Exam 2 APK2100C Nyugen

Three organs of the skeletal system

Bones cartilage and joints

Three types of cartilage

hyaline, elastic, fibrocartilage

hyaline cartilage

Found at end of bones, meant to reduce friction between bones

elastic cartilage

cartilage with abundant elastic fibers; more flexible than hyaline cartilage

Fibrocartilage

cartilage that contains fibrous bundles of collagen, absorbs force

A connective tissue with an abundant extracelullar matrix that is gel and fiber like

Cartilage

Gel like and opaque ecm

Hyaline

More elastic fibers within the ecm

Elastic

More strand like ecm

Fibrocartilage

Connective dense irregular tissues that surrounds elastic cartilage

Perichondrium

functions of bones:

support, protection, movement, storage, blood cell formation

Long bone

Elongated shape with 2 distinct ends

Short bone

Cube shaped bone with no distinct ends,

sesamoid bones

round bones found near joints (e.g., the patella)

Flat bones

These bones are thin, flat, and curved.

Irregular bones

bones of the vertebrae and face, don't fall into categories of others

compact bone

Dense outer layer that has no air pockets

Spongy bones

Airy porricle bone (trabecular bone)

End closest to the point of attachment in a long bone

Proximal Ephiphysis

End furthest from point of attachment of attachment on long bone

Distal Ephiphysis

Shaft (stick) of bone between both ends

Diaphysis

Region between Ephiphysis and diaphysis

Metaphysis

Calcified area of bone where growth plate used to be

Epiphyseal Line

Hyaline cartilage found on ends of epiphysis to prevent friction between bones

Articular Cartilage

Membrane around bone

periosteum

Where yellow blood marrow is found, cavity in diaphysis

Medullary Cavity

Membrane lining medullary cavity and cavities in spongy bone

Endosteum

Only have inner spongey bone lined by continuous compact bone

All other bones then long bones

Membrane on outer surface that isn't present where articular cartilage is

Periosteum

Made of dense irregular CT

Periosteum Superficial Layer

Made of osteoblasts and osteoclasts

Periosteum Deep Layer

Attach periosteum to the bone

Sharpey's fibers (perforating collagen fibers)

Thin osteogenic membrane that lines inner surfaces of bone

Endosteum

Bone generating

Osteogenic

Bone creating cells

osteoblasts

Bone deteriorating cells

Osteoclasts

Reflects stresses applied to specific locations

Bone markings

Bump on bone

Projection

Smooth and flat surface

Joint surface

Foramens (openings) to allow blood vessels in

Depressions and Openings

Made up of central canal surrounded by concentric lamellae

Osteon or Haversian System

Canal where blood vessels run through in compact bone

Central canal

Calcified ECM that forms rings of osteon

Concentric Lamellae

Go around entire bone circumference, don't form osteons

Circumferential Lamellae

Longitudinal canal that connects different osteons together

perforating Canal

Tunnels that run through Lamellae, osteocytes run through these to reach other osteocytes for nutrients

Canaliculi

Pits in tissue where cells are found

Lacunae

Lamellae filling in gaps between osteons, calcified ecm

Interstitial Lamellae

Run through Lamellae with each section running in different directions

Collagen fibers

Allows bone to resist twisting forces

Collagen fibers

The "little beams" that make up spongy bone are called

trabeculae

Solid, fed nutrients from surround Endosteum

Trabeculae

Found in spaces between trabeculae

Red bone marrow

Process by which bones forms

Ossification or Osteogenesis

Bone genesis can happen in 4 situations

- formation of bone in uterus

- normal growth through adulthood

- recycling of bones throughout life

- repair of fractures or injuries

Has good regenerative capacity

Bone

Bone forms from mesenchyme arranged in layers that resemble membranes

Intramembranous Ossification

Ossification found in skulls and clavicles

Intramembranous

Bone replaces hyaline cartilage

endochondral ossification

Ossification found in all other bones then skull and claviciles

Endochondrol Ossifcation

mesenchymes form into osteoblasts which then calcify to form compact bone on both sides and periosteum

Intermembranous Ossification

endochondral ossification

process in which bone forms by replacing hyaline cartilage

allows for bone growth by growing more caritlage and replacing old cartilage with bone tissue by calcifying it

Epiphyseal Plate

when you stop growing the entire plate calcifies and becomes bone:

Epiphyseal Line

bones get wider by

osteoblasts adding more circumferential lammellae to outer side

ostesoclasts remove bone from inner wall:

about the same rate as osteoblasts add to outside

_______ widens not bone

medullary cavity

taking away bone tissue via osteoclasts

Bone Resorption

secrete hydrochloric acid and lysozomal enzymes to break down bone

osteoclasts

bones break down into this which then get sent to blood stream for reuse

calcium

remaining collagen fibers and osteocytes are removed via

phagocytosis

have ruffled border and multiple nuclei

osteoclasts

creation of bone tissue when needed

Bone Deposition

essential ions and nutrients needed for this to occur

Bone Deposition

Osteoblasts become ____ once calcified

osteocytes

Interchangeable with joints

Articulation

Bones meet at joints however not all joints are

Bone to bone

Meeting site for 2 or more rigid elements

Joint or Articulation

Joints are classified both

structurally and functionally

Criteria for structural classification

- Presence of Synovial Cavity

- types of connective tissue binding rigid elements together

Bones held together by dense collagen fibers with no synovial cavity

Fibrous Joints

Bones held together by cartilage with no synovial cavity

Cartilaginous Joints

Bones held together by ligaments with a synovial cavity

Synovial Joints

Encapsulated space between 2 rigid elements

Synovial Cavity

Based on type and degree of movement allowed

Functional Classification

Immovable joints

synarthroses

Slightly mobile joints (limited)

Amphiarthroses

Free mobile joints (unlimited)

Diarthroses

Only in skull, bones held together by short interconnecting fibers (immobile: synarthroses)

Suture

Joint held together by ligament, no synovial cavity, fibrous tissue length varies (Amphiarthroses)

Syndemosis

Relates to tooth, peg in socket fibrous joints, periodontal ligament holds pegs in socket, no synovial (syntharioses)

Gomphosis

Bones united by hyaline cartilage (areas of high possible friction) (synarthroses)

Syndochondroses

Bones united by fibrocartilage (areas of high possible impact) (Amphiarthroses)

Symphyses

All are freely mobile (diarthroses)

Synovial Joints

Ligaments hold bone together with a synovial cavity present, makes up most joints of body

Synovial Joints

Connects rigid elements together in synovial joints

Ligament

Capsule that encapsulates joint cavity

Articular Capsule

Continuous with periosteum, made of dense irregular ct proper and functions as a strengthening joints

Fibrous Layer of Articular Capsule

Covers insides of any synovial cavity, loose ct that secretes synovial fluid (not present where Articular cartilages is present)

Synovial Membrane

Ends where Articular cartilage begins

Periosteum