2. The Musculoskeletal System And Exercise Flashcards
What is the outer membrane of a muscle called?
Epimysium.
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What is the term given to a bundle of muscle fibres?
Fasciculi.
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What is the outer sheath of a bundle of muscles fibres?
Perimysium.
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What is the name of the membrane around each muscle fibre?
Endomysium.
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Individual muscle fibre are formed from what structure?
Rod-like.
What mechanism result in muscles contraction?
The sliding filament mechanism.
What are the two types of myofilaments?
Actin and myosin.
What is the name given to the compartments that myofilaments are arranged in?
Sarcomeres.
Describe a tendon and its attachments.
Tendon: tough, inelastic fibres which wrap around the end of the muscles and attached to the outer layer of the bone.
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Which are the thin and which are the thick myofilaments?
Actin – thin
Myosin - thick
Which structure attaches to the actin filaments and pulls on these filaments?
A series of ‘hook like’ projections referred to as myosin heads.
Why is calcium important to muscle contraction?
Myosin binding sites on the actin are blocked by a combination of other molecules (troponin and tropomyosin) that must be moved before myosin can be attached. Calcium causes the blocking molecule to move away from the binding site, thus allowing the ‘primed’ myosin head to bind with the actin.
Describe the location and function of the sarcoplasmic reticulum.
Surrounding the myofibrils is a network of tubes called the sarcoplasmic reticulum (SR) that act as calcium reservoirs.
Identify the three types of muscle fibre.
- Type I: slow twitch fibres
- Type IIa: intermediate twitch fibres
- Type IIb: fast twitch fibres
Which muscle fibre type is the most associated with long-duration, aerobic activities?
Type I: slow twitch fibres.
Which muscle fibre type is very anaerobic in nature?
Type IIb: fast twitch fibres.
Which type of muscle fibre will take more slow twitch or fast twitch characteristics depending on the training stimulus?
Type IIa: intermediate twitch fibres
What is the term for soreness experience in muscles one to three days after exercise?
Delayed onset muscle soreness (DOMS).
Which axis of movement is generally associated with the sagittal plane of movement?
The medial-lateral axis.
Which plane of movement is generally associated with the longitudinal axis of movement?
The transverse plane.
List the joint action and planes of movement available at the shoulder joint.
Flexion – extension
Abduction – adduction
Internal – external rotation
List the joint actions, planes of movement and axes of movement available at the ankle joint.
Joint action = plantarflexion – dorsiflexion
Plane of movement = sagittal
Axis of movement = medial - lateral
Name the muscles of the rotator cuff.
- Teres minor
- Supraspinatus
- Infraspinatus
- Subscapularis
The shoulder girdle is comprised of what bony structures?
Scapulae and clavicles.
Name four muscles of the shoulder girdle.
- Rhomboid major
- Rhomboid minor
- Levator scapulae
- Trapezius
Describe the attachments and actions of the quadratus lumborum muscle.
This runs from the iliac crest to the lumbar vertebrae and lower ribs. It helps to laterally flex and extend the spine and also assist in laterally tilting the pelvis.
With reference to their relative mobility and stability, compare the structures and functions of the shoulder and hip joints.
The hip joint sacrifices mobility for stability, whereas the shoulder joint sacrifices stability for mobility.
Which is the only bi-axial muscle of the quadriceps muscle group?
Rectus femoris.
Identify the three bones that form one half of the pelvis.
- Ilium
- Pubis
- Ischium
Identity the four groups of ligaments associated with pelvic girdle.
- Sacrotuberous ligaments
- Sacroiliac ligaments
- Sacrospinious ligaments
- Symphysis pubis ligaments
Which five muscles internally rotate the shoulder joint?
- Deltoids
- Subscapularis
- Teres major
- Latissimus dorsi
- Pectoralis major
Name the rotator cuff muscles of the shoulder joint.
- Teres minor
- Supraspinatus
- Infraspinatus
- Subscapularis
Which muscles retract the shoulder girdle?
Trapezius.
What are the concentric actions of the piriformis muscles?
Abduction and external rotation of the hip.
Name the muscles that flex the hip joint.
