Spine (medical term)

Skeletal System Study Notes

Course: HPR 76A
Subject: Medical Terminology

Objectives

  • Name and describe skeletal structures

  • Formation of bone tissue

  • Define joint types

  • Review skeletal disorders

Overview of the Skeleton

  • Function of the Skeleton:

    • Framework for the body

    • Protects internal organs

    • Enables movement through joints

  • Composition:

    • Composed of 206 bones in adults

    • Key bones include:

    • Scapula

    • Humerus

    • Radius

    • Ulna

    • Femur

    • Tibia

    • Fibula

    • Calcaneus

    • Phalanges

    • Patella

    • Mandible

Divisions of the Skeleton

1. Axial Skeleton

  • Skull

  • Vertebral column

  • Chest

2. Appendicular Skeleton

  • Shoulder girdle

  • Arm

  • Hand

  • Pelvic girdle

  • Leg

  • Foot

The Vertebral Column

  • Regions:

    • Cervical Vertebrae: 7

    • Thoracic Vertebrae: 12

    • Lumbar Vertebrae: 5

    • Sacral Vertebrae: 5

    • Coccygeal Vertebrae: 4

The Skull

Key Bones Include:

  • Frontal

  • Parietal (right and left)

  • Occipital

  • Temporal (right and left)

  • Zygomatic (right)

  • Mandible

  • Sphenoid

  • Nasal (right)

  • Maxillary (right)

The Pelvis

Key Components:

  • Coxal Bone (Os Coxae or Hip Bone)

  • Bones:

    • Ilium

    • Pubic Bone

    • Ischium

  • Other Structures:

    • Sacrum

    • Coccyx

    • Pubic Arch

    • Iliac Fossa

    • Iliac Crest

    • Sacroiliac Joint

    • Sacral Promontory

    • Pelvic Brim

    • Ischial Spine

    • Acetabulum

    • Pubic Crest

    • Pubic Symphysis

Bone Formation

  • Bone is formed by the addition of calcium and phosphorus to cartilage (connective tissue) at the epiphyseal line.

  • Key Cells Involved:

    • Osteoblasts: Cells that produce bone

    • Osteocytes: Mature bone cells that maintain bone

    • Osteoclasts: Cells that break down bone tissue to release calcium and other minerals

Bone Structure

Types of Bones:

  1. Long Bones: (e.g., hands, legs, arms, feet)

  2. Flat Bones: (e.g., ribs)

  3. Short Bones: (e.g., wrist, ankle)

  4. Irregular Bones: (e.g., face, vertebrae)

Joints

Joint Types:

  1. Suture:

    • Immovable joint held together by fibrous connective tissue (e.g., skull)

  2. Symphysis:

    • Slightly movable joint connected by cartilage (e.g., vertebral and pubic bone joints)

  3. Synovial or Diarthrosis:

    • Moveable joint, can be hinge or ball-and-socket

  4. Key Structures:

    • Tendons: Attach muscle to bone

    • Ligaments: Attach bone to bone

Joint Anatomy: Knee

  • Structures:

    • Parasagittal section lateral to midline of knee

    • Articularis genus muscle

    • Quadriceps femoris tendon

    • Suprapatellar fat body

    • Synovial components:

    • Suprapatellar bursa

    • Subcutaneous prepatellar bursa

    • Infrapatellar fat body

    • Subcutaneous infrapatellar bursa

    • Deep (subtendinous) infrapatellar bursa

    • Articular cartilage

    • Lateral meniscus

    • Patellar ligament

Pathophysiology of Skeletal Disorders

Infection:

  • Osteomyelitis: Inflammation of bone caused by pus-forming bacteria

  • Tuberculosis: Infection of the lung that may spread to bone

Osteomyelitis Development Stages:

  1. Initial Infection: Infection begins.

  2. First Stage: Development of subperiosteal abscess (pus).

  3. Second Stage: Formation of sequestrum (dead bone) and involucrum (new bone formation).

Types of Fractures

  • Closed (Simple): Bone breaks but does not penetrate the skin.

  • Open (Compound): Bone breaks and protrudes through the skin.

  • Comminuted: Bone shatters into multiple fragments.

  • Spiral: Bone twisted apart.

  • Compression: Bone crushed, common in vertebrae.

  • Avulsion: Fragment of bone pulled away by tendon or ligament.

Trauma Injuries

  • Definition: Physical injuries caused by external force.

