Muscular system Flashcards
(98 cards)
1
Q
The functions of Muscle system
A
- Provides voluntary movement of body
- Maintain Posture
- Produces heat
- Provides movement of internal organs
- Causes involuntary actions
2
Q
Voluntary movement produced by the body
A
- Enables breathing, blinking, and smiling
- Allows you to hop, skio or do push-ups
3
Q
The movements of internal organs provided by muscular system
A
- Moves food through digestive tract
- Enables bladder control
4
Q
What involuntary actions does muscular system cause?
A
- Reflex actions
- Adjusts opening of pupils
- Causes hair to stand on
end
5
Q
Properties of muscle
A
- Excitability
- Contractility
- Extensibility
- Elasticity
6
Q
capacity of muscle to respond to a stimulus
A
Excitability
7
Q
ability of a muscle to shorten and generate pulling force
A
Contractility
8
Q
muscle can be stretched back to its original length
A
Extensibility
9
Q
ability of muscle to recoil to original resting length after stretched
A
Elasticity
10
Q
Characteristics of muscle tissue
A
- Made up of contractile fibers
- Provides movement
- Controlled by nervous system
11
Q
consciously controlled
A
Voluntary
12
Q
not under conscious
control
A
Involuntary
13
Q
Two main types of colored muscle fibers
A
- Red (slow) fibers
- White (fast) fibers
14
Q
- greater number of mitochondria
- contain high concentration of myoglobin
- react at a slow rate; do not undergo fatigue even with sustained contraction
A
Red (slow) fibers
15
Q
Example of red fibers
A
- Postural muscles
16
Q
muscles which are opposed to gravity
A
Postural muscle
17
Q
-contain little myoglobin/mitochon
- react rapidly and undergo anaerobic respiration
-generate force quickly but not for long durations
A
White (fast) fibers
18
Q
Example of white fibers
A
Fingers and eye movements
19
Q
postural muscles that are capable of rapid contraction at times
A
Intermediate fibers
20
Q
Example of intermediate fibers
A
Calf muscle
21
Q
supports leg but also capable of running, walking, jumping
A
Calf muscle
22
Q
Differences between red and white fibers
A
- Number of mitochondria and concentration of myoglobin
23
Q
- stimulate muscle fibers to contract
- Neuron axons branch so that each muscle fiber is innervated
- Form a neuromuscular junction
A
Motor neurons
24
Q
- Muscles require large amts of energy
- Extensive vascular network delivers necessary oxygen and nutrients and carries away metabolic waste produced by muscle fibers
A
Capillary beds surround muscle fibers
25
Location of skeletal muscle type
attached to bone
26
Location of cardiac muscle type
Heart
27
Location of smooth muscle type
Walls of internal organs + skin
28
Function of skeletal muscle type
Movement of bone
29
Function of cardiac muscle type
Beating of heart
30
Function of smooth muscle type
Movement of internal organs
31
Control mode of skeletal muscle type
Voluntary
32
Control mode of cardiac and smooth muscle type
Involuntary
33
Shape of skeletal muscle type
Long + slender
34
Shape of cardiac muscle type
Branching
35
Shape of smooth muscle type
Spindle shape
36
Characteristics of skeletal muscle type
- Striated- light and dark bands
- Many nuclei
37
Characteristics of cardiac muscle type
- Striated
- One or two nuclei
38
Characteristics of smooth muscle type
- Non-striated
-One nucleus (visceral)
39
Contain two types of protein filaments
Myofibril
40
types of protein filaments present in myofibril
Actin and Myosin
41
point of anchor of actin
Z disc
42
functional unit of a myofibril, region between Z discs
Sarcomere
43
Also known as the "thick" myofilament
Myosin
44
Also known as the "thin" myofilament
Actin
45
Many elongated myosin molecules shaped like ____ ____
golf club
46
Single filament contains roughly ___ myosin molecules
300
47
Molecule consists of two heavy myosin molecules wound together to form a ___ ___ ___ ___ to the myosin myofilament and two heads that ___ ___.
- rod portion lying parallel
- extend laterally
48
What does myosin heads do?
