Muscle Tissue and Muscles of the Human Body

Lab List Practical 3

Chapter 10 – Muscle Tissue

  • Sarcomere

    • A Band

    • The dark band composed mainly of thick myosin filaments.

    • H Band

    • The central part of the A band that contains only thick filaments. It appears lighter because it lacks thin filaments.

    • M Line

    • The line that bisects the H band and consists of proteins that hold the thick filaments in place.

    • I Bands

    • The light bands that contain only thin filaments (actin).

    • Z Lines

    • The boundaries of each sarcomere where thin filaments attach; bisect the I band.

    • Zone of Overlap

    • The region where thin and thick filaments overlap; crucial for muscle contraction.

  • Muscle Fiber

    • Troponin

    • A protein complex that binds to calcium ions and facilitates the contraction process by moving tropomyosin away from actin's myosin-binding sites.

    • Tropomyosin

    • A filamentous protein that winds around actin filaments and blocks binding sites for myosin when muscles are relaxed.

    • Myosin

    • The thick filament protein; acts as the motor protein that interacts with actin to produce muscle contraction.

    • Actin

    • The thin filament protein that interacts with myosin to contract muscle.

    • Sarcolemma

    • The cell membrane surrounding a muscle fiber. It separates the muscle fiber’s internal environment from the outer environment.

    • Triad

    • Composed of two terminal cisternae and one T-tubule; plays a key role in muscle contraction signaling.

    • T-tubules

    • Invaginations of the sarcolemma that allow the action potential to reach deep into the muscle fiber cells.

    • Sarcoplasmic Reticulum

    • A specialized smooth endoplasmic reticulum that stores calcium ions, crucial for muscle contraction.

    • Terminal Cisternae

    • Enlarged regions of the sarcoplasmic reticulum that are adjacent to T-tubules, serving as reservoirs for calcium ions.

    • Thin Filaments

    • Composed mainly of actin and associated proteins (troponin and tropomyosin).

    • Thick Filaments

    • Composed mainly of myosin.

    • Neuromuscular Junction

    • The synapse between a motor neuron and a skeletal muscle fiber; essential for muscle activation.

    • Motor Unit

      • A motor neuron and all the muscle fibers it innervates; determines the precision of muscle control.

    • Synaptic Knob

      • The swollen end of the motor neuron that contains synaptic vesicles filled with acetylcholine.

    • Synaptic Cleft

      • The gap between the synaptic knob and the muscle fiber membrane where neurotransmitters are released.

  • Fascicle

    • Epimysium

    • A layer of connective tissue that envelops entire muscles.

    • Perimysium

    • A sheath of connective tissue surrounding individual fascicles (bundles of muscle fibers).

    • Endomysium

    • The delicate connective tissue surrounding each muscle fiber within a fascicle.

Chapter 11 - Muscles

Head, Face, and Neck Muscles

  • Occipitofrontalis

    • Composed of the frontal and occipital bellies and connected by the epicranial aponeurosis; raises eyebrows and wrinkles forehead.

  • Orbicularis Oculi

    • Muscle surrounding the eye; responsible for closing the eyelids.

  • Orbicularis Oris

    • Muscle surrounding the mouth; responsible for movements such as puckering.

  • Buccinator

    • Muscle of the cheek; aids in chewing by holding food between teeth.

  • Masseter

    • A primary muscle for mastication; elevates the mandible to close the jaw.

  • Temporalis

    • A fan-shaped muscle that also aids in biting by closing the jaw.

  • Sternocleidomastoid

    • Responsible for rotating and flexing the neck; extends from the sternum and clavicle to the mastoid process of the temporal bone.

  • Superior Rectus

    • Muscle controlling upward eye movement.

  • Inferior Rectus

    • Muscle controlling downward eye movement.

  • Medial Rectus

    • Muscle responsible for inward eye movement.

  • Lateral Rectus

    • Muscle responsible for outward eye movement.

  • Superior Oblique

    • Muscle that aids in downward and outward eye movement.

  • Inferior Oblique

    • Muscle that helps in upward and outward eye movement.

  • Medial Pterygoid

    • Muscle involved in mastication, moving the jaw sideways and forward.

  • Lateral Pterygoid

    • A muscle that helps in opening the mouth and moving the jaw side to side.

Torso Muscles

  • Diaphragm

    • The primary muscle for respiration; separates the thoracic cavity from the abdominal cavity.

  • Internal Intercostal

    • Muscles located between the ribs, aiding in forced expiration.

  • External Intercostal

    • Muscles between the ribs, assisting in inhalation.

  • Rectus Abdominis

    • A muscle that compresses abdominal contents and flexes the vertebral column; known as the 'abs.'

