Human Skeletal System Quiz

Cartilages

• Fibrocartilage is found in intervertebral discs, the pubic symphysis, and menisci (knee joint).

Bones of the Skeleton

• The axial skeleton includes bones of the head, vertebral column, and thorax.
• The appendicular skeleton consists of the bones of the limbs and girdles.
• Cartilages include hyaline, elastic, and fibrocartilages.

Types of Bones

• Long bones (e.g., humerus) have a long shaft and expanded ends.
• Flat bones (e.g., sternum) are thin, flat, and somewhat curved.
• Short bones (e.g., talus) are roughly cube-shaped.
• Irregular bones (e.g., vertebra) have complex shapes.

Structure of a Long Bone

• Diaphysis: The long shaft of the bone.
• Epiphyses: The expanded end of a long bone.
• Articular cartilage: A layer of hyaline cartilage that covers the epiphysis where the bone forms a joint.
• Periosteum: A tough connective tissue covering bone surfaces, except at articular cartilages.
• Compact bone: Dense outer layer of bone, strong and dense.
• Spongy bone: Porous inner layer of bone, with trabeculae.
• Medullary cavity: Central cavity within the diaphysis, filled with yellow bone marrow.

Bone Tissue

• Osteons/Haversian systems: Cylindrical units of compact bone.
• Lamellae: Rings of bone tissue surrounding the central canal in osteons.
• Central/Haversian canal: Contains blood vessels and nerves.
• Canaliculi: Tiny canals that connect lacunae, allowing communication between osteocytes.
• Lacunae: Small spaces in bone that contain osteocytes.
• Osteocytes:Mature bone cells.
• Perforating/Volkmann's canals: Canals that connect central canals and periosteum, allowing for vessels and nerves to pass through.
• Circumferential lamellae: Rings of bone tissue that run around the bone's outer surface.

Endochondral Ossification

• Bone formation begins in a hyaline cartilage model and follows a sequence of events, eventually replacing the cartilage with bone.
• The primary ossification center occurs at the center of the cartilage model.
• Secondary ossification centers occur at the epiphyses.

Bone Fracture Repair

• Four stages occur during bone fracture repair; hematoma formation, fibrocartilaginous callus formation, bony callus formation, and bone remodeling.
• A hematoma is formed and then inflammation of the site begins
• A soft callus of cartilage and fibrous tissue forms and fills the gap.
• A hard callus of bone replaces the soft callus.
• Bone remodeling occurs, restoring the bone to its original shape and structure

Types of Fractures

• Closed fracture: the skin is intact
• Open fracture: skin is broken, exposing the fracture
• Greenstick fracture: incomplete fracture common in children
• Impacted fracture: the broken ends are forced into each other
• Comminuted fracture: the bone is broken into many fragments
• Spiral fracture: the bone has been twisted apart
• Transverse fracture: the break is at a right angle to the long axis of the bone
• Oblique fracture: not at a right angle to the long axis of the bone

Skull Bones

• Various bones form the skull; each serves a specific function
• Frontal, parietal, temporal, occipital, sphenoid, ethmoid, nasal, lacrimal, zygomatic, maxilla, mandible, and palatine

Vertebrae

• Vertebral column consists of cervical, thoracic, lumbar, sacral, and coccygeal vertebrae.
• Characteristics include; superior articular facets, inferior articular facets, transverse processes, spinous processes, lamina, pedicle, vertebral body, and vertebral foramen.

Thoracic Cage

• Ribs (true, false, floating), sternum (manubrium, body, xiphoid process), intercostal spaces, costal cartilage, and costal margin form the thoracic cage.

Pectoral Girdle

• Clavicle and scapula.

Humerus

• Head, greater tubercle, lesser tubercle, anatomical neck, surgical neck, shaft, radial groove, lateral epicondyle, medial epicondyle, capitulum, and trochlea.

Radius and Ulna

• Both radius and ulna are important forearm bones, with articular notches, heads, necks, radial tuberosity, and styloid processes.

Pelvic Girdle/Hip Girdle

• Coxal bones (illium, ischium, pubis) and sacrum are combined.
• Ilium, ischium, and pubis form the coxal bone
• Sacroiliac joint, acetabulum, pelvic brim, ischial spine, and iliac crest are parts of the pelvis.

Femur

• Femoral head, neck, greater trochanter, lesser trochanter, intertrochanteric line, intertrochanteric crest, linea aspera, medial and lateral supracondylar ridges, intercondylar fossa, lateral and medial condyles and patellar surface form the femur.

Tibia and Fibula

• Tibia and fibula form the lower leg.
• Articulations include superior tibiofibular joint, inferior tibiofibular joint, lateral and medial malleoli.

Sinuses of the Skull

• Frontal, sphenoid, ethmoid are the main sinuses in the skull.