The Skeletal System

Front 1

Introduction to Bone

Back 1

A. CHEMICAL COMPOSITION
1. Organic Components
2. Inorganic Components

B.Bone Types

Front 2

Chemical Composition

Back 2

1. Organic Components:
a) Osteoid- 35% of bone- soft material made of protecoglycan & collagen fibers

* Allows bone to bend/gives flexibility (resists tension/bending forces)

b) Bone Cells--- i) Osteoblasts- create/build bone by making osteoid
ii) Osteoclasts-(similar to macrophages) break down by releasing acid enzymes (work with Osteoblasts to rebuild bone).

2. Inorganic Components:
Hydroxyapatites---65% of bone->3 types calcium, mainly Ca Phosphate.
***Significance: Harden Osteoid-> responsible for hardness of bone; Helps bone resist compression (crushing forces).

Front 3

Organic Components

Back 3

a) Osteoid- 35% of bone- soft material made of protecoglycan & collagen fibers

* Allows bone to bend/gives flexibility (resists tension/bending forces)

b) Bone Cells---
i) Osteoblasts- create/build bone by making osteoid
ii) Osteoclasts-(similar to macrophages) break down by releasing acid enzymes (work with Osteoblasts to rebuild bone).

Front 4

Inorganic Components

Back 4

Hydroxyapatites---65% of bone->3 types calcium, mainly Ca Phosphate.
***Significance: Harden Osteoid-> responsible for hardness of bone; Helps bone resist compression (crushing forces).

Front 5

Bone Types

Back 5

1. Bone is organised into layers called lamellae.
a) In compact bone, the lamellae form circular patterns: Osteons (Concentric lamellae) -->Target pattern-> made of circular rings.
*Designed to with stand stress from one direction
b) In cancellour/spongy bone, the lamellae from trabeculae, or narrow branches that connect together to form a loose web or net structure.
2. Blood vessels and nerves are found in Haversian Canals, located in the center of osteons, and in Perforating/Volkmann's Canals which lie at right angles to the Haversian Canals. in same direction as bone shaft. (parallel)

Front 6

Bone Anatomy

Back 6

A. Diaphysis---The hollow shaft made of compact bone
B. Epiphysis---The round ends, filled with spongy bone and covered by outer layer of compact bone
C. Metaphysis/Growth Plate---Bandof hyaline cartilage located between diaphysis and epphysis whic allows for growth in bone length
D. Articulation---Where two or more bones come together to form a joint
E. Medullary Cavity (Bone Marrow Cavity)
1. Red Bone Marrow/Myeloid Tissue-(Reticular C.T.) The birthplace of RBC's and WBC's; Located throughout skeleton of children but only in select locations of adult skeleton.-Pelvic bone, Top epiphyes of femor, humerous. Miner locations; Vertabrae, ribs, skull
2. Yellow Bone Marrow- Primarily fat tissue; Most myeloid tissue turns into this.

Front 7

Bone Types

Back 7

1. Bone is organised into layers called lamellae.
a) In compact bone, the lamellae form circular patterns: Osteons (Concentric lamellae) -->Target pattern-> made of circular rings.
*Designed to with stand stress from one direction
b) In cancellour/spongy bone, the lamellae from trabeculae, or narrow branches that connect together to form a loose web or net structure.

Front 8

Formation of Bone in the Early Skeleton

Back 8

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Front 9

Overview

Back 9

The skeleton of a human embryo is made of two tissues that will gradually be turned into bone. The process of making bone is called ossification.-->formation of bone

Front 10

Intramembranous ossification

Back 10

1. * Only forms flat bones of skul, Clavicles
*Forms bone from soft tissue (embryonic tissue) called mesenchyme (similar to dense/collagenous C.T.)
*Process complete by age 2
2. The skull bones are not fully ossified (turned into bone) at birth.
They becom ossified around age 2. Until then, the parts of these bones which are still mesenchyme are called FONTANELS or "soft spots"

Front 11

Endochondral ossification

Back 11

1. * Process forms rest of skeleton
*Forms bone from Hyaline Cartilage.
*Hyaline remains in growth plates after birth-->allow skeleton to grow in length.
*Process complete by end of puberty
2. At birth, some hyaline cartilage will remain in the skeleton. Hyaline cartilage remains in the growth plates. This means that endochondral ossification occurs in the young adult because it allows the long bones of the skeleton to grow in length up until 18-21 years of age.

Front 12

Articulations and their Movements

Back 12

A. Major Types Of Movement
1. Flexion & Extension
2. Abduction & Adduction
3.Supination & Pronation
B. Fibrous Joints
1. General Description
2. Sutures
Syndesmoses

Front 13

Flexion, Extension & Hyperextension

Back 13

Flexion= To bend a limb; also an anterior movement

Extention= To straighten a limb; Also a movement that returns the body part to the anatomical position; Also a posterior movement

= Movement behind/posterior to anatomical position. Ex: looking up, bending backwards at waist.

