Lecture 10 Flashcards
Muscles
4 Functions of Muscle Tissue
- Produce Body Movements
- Stabilize Body Positions
- Storage/Movements of substances
3 Properties of Muscle Tissue
- Electrical Excitability
- Contractility
- Extensibility
What are the 3 kinds of Muscle Tissue?
- Skeletal
- Cardiac
- Smooth
Which of the 3 Muscle Tissues ISN’T striated?
Smooth Muscle
What is the location of Smooth Muscle?
-attached to hair follicles in skin
-in walls of hollow organs
What is the location of Skeletal Muscle?
-attaches to bone, skin, or fascia
What is the location of Cardiac Muscle?
Heart
Which of the Muscle Types exhibits voluntary control?
Skeletal
Each skeletal muscle is made up of what?
Fascicles
The Fascicles of each skeletal muscle contains what? (3)
- Muscle Fibres
- Blood Vessels
- Nerves
Muscle Belly connect by ______ to skeleton
Tendons
What is Aponeurosis
strong sheet of tissue that acts as a tendon to attach muscles to bone
Rank the levels of organization of Skeletal Muscle?
Muscle > Fascicle > Muscle Fiber > Myofibril > Myofilament
What is the kind of CT that wraps the entire muscle?
Epimysium
What is the kind of CT that wraps the Fascicle?
Perimysium
What is the kind of CT that wraps the Muscle Fibre?
Endomysium
Skeletal muscle fibres vary in their contents of what? (3)
- Myoglobin
- Mitochondria
- Capillaries
More Myoglobin, more capillaries and more mitochondria results in what pigment?
Red pigment
Less Myoglobin, and less capillaries results in what pigment?
White Pigment
Muscles can be fast or slow depending on what?
How fast Myosin ATPase hydrolyzes ATP
What are the 3 classifications of Muscle Fibers?
- Type 1; Slow Oxidative
- Tybe 2a; Fast Oxidatice-Glycolytic
- Type 2b; Fast Glycolytic
Slow Oxidative Fibers are ____ in diameter
smallest in diameter
Fast Oxidative-Glycolytic fibers are ____ in diameter
larger/intermediate in diameter
Fast Glycolytic Fibers are ____ in diameter
Largest in diameter
Fast Glycolytic Fibers are used for what?
rapid intense movements of short duration
- throwing ball, weight lifting
Fast oxidative-glycolytic are used for what?
walking, sprinting
Slow oxidative fibers are used for what?
fatigue resistance
-posture maintenance
-marathon running
the pigment of a Fast Oxidative Glycolytic Fiber is…
slight red
the pigment of a Fast Glycolytic Fiber is..
White
the pigment of a Slow Oxidative Fiber is…
Red
Rank the muscle fibers from high ATP generation to low
SO, FOG, FG
Rank the muscle fibers from slow to fast rates of contraction
SO, FOG, FG
Rank the muscle fibers from high to low resistance to fatigue
SO, FOG, FG
Which of the 3 muscle fibers uses ATP slowly?
SO
True or false: most muscles contain a mixture of all 3 fiber types?
True
The proportion of each muscle fiber type in muscles depend on what 3 factors?
- Action of muscle
- Training regime
- Genetics
Postural Neck and Back Muscles primarily contain what kind of fibers?
Type 1; Slow Oxidative Fibers
Shoulder and Arm Muscles contain what kind of fibers?
all 3; SO, FOG, FG
Leg muscles contain what kind of muscle fibers?
-mainly Type 1; SO -
but all 3 : SO, FOG, FG
-
Slide 12
What are the effects of Anabolic Steroids?
Increases in;
-Muscle Size
-Strength
-Endurance
What are the serious side effects of Anabolic Steroid use?
- liver damage
- kidney damage
- heart disease
- mood swings
- facial hair, voice deepening in females
- testicular atrophy, baldness in men
What are the 2 kinds of Smooth Muscles/
- Visceral / Single unit
- Multiunit
Describe Visceral Smooth Muscle composition
-large sheets wrapping around walls of hollow viscera & small viscera
Describe Multiunit Smooth Muscle composition
individual fibers with their own motor neuron ending
What causes Visceral smooth muscles to contract in unison?
