Skull, Sinuses & Vertebral Column – Review Flashcards

Question-and-Answer style flashcards covering key lecture points on sinuses, skull anatomy, cranial bones, palate formation, vertebral structures, spinal curves, and related clinical concepts.

What are the two main functions of the paranasal sinuses?

(1) lighten the weight of the skull and (2) act as resonating chambers that contribute to voice quality.

Which sinus is hardest to drain and therefore prone to mastoiditis?

The mastoid sinus (in the temporal bone).

Why can mastoiditis become life-threatening?

The mastoid air cells lie close to the cranial cavity; drilling to drain infection risks penetrating the thin wall and causing a brain infection.

What type of membrane lines all sinuses and other cavities opening to the exterior?

Mucous membranes (epithelial lining that secretes mucus and antibodies for protection).

Which two bones form the zygomatic arch?

The zygomatic process of the temporal bone (posterior) and the temporal process of the zygomatic bone (anterior).

Which muscle passes under the zygomatic arch to insert on the coronoid process of the mandible?

The temporalis muscle.

What large opening in the occipital bone transmits the spinal cord?

Foramen magnum ('big hole').

Which bony structures articulate with the atlas (C1) to allow the ‘yes’ nodding motion?

Occipital condyles on the occipital bone.

Memory aid: Which two cranial bones appear in BOTH the cranial and facial bone lists?

Ethmoid and Frontal (remember "FE").

Name the vertical projection of the ethmoid bone that anchors the falx cerebri.

Crista galli.

Which ethmoid plate contains olfactory foramina for CN I?

Cribriform plate.

What gland sits in the sella turcica of the sphenoid bone?

The pituitary gland (hypophysis).

Why is the sphenoid called the "central bone" of the cranial floor?

It articulates with all other cranial bones (frontal, occipital, temporal, parietal, ethmoid).

Which process on the maxilla forms the anterior two-thirds of the hard palate?

Palatine process of the maxilla.

Which bone forms the posterior one-third of the hard palate and is L-shaped?

Palatine bone (right & left).

Failure of the maxillae and palatine bones to fuse medially results in what congenital condition?

Cleft palate (± cleft lip).

Which bone in the body does NOT articulate with any other bone?

The hyoid bone.

The mandibular condyle articulates with which specific depression on the temporal bone?

Mandibular fossa (forming the temporomandibular joint).

Extra small bones sometimes seen within cranial sutures are called what?

Wormian (sutural) bones – usually of no clinical significance.

At what age do the major fontanels typically close?

Around 2 years of age.

Give the normal numbers of vertebrae in each region: cervical, thoracic, lumbar.

Cervical 7, Thoracic 12, Lumbar 5.

What is the name of the fused bone formed from five sacral segments?

The sacrum.

Which spinal curvatures are lordotic and which are kyphotic in adults?

Lordotic: cervical & lumbar; Kyphotic: thoracic & sacral.

An abnormal lateral curvature of the spine is called what?

Scoliosis.

Name the large anterior portion of a vertebra that bears weight.

Centrum (vertebral body).

What passes through the vertebral foramen?

Spinal cord (above L2) and the cauda equina nerve roots (below L2).

Why are lumbar punctures performed below L2?

Because the spinal cord ends at L2; below that level only nerve roots are present, decreasing risk of cord injury.

Which two bony parts form the vertebral arch between body and processes?

Pedicle (between body & transverse process) and Lamina (between transverse & spinous processes).

Surgical removal of the lamina to relieve spinal stenosis is called what?

Laminectomy.

What type of joint exists between superior and inferior articular facets of adjacent vertebrae?

Synovial (facet) joint, which can develop osteoarthritis.

Define stenosis in the context of the spine.

Narrowing of a canal or foramen (e.g., spinal or intervertebral foramina) that can compress nerves.

What fluid bathes the brain and spinal cord, providing nutrients and cushioning?

Cerebrospinal fluid (CSF).

Which barrier limits direct contact of blood with brain tissue?

The blood–brain barrier (BBB).