Chapter 11- Joints of the Skull BOOK

how are sutures classified?

as fibrous joints, suture in type

what are the bony surfaces of sutures?

1. sagittal suture

2. frontal (coronal) suture

3. lambdoid suture

4. squamous suture

what is the sagittal suture?

the articulation of the two parietal bones in the median plan of the skull

frontal suture is aka

coronal suture

what is the frontal (coronal) suture?

the articulation of the parietal bones with the frontal bone

what is the lambdoid suture?

the articulation of the parietal bones with the occipital bone

what is the squamous suture?

the articulation of the parietal and temporal bones

there (are, are not) ligaments and movements at these suture joints

ARE NOT

how is the temporomandibular joint (TMJ) classified?

as a synovial joint, combined hinge and plane in type

what are the bony surfaces of the temporomandibular joint?

1. mandibular fossa of the temporal bone

2. head (condyloid process) of the mandible

there (are, are not) ligaments at the TMJ

ARE

what is the ligament of the TMJ?

one prominent intraarticular ligament called the articular disc

what is the articular disc composed of?

an oval plate of fibrous tissue that sometimes contains patches of fibrocartilage

what does the circumference of the articular disc attach to?

articular capsule

what does the articular disc do?

divides the joint cavity into two separate compartments

what are the two compartments of the joint cavity?

-superior compartment

-inferior compartment

where is the superior compartment located?

between the articular disc and the mandibular fossa

where is the inferior compartment located?

between the articular disc and the mandible

what are the movements of the mandible at the temporomandibular joint (TMJ)?

HINGE movements and PLANAR movements

what are the hinge movements?

depression and elevation

what is the depression movement?

inferior movement of the mandible (OPEN the mouth)

what is the elevation movement?

superior movement of the mandible (CLOSE the mouth)

what are the planar movements?

protraction, retraction, and lateral movement

what is the protraction movement?

anterior movement of the mandible in a horizontal plane

what is the retraction movement?

posterior movement of the mandible in a horizontal plane

what is the lateral movement?

side-to-side movement (grinding)

the bones of the fetal skull (are, are not) completely ossified at birth

ARE NOT

what are the unossified areas between the cranial bones called?

fontanelles

what are fontanelles?

six major UNOSSIFIED, MEMBRANOUS areas between the cranial bones

from French, fontanelle means what?

a little fountain

what are the 4 fontanelles (that we need to know)?

-anterior fontanelle

-posterior fontanelle

-anterolateral fontanelle

-posterolateral fontanelle

what is the LARGEST of the fontanelles?

anterior fontanelle

where is the anterior fontanelle located?

at the junction of the coronal and sagittal sutures

where is the anterior fontanelle located in ADULTS?

the BREGMA

where is the triangular posterior fontanelle located?

at the junction of the lambdoid and sagittal sutures

where is the posterior fontanelle located in ADULTS?

the LAMBDA

anterolateral and posterolateral fontanelles are what?

small, irregular fontanelles

anterolateral fontanelles are aka

sphenoid fontanelles

where is the anterolateral fontanelles located?

at the junction of the frontal, parietal, sphenoid, and temporal bones

where is the posterolateral fontanelles located?

at the junction of the occipital, parietal, and temporal bones

which fontanelle is useful to physicians?

anterior fontanelle

how is the anterior fontanelle useful to physicians?

FOUNTAINS are (put in drains)

in determining...

1. the position of the fetal head in utero

2. the development of the skull

3. the extent of pathological intracranial pressure

how does the anterior fontanelle help in determining the development of the skull?

unlike other fontanelles, which ossify within a few months, the anterior fontanelle becomes bony at 2 years of age--> so in babies, this is called the SOFT SPOT