Overview of the Axial Skeleton

Study Notes

Overview of the Axial Skeleton

The axial skeleton is one of two main skeleton divisions (the other is the appendicular skeleton).
Comprises the bones of the skull, vertebral column, rib cage, and sternum.
Total of 80 bones in adults.

Components of the Axial Skeleton

Skull
- Divided into two parts:
  - Cranial Bones: Protects the brain; consists of 8 bones (frontal, parietal, temporal, occipital, sphenoid, ethmoid).
  - Facial Bones: Supports facial structure; consists of 14 bones (maxilla, mandible, nasal, zygomatic, palatine, lacrimal, inferior nasal concha, vomer).
- Mandible is the only moveable bone.
Vertebral Column (Spine)
- Composed of 33 vertebrae divided into five regions:
  - Cervical (7): C1-C7, supports the skull and allows neck movement.
  - Thoracic (12): T1-T12, each articulates with ribs.
  - Lumbar (5): L1-L5, supports lower back.
  - Sacral (5): fused into the sacrum.
  - Coccygeal (4): fused into the coccyx (tailbone).
- Provides structural support, protects the spinal cord, and allows flexibility.
Rib Cage
- Composed of 24 ribs (12 pairs) attached to the thoracic vertebrae.
- Types of ribs:
  - True Ribs (1-7): Directly attached to the sternum.
  - False Ribs (8-10): Indirectly attached to the sternum via cartilage.
  - Floating Ribs (11-12): No anterior attachment.
- Protects thoracic organs (heart, lungs) and supports the upper body.
Sternum (Breastbone)
- Located at the front of the rib cage.
- Composed of three parts:
  - Manubrium: Upper section, connects with the clavicles.
  - Body: Main section, where ribs attach.
  - Xiphoid Process: Small, pointed lower segment.

Functions of the Axial Skeleton

Provides anchor points for muscles and ligaments.
Protects vital organs (brain, spinal cord, heart, and lungs).
Supports the body’s weight and upright posture.
Assists in the movement of the head and trunk.

Key Concepts

The axial skeleton plays a crucial role in overall body structure and stability.
Understanding its components is essential for studying human anatomy and physiology.
Knowledge of the axial skeleton is foundational for various medical and health-related fields.

Axial Skeleton Overview

The axial skeleton is one of two main skeletal divisions, the other being the appendicular skeleton.
It comprises bones of the skull, vertebral column, rib cage, and sternum.
Contains 80 bones in adults.

Components of the Axial Skeleton

Skull

Divided into two parts:
- Cranial Bones: Protect the brain and consist of 8 bones (frontal, parietal, temporal, occipital, sphenoid, ethmoid).
- Facial Bones: Support facial structure and consist of 14 bones (maxilla, mandible, nasal, zygomatic, palatine, lacrimal, inferior nasal concha, vomer).
The mandible is the only movable bone in the skull.

Vertebral Column (Spine)

Composed of 33 vertebrae divided into five regions:
- Cervical (7): C1-C7, supports the skull and enables neck movement.
- Thoracic (12): T1-T12, each articulates with ribs.
- Lumbar (5): L1-L5, supports the lower back.
- Sacral (5): Fused into the sacrum.
- Coccygeal (4): Fused into the coccyx (tailbone).
The vertebral column provides structural support, protects the spinal cord, and allows flexibility.

Rib Cage

Composed of 24 ribs (12 pairs) attached to the thoracic vertebrae.
Ribs are categorized as:
- True Ribs (1-7): Directly attached to the sternum.
- False Ribs (8-10): Indirectly attached to the sternum via cartilage.
- Floating Ribs (11-12): No anterior attachment.
The rib cage protects thoracic organs (heart, lungs) and supports the upper body.

Sternum (Breastbone)

Located at the front of the rib cage.
It is composed of three parts:
- Manubrium: Upper section, connects with the clavicles.
- Body: Main section, where ribs attach.
- Xiphoid Process: Small, pointed lower segment.

Functions of the Axial Skeleton

Provides anchor points for muscles and ligaments.
Protects vital organs (brain, spinal cord, heart, and lungs).
Supports the body's weight and upright posture.
Assists with the movement of the head and trunk.

Key Concepts

The axial skeleton plays a crucial role in overall body structure and stability.
Understanding its components is essential for studying human anatomy and physiology.
Knowledge of the axial skeleton is foundational for various medical and health-related fields.

Description

This quiz covers the axial skeleton, which includes the skull, vertebral column, rib cage, and sternum. It details the components and number of bones, providing insights into the structure and function of the axial skeleton. Test your knowledge of these vital parts of the human body.