Human Biology Bones/Skeletal System Quiz

Perichondrium

forms capsule around cartilage
made of Dense Irregular CT

Fibrocartilage Location

Knee Joint
Pubic symphysis
in b/w vertebrae

Hyaline Location

Nose
Hip
Wrist Joints
(Rest of body)

Elastic Location

Ear

Skeletal Cartilage Growth

Apositional growth
Interstitial growth

Apositional growth

Chondroblasts in perichondrium divide & secrete new cartilage along inside edge of perichondrium

Interstitial growth

Chondrocytes in lacunae divide & secrete new matrix

Regions of the Skeleton

Axial Skeleton
Appendicular Skeleton

Axial Skeleton

Skull
Vertebral column
Ribcage
-Ribs
-Sternum

Appendicular Skeleton

Limb girdles
(attach limb to axial skeleton |)
Limbs

Types of Bone

Long bones
Short bones
Flat bones
Irregular bones
Sesamoid bones
Sutural or Wormian bones

Long bones

-Greater length than width
-Consists mainly of compact bone tissue, some spongy bone
-Include bones of thigh, legs, toes, arms, forearms & fingers

Short bones

-Kinda cube-shaped & about = in length/width
-Spongy except @ surface(thin layer of compact bone)
-wrist & anklebones

Flat bones

-Thin
-Composed of // plates of compact bone surrounding spongy bone
-Found in cranium, sternum & ribs scapulas

Irregular bones

-complex shapes
-can't be in other categories
-varying amounts of compact & spongy bones
-vertebrae & certain facial bones

Sesamoid bones

-small bones in tendons where considerable pressure is exerted (e.g. wrist)
-vary from person to person
[but everyone has patella]

Sutural or
Wormian bones

-small bones b/w joints of certain cranial bones
-vary from person to person

Functions of Bone

-Support
-Protection
-Movement
-Mineral storage & homeostasis
-Site of blood cell production
-Storage of energy

Bone Function:
Support

-framework for body
-points of attachment for skeletal muscle

Bone Function:
Protection

-protects internal organs from injury
(e.g. skull/ribcage protect brain/<3/lungs)

Bone Function:
Movement

-Skeletal muscle attach to bones, pulling bones together when muscle contracts

Bone Function:
Mineral storage & homeostasis

-bones store minerals e.g. calcium, phosphorous can be distributed throughout the body

Bone Function:
Site of blood cell production

-in certain bones, RBCs are produced during process of 'hematopiesis'
-red bone marrow = source of RBS (flat)
-found in developing bones, pelvis, ribs, breastbone, backbones, skull & ends of arm bones & thigh bones

Bone Function:
Storage of energy

lipids stored in yellow(fat) bone marrow
(long bones)

hematopiesis

blood cell production

Gross Anatomy of a Flat Bone

Compact bone - outside
Spongy bone - inside

Gross Anatomy of a Long Bone
Anatomical Regions

-Diaphysis
-Epiphysis
-Epipshyseal Line
-Periosteum
-Articular Cartilage
-Compact bond
-Spongy bone
-Medullary Cavity

Diaphysis

shaft
middle

Epiphysis
(epiphyses pl.)

ends
proximal & distal

Epiphyseal Line
(plate)

-growth plate
-marks anatomical boarder b/w epipshysis & diaphysis

Periosteum

Layer of CT

Articular Cartilage

reduce joint friction
(smooth)

Compact bone

2nd most superficial

Spingy bone

ends & by edge of
Medullary Cavity

Medullary Cavity

center
marrow cavity

Gross Anatomy of a Long Bone
Anatomical Regions

-Spongy bone
-Compact bone
-Articular cartilage
-Periosteum (Sharpey's fibers)
-Endosteum
-Nutrient Arteries

Histology of Bone
Cell Types

Osteoprogenitor cells
Osteoblasts
Osteocytes
Osteoclasts

Osteoprogenitor cells

-embryonic stem cell
-in periosteum, endosteum & canals w/ blood vessels
-mitosis --> osteoblasts

