Skeletal System Quiz

Skeletal System

• Refers to the framework of hard structures (bones and cartilages) that supports and protects soft tissues in animals.
• The skeleton provides support to the body and serves as levers for locomotion.
• The skeleton protects soft parts of the body.

Bone

• Primary skeletal tissue.
• Involved in mineral homeostasis (calcium, phosphate, and other ions).
• Provides support and makes red blood cells

Structure of a Bone

• Epiphysis: Refers to the end of a long bone.
• Diaphysis: The cylindrical shaft of a long bone that lies between the two epiphyses.
• Articular cartilage: Thin layer of cartilage covering the articular surface of a bone.
• Medullary cavity: Space within the diaphysis that houses bone marrow.
• Nutrient foramen: Small openings in the bone that allow blood vessels to enter and leave.
• Endosteum: Fibrous membrane lining the marrow cavity.
• Periosteum: Tough, fibrous membrane covering the outer surface of a bone (except where articular cartilage is).

Compact Bone

• Dense outer layer of bone.
• Composed of cells in a hard matrix of protein fibers and minerals like calcium.
• Provides amazing strength to bones.

Spongy Bone

• Middle layer of the bone.
• Consists of a variety of cell types in a matrix of mineralized protein fibers.
• In adults, spongy bone contains red marrow.

Medullary Cavity and Bone Marrow

• Inner layer in the shaft of a long bone.
• Inner portion of other bones.
• Houses yellow marrow primarily composed of fat.
• Houses red marrow—the site of hematopoiesis (blood cell production).

How the Skeleton Develops

• Long bones in a fetus form from hyaline cartilage.
• Bone shape mirrors cartilage shape and serves as a template.
• Calcium deposits onto the cartilage during endochondral ossification, causing calcification.
• Ossification and bone growth occur simultaneously as animals grow.
• Epiphyses, at the ends of certain bones, are the primary growth areas.
• Bone stops growing in length when cartilage cells in the epiphyses stop dividing.
• Bone development continues throughout life through a constant process of mineral deposition and dissolving, and cell birth, growth, and death.
• Cartilage building slows but never stops with age.

Classifying Bones

• Long bones: Longer than wide. Provide rigidity to support and enable movement. Example—femur, humerus
• Short bones: Cube-shaped. Protect long bones and cushion shock; diminish friction. Example—carpals, tarsals
• Flat bones: Relatively thin, flat, and usually curved. Protect vital organs. Example—scapula, pelvis, skull
• Irregular bones: Have no uniformity in development. Support and protect the central nervous system. Example—vertebrae
• Pneumatic bones: Found in birds. Lined by mucous membrane, rather than marrow, and communicate with the respiratory system.
• Aberrant long bones: Ribs cannot be included in these.
• Sesamoid bones: Developed in tendons to increase leverage. Example—patella, navicular bone

Parts of the Skeleton

• Axial skeleton: Skull, vertebral column, ribs, and sternum.
• Appendicular skeleton: Bones of the limbs and bones connecting the limbs to the axial skeleton.
• Splanchnic skeleton: Bones associated with visceral organs (e.g., os cordis in cattle, os rostri in pigs).

Specific animal skulls (Axial skeleton)

• Horse: Facial crest in the maxilla. Complete orbit. Upper incisors.
• Cattle (Polled): Facial tuber in the maxilla. Absence of upper dental incisors. Complete orbit
• Pig: Unique bone in the nose—os rostri. Incomplete orbit.

Vertebral Column

• Number of vertebrae varies by species. Examples given.

Ribs

• General descriptions of rib features (e.g., neck, head, angle)
• Number of ribs in different species (given in tabular form).

Sternum

• Number of sternal ribs and asternals in different species (given in tabular form).

Forelimbs/Hindlimbs

• List bones for given species.

Skeletal systems of different animals

Connective Tissue

• Ligaments connect bone to bone.
• Tendons attach muscle to bone.
• Three types of cartilage (hyaline, elastic, fibrocartilage) are found in the body.
• Hyaline cushions joints.
• Elastic cartilage forms body parts like ears.
• Fibrocartilage cushions joints.
• Fascia is found between skin and underlying muscles/bones. Divided into two layers—superficial—and deep.

Joints

• Articulations (unions) between bones.
• Three types: fibrous, cartilaginous, synovial.
• Can be highly movable (e.g., shoulder)
• Partially movable (e.g., ribs)
• Immovable (e.g., suture joints of the skull).
• Synovial joints allow the greatest range of movement (e.g., gliding, flexion, extension, hyperextension, rotation, abduction, adduction, circumduction).

Synovial Joint

• Structure (ligament, synovial membrane, synovial cavity, meniscus, articular cartilage, epiphysis, bone)

Test your knowledge on the skeletal system with this quiz. Explore the functions of bones, types of marrow, and the role of cartilage in bone development. Perfect for students studying human anatomy or biology.