Articulation

Examples of Articulation in the following topics:

• Tibia and Fibula (The Leg)

  • The tibia and the smaller fibula bones comprise the lower leg and articulate at the knee and ankle.
  • 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.
  • Laterally there is the fibular notch which articulates with the fibula.
  • Proximally the fibula head articulates with the lateral condyle of the tibia, the biceps femoris attaches to the fibula head.

• Ulna and Radius (The Forearm)

  • The forearm contains two bones the radius and the ulna which extend in parallel from the elbow where they articulate with the humerus to the wrist where they articulate with the carpals.
  • Laterally to the trochlear notch lies the radial notch which articulates with the head of the radius forming the proximal radioulnar joint.
  • Proximally the radius terminates with a disk shaped head which articulates with the capitulum of the humerus and the radial notch of the ulna.
  • Distally the radius expands, medially the ulnar notch articulates with the head of the ulnar.
  • Immediately adjacent to the ulnar notch the radius articulates with the scaphoid and lunate carpal bones forming part of the wrist.

• Carpals, Metacarpals, and Phalanges (The Hand)

  • The scaphoid and lunate articulate with the radius, and the lunate and triquetrum articulate with the articular disk of the wrist.
  • The trapezium articulates with the scaphoid proximally and the first, thumb, and second metacarpal distally.
  • The trapezoid articulates with the scaphoid proximally and the second metacarpal distally.
  • The capitate articulates with the scaphoid and lunate proximally and the third and fourth metacarpal.
  • The hand contains five metacarpal bones which articulate proximally with the carpals and distally with the proximal phalanges.

• Structure of Synovial Joints

  • A synovial joint or diarthrosis occurs at articulating bones to allow movement and is distinguished by a surrounding synovial capsule.
  • Diarthroses are freely movable articulations.
  • As with most other joints, synovial joints achieve movement at the point of contact of the articulating bones.
  • The main structural differences between synovial and fibrous joints are the existence of capsules surrounding the articulating surfaces of a synovial joint and the presence of lubricating synovial fluid within those capsules (synovial cavities).
  • The articular capsule is fibrous and continuous with the periosteum of articulating bones: it surrounds the diarthrosis and unites the articulating bones.

• Structures Used in Voice Production

  • The articulation of consonants occurs at a point of either active or passive articulation, which is a place in the vocal tract where an obstruction stops the sound.
  • The passive place of articulation is the place on the more stationary part of the vocal tract where the articulation occurs.
  • Passive places of articulation include:
  • Active places of articulation include:
  • Places of articulation (active and passive): 1.

• Humerus (The Upper Arm)

  • Proximally it articulates with the scapula forming the shoulder joint, or glenohumeral joint.
  • Distally the humerus articulates with the radius and ulna to form the elbow joint.
  • Distally the humerus flattens to articulate with the ulna and radius at the elbow joint.
  • The medially located trochlea articulates with the ulna.
  • Located laterally to this is the capitulum which articulates with the radius.

• Parts of a Vertebra

  • When articulated together the vertebrae form a strong yet flexible structure which encloses the vertebral foramen, or opening, in which the spinal cord sits; whilst also providing a base for numerous muscle attachments and articulations with other bones.
  • A typical vertebra of the upper region of the spine consists of two regions; the anterior vertebral body which is the point of articulation between the vertebrae and the posterior vertebral or neural arch which encloses the spinal cord.
  • Four articular processes originate from the join between the pedicles and laminae, two point superiorly and two point inferiorly and they interact with the zyhapophysis, a socket for the articular processes, of the adjacent vertebrae making the spine more stable and facilitating a small degree of articulation.
  • In conjunction with the vertebral body the transverse processes articulate with ribs.

• Tarsals, Metatarsals, and Phalanges (The Foot)

  • The proximal row contains the talus which is the most superior of the tarsals and articulates with the tibia and fibula forming the ankle joint, the calcaneus inferiorly to it and anteriorly to the navicular of the intermediate group.
  • It articulates with the talus superiorly and anteriorly with the cuboid of the distal group.
  • The intermediate group contains only the navicular bone, which articulates with all of the tarsals with the exception of the calcaneus.
  • The distal tarsals articulate with the metatarsals and also maintain the transverse arch of the foot.
  • The proximal base artciualtes with the cuboid bones, distally with the proximal phalanges and each metatarsal also articulates laterally with adjacent metatarsals.

• Arch of the Aorta

  • The arch of the aorta follows the ascending aorta and begins at the level of the second sternocostal articulation of the right side.
  • The arch of the aorta, or the transverse aortic arch, is continuous with the upper border of the ascending aorta and begins at the level of the upper border of the second sternocostal articulation of the right side.

• Cranial Bones

  • The two bones articulate have a very serrated border and articulate to form he sagittal suture.
  • The body which forms the middle of the sphenoid bone articulates with the ethmoid and occipital bone and forms a key part of the nasal cavity and contains the sphenoidal sinuses.
  • 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.
  • The nasal part is smaller and articulates with the nasal bones and maxilla to contribute to the roof of the nose.
  • It also articulates with the zygomatic and nasal bones and the maxilla.