Gap Junctions
Which of the 2 types of Smooth Muscles are Autorhythmic?
Visceral / Single Unit
Where are Multiunit Smooth Muscles found?
large arteries, large airways
(arrector pilli muscles, iris & ciliary)
How many skeletal muscles are there?
700
What is meant by Muscle Belly?
The main body of muscle
What is the term for the fixed point in which muscles make bones move/pivot around?
Fulcrum
What is the term for the weight of a body part/object
Resistance/Load
What is the term for the work done by the muscle contraction?
Effort
What determines if a lever works at a mechanical advantage or disadantage (ratio of load:effort)
the relative positions of Effort, Load, and Fulcrum along the Lever
What circumstances result in a Mechanical Advantage?
-Load is closer to Fulcrum
-Effort is further from Fulcrum
-Small effort is required to move the load over large distance
What is a Fulcrum?
The fixed point in which a bone pivots around due to muscle action
What circumstances result in a Mechanical Disadvantage?
-Load is further from Fulcrum
-Effort is closer to Fulcrum
-Large effort required to move small load
Between Mechanical Advantage and Disadvantage, which facours speed and ROM force?
Mechanical Disadvantage
Between Mechanical Advantage and Disadvantage, which sacrifices speed for force?
Mechanical Advantage
What are the 3 types of Levers?
1st Class Lever
2nd Class Lever
3rd Class Lever
Which is the most common of the 3 levers in the body?
3rd Class Lever
Which of the 3 levers ALWAYS produce a Mechanical Disadvantage?
3rd Class lever
Why would a lever produce a Mechanical Disadvantage?
because the Effort is closer to the Fucrum than the load is.
Why would a lever produce a Mechanical Advantage?
because the Load is closer to the Fucrum than the Effort is.
In terms of a 1st class lever, what determines whether its at a Mechanical Advantage or Disadvantage?
Whether the Load is closer to the Fulcrum
What is an example of a 1st class lever? What acts as the load, the fulcrum, and the effort?
Head Resting on Vertebral Column
Load: weight of face
Fulcrum: Joint b/w skull & atlas
Effort: posterior neck region
What is an example of a 2nd class lever? What acts as the load, the fulcrum, and the effort?
Standing on Tippie Toes
Load: body weight
Fulcrum: ball of foot
Effort: calf muscle contracting ; pulls heel off floor
What is an example of a 3rd class lever? What acts as the Resistance, the fulcrum, and the effort?
Flexor Muscles at the Elbow
Resistor: weight in hand
Fulcrum: elbow joint
Effort: contraction of bicep brachii
Explain “Opposing Pairs”
Muscles often come in pairs working against each other
-while one muscle contracts, the other relaxes
What about a 2nd class lever results in its Mechanical Advantage?
its Load being closer to the Fulcrum than its Effort is?
What about a 3rd class lever results in its Mechanical Disadvantage?
its Effort being closer to the Fulcrum than its Load
In each “Opposing Pair” there are each of the following roles:
- Prime Mover / Agonist
- Antagonist
The Prime Mover / Agonist does what?
Contracts to cause action
The Antagonist does what?
relaxes and stretches in response to agonist stretching
What are the 2 kinds of muscles that act as supporters to the opposing pair?
- Synergists
2/ FIxators
What are Synergists?
Muscles that assist the prime mover/agonist, through stabilization
What are FIxators?
Muscles that stabilize the origin/body part from which the prime mover originates
(hold origin steady)
Skeletal Muscle DIRECTION is named based on what
orientation of fascicles relative to
midline
“Rectus” in terms of directional nomenclature of skeletal muscle refers to what?
parallel to midline
Skeletal Muscle LOCATION is named based on what
the structure near which a muscle is found
Skeletal Muscle ORIGIN & INSERTION is named based on what
Sites where muscle originates and inserts
ex: sternocleidomastoid: origin on sternum & clavicle // inserts on mastoid process of temporal bone
