Joints of the Skull and Trunk

What types of joints are included in the skull articulations?

Synchondroses, osseus sutures, intermandibular joint, temporohyoid joint, and temporomandibular joint.

What are synchondroses?

Cartilaginous junctions found in young animals.

What type of joints are osseus sutures?

They are ossified cartilaginous junctions and fibrous joints between skull bones, classified as synarthrosis (immovable) joints.

What is the intermandibular joint?

A median osseous junction that unites the right and left mandibular bodies.

What type of cartilage forms the intermandibular joint?

A small articular area remains cartilaginous, forming a synchondrosis (hyaline cartilage joint).

What structure does the temporohyoid joint connect?

It connects the suspensory part of the hyoid apparatus at the base of the skull.

What components make up the hyoid apparatus?

Basihyoid, thyrohyoid, and ceratohyoid.

How do the ossicular components of the hyoid apparatus articulate in ruminants and horses?

The tympanohyoid articulates with the styloid process.

What characterizes the temporomandibular joint in cats and dogs?

It is nearly congruent and formed by the head of the condyloid process of the mandible and the articular area of the temporal bone.

What are the components of the articular area of the temporal bone?

Articular tubercle rostrally, mandibular fossa in the middle, and retroarticular process caudally.

What is the function of the joint capsule in the temporomandibular joint?

It extends from the free margins of the articular surfaces and attaches to the entire edge of the disc.

What do the inner synovial layer and outer fibrous layer of the temporomandibular joint do?

The inner synovial layer divides the joint into two compartments, while the outer fibrous layer is strengthened by ligaments.

Which animals lack a caudal ligament in the temporomandibular joint?

Carnivores and pigs.

What is the atlanto-occipital joint?

A joint located between the skull and C1 (atlas), formed by the occipital condyles and concavities of the atlas.

What type of joint is the atlanto-occipital joint classified as?

Ellipsoidal joints allowing flexion and extension in the sagittal plane.

What is the atlanto-axial joint?

A joint between C1 (atlas) and C2 (axis), formed by the dens of C2 and the cavity of C1.

What type of motion does the atlanto-axial joint allow?

Rotation around the longitudinal axis.

What is the role of the ligamenta alaria in the atlanto-axial joint?

They strengthen the dens of C2.

What type of disc connects adjacent vertebrae?

Intervertebral discs.

What are the components of intervertebral discs?

A fibrous ring and nucleus pulposus.

What factors affect the thickness of intervertebral discs?

The thickness varies by region, decreasing from cervical to lumbar regions.

What can cause degeneration of the nucleus pulposus in the intervertebral discs?

Advanced age.

What are short ligaments that bridge successive vertebrae?

Interarcuate, intertransverse, and interspinous ligaments.

What are long ligaments forming functional units in the vertebral column?

Dorsal longitudinal ligament, ventral longitudinal ligament, nuchal ligament, and supraspinous ligament.

What is composed of paired funiculus and cranial lamellar part in ruminants?

The nuchal ligament.

What articulates between the thoracic vertebrae and ribs?

Costovertebral joint for the head of the ribs and costotransverse joint for the tubercle of the ribs.

How do ribs articulate with costal cartilages?

Via costochondral joints.

What type of joint are costochondral joints in carnivores and horses?

Symphyses.

What type of joints are costochondral joints in pigs and ruminants?

Firm joints.

What are the components involved in the articulation of the sternum with costal cartilages?

Sternocostal joints.

What joins the costal cartilages of the asternal ribs together?

Elastic soft tissue forming the costal arch.

What connects individual sternebrae?

Intersternebral cartilages, sternal cartilaginous joints, and the sternal ligament.

What animals have two joint cavities in the atlanto-occipital joint?

Carnivores, ruminants, aged pigs, and horses.

What is the primary function of the nuchal ligament?

To provide support and flexibility to the neck in various animals.

How does the temporomandibular joint differ in structure between species?

Variations in joint shape and ligament presence exist between carnivores, ruminants, and pigs.

What is a common condition affecting the intervertebral discs with age?

Herniation of the disc towards the vertebral canal.

What anatomical feature of the atlanto-axial joint protects the medulla oblongata?

Transverse ligaments of the atlas.

What defines the movements allowed by the atlanto-occipital joint?

Flexion and extension in the sagittal plane.

What unique characteristic is found in the temporohyoid joint?

It connects components of the hyoid apparatus to the skull.

What purpose do the dorsal and ventral atlanto-occipital membranes serve?

They reinforce the joint capsule of the atlanto-occipital joint.

Which animals have a common joint cavity shared by the atlanto-occipital and atlanto-axial joints?

Carnivores.

What does the nuchal funiculus consist of?

It is a part of the nuchal ligament found in various animals.