Muscles
Explain the sliding filament theory.
- The sliding filament model describes the process used by muscles to
contract. It is a cycle of repetitive events that causes actin and myosin
myofilaments to slide over each other, contracting the sarcomere and
generating tension in the muscle.
Describe the pathology of muscular dystrophy.
- Over time, the dead muscle shell is replaced by a fibrofatty
infiltrate, which clinically appears as pseudohypertrophy of the
muscle. The lack of functioning muscle units causes weakness and,
eventually, contractures. Other types of MDs are caused by
alterations in the coding of one of the DAG complex proteins.
Identify the components of the neuromuscular junction.
- The neuromuscular junction comprises four cell types: the motor
neuron, terminal Schwann cell, skeletal muscle fibre and kranocyte,
with the motor neuron and muscle fibre separated by a gap called the
synaptic cleft.
Muscle Locations and functions
Explain the four patterns of muscle fascicle organization.
- I don’t know if this answers the question but
, - Fascicles can be parallel, circular, convergent, pennate, fusiform,
or triangular. Each arrangement has its own range of motion and
ability to do work.
Describe the classes of levers and give examples in the body.
- First Class – head next joint
• The fulcrum is in the middle of the effort and the load.
- Second Class – Ankle joint
• The load is in the middle between the fulcrum and the effort.
- Third Class – Elbow joint
• The effort is in the middle between the fulcrum and the load.
Explain the difference between origins and insertions.
- The site at which a muscle begins is the origin and the site at which it
ends is the insertion. During the movement of the muscle, the origin
does not move, whereas, the insertion does move with the contraction.
Define and explain the differences between an agonist, antagonist and
synergist.
- Agonist: The primary or major mover. Its contraction is primarily
, responsible for the given movement
- Antagonist: Opposite of the agonist. Its contraction opposes the
movement of the agonist
- Synergist: Assists or helps the agonist. Its contraction helps the
large agoinst work more efficiently
- Fixator: A type of synergist that assists an agonist by stabilizing its
origin
, Identify the locations and functions of the following facial and neck muscles
- Orbicularis Oris - control the shape and movements of the lips.
- orbicularis oculi - closes the eyelids and assists in pumping the
Explain the sliding filament theory.
- The sliding filament model describes the process used by muscles to
contract. It is a cycle of repetitive events that causes actin and myosin
myofilaments to slide over each other, contracting the sarcomere and
generating tension in the muscle.
Describe the pathology of muscular dystrophy.
- Over time, the dead muscle shell is replaced by a fibrofatty
infiltrate, which clinically appears as pseudohypertrophy of the
muscle. The lack of functioning muscle units causes weakness and,
eventually, contractures. Other types of MDs are caused by
alterations in the coding of one of the DAG complex proteins.
Identify the components of the neuromuscular junction.
- The neuromuscular junction comprises four cell types: the motor
neuron, terminal Schwann cell, skeletal muscle fibre and kranocyte,
with the motor neuron and muscle fibre separated by a gap called the
synaptic cleft.
Muscle Locations and functions
Explain the four patterns of muscle fascicle organization.
- I don’t know if this answers the question but
, - Fascicles can be parallel, circular, convergent, pennate, fusiform,
or triangular. Each arrangement has its own range of motion and
ability to do work.
Describe the classes of levers and give examples in the body.
- First Class – head next joint
• The fulcrum is in the middle of the effort and the load.
- Second Class – Ankle joint
• The load is in the middle between the fulcrum and the effort.
- Third Class – Elbow joint
• The effort is in the middle between the fulcrum and the load.
Explain the difference between origins and insertions.
- The site at which a muscle begins is the origin and the site at which it
ends is the insertion. During the movement of the muscle, the origin
does not move, whereas, the insertion does move with the contraction.
Define and explain the differences between an agonist, antagonist and
synergist.
- Agonist: The primary or major mover. Its contraction is primarily
, responsible for the given movement
- Antagonist: Opposite of the agonist. Its contraction opposes the
movement of the agonist
- Synergist: Assists or helps the agonist. Its contraction helps the
large agoinst work more efficiently
- Fixator: A type of synergist that assists an agonist by stabilizing its
origin
, Identify the locations and functions of the following facial and neck muscles
- Orbicularis Oris - control the shape and movements of the lips.
- orbicularis oculi - closes the eyelids and assists in pumping the
