Bones And Skeletal Tissue

Front 1

Skeletal Cartilages

Back 1

Found where flexibility is needed
Surrounded by dense, irregular CT called perichondrium which acts like a girdle and has blood vessels
All types of cartilage tissue are found in skeletal cartilage
Grows in 2 ways : appositional and interstitial

Front 2

Hyaline cartilage in Skeleton

Back 2

Articulated cartilage
Costal cartilage
Respiratory cartilage
Nasal cartilage

Front 3

Fibrocartilage in Skeleton

Back 3

Found in the knee miniscus
Vertebral discs

Front 4

Elastic cartilage in skeleton

Back 4

External ear
Epiglottis

Front 5

Classification of Bones

Back 5

By location
Axial
Appendicular
By Shape;
Long
Short
Flat
Irregular

Front 6

Axial Skeleton

Back 6

The long axis of the body, including skull, vertebral column, and rib cage

Protects, supports, and carries other body parts

Front 7

Appendicular Skeleton

Back 7

Bones of upper and lower limbs
Girdles that attach limbs to axial skeleton (shoulder and pelvis)

Locomotion ans environmental manipulation

Front 8

Long Bones

Back 8

Contain a shaft plus two expanded ends

Limbs bones except patella, wrist, and ankle

Front 9

Short Bones

Back 9

Roughly cube shaped

Wrist and ankle bones

Patella is special short bone called a Sesamoid bone that forms in a tendon

Front 10

Flat Bones

Back 10

Thin, flattened and a bit curved

Sternum, scapulae, ribs, skull

Front 11

Irregular Bones

Back 11

Complicated shapes that don't fit into other categories

Hips and vertebrae

Front 12

7 Functions of Bones

Back 12

1. Support
2. Protection
3. Movement
4. Mineral and growth factor storage
5. Blood cell formation
6. Triglyceride storage
7. Hormone production (osteocalcin)

Front 13

Bone Textures: Compact and Spongy

Back 13

Compact bone is smooth and solid external layer

Spongy bone is a honeycomb of flat pieces called trabeculae. Spaces are filled with red or yellow marrow.

Front 14

Structure of Short, Flat and Irregular Bones

Back 14

All shapes consist of thin plates of spongy bone covered by compact bone.
Covered inside and out with CT membranes called periosteum and endosteum
Not cylindrical
No shaft or epiphysis
No defined marrow cavity. Marrow is between trabeculae
Hyaline cartilage is found at articulating joints
In flat bones, spongy layer is called diploe

Front 15

Structure of Long Bones

Back 15

Shaft, bone ends, and membranes

Diaphysis is the shaft of a long bone. Has a thick collar of compact bone around a medullary cavity. In adults the cavity contains yellow marrow

Epiphyses are the bone ends which are broader than shaft. Hyaline cartilage covers joint surfaces.

Epiphyseal line between shaft and bone ends is remnant of epiphyseal plate.

Front 16

Membranes of Long Bones

Back 16

Periosteum
Endosteum

Front 17

Periosteum

Back 17

White, double layered membrane
Covers entire external surface except at joints
Fibrous layer on outside is dense irregular CT
Osteogenic layer on bone surface consists of stem cells
Nerve fibers and blood vessels from periosteum enter marrow though nutrient foramina
Provides anchoring sites for tendons and ligaments

Front 18

Endosteum

Back 18

Covers internal bone surface
Covers trabeculae of spongy bone and lines canals that pass through compact bone
Contains osteogenic cells

Front 19

Hematopoietic Tissue

Back 19

Found in red bone marrow in trabeculae cavities of long bones and diploe of flat bones

In infants, red marrow is in medullary cavity and all spongy bone

In adults, little red marrow in spongy bone. Mostly in heads of femur and humerous and flat bones

Red marrow in diploe is more active

Front 20

Bone Markings

Back 20

Projections
Depressions
Openings

Sites of attachment for ligaments, tendons and muscles

Conduits for blood vessels and nerves

Front 21

Cells of Bone Tissue

Back 21

Osteogenic cells
Osteoblasts
Osteocytes
Bone Lining Cells
Osteoclasts

Front 22

Osteogenic cells

Back 22

Mitotically active
Found in periosteum and endosteum
Are squamous in growing bones

Front 23

Osteoblasts

Back 23

Bone forming cells that secrete matrix
Actively mitotic
Matrix includes collagen and calcium binding proteins
Cuboidal when active, flattened when inactive
Once completely surrounded by matrix they become osteocytes

Front 24

Osteocytes

Back 24

Spidery
Mature bone cells in lacunae
Monitor and maintain the matrix
Act as stress sensors

Front 25

Bone Lining Cells

Back 25

Flat cells on surfaces where bone remodeling is not taking pllace.
Help maintain matrix

Front 26

Osteoclasts

Back 26

Giant, multinucleate cells at sites of bone resorption
When active, they rest in a resorption bay with ruffled border

Front 27

Osteon

Back 27

aka Haversian system
Elongated, cylinder parallel to long axis
Weight bearing pillars
Groups pf hollow tubes of matrix like tree rings
Tubes are lamellae

Front 28

Central (Haversian) Canal

Back 28

Runs through core of each osteon

Front 29

Perforating (Volkmann's) Canals

Back 29

Found at 90 degree angles to long axis of bone
Connects blood and nerve supply of periosteum to those in central canals and medullary cavity

Front 30

Canaliculi

Back 30

Thin canals connecting lacunae to each other and to central cavity

Front 31

Interstitial Lamellae

Back 31

Fill gaps between forming osteons or are remnants of osteons that have been cut through due to remodeling

Front 32

Circumferential Lamellae

Back 32

Extend around circumference of diaphysis and resists twisting of the bone

Front 33

Organic Components of Bone

Back 33

Contain cells and osteoid (organic part of matrix).
Osteoid consists of ground substance and collagen fibers made by osteoblasts
Resilience from sacrifical bonds between collagen molecules

Front 34

Inorganic Components of Bone

Back 34

Hydroxyapatites are mineral salts stored in bone. Mainly calcium and phosphates in needle-like crystals around collagen
Crystals provide bones exceptional hardness

Front 35

Ossification or Osteogenesis

Back 35

process of bone formation

Front 36

2 types of Ossification

Back 36

Endochondral Ossification
Intramembranous Ossification

Front 37

Endochondral Ossification

Back 37

Bone developes by replacing existing hyaline cartilage
All bone below base of skull except clavicles form this way
Process being at primary ossification center in hyaline cartilage shaft
After birth, epiphyses ossify beginning at secondary ossification centers (short bones only have primary centers)

Front 38

Intramembranous Ossification

Back 38

Forms cranial bones and clavicles
Ossification begins within fibrous CT membrane formed by mesenchymal cells

Front 39

5 Steps of Endochondral Ossification

Back 39

1. Bone collar forms around diaphysis of cartilage model
2. Cartilage in center of diaphysis calcifies and develops cavities. Chondrocytes die and cartilage matrix deteriorates
3. Periosteal bud invades internal cavities and spongy bone forms
4. Diaphyses elongate and medullary cavity forms
5. Epiphyses ossify after birth