Skeletal System Overview

These flashcards review the key concepts and details of the skeletal system, focusing on bone types, functions, structures, and the cellular makeup of bones.

What are the two main parts of the skeleton?

Axial skeleton and appendicular skeleton.

How many bones are in the human skeleton?

206 bones.

What bones are included in the axial skeleton?

Skull, rib cage, and vertebral column.

How many bones are in the appendicular skeleton?

126 bones.

What does the skeletal system consist of?

Bones, cartilages, and ligaments.

What are the five primary functions of the skeletal system?

Support, storage of minerals, blood cell production, protection, and leverage.

What type of cartilage is the most common?

Hyaline cartilage.

What is the main function of fibrous cartilage?

Resists compression and provides padding between bones.

What are sutural bones also known as?

Wormian bones.

What type of bones are the vertebrae classified as?

Irregular bones.

Give an example of a long bone.

Humerus, radius, femur, or tibia.

What is a defining feature of short bones?

They are boxlike in appearance.

What is the name of the small, round bone found in the patella?

Sesamoid bone.

What are the two main types of bone?

Compact bone and spongy bone.

What is the structural unit of compact bone called?

Osteon.

Where do osteocytes reside?

In lacunae.

What does the diaphysis of a long bone contain?

Medullary cavity containing yellow marrow.

What surrounds spongy bone in a long bone?

Compact bone.

What lines the trabeculae of spongy bone?

Endosteum.

What differentiates osteoblasts from osteocytes?

Osteoblasts secrete bone matrix, while osteocytes maintain bone.

What is the primary function of osteoclasts?

To dissolve bone matrix and increase blood calcium levels.

What do you call a passageway for blood vessels and/or nerves in bone?

Foramen.

What is a fossa?

A shallow depression in a bone.

What does a sinus refer to in bone anatomy?

A chamber within a bone, usually filled with air.

What is a trochanter?

A large, rough projection on a bone.

What is the periosteum?

A fibrous layer that wraps the outside of each bone.

What type of cartilage is found in the pubic symphysis?

Fibrous cartilage.

Where is elastic cartilage primarily found?

In the ear and epiglottis.

What are the key components of spongy bone?

Trabeculae and red marrow.

Which bone marking refers to a smooth, rounded articular process?

Condyle.

What are interstitial lamellae?

Fragments of older osteons between newer osteons.

What type of bone has complex shapes?

Irregular bones.

What are the major types of cartilage?

Hyaline, elastic, and fibrocartilage.

What type of marrow is found in yellow marrow?

Fat storage.

What type of movement do long bones facilitate?

Leverage for skeletal muscles.

What structure provides tensile strength in bone?

Collagen fibers.

Where does blood cell production occur in bones?

In the red marrow.

What are the two parts of the periosteum?

An inner cellular layer and an outer fibrous layer.

What is the role of osteogenic cells?

They are stem cells that can become osteoblasts.

Identify the major types of bone cells.

Osteogenic cells, osteoblasts, osteocytes, and osteoclasts.

What is contained within the central canal of an osteon?

Blood vessels and nerves.

What is the main advantage of having trabecular bone?

It provides strength without excessive weight.

What occurs at the metaphysis of long bones during growth?

Lengthening of the bone through growth plates.

What role do osteoclasts play in bone remodeling?

They break down bone tissue to release calcium into the bloodstream.

What is the function of articular cartilage in joints?

To reduce friction and absorb shock.

What type of joint is the pubic symphysis?

Cartilaginous joint.

What do you call the attachment site for tendons and ligaments on bones?

Processes.

What is the significance of the ruffled border of osteoclasts?

It increases the surface area for bone resorption.

What describes the shape of flat bones?

Thin and parallel surfaces.

What is the primary component of the bone matrix?

Calcium phosphate.

What type of cartilage provides support while allowing for distortion?

Elastic cartilage.

What is a canaliculus?

A small channel in bone that connects lacunae to each other.

How many vertebrae are in the human spine?

24 vertebrae plus sacrum and coccyx.

What is the role of the trabeculae in spongy bone?

To support and protect the bone marrow.

What happens to osteoblasts once they become fully embedded in matrix?

They become osteocytes.

What is the term for the rounded end of a long bone?

Epiphysis.

What shape do sesamoid bones typically have?

Small, round, and flat.