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Anatomy & Physiology: Muscles of the Body

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Terms in this set (29)

  • What are the three connective tissue layers surrounding skeletal muscle?
    Endomysium surrounds each muscle fiber, Perimysium surrounds fascicles, and Epimysium surrounds the whole muscle.
  • What is the difference between direct and indirect muscle attachment?
    Direct attachment is when the epimysium fuses directly to bone or cartilage. Indirect attachment involves tendons or aponeuroses connecting muscle to bone.
  • Define origin and insertion in muscle attachment.
    Origin is the fixed attachment point of a muscle, usually proximal. Insertion is the movable attachment point, usually distal.
  • What is a prime mover (agonist) muscle?
    The prime mover is the muscle that provides the major force for a specific movement.
  • What role does an antagonist muscle play?
    An antagonist opposes or reverses a movement, providing resistance or controlling the rate of movement.
  • What is a synergist muscle?
    A synergist assists the prime mover by promoting the same movement or reducing unwanted motion.
  • What is a fixator muscle?
    A fixator is a type of synergist that immobilizes a bone or muscle origin to provide stability during movement.
  • Name the six common criteria used in naming skeletal muscles.
    Muscle location, shape, size, fiber direction, number of origins, attachment points, and action.
  • Describe the circular muscle fascicle arrangement.
    Fascicles form concentric rings around openings and contract to close them, e.g., orbicularis oris.
  • What characterizes parallel muscle fascicles?
    Fascicles run parallel to the muscle's long axis; can be strap-like or fusiform, e.g., sartorius or biceps brachii.
  • Describe pennate muscle fascicles and their types.
    Short fascicles attach obliquely to a tendon. Types: unipennate, bipennate, multipennate, e.g., rectus femoris.
  • What is a convergent muscle fascicle arrangement?
    Fascicles converge toward a single tendon; muscle is triangular or fan-shaped, e.g., pectoralis major.
  • Which muscles are involved in facial expression?
    Muscles like orbicularis oculi, zygomaticus major, orbicularis oris, mentalis, and platysma control facial movements.
  • What are the prime muscles of mastication?
    Masseter, temporalis, medial and lateral pterygoids; all innervated by mandibular division of cranial nerve V.
  • Which muscles move the tongue and what nerve innervates them?
    Genioglossus, hyoglossus, styloglossus; all innervated by cranial nerve XII (hypoglossal nerve).
  • What is the function of the sternocleidomastoid muscle?
    Flexes the head when both sides contract; rotates head to opposite side and tilts to same side when one contracts.
  • Name the three columns of the erector spinae muscles and their function.
    Iliocostalis, longissimus, spinalis; prime movers of back extension and maintain posture.
  • What are the main muscles involved in respiration?
    Diaphragm (prime mover of inspiration), external intercostals (elevate ribs), internal intercostals (depress ribs).
  • List the four paired muscles of the abdominal wall.
    External oblique, internal oblique, transversus abdominis, rectus abdominis; involved in trunk movement and support.
  • What is the pelvic diaphragm and its function?
    Funnel-shaped muscle group (levator ani and coccygeus) that supports pelvic organs and controls openings of pelvis.
  • How can you predict a muscle's action based on its position relative to a joint?
    A muscle generally pulls a bone toward the side of the joint it crosses, e.g., anterior crossing causes flexion.
  • Name the prime movers of arm movement at the shoulder joint.
    Pectoralis major (flexion), latissimus dorsi (extension), deltoid (abduction).
  • What are the rotator cuff muscles and their role?
    Supraspinatus, infraspinatus, teres minor, subscapularis; stabilize shoulder joint and act as synergists.
  • Which muscles flex and extend the elbow joint?
    Flexors: biceps brachii, brachialis, brachioradialis; Extensor: triceps brachii.
  • What muscles are involved in wrist flexion and extension?
    Flexors: flexor carpi radialis, flexor carpi ulnaris; Extensors: extensor carpi radialis longus/brevis, extensor carpi ulnaris.
  • What are the main muscles of the anterior thigh and their actions?
    Quadriceps femoris group extends knee; iliopsoas flexes hip; sartorius flexes and laterally rotates thigh.
  • Which muscles make up the hamstrings and their function?
    Biceps femoris, semitendinosus, semimembranosus; extend thigh and flex knee.
  • What muscles are responsible for dorsiflexion and plantarflexion of the foot?
    Dorsiflexion: tibialis anterior; Plantarflexion: gastrocnemius, soleus.
  • What is the function of the intrinsic muscles of the hand and foot?
    Control precise movements like flexion, extension, abduction, and adduction of fingers and toes.