Organization Of TheTHE SKELETAL SYSTEMExercise #9 Page # 73

Laboratory Manual for Anatomy and Physiology. Custom edition for Miami Dade College-Kendall Campus. BSC2085L by Michael G. Wood.

Fundamentals of anatomy & physiology by martini, 88h edition

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Competency 4: The Skeletal System

– Upon successful completion of this laboratory, the student will be able to identify the microscopic and macroscopic structure of bones and the structural and functional classification of selected articulations by:

– Distinguishing between compact and spongy bone.– Identifying the components of the osteon or Haversian

system. – Locating the major anatomical structures of a long bone.

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FUNCTIONS OF THE SKELETAL SYSTEM

• STRUCTURE SUPPORT- IT IS A FRAMEWORK FOR ATTACHEMENT OF SOFT TISSUE & ORGANS

• • STORAGE MINERALS & LIPIDS- CALCIUM (THE MOST

ABUNDANT), FAT IN YELLOW MARROW• • BLOOD CELLS PRODUCTION- (RBC & WBC) IN RED MARROW• PROTECTION- TO SURROUND DELICATE TISSUE & ORGANS,

EX RIBS • EX: RIBS (HEART & LUNGS) SKULL (BRAIN) VERTEBRAE (SPINAL CORD) PELVIS (DIGESTIVE & REPRODUCTIVE ORGANS)

• LAVERAGE- TO PROVIDE SITE FOR MUSCULAR ATTACHEMENT, POINT OF • SUPPORT AND BODY MOVEMENT•

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PARTS OF THE SKELETAL SYSTEM

• THE SKELETON (206 BONES)

• MICROSCOPIC STRUCTURE: OSSEOUS TISSUE• MACROSCOPIC STRUCTURE: AXIAL AND APPENDICULAR • SKELETON

• THE JOINTS• THE PLACE WHERE TWO OR MORE BONES CONNECT

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OSSEOUS TISSUE• ORGANIC MATER:• CELLS: OSTEOBLAST- BONE FORMING CELLS• OSTEOCLASTS- BONE DISSOLVING CELLS• OSTEOCYTES- BONE MAINTAINING CELLS• POLISACCARIDES- TO FORM GROUND SUBSTANCE • COLLAGEN FIBERS- TENSILE STRENGHT

• INORGANIC MATER:• HYDROXYAPATITE- CALCIUM + PHOSPHATE SALTS • THAT MAKE THE BONE HARD

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TYPES OF BONE CELLS

Bone Textures

Classification of Bones• Bone Shapes

– Long bones

• Are long and thin

• Are found in arms, legs, hands, feet, fingers, and toes

– Flat bones

• Are thin with parallel surfaces

• Are found in the skull, sternum, ribs, and scapulae

– Sutural bones

• Are small, irregular bones

• Are found between the flat bones of the skull

Classification of Bones• Bone Shapes

– Irregular bones• Have complex shapes • Examples: spinal vertebrae,

pelvic bones – Short bones

• Are small and thick• Examples: ankle and wrist

bones– Sesamoid bones

• Are small and flat• Develop inside tendons near

joints of knees, hands, and feet.• Patella

Classification of Bones• Structure of a Long Bone

– Diaphysis • The shaft • A heavy wall of compact bone, or dense bone• A central space called medullary (marrow)

cavity– Epiphysis

• Wide part at each end• Articulation with other bones• Mostly spongy (cancellous) bone • Covered with compact bone (cortex)

– Metaphysis • Where diaphysis and epiphysis meet

Classification of Bones

• Structure of a Flat Bone– The parietal bone of the skull

– Resembles a sandwich of spongy

bone

– Between two layers of compact bone

– Within the cranium, the layer of

spongy bone between the compact

bone is called the diploë

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin

Cummings

Bone (Osseous) Tissue• Characteristics of Bone Tissue

– Dense matrix, containing• Deposits of calcium salts• Osteocytes (bone cells) within lacunae organized around blood vessels

– Canaliculi • Form pathways for blood vessels• Exchange nutrients and wastes

– Periosteum • Covers outer surfaces of bones • Consists of outer fibrous and inner cellular layers

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PERIOSTEUM & ENDOSTEUM(MARTINI)

• COMPACT BONE It forms the walls & outer surfaces of the bones • Osteon- functional unit of the compact bone It is thickest where angular stress is applied. • Lamella- the layers of the matrix that makes the bone ( thin

plate)• Central canals (Harvesian canals)• F-they contain blood vessels that carry blood to

& from the Osteon.

Perforating canals (Canals of Volkmann) They extend perpendicular to the surface F- they connect central canals of adjacent osteons

to each other• Lacuna- thin holes that contains an osteocyte It is a pocket sandwiched between layers of matrix • Canaliculus- narrow pathway that penetrates the lamellae

Function- to deliver nutrients and removal of waste

products to and from osteocytes. 04/21/23 14

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Compact and spongy bone

HISTOLOGY OF COMPAC BONE(MARTINI)

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Compact and Spongy Bone• The Structure of Spongy Bone

– Does not have osteons– The matrix forms an open network of

trabeculae– Trabeculae have no blood vessels– The space between trabeculae is filled

with red bone marrow:• Which has blood vessels• Forms red blood cells• And supplies nutrients to osteocytes

– Yellow marrow• In some bones, spongy bone holds

yellow bone marrow• Is yellow because it stores fat

SPONGY BONE

• It makes the inner layer(s) of bones• It is formed by trabeculae (bony

bars or plates)• It has spaces for blood cell

formation• Trabeculae contains lacuna with

osteocytes

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LONG BONES STRUCTURE

• Periosteum: structure that surrounds the bone formed by fibrous connective tissue.

• It has 2 layers: a fibrous outer layer and a cellular inner layer• Sharpey’s fibers- collagen fibers that penetrate into the bone

tissue from tendons & ligaments• Epiphyses- enlarge area at both sides of a long bone. • It’s internal part is made of spongy bone that contains the • medullary cavity• Articular cartilage- thin layer of hyline cartilage covering the

surface of the •

epiphysis• Diaphysis- tubular shaft in long bones extending between the

epiphysis• Epiphysial plate or cartilage (textbook fig 6-9)- it is a • cartilaginous disk that join the epiphyses of inmature bone to • diaphysis• Epiphysial line- joins the epiphysis to diaphysis in matute bone• it remains after epiphysial growth has ended04/21/23 19

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LONG BONE(MARTINI)

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PERIOSTEUM & ENDOSTEUM(MARTINI)

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EPIPHYSEAL PLATES AND LINES

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REMEMBER, GO TO THE TUTORING ROOM AND PRACTICE WITH MODELS!

ROOM 3326

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