Anatomy of the Skull, Vertebral Column, and Thoracic Cage

What are the main components of the skeleton?

Bones, cartilages, joints, ligaments.

How many bones are in the axial skeleton?

80 bones.

What are the functions of the axial skeleton?

Supports the head, neck, and trunk; protects the brain, spinal cord, heart, and lungs.

How many bones make up the skull?

22 bones.

What are the two main categories of skull bones?

Cranial bones (8) and facial bones (14).

What is the only freely movable bone in the skull?

Mandible.

What are the divisions of the cranium?

Cranial vault (calvaria) and cranial base.

What is the mnemonic for the eight cranial bones?

Funny People Try Out Spicy Eggs (Frontal, Parietal, Temporal, Occipital, Sphenoid, Ethmoid).

What are the four major sutures of the skull?

Coronal, sagittal, lambdoid, squamous.

What is the function of the occipital bone?

Forms the posterior skull and base; contains foramen magnum for brainstem connection.

What is the significance of the temporal bones?

Involved in ear structure, jaw joint, and contain major openings for nerves and blood vessels.

What is the shape of the sphenoid bone?

Butterfly-shaped.

What does the ethmoid bone help form?

The roof of the nasal cavity.

What are the components of the facial bones?

Mandible, vomer, maxillae, zygomatic, nasal, lacrimal, palatine, inferior nasal conchae.

What is the function of the mandible?

Forms the lower jaw.

What is the role of the maxillae?

Forms the upper jaw and holds upper teeth.

What is the function of the zygomatic bones?

Form the cheekbones and inferolateral orbit.

What do the nasal bones form?

The bridge of the nose.

What is the purpose of the lacrimal bones?

Form the medial walls of the orbits and assist in tear drainage.

What is the function of the palatine bones?

Form the posterior hard palate.

What does the vomer bone form?

The inferior portion of the nasal septum.

What is the role of the inferior nasal conchae?

Help warm, moisten, and filter air in the nasal cavity.

What structures are contained within each orbit?

Eye, fatty tissue, eye muscles, lacrimal gland.

How many bones form each orbit?

Seven bones: frontal, sphenoid, zygomatic, maxilla, palatine, lacrimal.

What structures make up the nasal cavity?

Bone and hyaline cartilage.

What forms the roof of the nasal cavity?

Cribriform plate of ethmoid, sphenoid, and frontal bones.

What bones constitute the lateral walls of the nasal cavity?

Superior and middle conchae of ethmoid, palatine bones, inferior nasal conchae, and maxillae.

What is the nasal septum composed of?

Vomer, perpendicular plate of ethmoid, and septal cartilage.

What are the functions of the paranasal sinuses?

Lighten the skull and improve voice resonance.

Where is the hyoid bone located?

Inferior to the mandible in the anterior neck.

How many bones are in the adult spine?

26 bones.

How many separate vertebrae does a fetus have?

33 separate vertebrae.

What are the five regions of the vertebral column?

Cervical (7), Thoracic (12), Lumbar (5), Sacral (5 fused), Coccygeal (3-5 fused).

What are the primary functions of the spine?

Supports head and trunk, protects spinal cord, transfers trunk weight to lower limbs.

What are the primary curvatures of the spine?

Thoracic and sacral curvatures, present at birth and convex posteriorly.

What are the secondary curvatures of the spine?

Cervical and lumbar curvatures, develop after birth and concave posteriorly.

What is scoliosis?

A lateral/sideways curve of the spine.

What is kyphosis?

An exaggerated thoracic curve, often referred to as hunchback.

What is lordosis?

An exaggerated lumbar curve, often referred to as swayback.

What are the major ligaments of the spine?

Anterior longitudinal ligament and posterior longitudinal ligament.

What are the components of an intervertebral disc?

Nucleus pulposus (soft center) and annulus fibrosus (strong outer ring).

What happens in a herniated disc?

The annulus fibrosus tears, allowing the nucleus pulposus to push outward, potentially pressing against a spinal nerve.

What is the body/centrum of a vertebra?

The anterior, weight-bearing part of the vertebra.

What are the seven processes of a typical vertebra?

1 spinous process, 2 transverse processes, 2 superior articular processes, and 2 inferior articular processes.

What characterizes cervical vertebrae C3-C7?

Small oval body, large triangular vertebral foramen, transverse foramina, and usually bifid spinous process.

What is unique about C1 (Atlas)?

It has no body or spinous process and supports the skull.

What is the function of C2 (Axis)?

It contains dens, acting as a pivot for head rotation.

What is the thoracic cage composed of?

Sternum, 12 pairs of ribs, thoracic vertebrae, and costal cartilages.

What are the three parts of the sternum?

Manubrium, body, and xiphoid process.

What are true ribs?

Ribs 1-7 that attach directly to the sternum.

What are false ribs?

Ribs 8-10 that attach indirectly to the sternum.

What are floating ribs?

Ribs 11-12 that have no anterior attachment to the sternum.