  • Common Mechanisms:

    • Blunt force

    • Penetrating injuries

    • Falls

    • Motor vehicle accidents

  • Consequences: Often result in damage to bones, joints, and soft tissues.

Dislocations and Subluxations

  • Dislocation: Complete displacement of bone from joint.

  • Subluxation: Partial dislocation with joint surfaces in partial contact.

  • Clinical Signs:

    • Deformity

    • Loss of function

    • Pain

    • Swelling

Spinal Cord Injuries

Mechanisms of Injury

  • Hyperflexion

  • Hyperextension

  • Axial Loading

  • Rotation

Injury Classifications

  1. Complete Injury: Total loss of motor and sensory function below injury level.

  2. Incomplete Injury: Partial preservation of function.

  3. Paraplegia: Paralysis of lower limbs.

  4. Quadriplegia (Tetraplegia): Paralysis of all four limbs.

  5. Neurogenic Shock: Loss of sympathetic tone after spinal injury.

Medical Management of Trauma Injuries

  • Initial Assessment: Check ABCs (Airway, Breathing, Circulation) and protect cervical spine.

  • Imaging Techniques:

    • X-ray

    • CT scan

    • MRI

  • Treatment Approaches:

    • Reduction

    • Immobilization

    • Surgical intervention

  • Potential Complications:

    • Infection

    • Compartment syndrome

    • Neurovascular injury

Key Medical Terms in Trauma

  • Hematoma: Localized collection of blood outside blood vessels.

  • Ecchymosis: Bruising.

  • Crepitus: Grating sound or sensation from friction between bone/cartilage.

  • Malunion/Nonunion: Improper or failed healing of a fracture.

Pathophysiology of Skeletal Conditions

Osteomalacia

  • Definition: Softening of bone due to diminished phosphorus and calcium absorption.

Neoplasms (Bone Tumors)

1. Osteogenic Sarcoma (Osteosarcoma)

  • Origin: Osteoblasts

  • Common Sites: Around the epiphyseal line; primarily the femur, tibia, humerus

  • Age Group: Adolescents and young adults

  • Radiographic Signs:

    • Sunburst pattern

    • Codman triangle

  • Treatment: Chemotherapy, limb-sparing surgery

2. Chondrosarcoma

  • Origin: Cartilage cells

  • Common Sites: Pelvis, femur, shoulder

  • Age Group: Middle-aged adults

  • Imaging: Lobulated mass with calcifications

  • Treatment: Surgical resection

3. Ewing Sarcoma

  • Origin: Small round blue cells

  • Common Sites: Femur, tibia, pelvis

  • Age Group: Children and adolescents

  • Genetic Marker: EWS-FLI1 fusion gene

  • Treatment: Chemotherapy, radiation, surgery

Joint Disorders

  1. Arthritis: Inflammation of the joint.

    • Osteoarthritis: Gradual deterioration of articular cartilage.

    • Rheumatoid Arthritis: Systemic inflammatory joint disease of unknown cause; potentially autoimmune.

    • Gout: Caused by increased levels of uric acid in blood, leading to deposition in joints and inflammation.

Visual Comparisons

  • Normal Joint vs. Osteoarthritis:

    • In osteoarthritis, bone ends rub together and erosion occurs.

Joint Repair Procedures

Key Terms

  • Arthroscopy: Endoscope inserted into joint space for examination and repairs.

  • Arthroplasty: Joint reconstruction, can be full or partial joint replacements.

  • Arthrodesis: Fusion of joint to relieve pain, using pins/screws, leading to loss of movement.

Disorders of the Spine

Types of Spinal Conditions

  • Normal Disc vs. Degenerative Disc:

  • Bulging Disc: Exhibits abnormal protrusion.

  • Herniated Disc: Compression of intervertebral disks causing an issue with spinal nerves.

Curvatures

  • Normal

  • Scoliosis

  • Kyphosis

  • Lordosis

Spinal Nerves Overview

  • Cervical Nerves: 8 pairs, connected to arms and neck functions.

  • Thoracic Nerves: 12 pairs, connected to chest muscles and abdominal functions.

  • Lumbar Nerves: 5 pairs, controlling leg muscles.

  • Sacral Nerves: Connect to bowel, bladder, and sexual function.

Imaging Diagnostics

  • MRI Showing Degenerative Disc Disease: Healthy discs appear white. Unhealthy or dessicated discs are darker or black in color.