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Chapter 6 Bones and Skeletal Tissues. Part A Skeletal Cartilages, Classification of Bones, and Functions of Bones. Without Bones. We would look like Slugs. Skeletal Cartilages. Skeletal Cartilages. Cartilage tissue consists primarily of water - PowerPoint PPT Presentation
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Chapter 6Bones and
Skeletal TissuesPart A
Skeletal Cartilages, Classification of Bones, and
Functions of Bones
Without BonesWe would look
like Slugs
Skeletal Cartilage
s
Skeletal Cartilages• Cartilage tissue consists
primarily of water–Accounts for its resilience (ability to spring back to its original shape after being compressed)
• Contains no blood vessels or nerves
• Surrounded by the perichondrium
Perichondrium• Surrounds skeletal cartilage • Made from dense irregular
connective tissue• Resists outward expansion
when cartilage is compressed• Contains blood vessels from
which nutrients diffuse through matrix to reach cartilage cells–This limits cartilage thickness
Skeletal Cartilages• Three types of Skeletal Cartilages–Hyaline–Elastic–Fibrocartilage
• All contain chondrocyte cells and an extracellular matrix of ground substance and fibers
Hyaline Cartilage
• Looks like frosted glass when freshly exposed
• Provides support, flexibility, and resilience
• Is the most abundant skeletal cartilage
• Contains fine collagen fibers
Hyaline Cartilage• Is present in these cartilages:
–Articular – covers the ends of long bones
–Costal – connects the ribs to the sternum
–Respiratory – makes up the larynx and reinforces air passages
–Nasal – supports the nose
Hyaline Cartilage in Blue
Figure 6.1
Elastic Cartilage• Similar to
hyaline cartilage but contains more elastic fibers–Better able to stand repeated bending
Elastic Cartilage• Found in the
external ear and the epiglottis –Epiglottis is the flap that covers the opening of the larynx when we swallow
Elastic Cartilage in Green
Figure 6.1
Fibrocartilage• Highly
compressible with great tensile strength
• Contains thick collagen fibers
Fibrocartilage• Found in sites
subjected to both heavy pressure and stretch–menisci of the knee
–intervertebral discs
Fibrocartilage in Red
Figure 6.1
Growth of Cartilage• Cartilage grows in two ways• 1. Appositional – Growth from
outside–cells in the perichondrium secrete matrix against the external face of existing cartilage
Growth of Cartilage• Cartilage grows in two ways• 2. Interstitial – Growth from
inside–lacunae-bound chondrocytes inside the cartilage divide and secrete new matrix, expanding the cartilage from within
Growth of Cartilage• Typically cartilage growth ends
during adolescence (same time as skeleton)
• Calcification of cartilage occurs under certain conditions–During normal bone growth in youth
–During old age
Growth of Cartilage
• Calcified cartilage is not bone• Calcification is when calcium
salts are deposited in the matrix and harden
Classification of
Bones
Classification of Bones• Two basic types
of bone tissue–Compact Bone
•Homogeneous
•Dense - looks smooth and solid to the naked eye
Classification of Bones• Two basic types
of bone tissue–Spongy Bone
•Honey comb of small needle-like pieces of bone
•Many open spaces
Classification of Bones• The 206 named bones of the
human skeleton are divided into two groups:–Axial skeleton–Appendicular skeleton
Axial Skeleton
• Includes bones of the skull, vertebral column, and rib cage
• Most involved in protecting, supporting, or carrying other body parts
Axial Skeleton in dark tan
Figure 6.1
Appendicular Skeleton• Includes bones of the upper and
lower limbs, shoulder, and hip
Appendicular Skeleton• Locomotion
–Helps us move–Helps us manipulate our environment
Appendicular Skeletons in yellow
Figure 6.1
Classification of Bonesby Shape
• Long Bones• Short bones• Flat bones• Irregular bones
Long Bones• Longer than
they are wide
• Has a shaft with heads at both ends
• Contains mostly compact bone
Figure 6.2a
Long Bones• Examples of
long bones–Humerus–Femur–The bones in your fingers
Figure 6.2a
Short Bones• Contains mostly
spongy bone • Cube shaped
–Wrist and ankles•Carpals – Tarsals
Short Bones• Sesamoid
bones–shaped like a sesame seed
–Special bones that form within tendons•Example: Patella
Flat Bones• Thin &
Flattened• Usually
curved• Thin layers
of compact bone around a layer of spongy bone Figure 6.2c
Flat Bones• Examples
–Sternum–Ribs–Scapulae–most skull bones
Figure 6.2c
Irregular Bones• Irregular
shape• Bones with
complicated shapes or ones that do not fit into other categories
Figure 6.2d
Irregular Bones• Examples
–vertebrae –hip bones
Figure 6.2d
Functions of
Bones
Function of Bones• Support• Protection • Movement • Mineral storage• Blood cell formation
Function of Bones• Support of the body
–form the framework that supports the body and cradles soft organs
• Protection of soft organs–provide a protective case for the brain, spinal cord, and vital organs
• Movement due to attached skeletal muscles–provide levers for muscles
Function of Bones
• Storage of minerals and fats–reservoir for minerals, especially calcium and phosphorus
• Blood cell formation–hematopoiesis occurs within the marrow cavities of bones
Study Guide
• You should be able to complete pages 120-122 of the study guide for the study guide check.
QuizNext time! If you
snooze, you lose.
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