skeletal system. the structures of the skeletal system include: bones, joints, and ligaments

SKELETAL SYSTEMSKELETAL SYSTEM


THE STRUCTURES OF THE SKELETALTHE STRUCTURES OF THE SKELETAL

SYSTEM INCLUDE:SYSTEM INCLUDE:

BONES, JOINTS, AND LIGAMENTS.BONES, JOINTS, AND LIGAMENTS.


FUNCTIONS OF THE SKELETAL SYSTEMFUNCTIONS OF THE SKELETAL SYSTEM

1.1. SUPPORT SUPPORT

2.2. PROTECTION PROTECTION

3.3. MOVEMENT MOVEMENT

4.4. MINERAL STORAGE MINERAL STORAGE

5.5. BLOOD CELL FORMATION BLOOD CELL FORMATION

CLASSIFICATION OF BONES BY CLASSIFICATION OF BONES BY POSITIONPOSITION

THE THE 206206 BONES OF THE HUMAN BONES OF THE HUMAN

BODY ARE GROUPED INTOBODY ARE GROUPED INTO

THE THE AXIAL AND THE AXIAL AND THE

APPENDICULAR SKELETONS.APPENDICULAR SKELETONS.

AXIAL SKELETONAXIAL SKELETON

THE THE AXIAL SKELETONAXIAL SKELETON

FORMS THE LONG AXIS OF THEFORMS THE LONG AXIS OF THE

BODY AND INCLUDES THE BODY AND INCLUDES THE

BONES OF THE SKULL, VERTEBRALBONES OF THE SKULL, VERTEBRAL

COLUMN, AND THE RIB CAGE.COLUMN, AND THE RIB CAGE.


GENERALLY THESE BONES ARE MOSTGENERALLY THESE BONES ARE MOST

INVOLVED IN PROTECTING, ANDINVOLVED IN PROTECTING, AND

SUPPORTING. SUPPORTING.

APPENDICULAR SKELETONAPPENDICULAR SKELETON

THE THE APPENDICULAR SKELETONAPPENDICULAR SKELETON

CONSISTS OF THE BONES OF THECONSISTS OF THE BONES OF THE

UPPER AND LOWER LIMBS,UPPER AND LOWER LIMBS,

AND THE GIRDLES THATAND THE GIRDLES THAT

ATTACH THE LIMBS TO THEATTACH THE LIMBS TO THE

AXIAL SKELETON.AXIAL SKELETON.


THE APPENDICULAR SKELETONTHE APPENDICULAR SKELETON

CONSISTS OF CONSISTS OF 126126 BONES. IT BONES. IT

FUNCTIONS TO HELP IN MOVEMENT.FUNCTIONS TO HELP IN MOVEMENT.

AXIAL and APPENDICULARAXIAL and APPENDICULARSKELETONSSKELETONS

CLASSIFICATION OF BONE BY CLASSIFICATION OF BONE BY SHAPESHAPE

THE BONES OF THE HUMANTHE BONES OF THE HUMAN

SKELETON COME IN MANY SIZESSKELETON COME IN MANY SIZES

AND SHAPES. BONES CAN BE AND SHAPES. BONES CAN BE

CLASSIFIED BY SHAPE INTO:CLASSIFIED BY SHAPE INTO:

LONG; SHORT; FLAT; IRREGULAR.LONG; SHORT; FLAT; IRREGULAR.

LONG BONESLONG BONES

Long bonesLong bones are are longer than they are longer than they are wide.wide.Long bones have 2 Long bones have 2 epiphysesepiphyses, and a , and a diaphysisdiaphysis..All of the bones of All of the bones of the limbs, except the the limbs, except the patella, ankle, and patella, ankle, and wrist, are long bones.wrist, are long bones.

SHORT BONESSHORT BONES

Short bonesShort bones are are cube shaped, nearly cube shaped, nearly equal in length and equal in length and width.width.The bones of the The bones of the wrist and ankle are wrist and ankle are examples of short examples of short bones.bones.

SHORT BONESSHORT BONES

A SPECIAL TYPE OF SHORT A SPECIAL TYPE OF SHORT

BONE IS A BONE IS A SESAMOND BONE.SESAMOND BONE.

THIS TYPE OF BONE IS A THIS TYPE OF BONE IS A

SHORT BONE WHICH FORMS SHORT BONE WHICH FORMS

WITHIN A TENDON. AN EXAMPLE WITHIN A TENDON. AN EXAMPLE

IS THE PATELLA, AND THE PISIFORM.IS THE PATELLA, AND THE PISIFORM.

FLAT BONESFLAT BONES

Flat bonesFlat bones are thin, are thin, flattened, and a bit flattened, and a bit curved. curved. The sternum, The sternum,

scapulae, ribs, and scapulae, ribs, and most of the bones of most of the bones of the skull are flat the skull are flat bones.bones.

IRREGULAR BONESIRREGULAR BONES

Irregular bonesIrregular bones havehave

complicated shapes complicated shapes that fit none of the that fit none of the preceding classes.preceding classes.The vertebrae, the The vertebrae, the bones of the hip, and bones of the hip, and some facial bones.some facial bones.