- Iliacus
- Tensor fasciae latae
- Pectineus
- Rectus femoris
What are the concentric actions of the gluteus maximus muscle?
Extension, external rotation and abduction of hip.
What are the concentric actions of the quadratus lumborum muscle?
Lateral flexion and extension of the spine and laterally tilts the pelvis.
Name the five hip adductor muscles.
- Adductor magnus
- Adductor longus
- Adductor brevis
- Gracilis
What are the three hamstring muscles?
- Biceps femoris
- Semimembranosus
- Semitendinosus
What are the concentric actions of the gastrocnemius muscle?
Plantarflexion of the ankle and flexion of the knee.
What are the four stages of the sliding filament theory?
- Cocking phase
- Binding phase
- Power stroke
- Re-setting
Which axis of movement is generally associated with the frontal plane of movement?
The anterior-posterior axis.
Which three large superficial muscles provide the majority of movement at the shoulder joint?
- Pictorials major
- Latissimus dorsi
- Deltoids
Which muscles enables the shoulder girdle to protract and depress?
The pectoralis minor and serratus anterior.
What major muscles of the trunk controls the gross movement of the spine?
- Rectus abdominis
- Erector spinae
- Internal & external oblique’s
What is the function of the multifidus muscle?
It facilitates control of flexion and rotation in the vertebral column.
The cellular structure of muscle fibres
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Force generation and sliding filament theory
- Muscular force is created by the action of myosin pulling on actin.
- When they’re stimulated, the hook-like heads of the myosin protein attach to the actin and rotate.
- ATP provides the energy for the movement.
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Exercise and type 2a skeletal muscle
Type 2a fibres can take on more slow- or fast-twitch characteristics to suit the training stimulus applied to them.
Muscles of the shoulder joint
- Formed by the articulation of the scapula and humerus.
- A shallow ball-and-socket joint.
- Superficial muscles: pectoralis major, latissmus dorsi and deltoids.
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Deep musculature of the shoulder
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Muscles of the shoulder girdle
- The shoulder girdle:
- Formed by the articulation of the scapulae and clavicles.
- Trapezius, rhomboids and levator scapulae muscles act to create elevation, retraction and depression.
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Anterior musculature of the shoulder girdle
- Anterior shoulder girdle muscles:
- Pectoralis minor and serratus anterior.
- Arranged to enable protraction and depression of the shoulder girdle.
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Superficial musculature of the vertebral column
- Major superficial muscles of the spine:
- Rectus abdominis.
- Internal obliques.
- External obliques.
- Erector spinae.
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Posterior musculature of the vertebral column
Multifidus:
- Runs from the sacrum to the cervical spine
- Linked to every 2nd and 4th vertebrae above it
- Facilitates control of flexion and rotation
- Key component of core musculature
Quadratus lumborum:
- Runs from the iliac crest to the lumbar vertebrae and lower ribs
- Helps to laterally flex and extend the spine
- Assists in laterally tilting the pelvis
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The pelvic girdle
- Comprised of six bones: ilium, ischium and pubis (a pair of each).
- Control and support is provided via ligaments and muscles.
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Hip flexion
- Iliacaus/psoas (ilipsoas)
- Rectus femoris
Hip extension
- Hamstring
- Gluteus maximus
Hip Adduction
- Adductor longus/ brevis/ magnus
- Pectineus and gracilis
Hip Abduction
- Piriformis and tensor facia latae
- Gluteus minimus/ medius
Anterior muscles of the knee (knee extension)
Quadriceps:
- Erectus femoris
- Vastus lateralis
- Vastus medialis
- Vastus intermedius
Muscles to posterior of the knee (extension of the hip & flexion of the knee)
Hamstring:
- Biceps femoris (external rotation)
- Semitendinosus (internal rotation)
- Semimembranosus (internal rotation)
Planes of movement
- Frontal plane: a vertical plane that divides the body into anterior and posterior parts.
- Sagittal plane: a vertical plane that divides the body into left and right parts.
- Transverse plane: a horizontal cross-section through the body which separates the upper and lower body.
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Axis of movement
- Medial-lateral axis: passes through the sagittal plane.
- Anterior-posterior axis: passes through the frontal plane.
- Longitudinal axis: passes through the transverse plane.
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