bone tissues flash cards

section 5

5

What organs make up the skeletal system?

Bone, cartilage, ligaments

What are the main functions of the skeletal system?

Supports and protects organs, movement, blood production, mineral storage

Long bone

Act as levers

Short bone

Stability and support

Sesamoid bone

Protects tendons

Flat bone

Muscle attachment and protection

Irregular bone

Catch all; bones that don't fit other categories

Diaphysis

Shaft of a long bone; contains the primary ossification center and medullary cavity.

Epiphysis

Ends of a long bone; contains secondary ossification centers and spongy bone.

Medullary cavity

Hollow space in the diaphysis that contains bone marrow (yellow in adults). Forms in stage 4

Spongy bone

Lightweight, helps movement, supports marrow

Compact bone

Provides strength and structure

Endosteum

Tissue inside the medullary cavity, contains blood vessels to bring in nutrients

Periosteum

Fibrous outer membrane, anchors tendons and ligaments

Articular cartilage

Hyaline cartilage lining the bones between joints, reduces friction during movement and absorbs shocks

Osteoblast

Build bone by secreting collagen and calcium salts

Osteoclasts

Reabsorbs bone

Osteocytes

Aid in maintaining mineral concentration inside the bone; found inside each of the lacuna

Osteogenic cells

Bone stem cells; they divide to make more osteogenic cells, osteoblasts, and osteoclasts

Perforating fibers

Connects periosteum to bone

Collagen

A protein, gives bones flexibility

Calcium salt

A mineral, gives bones strength

Red marrow

Where red blood cells, platelets, and most of the white blood cells are born and raised

Yellow marrow

Stores fat for energy

What does 'articulate' mean?

When two bones come together to form a joint

Ossification means?

The process of creating bone

In endochondral ossification, what material is the original template made out of?

Hyaline cartilage

What are chondrocytes?

Cartilage cells

Endochondral ossification Stage 1

Hyaline template is made; chondrocytes start building hyaline skeleton once template is done it's covered with a membrane called perichondrium

Endochondral ossification Stage 2

Center of cartilage begins to calcify; chondrocytes die off; blood vessels grow in perichondrium then becomes periosteum and produces osteoblasts that form a bone collar around the outside

Endochondral ossification Stage 3

Blood vessels grow into the core of the cartilage; primary ossification center is built

Endochondral ossification Stage 4

Happens after birth; secondary ossification center is built; osteoclasts hollow out bone and create the medullary cavity

Primary ossification center (location + function)

Location: diaphysis; Function: bone building center

Secondary ossification center (location + function)

Location: epiphysis; Function: another bone building center

Zone of reserve

Holds the epiphysis and the epiphyseal plate together

Zone of proliferation

Mitosis center of bone (chondrocytes divide)

Zone of maturation and hypertrophy

Cells stop dividing and increase in size

Zone of calcification

Cartilage starts to calcify; chondrocytes die off from calcium salts

Zone of ossification

Osteoclasts chip away at old cartilage and salts; osteoblasts replace it with bone tissue

When does epiphyseal line form?

When the hyaline cartilage in the epiphyseal plate is replaced by bone

Do adults have epiphyseal plates or epiphyseal lines?

Epiphyseal line

What is appositional growth?

Bones growing in width (diameter)

How do adult bones change, adapt, grow, and shrink?

Use/strength training → bone builds; No use → bone shrinks; Injury → bone repairs; Hormones regulate bone growth and breakdown; Aging → bone loss

Lacuna

Houses osteocytes

Central canal

Contains blood vessels and nerves, runs vertically through the osteon

Perforating canals

Contains blood vessels and nerves, runs horizontally between multiple osteons

Where does the primary ossification center develop?

Diaphysis

What structure allows blood vessels to run lengthwise through compact bone?

Central canal

What structure allows blood vessels to move between osteons?

Perforating canals

Where are osteocytes found?

The Lacuna