GROSS ANATOMY OF AGROSS ANATOMY OF A LONG BONE LONG BONE

A long bone has a A long bone has a shaft, the shaft, the DiaphysisDiaphysis, , and two ends,the and two ends,the epiphyses.epiphyses.Covering a long Covering a long bone in all area, bone in all area, except the except the

articular surfaces, is articular surfaces, is

PeriosteumPeriosteum..


Covering the articular Covering the articular surfaces is surfaces is articular,or articular,or hyaline, cartilage.hyaline, cartilage.Deep to the periosteum Deep to the periosteum

is a layer of is a layer of compact compact bone.bone.

this layer is thicker in thethis layer is thicker in the

diaphysis than thediaphysis than the

epiphysis.epiphysis.


In the diaphysis of In the diaphysis of

the long bone deep to the long bone deep to the compact bone is the compact bone is

the the medullary cavity.medullary cavity.

in an adult it is full of in an adult it is full of

yellow bone marrow.yellow bone marrow.The medullary cavityThe medullary cavity

is lined with is lined with endosteumendosteum..


In the epiphyses deep In the epiphyses deep to the layer of compact to the layer of compact bone is bone is spongy bone.spongy bone. Between theBetween the

trabeculatrabecula of the spongy of the spongy bone is bone is red bone red bone marrow.marrow.

MICROSCOPIC STRUCTUREMICROSCOPIC STRUCTURE OF COMPACT BONE OF COMPACT BONE

THE STRUCTURAL UNIT OF THE STRUCTURAL UNIT OF

COMPACT BONE IS THE COMPACT BONE IS THE OSTEON,OSTEON,

OR HAVERSIAN SYSTEM.OR HAVERSIAN SYSTEM. EACH OSTEON EACH OSTEON

IS AN ELONGATED CYLINDER IS AN ELONGATED CYLINDER

ORIENTED PARALLEL TO THE ORIENTED PARALLEL TO THE

LONG AXIS OF THE BONE.LONG AXIS OF THE BONE.


AN OSTEON IS A GROUP OF HOLLOWAN OSTEON IS A GROUP OF HOLLOW

TUBES OF BONE MATRIX,TUBES OF BONE MATRIX,

ONE PLACED OUTSIDE THE NEXTONE PLACED OUTSIDE THE NEXT

LIKE THE GROWTH RINGS OF A LIKE THE GROWTH RINGS OF A

TREE TRUNK. EACH OF THE MATRIXTREE TRUNK. EACH OF THE MATRIX

TUBES IS A TUBES IS A LAMELLA.LAMELLA.


THE COLLAGEN FIBERS IN ATHE COLLAGEN FIBERS IN A

PARTICULAR LAMELLA RUN IN PARTICULAR LAMELLA RUN IN

A SINGLE DIRECTION. A SINGLE DIRECTION.


Running through the Running through the core of each osteon is the core of each osteon is the central,or Haversian canal.central,or Haversian canal. The canal contains The canal contains small blood vessels and small blood vessels and nerve fibers that serve the nerve fibers that serve the needs of the osteon’s cells.needs of the osteon’s cells.


Spider shaped Spider shaped osteocytes osteocytes occupy small cavities occupy small cavities called called lacunaelacunae at the at the junctions of the lamellae.junctions of the lamellae.Hair like canals called Hair like canals called

canaliculi canaliculi connect the connect the

lacunae to each other.lacunae to each other.The space between these The space between these

structures is occupied by structures is occupied by bony bony matrix.matrix.

GROSS ANATOMY OF GROSS ANATOMY OF FLAT BONEFLAT BONE

OSSIFICATIONOSSIFICATION

OSSFICATION OR OSTEOGENESISOSSFICATION OR OSTEOGENESIS

IS THE PROCESS OF BONE FORMATION.IS THE PROCESS OF BONE FORMATION.

THERE ARE 2 MECHANISM THERE ARE 2 MECHANISM

WHICH FORM BONE:WHICH FORM BONE:

1. INTRAMEMBRANOUS1. INTRAMEMBRANOUS

2. ENDOCHONDRAL2. ENDOCHONDRAL


INTRAMEMBRANOUS OSSIFICATIONINTRAMEMBRANOUS OSSIFICATION

RESULTS IN THE FORMATION RESULTS IN THE FORMATION

OF THE CRANIAL BONES AND OF THE CRANIAL BONES AND

THE CLAVICLES.THE CLAVICLES.


ENDOCHONDRAL OSSIFICATIONENDOCHONDRAL OSSIFICATION

RESULTS IN THE FORMATION OF THERESULTS IN THE FORMATION OF THE

BONES BELOW THE BONES BELOW THE

SKULL, WITH THE EXCEPTION OF SKULL, WITH THE EXCEPTION OF

THE CLAVICLES.THE CLAVICLES.


