Muscles as Levers. Bones and muscles interact as levers : A simple machine used to transmit force A lever has 4 parts: Rigid bar/ rod Fulcrum or pivot where the bar turns Object moved against resistance Force that supplies energy for the bar to move Types: 1 st class lever
United by epicranialaponeurosis(tendinous muscle) that contracts to raise the eyebrows thus wrinkling the forehead
Orbicularis Oculi: close eyelid
Zygomaticus: draw angle of lip upward
Buccinator: draws cheeks against teeth
Orbicularis Oris: closes mouth
Platysma: draws lower lip down & back
Cranial Aponeurosis: connects frontalis to occipitalis
Temporalis: elevates mandible
Occipitalis: draws scalp back
Masseter: elevates mandible
Draws head toward shoulderHead & Neck Muscles
Erector Spinae: maintain posture of back/extension
Oblique Muscles: rotation of the vertebrae
Muscles of Quiet Respiration
Internal Intercostals—deep breaths
Quadratus LumborumMuscles of the Axial Skeleton
Anterior (Palmar) View
Posterior (Dorsal) View
** Gluteus Minimus is under the Gluteus Medius
**Vastus Intermedius is beneath Rectus Femoris
Flexion – movement reduces the angle between two bones at their joint.
Extension – opposite of flexion – increases the angle at a joint.
Abduction – moving a body part away from the midline of the body.
Adduction – moving a body part toward the midline of the body.
Rotation – movement of a body part around an axis.
Supination – refers to hand position – movement turns palm up to the anterior position (anatomical position).
Pronation – palm of hand turned posteriorly.
Dorsiflexion – top of foot is elevated with toes pointing upward.
Plantar flexion – foot directed downward (standing on your toes).