
- arranged into packages that attach to and cover the bony skeleton
- contracts rapidly, but tire easily
- may exert great force
10
Q
1 muscle =
A
fiber
11
Q
main portion of a muscle— attached to tendons
A
Belly (Gaster)
12
Q
are attached to bone
A
tendon
13
Q
dense irregular CT around muscle. holds muscle in place and separates it from other muscles
A
deep fascia
14
Q
Loose CT beneath the skin, surrounds several muscles
A
subcutaneous fascia
15
Q
layers of fascia
A
deep fascia and subcutaneous fascia
16
Q
many muscle fibers bundled together into groups
A
fascicle
17
Q
10 -100 muscle cells =
A
muscle fibers
18
Q
several fascicles together =
A
muscle
19
Q
all connective tissue extend beyond the muscle belly to form…. part of CT framework of muscle
A
tendon
20
Q
tendon may form thick flattened sheet called
A
aponeuroses
21
Q
skeletal muscle CT that surrounds the whole muscle
A
epimysium
22
Q
skeletal muscle CT that surrounds the fascicles
A
perimysium
23
Q
skeletal muscle CT that separates individual muscle fibers (cells)
A
endomysium
24
Q
embryonic cells (stem cells) that fuse to form muscle fibers
A
myoblasts
25
embryonic cells (myoblasts) fuse together into 1 long multi nucleated cells create =
muscle fiber
26
myoblasts that do not fuse together.... assist in repair of damaged cells
myosatellite
27
cytoplasm of fiber
sarcoplasm
28
plasma membrane of a fiber
sarcolemma
29
extension of the sarcolemma in to the sarcoplasm. weaved within the the entire cell. allows for change in permeability of membrane to exist within the cells.
transverse tubule
30
contractile organelles. extend the length of the fiber. surrounded by the sarcoplasmic reticulum
myofibrils
31
the functional unit of a myofibril. made up of thick and thin filaments
sarcomere
32
type of sarcomere-- twisted protein with globular head. 1.6 micro meter long. 500 thick. contains a head, hinge and tail
myosin/thick filament
33
500 myosins interwoven together =
thick filament
34
components of thin filaments
actin and regulatory proteins-- topomyosin and troponin
35
type of sarcomere that is the structural protein. double helical beaded string. contains active site for bonding to myosin
actin
36
type of sarcomere, thin filament-- regulatory protin that allows for the attachment between actin and mysoin
tropomyosin and troponin
37
regulatory protein of thin filament that covers the active site of the actin-- preventing binding to myosin
tropomyosin
38
regulatory protein of thin filament that has job to move tropomyosin off of the active site of actin when right concentration of Calcium is sensed
troponin
39
causes the striated appearance of muscle
sarcomere bands
40
band that is the entire thick filament range (length)
A band
41
band that only incorporates thin filaments
I band
42
band that only incorporated thick filaments
H band
43
part of band that incorporates both thick and thin filaments
zone of overlap
44
divide and flank the sarcomere
sarcomere lines
45
the line that is at the end of the sarcomere. made of actin protein and anchors the filaments
Z line
46
the line that is in the middle of the sarcomere and helps to stabilize thick filaments-- stacked parallel. made of myosin.
M line
47
structural protein that anchors the thick filament to a Z line. accounts fir the elasticity and extensibility
Titin
48
structural protein that holds F actin together in think filaments-- base that double helical actin wraps around
nebulin
49
makes up the Z line. hold the thin filaments in place
actinin
50
neuron + all muscle cells stimulated by the 1 neuron
motor unit
51
point of contact between the neuron and the muscle-- where neuron meets fiber
neuromuscular junction
52
end of axon that contact motor end plate-- part of neuron that makes contact with fibers
synaptic terminal
53
part of fiber that makes contact to synaptic terminal. built to receive neurotransmitter released by neuron
motor end plate
54
neurotransmitter involved in skeletal muscle contraction
acetlycholine
55
chemical signal that travels from synaptic terminal to the motor end plate
neurotransmitter
56
gap between the muscle fiber and the synaptic terminal
synaptic cleft
57
tension produced by a muscle is determined by....
frequency of stimulation and number of motor units stimulated
58
all fibers in a motor unit fully contract if stimulated
all or none law
59
steady increase in tension by increasing the number of contracting motor units
recruitment
60
muscle never begins to relax, continuous fused conctraction
tetanus
61
when motor units contract randomly-- tension but no movement. stabilizes joints, holds objects in place and maintains posture
muscle tone
62
constant, exhaustive stimulation that increases the number of organelles/proteins in a muscle fiber-- increase in mitochondria, glycolytic enzyme reserves, myofibrils, filaments within myofibrils-- overall enlargement of the muscle
hypertrophy
63
lack of constant motor neuron stimulation reduces organelles and proteins-- due to age, hormones, lack of use and nerve damage-- reversible if not dead
atrophy
64
attachment site that does not move
origin
65
attachment site that moves
insertion
66
tension
force
67
fascicles parallel to long axis-- unidirectional force
| ex: biceps brachi
parallel muscles
68
fan shaped. multidirectional force. versatility. generates least amount of force. ex: pectoralis major
convergent muscles
69
feather shaped muscles. fascicles oblique to long axis. tendon passes through muscle. greatest force. ex: deltoid
pennate muscles
70
concentric fascicles around and opening. contraction decreases lumen diameter. ex: orbicularis oculi
circular muscles
71
rotation around one axis
unidirectional
72
movements of unidirectional muscle
rotation and hinge
73
movement occurs in two axes
biaxial
74
movements if biaxial muscle
flexion, extension, abduction, adduction
75
movement on all axes
multidirectional
76
movements of multiaxial muscle
angular motion, rotation, circumduction
77
main muscle causing directional force
agonist
78
muscle that contracts to oppose agonist
antagonist
79
muscle that assists/ modifies movement
synergist
80
muscle that stabilizes elements associated with agonists
fixator
81
example of antagonist
tricepts brachi
82
example of synergists
brachialis and pronator teres
83
example of fixator
deltoid stabilizes glenohumeral joint
84
component of lever system-- skeletal element
lever
85
component of lever system-- applied force
effort
86
component of lever system-- joint
fulcrum
87
component of lever system-- body part or object moved
resistance
88
fast acting, high energy requirement. anaerobic. densely packed myofibrils. large glycogen reserves, few mitochondria. rapid, powerful brief contractions
fast fibers
89
more myoglobin. slower sustained contractions. aerobic. smaller diameter. takes longer to contract. contract for longer time period
slow fibers
90
attributes of both fast and slow fibers, more similar to fast fibers. great resistance to fatigue
intermediate fibers
91
smooth muscle characteristics
- attached to hair follicles in the skin
- in walls of hollow organs and blood vessels
- nonstriated
- involuntary control
- contractions are slow and sustained
- spindle shaped
- very elastic
92
type of muscle that contracts slowly. resistant to fatigue and is stimulated by nervous system, hormones, ions, and stretching
smooth muscle
93
type of smooth muscles
single unit and multi unit
94
many gap junctions. sheets of spindle- shaped cells. contract together (in sync with each other)
single unit smooth muscle
95
no or few gap junctions. sepeerate fibers-- contract independently. only contract when stimulated by motor nerve
multi-unit smooth muscle type
96
type or muscle-- striated in appearance. involuntary control. autorhythmic. network of fibers with intercalated disks at ends. found only in heart
cardiac muscle
