Exam 2

Functions of Skeletal System

• Support/ Protections

• Movement

• Hematopoiesis (produce blood)

• Storage of minerals

  • Calcium

  • Phosphate Lipds

Types of Bones

Long Bones : longer than wide, spongy bone on the ends ex: Humerus, Ulna, Phalanges

Short Bones: Cube shape

equal length with wideness ex: carpals and tarsals

Flat Bones: Cranial bone, ribs, scapula

Irregular Bones: Complex bones ex: Coxae & Ethmoid

Diaphysis

Shaft of a long bone

• yellow bone marrow can be found

Epiphysis

Ends of the long bone

• red bone marrow can be found

Epiphyseal Plate/line

Found in : Metaphysis ( middle)

where the final fuse of bone grown

• growth plate 

Medullary Cavity

yellow bone marrow can be found

Endosteum

Inside membrane *

Periosteum

Outside membrane

Osteoprogenitor Cells

Bone Stem Cells derived from mesenchyme; divide to produce another stem cell and an osteoblast;

located in periosteum and endosteum ( Membranes)

Osteoblasts

Deposit osteoid (Bone Matrix) differentiate into osteocytes; bone builders

“Builders”

Osteocytes 

Mature bone cells; maintain bone matrix reside within Lacunae ( place where they live) 

Osteoclasts

Break down bone tissue ( Bone resorption) using hydrochloric acid and enzymes

• Damaged bone tissue

Compact Bone

Named: Cortical or Dense

• Solid & Dense

• Forms at the external walls

Spongy Bone

Names: Tabeculae

Appears Spongy & Porous

Located: internally epiphyses

Irregular network of parallel lamellae 

Provides resistance to stress by distributing it throughout the framework Thin plates of bone with lots of
intercellular space
• Spaces filled with Red Bone Marrow
- Hematopoiesis

Osteons

Basic

Functional and structural unit of compact bone

Runs Parallel to diaphysis

Central Canal 

Cylindrical channel in the center

that contains blood vessels and nerves 

• * in the middle

Concentric Lamellae 

Rings of bone surrounding central canal 

• * each ring 

Lacunae

Spaces in matrix where osteocytes reside

• each little space where osteocytes live in

Canaliculi

Tiny, interconnecting channels w/ in bone connects lacunae and central canal

“Little Canals” that connect lacunae to reach center canal for nutrients and osteocytes

Perforating Canals

run perpendicular to central canal

create vascular and innervation network among osteons

Circumferential lamellae

Rings of the bond

internal to the periosteum or endosteum

Interstitial Lamellae

Leftover parts of osteons that been partially resorbed

Hyaline Cartilage

Becomes Bone

• Epiphyseal Growth plate

• Length wise growth *

Interstitial bone growth

Is the ossification of cartilage which occurs within the epiphyseal plate

with ( 5 Zones )

Bone Remodeling 

Deposition and resorption of bone 

Helps maintain calcium and phosphate levels in body fluids and be stimulated by stress on a bone (fractures)  

Older Adults: Bone resorption tends to exceed bone formation 

Projections

Tendon/Ligament attachment

Smooth Areas

Articulations between bones

Depression/grooves/tunnels

Blood and nerves

Vertebral Column

Cervical - 7

Thoracic - 12

Lumbar - 5

Function of Vertebral Column

Provide support for body

support weight of head

Maintain upright body position

Protect spinal cord

Vertebra Structure

Vertebral Body

Vertebral Spinous

• transverse a

• articular facets

• pedicle and laminae

Appendicular Skeleton

-Attached to axial skeleton

• Pectoral Girdle

• Pelvic Girdle

• Upper and Lower extremities

Pectoral Gridle 

attaches the bones of the upper extremities to the axial skeleton 

• Articulates with trunk and supports upper limbs 

• Consist of: Clavicle and scapula 

• Attach to many muscles 

• Upper limb mobility

Upper Extremity

Humerus

Radius

Ulna

Carpals

The Pelvis

Sacrum

Coccyx

Right and left Ossa Coxae

Lower Extremity

Os coxa- pelvis
• Ilium
• Ischium
• Pubis
• Femur – thigh
• Patella – kneecap
• Tibia – shin
• Fibula – outer lower leg
• Tarsals - ankle

Articulation (Joint)

Place of contact between bones

• bones to cartilage

• Bones to teeth

Structure of Joint

Structure determines it’s mobility and stability

Joints Structures

Joints are classified structurally on basis of

connective tissue that binds to the joint

Ex:

Fibrous

Cartilaginous

Synovial

Joints Functionally 

Basis of movement at joint

Examples: 

Synarthrosis (Don’t move)

Amphiarthrosis (Slightly movable)

Diarthrosis (Move freely)

Fibrous Joints

Immovable or slightly movable

• thin layer of CT

• Ex:

• Gomphoses - roots of teeth

• Synarthroses ( Skull)

• the small ct in between the bones like in the tibia and fibula

Cartilaginous Joints

Connected by Hyaline or Fibrocartilage (Cartilage)

• Slightly movable

• Synarthoroses - found at ribs to manubrium

• Ampiarthroses- Found to Pubic symphysis

Synovial Joints

Found in joint cavity, synovial fluid and ligaments 

• Free movable 

• Accessory structures like: Bursa, fat pads and tendons 

Types of Synovial Joints

Saddle Joint

Ball and Socket Joints

Pivot

Planar Joint

Condyloid Joint

Hinge Joint

Movement of Synovial Joints

• Flexion/Extension/Hyperextension

• Lateral flexion

• Abduction/adduction

• Circumduction

• Rotation

• Lateral/medial rotation

• Pronation/supination

• Depression/elevation

• Dorsiflexion/plantarflexion

• Inversion/eversion

• Protraction/retraction

• Opposition