Osteoblasts

-secrete matrix of bone
-found on bone tissue surface
-form bone but can't divide by mitosis
-form collagen & other compounds needed to build bone

Osteocytes

-mature bone cells
-isolated in bony matrix
-maintain daily cellular activity of bone

Osteoclasts

surface of bone tissues & function in bone resorption

compact bone

resist compression but easy to snap in half

spongy bone

resists bending
(but not compression)

Lamellae

layers of bone matrix
mineral =hydroxyapatite

Osteon

Haversian Canal
-compact bone

Trabeculae

small beam

Volkmann's Canals

carry small arteries throughout the bone

Concentric lamellae

One of the concentric tubular layers of bone surrounding the central canal in an osteon

Canaliculi

small passageway

Bone Openings & Depressions

-Foramen
-Meatus
-Paranasal sinus
-Fossa

Foramen

opening through which blood vessels, nerves or ligaments pass

Meatus

a tube-like passageway running w/n a bone

Paranasal sinus

an air-filled cavity w/n the bone connected to the nasal cavity

Fossa

a depression in or on a bone

Processes that form joints

-Condyle
-Head
-Facet

Condyle

a large, rounded prominence that forms a joint

Head

a rounded projection that forms a joint & supported on the constricted portion of a bone

Facet

a smooth, flat surface

Processes to which ligaments, tendons & other CT attach

-Tuberosity
-Spinous process
-Trochantor
-Crest

Tuberosity

a large, rounded, usually roughened process

Spinous process

a sharp, slender projection

Trochantor

a large, blunt projection found only on the femur

Crest

a prominent ridge or border

Osteogenesis /
Ossification

Formation of new bone

Formation of new bone

-Formation of bony skeleton
-Bone Growth during childhood
-Bone Remodeling throughout life
-Repair of Fracture

Intramembranous ossification

flat bones

Endochondral ossification

other bones

Prior to week 8 the skeleton is made of...

hyaline cartilage &
fibrous CT membranes

When bone replaces fibrous CT

Intramembranous ossification

When bones replaces hyaline cartilage

endochondral

Ossification center

selected centrally located mesenchymal(embryonic CT) cells cluster & differentiate into osteoblasts

When Bone matrix (osteoid) is secreted w/n the fibrous membrane

-osteoblasts begin to secrete osteoid, which is mineralized w/n a few days
-trapped osteoblasts become osteocytes

When Woven bone & periosteum form

-accumulating osteoid is laid down b/w embryonic blood vessels, which form a random network. the result is a network (instead of lamellae) of trabeculae (woven bone)
-vascularized mesenchyme condenses on the external face of the woven bone & becomes the periosteum

When Bone collar of compact bone forms & red marrow appears

-trabeculae just deep to the periosteum thicken, forming a woven bone collar that is later replaced w/ mature lamellar bone
-spongy bone(diploe), consisting of distinct trabeculae, persists internally & its vascular tissue becomes red marrow

When osteoblasts in periosteum secrete matrix along diaphysis you get a

bone collar

chondrocytes inside hypertrophy & cause...

cartilage matrix to calcify

calcified cartilage causes ...

chondrocytes to die

cartilage matrix deteriorates forming a cavity

cavitation

periosteal bud invades internal cavity

nutrient artery & vein, lymphatic vessel, nerve, red marrow, osteoblasts & osteoclasts

osteoclasts erode

calcified cartilage

osteoblasts secrete bone matrix around...

remaining cartilage - spongy bone trabeculae

osteoclasts break down newly formed bone forming...

the medullary cavity

cartilage @ the epiphyses continues to..

grow in length
-cartilage then ossifies, dies & is eroded by osteoclasts & covered in bone by osteoblasts

secondary ossification center forms

same way as first

hyaline cartilage remains only as

-articular cartilage
-epiphyseal plate