Human Anatomy Lab: Articulated and Disarticulated Skeleton Study Notes

Articulated Skeleton

Axial Skeleton

The axial skeleton forms the central axis of the human body and provides support and protection for the brain, spinal cord, and vital organs within the thorax.

• Skull

  • Cranial bones: Protect the brain and form the structure of the head.

  • Facial bones: Form the face and support sensory organs.

• Hyoid bone: Located in the neck, supports the tongue and is associated with swallowing.

• Vertebral column:

  • Cervical vertebrae: 7 vertebrae in the neck region.

  • Thoracic cage: Includes the ribs and sternum, protects thoracic organs.

  • Sacrum: Fused vertebrae at the base of the spine.

  • Coccyx: Tailbone, composed of fused vertebrae.

Appendicular Skeleton

The appendicular skeleton consists of the limbs and girdles, facilitating movement and interaction with the environment.

• Pectoral Girdle: Connects the upper limb to the axial skeleton.

  • Clavicle

  • Scapula

• Upper Limb:

  • Humerus

  • Radius

  • Ulna

  • Carpals (wrist bones)

  • Metacarpals (hand bones)

  • Phalanges (finger bones)

• Pelvic Girdle: Connects the lower limb to the axial skeleton.

  • Coxal bones

  • Symphysis pubis

• Lower Limb:

  • Femur

  • Patella

  • Tibia

  • Fibula

  • Tarsals (ankle bones)

  • Metatarsals (foot bones)

  • Phalanges (toe bones)

Disarticulated Axial Skeleton

Skull External Features: Anterior View

The anterior view of the skull reveals bones that form the face and the front of the cranium.

• Frontal bone

• Nasal bone

• Zygomatic bone

• Maxilla

• Mandible

• Perpendicular plate of ethmoid bone

• Inferior nasal concha

Skull External Features: Orbit

The orbit is the bony cavity containing the eye and associated structures.

• Maxilla

• Lacrimal bone

• Ethmoid bone

• Sphenoid

• Zygoma

Skull External Features: Lateral View

The lateral view of the skull highlights bones and processes visible from the side.

• Frontal bone

• Parietal bone

• Occipital bone

• Temporal bone

  • External acoustic meatus

  • Styloid process

  • Mastoid process

  • Zygomatic process of temporal bone

• Nasal bone

• Zygomatic bone

• Maxilla

• Mandible

  • Mandibular condyle

  • Mental foramen

  • Coronoid process

• Sphenoid bone

• Lambdoid suture

Skull External Features: Posterior & Superior Views

These views show the bones forming the back and top of the skull.

• Parietal bone

• Occipital bone

  • External occipital protuberance

  • Lambdoid suture

Skull External Features: Base

The base of the skull contains openings for nerves and blood vessels.

• Maxilla

• Palatine bone

• Vomer

• Zygomatic bone

• Temporal bone

  • Carotid canal

  • Mandibular fossa

Skull Internal Features: Base

The internal base of the skull supports the brain and contains foramina for cranial nerves.

• Ethmoid bone

  • Cribriform plate

• Sphenoid bone

  • Sella turcica

• Temporal bone

  • Jugular foramen

• Occipital bone

  • Foramen magnum

Vertebral Column

General Features

The vertebral column is composed of individual vertebrae separated by intervertebral discs, providing support and flexibility.

• Cervical vertebrae

• Thoracic vertebrae

• Lumbar vertebrae

• Sacrum

• Coccyx

• Intervertebral discs

• Intervertebral foramen

Cervical Vertebrae General Features

Cervical vertebrae are the smallest and lightest vertebrae, located in the neck.

• Atlas (C1)

• Axis (C2)

• Transverse process

• Spinous process

• Vertebral foramen

• Transverse foramen

• Superior articular process (bifid)

Thoracic Vertebrae General Features

Thoracic vertebrae articulate with the ribs and have long spinous processes.

• Transverse process

• Spinous process

• Lamina

• Pedicle

• Superior articulating facet

• Inferior articulating facet

• Vertebral foramen

• Superior notch

• Inferior notch

Lumbar Vertebrae General Features

Lumbar vertebrae are large and robust, supporting much of the body's weight.

• Spinous process

• Lamina

• Transverse process

• Pedicle

• Vertebral foramen

• Superior articulating facet

• Inferior articulating facet

• Body

• Inferior notch

Sacrum Features

The sacrum is a triangular bone at the base of the spine, formed by the fusion of five sacral vertebrae.

• Sacral base

• Sacral canal

• Sacral ala

• Sacral promontory

• Sacral foramina

Coccyx

The coccyx, or tailbone, is attached to the inferior sacrum and consists of fused vertebrae.

• Coccygeal bones

Thoracic Cage

General Features

The thoracic cage protects vital organs and supports the upper body.

• Sternum

  • Manubrium

  • Jugular notch

  • Clavicular notch

  • Sternal angle

  • Body

  • Xiphoid process

• Ribs (not attached)

Summary Table: Major Bones of the Axial Skeleton

Region	Main Bones	Key Features
Skull	Frontal, Parietal, Occipital, Temporal, Sphenoid, Ethmoid, Maxilla, Mandible, Zygomatic	Protects brain, forms face, sensory organ support
Vertebral Column	Cervical, Thoracic, Lumbar, Sacrum, Coccyx	Supports body, protects spinal cord, allows movement
Thoracic Cage	Sternum, Ribs	Protects heart and lungs, supports upper limbs

Key Terms and Definitions

• Foramen: An opening or hole in a bone for nerves and blood vessels.

• Process: A projection or outgrowth of bone for muscle attachment or articulation.

• Facet: A smooth, flat surface on a bone for articulation with another bone.

• Suture: An immovable joint between skull bones.

Example: Vertebral Formula

The vertebral column is often described by the number of vertebrae in each region:

• Cervical: 7

• Thoracic: 12

• Lumbar: 5

• Sacrum: 5 (fused)

• Coccyx: 4 (fused)

Formula: $C_7T_{12}L_5S_5Co_4$

Additional info: The study notes expand on the brief points in the original material, providing definitions, context, and examples for clarity and completeness.