Chapter 6- Muscular System Flashcards
What do the prefixes “myo-“, “mys-“ and “sacro-“ refer too?
muscle
The Function: Skeletal muscle
Cover’s bone framework
Skeletal Muscle: each muscle fibre is enclosed in a connective tissue sheath called…
Endomysium
Skeletal muscle: is a fibrous membrane over the endomysium
Perimysium
Skeletal Muscle: the perimysium forms a bundle of fibres called a..
Fascicle
The Function: Tendons
- Anchors muscles
- Provides durability
- Conserves space
Define the Structure: Tendons
Are mostly tough collagenic fibres
Name the Structure: Skeletal Muscle
Striated muscle
Voluntary muscle
Endomysium
Perimysium
Fascicle
Define: Smooth muscle
Found in the walls of hollow visceral organs
Define the Structure: Smooth muscle
Visceral
Non-striated
Involuntary
Where is smooth muscle found?
- Stomach
- Urinary bladder
- Respiratory passages
The Function: Cardiac Muscle
Propels blood into the blood vessels and to all tissues of the body
Define the Structure: Cardiac muscle
Cardiac
Striated
Involuntary
The Function: Muscles
- Produce movement
- Maintain posture and body position
- Stabilising Joints
- Generating heat
Name the 4 special functional properties of Skeletal Muscle
- Irritability/responsiveness
- Contractility
- Extensibility
- Elasticity
To contract, Skeletal Muscles Cells must be stimulated by..
Nerve impulses
(Nerve Stimulus & Action Potential)
Define: Motor Unit
One neuron and all the skeletal muscle cells it stimulates
The neurotransmitter that stimulates Skeletal Muscle Cells is..
Acetycholine (Ach)
Define: Graded Response
The whole muscle reacts to stimuli with graded responses, or different degrees of shortening
Graded Muscle contractions can be produced 2 ways..
- Changing the FREQUENCY of muscle stimulation
2. Changing the NUMBER of muscle cells being stimulated
Define: Tetanus
When the muscle is stimulated so rapidly that no evidence of relaxation is seen, and
the contractions are completely smooth and sustained
Name the 3 sources of Muscle Contraction
- Phosphorylation of ADP by creatine phosphate
- Stored ATP
- ATP generated by glucose oxidation
Define: Muscle Fatigue
Is when the muscle is unable to contract even though it is still being stimulated
Name possible causes of Muscle Fatigue
- Oxygen deficit
- Ion imbalance (CA2+ Calcuim, K+ Potassium)
Name the 2 types of muscle contraction
- Isotonic contractions
2. Isometric contractions
Define: Isotonic contractions
The myofilaments are successful in their sliding movements,
the muscle shortens and movement occurs
Give an example: isotonic contraction
bending the knee, bending the arm
Define: Isometric contractions
Are contractions where the muscle doesn’t shorten
- Myosin myofilaments are trying to to slide but the muscle is pitted against some more or less immovable object
Give an example: Isometric contractions
pushing against a wall with bent elbows, wall doesn’t move, muscles cannot shorten to straighten the elbow
Define: Muscle Tone
is a state of continuous partial contractions where the muscle remains firm and healthy while still being voluntarily relaxed
Muscles are attached to bones at 2 points..
Origin
Insertion
Define: Origin
the immovable or less movable bone
Define: Insertion
the movable bone
- when the muscle contracts the insertion moves toward the origin
Name the 6 types of Body/Muscle Movements
- Flexion
- Extension
- Rotation
- Abduction
- Adduction
- Circumduction
Give an example: Flexion
Bending the elbow (hinge joint)
Give an example: Extension
Straightening the elbow
Give an example: Rotation
Shake the head “No” (ball and socket)
Give an example: Abduction
Moving arm away from the body
Give an example: Adduction
Moving arm towards the body
Give an example: Circumduction
Making circular movements with arm
Give an example: Dorsiflexion
lifting toes towards the shin
Give an example: Plantar flextion
pointing toes to the ground
Give an example: Inversion
Turn the inner foot in towards the body
Give an example: Eversion
Turn the outer foot away from the middle of the body
Give an example: Supination
Forearm rotates laterally with palms facing upwards
Give an example: Pronation
Forearm rotates medially with palms facing posteriorly
Give an example: Opposition
Allows the thumb to move and tough fingers on the same hand
Define: Primary Mover
Muscle that has the major responsibility of causing a particular movement
Define: Antagonist
Muscles that oppose or reverse the movement
Define: Synergists
Helps prime movers by producing the same movement by reducing undesirable movements
Define: Fixators
The hold the bone still or stabilise the origin of a prime mover- so all tension can be used to move the insertion bone
Name the 3 Muscle types
Skeletal
Cardiac
Smooth
