Overview
This lecture covers expectations for diagram-based labeling on the upcoming midterm, the anatomy and features of cranial and facial bones, key skull structures, and important definitions.
Exam Expectations & Logistics
- Midterm will include diagram labeling where you write in the correct anatomical term; no multiple choice.
- Focus on diagrams and content posted; only label items provided in blank diagrams.
- Understand information (e.g., red vs. yellow marrow) even if not in diagram labels.
- Exam duration is 40 minutes; format and diagram/content balance will be announced Monday.
- The final exam is cumulative and will cover material from the entire course.
Planes & Layers Review
- Coronal plane divides the body into anterior (front) and posterior (back).
- Sagittal plane divides left and right; transverse divides superior (top) and inferior (bottom).
- The stratum corneum is the top non-vascular epidermal layer; the stratum basale is deeper and closer to the dermis, which is vascular.
Cranial Openings & Sutures
- There are 85 named skull openings: foramina (rounded), canals (tubular), and fissures (slits).
- Foramina, canals, and fissures allow passage of blood vessels and nerves.
- The foramen magnum is a large opening in the occipital bone for the spinal cord.
- Major cranial sutures include coronal, squamous, sagittal, and lambdoid, connecting various skull bones.
Cranial Bones
- Eight cranial bones: two paired (parietal, temporal) and four unpaired (frontal, occipital, sphenoid, ethmoid).
- Frontal: forehead, roof of orbit, contains the superciliary arch, forms anterior cranial fossa.
- Occipital: posterior base, contains foramen magnum, articulates with the atlas at the occipital condyles.
- Temporal: inferior-lateral skull, contains squamous, mastoid (muscle attachment), tympanic (ear canal), styloid process, and petrous (inner ear).
- Sphenoid: central "butterfly" bone, touches all other cranial bones, contains body, greater/lesser wings, sella turcica (pituitary gland).
- Ethmoid: between nasal cavity and orbits, includes cribriform plate (olfactory nerves), crista galli (membrane attachment), labyrinth (air filtration), and perpendicular plate.
Facial Bones
- Fourteen facial bones: two unpaired (mandible—lower jaw, vomer—inferior nasal septum), others paired.
- Mandible: body and rami, alveolar process supports lower teeth, forms temporomandibular joint (TMJ) with temporal bone.
- Maxilla: upper jaw, alveolar process supports upper teeth, forms hard palate with palatine bones, contains maxillary sinus.
- Zygomatic: forms cheeks and zygomatic arch with the temporal bone.
- Nasal: bridge of nose; lacrimal: small bone behind eye socket; inferior nasal concha and palatine: parts of nasal cavity and palate.
- Hyoid: only free-floating bone, between mandible and larynx, attachment for tongue and neck muscles.
Key Terms & Definitions
- Foramen (plural foramina) — Round or oval bone opening for nerves/vessels.
- Canal — Tubular bone opening for passage of nerves/vessels.
- Fissure — Narrow slit-like bone opening.
- Suture — Immovable joint of the skull formed by dense connective tissue.
- Fossa — Depression in a bone (e.g., for the brain).
- Process — Projection or outgrowth on bone (e.g., mastoid process).
- Condyle — Rounded articular bone surface.
- Articulation — Where two bones meet.
- Alveolar process — Tooth socket area in jaw bones.
- TMJ (temporomandibular joint) — Joint between mandible and temporal bone.
Action Items / Next Steps
- Review and practice labeling posted blank diagrams.
- Know definitions and identify major cranial/facial bones and their features.
- Study openings (foramen, canal, fissure) and their locations/functions.
- Check for further exam details on Monday and review posted slides.