Exam 2 Anatomy

What are the six main functions of the skeletal system?

Support, protection, assistance in movement, mineral homeostasis, blood cell production, and triglyceride storage.

What is support? .

Bones provide a framework that supports the body and supports soft tissues

What is protection?

Bones protect internal organs, such as the skull protecting the brain and ribs protecting the heart and lungs.

How does the skeleton assist in movement?

Bones act as levers, and muscles pull on them to produce movement.

What is mineral homeostasis?

Bone stores and releases minerals, especially calcium and phosphorus, to maintain proper blood levels.

What is hematopoiesis?

The production of blood cells in red bone marrow.

What is triglyceride storage?

Yellow bone marrow stores fat as an energy reserve.

What is the epiphysis?

The enlarged end of a long bone.

What is the diaphysis? T

he shaft or long central portion of a long bone.

What is the metaphysis?

The region between the epiphysis and diaphysis; it contains the growth plate in a growing bone.

What is articular cartilage?

Hyaline cartilage covering the ends of bones at joints; it reduces friction and absorbs shock.

What is the periosteum?

A tough outer connective tissue covering of bone, except at articular

What is the endosteum?

A thin membrane lining the medullary cavity and internal bone surfaces.

What is the medullary cavity?

The hollow central cavity in the diaphysis that contains bone marrow.

What are osteoprogenitor cells?

Stem cells that divide and develop into osteoblasts.

What are osteoblasts?

Bone-building cells that produce new bone matrix.

What are osteocytes?

Mature bone cells that maintain the bone matrix.

What are osteoclasts?

Large cells that break down and resorb bone.

What is compact bone?

Dense, strong bone tissue organized mainly into osteons; it provides strength and support.

What is spongy bone?

Lighter bone tissue made of a network of trabeculae; it helps distribute forces and often contains red bone marrow.

What are trabeculae?

Thin plates or rods of bone that form the framework of spongy bone.

What are lamellae?

Layers of mineralized bone matrix.

What is an osteon?

The basic structural unit of compact bone, consisting of concentric lamellae around a central canal.

What is the function of the nutrient artery?

It supplies blood to the inner compact bone, bone marrow, and much of the diaphysis.

What do periosteal arteries supply?

The outer portion of compact bone.

What do metaphyseal and epiphyseal arteries supply?

The metaphysis and epiphyses, respectively.

What is intramembranous ossification?

Bone formation directly from mesenchymal connective tissue; it forms many flat bones, including parts of the skull.

What is endochondral ossification?

Bone formation by replacing a hyaline cartilage model; it forms most bones of the body.

How does a long bone grow in length?

Cartilage cells divide at the epiphyseal plate, cartilage grows, and it is replaced by bone on the diaphyseal side.

How does a bone grow in thickness?

Appositional growth occurs when osteoblasts beneath the periosteum add bone to the outer surface while osteoclasts can remove bone from the inner surface.

What is bone remodeling?

The continuous removal of old bone by osteoclasts and formation of new bone by osteoblasts.

What is an open (compound) fracture?

A fracture in which the broken bone communicates with the outside through a wound.

What is a comminuted fracture?

A fracture in which the bone breaks into three or more pieces.

What is a greenstick fracture?

An incomplete fracture in which one side of the bone breaks and the other bends; common in children.

What is an impacted fracture?

A fracture in which one broken bone end is driven into the other.

What is a Pott fracture?

A fracture involving the distal fibula near the ankle, often with injury to the ankle joint or medial malleolus.

What is a Colles fracture?

A fracture of the distal radius in which the wrist fragment typically shifts backward (dorsally).

What are the stages of fracture repair?

Fracture hematoma forms, a fibrocartilaginous (soft) callus forms, a bony (hard) callus forms, and bone remodeling restores shape and strength.

How is blood calcium regulated?

Parathyroid hormone (PTH) raises blood calcium; calcitonin can lower it by inhibiting bone resorption, although its role in adults is relatively minor.

Why is calcium important in the body?

It is needed for muscle contraction, nerve signaling, blood clotting, and bone strength.

What are the two main divisions of the skeleton?

The axial skeleton and the appendicular skeleton.

What is the axial skeleton?

The bones along the body's central axis: skull, auditory ossicles, hyoid bone, vertebral column, ribs, and sternum.

What is the appendicular skeleton?

The bones of the limbs and the pectoral and pelvic girdles.

What are the five bone shape classifications?

Long, short, flat, irregular, and sesamoid.

What is a long bone?

A bone longer than it is wide, such as the femur or humerus.

What is a short bone?

A roughly cube-shaped bone, such as a carpal or tarsal.

What is a flat bone?

A thin, often curved bone, such as a rib, sternum, or parietal bone.

What is an irregular bone?

A bone with a complex shape, such as a vertebra.

What is a sesamoid bone? .

A bone that develops within a tendon, such as the patella

What is a fissure?

A narrow slit-like opening through a bone, often for nerves and blood vessels.

What is a foramen?

A hole through a bone that allows nerves or blood vessels to pass.

