SKELEON AND CONNECTION

Question 1

Structure and types of bones, innervation and blood supply of bone (draw scheme)

Question 3

Limb formation

Question 4

Connection of bones, structure and types of joints

Question 5

The osseous nasal cavity, relations to neighboring structures

Question 6

Bony orbit - walls, relation to neighboring structures, passages

Answer 6

Bony orbit

Bones contribute to the framework:

• Maxilla,
• Zygomatic,
• Frontal,
• Ethmoid,
• Lacrimal,
• Sphenoid,
• Palatine bones.

Shape

• Tetrahedral pyramid tilted dorsally
  
  • aditus (base, ventrally)
    
    • x
  • apex (optic canal/foramen, dorsally)
• 4 walls, completing the pyramid configuration
• 10 openings + their contetnt

orbita is divided by theoretical planes into 3 levels

Roof: superior wall

• Bones:
  
  • Orbital part of the frontal bone
  • Small contribution: sphenoid bone, lesser wing
• Function:
  
  • Separates the contents of the orbit from the brain in the anterior cranial fossa.
• Structures:
  
  • Anteromedially
    
    • Intrusion of part of the frontal sinus
    • Trochlear fovea: for the attachment of a pulley through which the superior oblique muscle passes
  • Anterolaterally
    
    • Depression (the lacrimal fossa) for the orbital part of the lacrimal gland.
  • Superiorlly
    
    • Incisura/foramen frontalis/supraorbitalis
  • Inferiorlly:
    
    • Superior orbital fissure

Medial wall

• Bones:
  
  • Maxilla: processus frontalis
  • Lacrimal
  • Ethmoid: lamina orbitalis
    
    • ​contains collections of ethmoidal cells, which are clearly visible in a dried skull.
  • Sphenoid bone: lesser wing
• Structures:
  
  • The anterior and posterior ethmoidal foramina.
    
    • The anterior and posterior ethmoidal nerves and vessels leave the orbit through these openings.
  • Lacrimal groove
    • Contains the lacrimal sac, bound by:
      
      • Posterior lacrimal crest (part of the lacrimal bone)
      • Anterior lacrimal crest (part of the maxilla).
  • Posterior to the ethmoid bone the medial wall is completed by a small part of the sphenoid bone, which forms a part of the medial wall of the optic canal.

Floor (inferior wall): which is also the roof of the maxillary sinus

• Bones:
  
  • Orbital surface of the maxilla
  • Small contributions from the zygomatic (facies orbitalis) and palatine bones (processus orbitalis)
• Structures:
  
  • Inferior orbital fissure.

Lateral wall

• Bones:
  
  • Zygomatic bone
  • Sphenoid bone: greater wing
• Structures:
  
  • Foramen zygomaticoorbitale
  • Superior orbital fissure

Contents:

Optic canal:

• Optic nerve
• Ophthalmic artery

Superior orbital fissure

• Lateral to the optic canal is a triangular-shaped gap between the roof and lateral wall of the bony orbit.
• Superior and inferior branches of the oculomotor nerve [III],
• Trochlear nerve [IV]
• Abducent nerve [VI]
• lacrimal, frontal, and nasociliary branches of the ophthalmic nerve [V1]
• Superior ophthalmic vein

Inferior orbital fissure

• Its borders are the greater wing of the sphenoid and the maxilla, palatine, and zygomatic bones.
• This long fissure allows communication between:
  
  • the orbit and the pterygopalatine fossa posteriorly;
  • the orbit and the infratemporal fossa in the middle; and
  • the orbit and the temporal fossa posterolaterally.
• Maxillary nerve [V2] and its zygomatic branch,
• Infra-orbital vessels,
• Vein communicating with the pterygoid plexus of veins.

Infra-orbital foramen

Beginning posteriorly and crossing about two-thirds of the inferior orbital fissure, a groove (the infraorbital

groove) is encountered, which continues anteriorly across the floor of the orbit (Fig. 8.82).

This groove connects with the infra-orbital canal that opens onto the face at the infra-orbital

foramen.

The infra-orbital nerve, a branch of the maxillary nerve [V2], and vessels pass through this structure

as they exit onto the face.

Other openings

Orbit 1247 / 1534

1247 / 1534

thelifesyndrome2.blogspot.com

Associated with the medial wall of the bony orbit are several smaller openings (Fig. 8.82).

The anterior and posterior ethmoidal foramina are at the junction between the superior and

medial walls. These openings provide exits from the orbit into the ethmoid bone for the anterior and

posterior ethmoidal nerves and vessels.

Completing the openings on the medial wall is a canal in the lower part of the wall anteriorly. Clearly

visible is the depression for the lacrimal sac formed by the lacrimal bone and the frontal process of

the maxilla. This depression is continuous with the nasolacrimal canal, which leads to the inferior

nasal meatus. Contained within the nasolacrimal canal is the nasolacrimal duct, a part of the lacrimal

apparatus.

Question 7

Skull, skull of neonate and its development

Question 8

Vertebrae, vertebral column and its development, connections, curvatures and motility

Craniovertebral joint

Skeleton of thorax and its development, connections and motility of ribs

Temporomandibular joint - structure and motility

Development and growth of limb, molecular mechanisms, limb defects

Shoulder joint - structure and movements Elbow joint - structure and movements

Bones and joints of hand including reading of X-ray images

Bony pelvis as complex, connections, passages, diameters, planes, sexual differences

Hip joint - structure, movements, developmental dysplasia of hip

Knee joint - structure, biomechanics, movements

Talocrural and subtalar joints - structure, movements

Bones and joints of foot including reading of X-ray images, plantar arches and their support