CH 7 & 8 SKELETAL SYSTEM
Functions of the Skeletal System
• Bones are made of OSSEOUS
TISSUE
• Support and Protection
• Body movement
• Blood cell formation (bone marrow) hematopoeisis
• Storage of inorganic materials
Bone Classification
• Long bones: longitudinal axes and
expanded ends
• Ex. Forearm and thigh bones
• Short bones: cubelike
• Wrists and ankles
• Flat bones: platelike with broad
surfaces
• Ribs, scapula, some skull bones
• Irregular bones: variety of shapes,
usually connected to other bones
• Vertebrae and facial bones
• *Sesamoid (round) bones: small and
nodular
• Kneecap
BONE STRUCTURE - Long Bone
1.Epiphysis
2.Diaphysis
3.Articular Cartilage
4.Periosteum
Inside the Long Bone
Medullary Cavity –
hollow chamber filled
with bone marrow
Red Marrow (blood)
Yellow Marrow (fat)
Endosteum:
lining of the
medullary
Structure of a Long Bone
Figure 6.3a-c
Types of Bone Tissue
Compact (wall of the diaphysis)
Spongy (cancellous, epiphysis) - red marrow
Compact Bone
BONE
COLORING!
BONE DEVELOPMENT & GROWTH
1.Intramembranous bones – flat, skull
2. Endochondral bones – all other
ALL BONES START AS HYALINE
CARTILAGE, areas graduallly turn to bone
PRIMARY OSSIFICATION CENTER (shaft)
SECONDARY OSSIFICATION CENTER (ends)
Bone Growth
ORGANIZATION
• About 206
bones
• 2 Main
Divisions –
Axial &
Appendicular
Axial Skeleton
•
•
•
•
•
Head, neck, trunk
Skull
Hyoid Bone
Vertebral Column
Thoracic Cage (ribs,
12 pairs)
• Sternum
Appendicular Skeleton
• Limbs & Bones that connect to the
o Pectoral Girdle (shoulders)
o Pelvic Girdle (hips)
The Rest of the Bones
Broken Bones
Abnormal Bone Conditions
• BONE SPURS: abnormal growth. Can occur on
any bone (e.g. heel).
• OSTEOPOROSIS: Increased activity of
osteoclasts cause a break down bone, and the
subsequent fewer minerals in the extracellular
matrix make it fragile. The spongy bone especially
becomes more porous.
• Men get it as well as women. What’s the best way
to prevent osteoporosis? Exercise! What does
exercise do? Makes bones bigger.
• The most common bone used for a bone graft is
the iliac bone of the hip.
Osteoporosis
Figure 6.15
Rheumatoid arthritis is an autoimmune disease which
causes joint stiffness and bone deformity
Source: http://www.thetimes.co.uk/tto/public/article3233439.ece
ABNORMALITIES OF THE SPINE
ABNORMALITIES OF THE SPINE
• SCOLIOSIS is a lateral curve in the spine
• KYPHOSIS is a hunchback curve
• LORDOSIS is a swayback in the lower
region.
• ANKYLOSIS is severe arthritis in the spine
and the vertebrae fuse.
SCOLIOSIS
LORDOSIS
ANKYLOSIS
FUN FACTS ABOUT BONES
Bone is made of the same type of minerals as
limestone.
• Babies are born with 300 bones, but by
adulthood we have only 206 in our bodies.
• The giraffe has the same number of bones
in its neck as a human: seven in total.
• The long horned ram can take a head butt
at 25 mph. The human skull will fracture at
5mph.
Joints
Chapter 8
Classification of Joints
Structural classification:
(1) Fibrous joints
• Dense connective tissues connect
bones
• Between bones in close contact
(2) Cartilaginous joints
• Hyaline cartilage or fibrocartilage
connect bones
(3) Synovial joints
• Most complex
• Allow free movement
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Structure of a Synovial Joint
• Synovial joints are freely
moveable (diarthroses)
• There are specific parts of a
diarthroses:
• Articular cartilage
• Joint cavity
• Joint capsule
• Synovial membrane
• Synovial fluid
• Meniscus
• Bursae
Spongy
bone
Joint
capsule
Joint cavity
filled with
synovial
fluid
Articular
cartilage
Synovial
membrane
29
Knee Joint
Femur Inc. Permission required for reproduction or display.
Copyright © The McGraw-Hill Companies,
Synovial membrane
Suprapatellar bursa
Quadriceps femoris tendon
(patellar tendon)
Patella
Prepatellar bursa
Joint cavity
Articular cartilage
Patellar ligament
Menisci
Infrapatellar bursa
Joint capsule
Tibia
(a)
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Types of Synovial Joints
• Pivot Joint
• Between atlas (C1) and
the dens of axis (C2)
Dens
Transverse
ligament
• Hinge Joint
• Elbow joint
• Between phalanges
Humerus
Radius
Atlas
Axis
Ulna
(e) Pivot joint
(d) Hinge joint
31
Types of Synovial Joints
• Saddle Joint
• Between carpal and 1st
metacarpal (of thumb)
• Condylar Joint
• Between metacarpals and
phalanges
• Between radius and carpals
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Metacarpal
First
metacarpal
Trapezium
Phalanx
(f) Saddle
joint
(b) Condylar
joint
32
Types of Synovial Joints
• Ball-and-Socket Joint
• Gliding Joint
• Hip joint
• Shoulder joint
• Between carpals
• Between tarsals
• Between facets of adjacent
vertebrae
Hip bone
Head of femur
in acetabulum
Femur
Carpals
(a) Ball-and-socket
joint
(c) Plane
joint
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