What is a fossa?

A shallow depression in a bone.

What is a sulcus?

A groove in a bone, often for a tendon, nerve, or blood vessel.

What is a meatus?

A canal-like passageway through a bone.

What is a condyle?

A rounded articular projection at the end of a bone.

What is a facet?

A smooth, nearly flat articular surface.

What is a head of a bone?

A rounded articular end supported by a narrower neck.

What is a crest?

A prominent ridge of bone

What is an epicondyle?

A projection located above or near a condyle, often serving as a muscle or ligament attachment.

What is a spinous process?

A slender projection from a bone, such as a vertebra, that provides attachment for muscles and ligaments.

What is a trochanter?

A large, blunt projection found on the femur.

What is a tubercle?

A small, rounded projection that often provides attachment for muscles or ligaments.

What is a tuberosity?

A large, roughened projection that often provides muscle or ligament attachment.

What is the difference between bone markings for muscle attachment and bone markings for passageways?

Projections often provide attachment or form joint surfaces; openings and grooves allow nerves, blood vessels, and tendons to pass.

What are the major bones of the skull?

Frontal, parietal, temporal, occipital, sphenoid, ethmoid, mandible, maxillae, zygomatic, nasal, lacrimal, palatine, vomer, and inferior nasal conchae.

What are the eight cranial bones?

Frontal (1), parietal (2), temporal (2), occipital (1), sphenoid (1), and ethmoid (1).

What are the major facial bones? Mandible, maxillae, zygomatic bones, nasal bones, lacrimal bones, palatine bones, vomer, and inferior nasal conchae.

What is the hyoid bone?

A U-shaped bone in the neck that supports the tongue and provides attachment for muscles involved in swallowing and speech.

What bones form the thoracic cage?

The sternum, 12 pairs of ribs, and thoracic vertebrae.

What are the three parts of the sternum?

Manubrium, body, and xiphoid process.

What are the three regions of the vertebral column?

Cervical (7 vertebrae), thoracic (12), and lumbar (5), followed by the sacrum and coccyx.

What is the vertebral foramen?

The opening in each vertebra through which the spinal cord passes within the vertebral canal.

What is the spinous process of a vertebra?

The posterior projection that provides muscle and ligament attachment.

What are the transverse processes?

Lateral projections of a vertebra that provide attachment for muscles and ligaments.

What are articular facets?

Smooth surfaces that connect adjacent vertebrae and guide their movement.

What is an intervertebral disc?

A fibrocartilage pad between most adjacent vertebral bodies that absorbs shock and allows flexibility.

What is the nucleus pulposus?

The soft, gel-like center of an intervertebral disc.

What is the annulus fibrosus?

The tough outer ring of fibrocartilage surrounding the nucleus pulposus.

What are the normal spinal curves?

Cervical and lumbar lordotic curves, and thoracic and sacral kyphotic curves.

What is scoliosis?

An abnormal lateral curvature of the vertebral column, often accompanied by vertebral rotation.

What is kyphosis?

An excessive posterior curvature of the thoracic region, producing a rounded back.

What is lordosis?

An excessive inward curvature of the lumbar region.

What is a herniated disc?

When disc material protrudes through a weakened or damaged annulus fibrosus and may compress a nearby nerve.

What are the three structural classifications of joints?

Fibrous, cartilaginous, and synovial.

What are the three functional classifications of joints?

Synarthroses (immovable), amphiarthroses (slightly movable), and diarthroses (freely movable).

What is a fibrous joint?

A joint in which bones are connected by dense fibrous connective tissue, with no joint cavity.

What is a suture?

A fibrous joint between skull bones, usually immovable in adults.

What is a synostosis?

A bony fusion in which two bones or parts of a bone become one continuous bone.

What is a syndesmosis?

A fibrous joint in which bones are connected by a ligament or interosseous membrane; it allows limited movement depending on the location.

What is a gomphosis?

A peg-in-socket fibrous joint that anchors a tooth in its alveolar socket.

What is a cartilaginous joint?

A joint in which bones are connected by cartilage, with no joint cavity.

What is a synchondrosis?

A cartilaginous joint connected by hyaline cartilage, such as an epiphyseal growth plate.

What is a symphysis?

A cartilaginous joint connected by fibrocartilage, such as the pubic symphysis or an intervertebral disc joint.

What is a synovial joint?

A freely movable joint with a joint cavity containing synovial fluid.

What are the parts of an articular capsule?

An outer fibrous layer and an inner synovial membrane.

What is the fibrous layer of the joint capsule?

The tough outer layer of dense connective tissue that strengthens and encloses the joint.

What is the synovial membrane?

The inner lining of the joint capsule that produces synovial fluid.

What is articular cartilage?

Hyaline cartilage covering the ends of bones in a synovial joint; it reduces friction and absorbs shock.

What is the synovial cavity?

The space between the articulating bones that contains synovial fluid.

What is synovial fluid?

A slippery fluid that lubricates joints, nourishes articular cartilage, and helps reduce friction.