- Can bind to active sites
- Attached to the rod portion by a hinge region
- Have ATPase activity
49
Major protein components of Actin "thin" myofilaments
1. F (fibrous) actin
2. Tropomyosin
3. Troponin
50
Two strands of fibrous (F) actin form a ___ ___ elongating the myofilament
Double helix
51
attached at either end at sarcomere
Two strands of Fibrous actin
52
Actin site can bind ___ during muscle contraction.
myosin
53
Actin: Composed of G actin monomers each of which has a ___-___ ___
myosin-binding site
54
an elongated protein winds along the groove of the F actin double helix.
Tropomysin
55
Subunits of troponin
- Tn-A
- Tn-T
- Tn-C
56
troponin subunit that binds to actin
Tn-A
57
Troponin subunit that binds to tropomyosin
Tn-T
58
Troponin subunits that binds to calcium ions
-Tn-C
59
is a motor neuron and all the muscle fibers it supplies
A Motor Unit
60
The Nerve-Muscle Functional Unit
Motor unit
61
HAVE SMALL MOTOR PROTEINS
Muscles that control fine movments (Fingers, Eyes)
62
Have large motor units
- Large weight-bearing muscles (Thighs, hips)
63
stores Ca++ when muscle not is contracting
SR (Sarcoplasmic reticulum)
64
Description of SR
- Elaborate, smooth endoplasmic reticulum
- Runs longitudinally, and surrounds each myofibril
- Form chambers on either side
65
Chambers created by SR on eitehr side of the T-tubules
Terminal cisternae
66
A single T-tubule and the 2 terminal cisternae form a
Triad
67
Where does stimulation occur?
Neuromuscular junction
68
How do motor neurons communicate with muscle cells?
Neurotransmitters, carry impulse signal across the gap
69
What happens when a muscle cell is stimulated?
Calcium ions are released into the muscle cell
70
What do calcium ions do?
Cause interaction between actin and myosin
71
How do actin and myosin interact?
Actin filaments slide over the myosin filaments
72
What model explains this (Muscle contraction)
Sliding Filament Model
73
What causes actin to slide over myosin?
The head of myosin connects to actin and pivots.
74
What is this connection
called?
cross-bridge
75
tension develops when filaments attempt to slide past each other
Mechanical changes
76
Types of Muscle contraction
1. Isotonic contraction
2. Isometric contraction
77
- ‘same tension'
- filaments are successful in sliding
- results in shortening of muscle but tension remains the same
Isotonic contraction
78
Ex of Isotonic contraction
Walking, lifting an object, bending knee, smiling
79
- ‘same length’
- contraction without shortening
- increased tension due to exertion against an immovable object
- not successful in sliding
Isometric contraction
80
Example of Isometric contraction
Posture, holding an object, standing still, opposing gravity
81
a device that records and displays motion or pressure as a graph over time
Kymograph
82
- response after application of threshold stimulus
- single, brief, jerky contraction
Muscle twitch
83
- stimuli applied in succession
- cells do not get chance to relax between stimuli
- can be summed up
Summation
84
- application of stimuli in rapid succession
- no period of relation between them
- contraction bec sustained and prolonged
- may dev tension 4x as during a single twitch
Tetanus
85
- stimuli applied at slower rate than tetanus
-increased fusion of twitches
- individual contraction gradually becomes stronger for a short time though stimulus strength is unchanged
Treppe (staircase effect)
86
state of partial contraction which gives muscles a certain firmness
Tone
87
- in smooth muscles only
-ability to stretch w/o developing lasting increase in tension
- dev resistance to stretching at first
-later tension decreases and muscle adjusts to new length
Plasticity
88
Example of Plasticity in muscle
in hollow visceral organs like urinary bladder, stomach, small intestines
89
Muscle disorders
- Strain
90
is an injury to a muscle or tendon, and is often caused by overuse, force, or stretching
Strain
91
Injured area experiences in strain
- pain and soreness
- swelling
- warmth, bruising, or redness
- difficulty using or moving the injured area in a normal manner
92
Treatement for Muscle injuries
RICE
93
Stop all activities which cause pain.
Rest
94
Helps reduce swelling. Never ice more than 10 - 15 min. at a time. Protect the skin.
Ice
95
Wrap the strained area to reduce swelling.
Compression
96
Keep the strained area as close to the level of the heart as is conveniently possible to keep blood from pooling in the injured area.
Elevation
97
stiffness of skeletal muscles after death
Rigor Mortis
98
Causes of rigor mortis
- Myosin-actin crossbridges are still intact
- Crossbridges left attached due to depletion of ATP
- Bonds not broken-rigid muscles
