medial pterygoid

Examples of medial pterygoid in the following topics:

• Chewing Muscles

  • Lateral Pterygoid - The lateral pterygoid muscle has a triangular shape with two head, superior and inferior.
  • Actions - Together, the lateral pterygoids protract the jaw, working independently to produce lateral movement.
  • Medial Pterygoid - The medial pterygoid muscle has a quadrangular shape with two heads, deep and superficial.
  • It is located inferior to the lateral pterygoid.
  • Arrows indicate the location of the lateral pterygoid, highlighted with the medial pterygoid in orange.

• Dislocated Mandible

  • For the mouth to close it requires the following muscles: the masseter, temporalis, and medial pterygoid muscle.
  • For the jaw to open it requires the lateral pterygoid muscle.
  • The muscles that are affected during anterior jaw dislocation are the masseter and temporalis, which pull up on the mandible, and the lateral pterygoid, which relaxes the mandibular condyle.

• Trigeminal (V) Nerve

  • The motor component of the mandibular division (V3) of the trigeminal nerve controls the movement of eight muscles, including the four muscles of mastication: the masseter, the temporal and the medial and lateral pterygoids.

• Cranial Bones

  • The sphenoid bone is divided into several: the body of the bone, two greater wings, two lesser wings, and the pterygoid processes.
  • The ethmoid bone forms the medial wall of the orbit, the roof of the nasal cavity and due to its central location articulates with numerous bones of the viscerocranium, within the neurocranium it articulates with the frontal and sphenoid bones.

• Carpals, Metacarpals, and Phalanges (The Hand)

  • The carpals are often split into two rows, the proximal row containing the scaphoid, lunate, triquetrum and pisiform moving lateral to medial.
  • In the distal row contains the trapezium, trapezoid, capitate and hamate moving lateral to medial.
  • They are numbered moving lateral to medial starting with the thumb which is metacarpal I, and ending with metacarpal V, the little finger.
  • Each metacarpal consists of a base, shaft and head, with the concave lateral and medial borders of the shaft allowing attachment of the interossei muscles.
  • The digits are named in a similar fashion to the metacarpals moving lateral to medial starting at the thumb.

• Orbits

  • Completing the basal and medial border of the orbital rim is the maxillary bone which also forms the inferior wall (floor) of the orbital surface.
  • The lacrimal and ethmoid bones contribute to the medial wall of the orbit and also the medial wall of the orbital canal.

• Tibia and Fibula (The Leg)

  • The tibia is located medially to the fibula and is much larger, both are bound together with the interosseous membrane.
  • Proximally there are five key feature of the tibia, it widens and forms two condyles the lateral and medial which articulate with the condyles of the femur.
  • The medial malleolus is a bony projection which articulates with the tarsal bones to form the ankle joint.
  • Distally the fibula forms the lateral malleolus, which is more prominent than the medial malleolus of the tibia and also articulates with the tarsal bones forming the ankle joint.

• Femur (The Thigh)

  • The femoral head projects medially and superiorly and articulates with the acetabulum of the pelvis forming the hip joint.
  • The shaft descends in a slightly medial direction which is designed to bring the knees closer to the body’s center of gravity, increasing stability.
  • Two rounded regions termed the medial and lateral condyles articulate with the tibia and at the most anterior projection the patella.
  • Finally, medial and lateral epicondyles lie immediately proximal to the condyles and are also regains where key internal knee ligaments attach.

• Tarsals, Metatarsals, and Phalanges (The Foot)

  • The navicular bone plays a key role in maintaining the medial longitudinal arch of the foot.
  • There are four distal tarsals, the lateral cuboid and the medial three cuneiforms.
  • The foot contains five metatarsals which are numbered I-V moving medial to lateral, big toe to little toe.
  • The digits are named in a similar fashion to the metatarsals medial to lateral from the big toe.

• Arches of the Feet

  • The main arches are the antero-posterior arches, which may, for descriptive purposes, be regarded as divisible into two types—a medial and a lateral.
  • As can be examined in a footprint, the medial longitudinal arch curves above the ground.
  • The ligament is strengthened medially by blending with the deltoid ligament of the ankle-joint, and is supported inferiorly by the tendon of the tibialis posterior, which is spread out in a fanshaped insertion and prevents undue tension of the ligament or such an amount of stretching as would permanently elongate it.
  • While these medial and lateral arches may be readily demonstrated as the component antero-posterior arches of the foot, the fundamental longitudinal arch is contributed to by both, and consists of the calcaneus, cuboid, third cuneiform, and third metatarsal: all the other bones of the foot may be removed without destroying this arch.
  • These are directed downward and medialward, so that when the medial borders of the feet are placed in apposition, a complete tarsal dome is formed.