Front 14

Abduction & Adduction

Back 14

Abduction= To move a part laterally, away from the midline of the body

Adduction= To move a part medially, toward the midline of the body

Front 15

* Supination & Pronation

Back 15

Supination= To rotate the forearm so that the palm faces upward

Promation= To rotate the forearm so that the palm faces downward

Front 16

Fibrous Joints

Back 16

1. General Description
a. A fibrous connective tissue small ligament joins the two bones
b. Little or no movement
2. Sutures---Seams between skull bones (which are attached via tiny ligaments)
3. Syndesmoses--Joints between tibia & fibula and between radius & ulna

Front 17

Cartilagenous Joints

Back 17

1. General Description
a. Cartilage joins the two bones
b. Little or no movement
2. Synchondroses--Hyaline Cartilage
a. Eppiphyseal Growth Plates/ Metaphyses
b.First Sternocastal Joint(Costosternal Synchondrosis)---cartilage connecting ribs to sternum (connection of 1st rib connecting to the sternum)
3. Symphyses---Fibrocartilage->little movement
a. Intervertebral Discc-Knee
b. Symphysis pubis

Front 18

*Synovial Joints

Back 18

1. General description
a. Allows for Free Movement-->diarthrotic
b. Contain a Joint Cavity---A space between the bones, filled with synovial fluid, created by a joint capsule.
c. Contain Bursa---A "sack" of fluid-filled synobial membrane located where tendons and ligaments rub against bone (cushioning)-proteccts tendons & ligaments form damage(rubbing).
* d. Has large ligaments

Front 19

Types of Synovial Joints

Back 19

a. Plane/Gliding Joint---Two flat articulating bone surfaces
1) Movement: Small slipping or gliding/least movement of all synovial joints. *Nonaxial
2) Intercarpals Joints (between wrist bones)
3) Sacroiliac Joint (btwn sacrum and iliac bones)
b. Saddle Joint---One bone surface is concave while the other is convex
**Thumb Joint
Movement: Biaxial->side to side->abduction & adduction, flexion & extension
c. Hinge Joint---Rounded process of one bone fits into concave surface of other bone
1) Movement; Uniaxial-> flexion & extention front 2 back
2) Knee, elbow Joints-Btwn Humerous & ulna
d. Pivot Joint---One bone has a round part that is held by a ligament to the 2nd bone; first bone rotates with respect to the 2nd bone
1) Movement: half-rotation
2) Between head of radius and ulna at the elbow.
This joint allows for...Pronation & Supination=Half-rotation *Neck; atlantoaxial joint. (btwn 1st 2 Cervical vertebrae)
e. Ball & Socket---Multiaxial Joint/Triaxial- Every possible movement.
1) Movement: *most movement of all synovial joint types.
2) Shoulder and hip joints
f. Ellipsoid/Condyloid---Modified ball and socket where "ball" is oval rather than round
**Knuckles (btwn metacarpals and phalanges) biaxial

Front 20

Type of Synovial Joint

Back 20

a. Plane/Gliding Joint---Two flat articulating bone surfaces
1) Movement: Small slipping or gliding/least movement of all synovial joints. *Nonaxial
2) Intercarpals Joints (between wrist bones)
3) Sacroiliac Joint (btwn sacrum and iliac bones)

Front 21

Type of Synovial Joint

Back 21

b. Saddle Joint---One bone surface is concave while the other is convex
**Thumb Joint
Movement: Biaxial->side to side->abduction & adduction, flexion & extension

Front 22

Type of Synovial Joint

Back 22

c. Hinge Joint---Rounded process of one bone fits into concave surface of other bone
1) Movement; Uniaxial-> flexion & extention front 2 back
2) Knee, elbow Joints-Btwn Humerous & ulna

Front 23

Type of Synovial Joint

Back 23

d. Pivot Joint---One bone has a round part that is held by a ligament to the 2nd bone; first bone rotates with respect to the 2nd bone
1) Movement: half-rotation
2) Between head of radius and ulna at the elbow.
This joint allows for...Pronation & Supination=Half-rotation *Neck; atlantoaxial joint. (btwn 1st 2 Cervical vertebrae)

Front 24

Type of Synovial Joint

Back 24

e. Ball & Socket---Multiaxial Joint/Triaxial- Every possible movement.
1) Movement: *most movement of all synovial joint types.
2) Shoulder and hip joints

Front 25

Type of Synovial Joint

Back 25

f. Ellipsoid/Condyloid---Modified ball and socket where "ball" is oval rather than round
**Knuckles (btwn metacarpals and phalanges) biaxial

Front 26

Types of Synovial Joints

Back 26

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