  • External Oblique

    • The largest and most superficial abdominal muscle; aids in trunk rotation.

  • Internal Oblique

    • Muscle located beneath the external obliques; assists in trunk rotation and lateral flexion.

  • Transversus Abdominis

    • The deepest abdominal muscle; compresses abdominal contents.

  • Linea Alba

    • A fibrous structure that runs down the middle of the abdomen; serves as an attachment site for abdominal muscles.

  • Serratus Anterior

    • A muscle that helps in the upward rotation of the scapula and protraction of the shoulder blade.

  • Trapezius

    • A large muscle that extends down the back of the neck and upper back, involved in moving the shoulder blades.

  • Latissimus Dorsi

    • A large muscle in the lower back, responsible for shoulder extension, adduction, and medial rotation.

  • Rhomboid Minor

    • A muscle that retracts the scapula, located above the rhomboid major.

  • Rhomboid Major

    • A muscle that retracts and stabilizes the scapula, located below the rhomboid minor.

Upper Extremity Muscles

  • Deltoid

    • Muscle responsible for shoulder abduction, flexion, and extension.

  • Pectoralis Major

    • A major chest muscle involved in shoulder adduction and flexion.

  • Pectoralis Minor

    • A muscle located beneath the pectoralis major that assists in stabilizing the scapula.

  • Rotator Cuff

    • A group of four muscles that stabilize the shoulder:

    • Supraspinatous

      • Abducts the arm.

    • Infraspinatous

      • Laterally rotates the arm.

    • Teres Minor

      • Also aids in lateral rotation.

    • Subscapularis

      • Medially rotates the arm.

  • Biceps Brachii

    • Responsible for elbow flexion and forearm supination.

  • Brachialis

    • A muscle that flexes the elbow joint.

  • Triceps Brachii

    • Responsible for elbow extension.

  • Palmaris Longus

    • A muscle that assists in wrist flexion.

Page 2 - Lower Extremity Muscles

  • Flexor Carpi Ulnaris

    • A muscle that flexes and adducts the wrist.

  • Flexor Carpi Radialis

    • A muscle that flexes and abducts the wrist.

  • Flexor Digitorum Superficialis

    • A muscle that flexes the fingers.

  • Extensor Carpi Ulnaris

    • A muscle that extends and adducts the wrist.

  • Extensor Carpi Radialis Longus

    • A muscle that extends and abducts the wrist.

  • Extensor Digitorum

    • A muscle that extends the fingers.

Lower Extremity Muscles

  • Iliopsoas

    • Composed of the iliacus and psoas major; flexes the hip.

  • Tensor Fascia Latae

    • A muscle that assists in hip abduction and medial rotation.

  • Gluteus Maximus

    • The main buttock muscle; responsible for hip extension.

  • Gluteus Medius

    • A muscle that abducts and medially rotates the hip.

  • Gracilis

    • A muscle involved in hip adduction and knee flexion.

  • Adductor Magnus

    • A muscle responsible for adducting the thigh.

  • Adductor Longus

    • Muscles involved in adduction of the thigh.

  • Sartorius

    • The longest muscle in the body that aids in flexing, abducting, and laterally rotating the hip.

  • Quadriceps

    • A group of four muscles that extend the knee:

    • Vastus Lateralis

    • Vastus Medialis

    • Vastus Intermedius

    • Rectus Femoris

  • Hamstrings

    • A group of three muscles that flex the knee and extend the hip:

    • Semimembranosus

    • Semitendinosus

    • Biceps Femoris

  • Tibialis Anterior

    • A muscle responsible for dorsiflexion of the ankle.

  • Soleus

    • A muscle that assists in plantarflexion of the foot.

  • Gastrocnemius

    • The major calf muscle, involved in plantarflexion of the foot and flexion of the knee.

  • Extensor Digitorum Longus

    • A muscle that extends the toes.

  • Fibularis (Peroneus) Longus

    • A muscle that plantarflexes and everts the foot.

Know the origin(s), insertion(s), and action(s) for the following muscles:

  1. Masseter

  2. Temporalis

  3. Sternocleidomastoid

  4. Rectus Abdominis

  5. Trapezius

  6. Latissimus Dorsi

  7. Deltoid

  8. Pectoralis Major

  9. Infraspinatous

  10. Teres Minor

  11. Subscapularis

  12. Biceps Brachii

  13. Triceps Brachii

  14. Flexor Carpi Radialis

  15. Extensor Carpi Ulnaris

  16. Extensor Digitorum

  17. Gluteus Maximus

  18. Adductor Magnus

  19. Sartorius

  20. Rectus Femoris

  21. Semimembranosus

  22. Biceps Femoris

  23. Soleus

  24. Gastrocnemius

  25. Extensor Digitorum Longus