THREE TYPES OF CELLS ARE INVOLVEDTHREE TYPES OF CELLS ARE INVOLVED

IN BOTH MECHANISM OF OSSIFICATION:IN BOTH MECHANISM OF OSSIFICATION:

1. OSTEOBLASTS1. OSTEOBLASTS

2. OSTEOCLASTS2. OSTEOCLASTS

3. OSTEOCYTES3. OSTEOCYTES

STEPS OF INTRAMEMBRANOUS STEPS OF INTRAMEMBRANOUS OSSIFICATIONOSSIFICATION

1. Selected 1. Selected mesenchymal cellsmesenchymal cells

cluster and form cluster and form osteoblasts.osteoblasts.

2. This forms an 2. This forms an ossification center.ossification center.


3. 3. Osteoblasts begin Osteoblasts begin to secrete osteoid, to secrete osteoid, which mineralized.which mineralized.

4. The osteoblasts 4. The osteoblasts are trapped are trapped differentiate into differentiate into osteocytes.osteocytes.


5. Accumulating 5. Accumulating osteoid is laid down osteoid is laid down between embryonic between embryonic blood vessels.blood vessels.

6. This forms a 6. This forms a network of trabulae.network of trabulae.


7. Vascularized 7. Vascularized mesenchyme mesenchyme condenses on the condenses on the external face external face

of the woven bone and of the woven bone and becomes the becomes the periosteum.periosteum.


8. Trabeculae just 8. Trabeculae just deep to the deep to the periosteum thicken, periosteum thicken, forming a bone collar.forming a bone collar.

9. The bony collar is 9. The bony collar is later replaced with later replaced with mature compact bone.mature compact bone.


10. Spongy bone, 10. Spongy bone, consisting of distinct consisting of distinct trabeculae, are trabeculae, are presentpresent

internally. Blood internally. Blood vessels vessels

differentiate into red differentiate into red bone marrowbone marrow..

STEPS OF ENDOCHONDRAL STEPS OF ENDOCHONDRAL OSSIFICATIONOSSIFICATION

1. The perichondrium 1. The perichondrium covering the hyaline covering the hyaline cartilage “bone” is cartilage “bone” is infiltrated with bloodinfiltrated with blood

vessels.vessels.

2. Osteoblasts secrete 2. Osteoblasts secrete osteoid against the osteoid against the hyaline cartilage hyaline cartilage diaphysis, encasing it in diaphysis, encasing it in a bony collar.a bony collar.


3. Chondrocytes 3. Chondrocytes within the diaphysis within the diaphysis hypertrophy and hypertrophy and signal the signal the surrounding cartilage surrounding cartilage matrix to calcify.matrix to calcify.

4. The chondrocytes, 4. The chondrocytes, however, die and the however, die and the matrix begins to matrix begins to deteriorate.deteriorate.


5. In month 3, the 5. In month 3, the forming cavities are forming cavities are invaded by a invaded by a collection of collection of elements called the elements called the periosteal bud.periosteal bud.

6. The entering 6. The entering osteoclasts partially osteoclasts partially erode the calcified erode the calcified cartilage matrix.cartilage matrix.


7. Osteoblasts 7. Osteoblasts secrete osteoid secrete osteoid around the around the remaining fragments remaining fragments of hyaline cartilage of hyaline cartilage forming trabeculae.forming trabeculae.


8. As the primary 8. As the primary ossification center ossification center enlarges, osteoclasts enlarges, osteoclasts break down the newly break down the newly formed spongy bone formed spongy bone and open up a and open up a medullary cavity in medullary cavity in the center of the the center of the diaphysis.diaphysis.


9. The epiphyses remain 9. The epiphyses remain formed of cartilage until formed of cartilage until shortly before or after shortly before or after birth.birth.

10. Secondary 10. Secondary ossification centers form ossification centers form in the epiphyses. The in the epiphyses. The events of ossification are events of ossification are like the events of the like the events of the diaphysis, except, that diaphysis, except, that spongy bone mains in the spongy bone mains in the internal and no medullary internal and no medullary cavity forms.cavity forms.

BONE GROWTHBONE GROWTH

THERE ARE 2 TYPES OF THERE ARE 2 TYPES OF

BONE GROWTH:BONE GROWTH:

1.1. LONGITUDINAL--LENGTH LONGITUDINAL--LENGTH

2. APPOSITIONAL--DIAMETER 2. APPOSITIONAL--DIAMETER

LONGITUDINAL BONE GROWTH

Epiphysealplate

APPOSITIONAL BONE GROWTH

Osteoblast

BONE GROWTHBONE GROWTH

CALCIUM HOMEOSTASISCALCIUM HOMEOSTASIS

FACTORS OF CALCIUMFACTORS OF CALCIUM

HOMEOSTASIS:HOMEOSTASIS:

1. HORMONES1. HORMONES

2. VITAMIN D—MILK2. VITAMIN D—MILK

3. CALCIUM—MILK3. CALCIUM—MILK

4. VITAMIN A—CARROTS4. VITAMIN A—CARROTS

5. PHOSPHORUS—MEAT 5. PHOSPHORUS—MEAT

HORMONAL CONTROL OF HORMONAL CONTROL OF CALCIUM HOMEOSTASISCALCIUM HOMEOSTASIS


OTHER FACTORS IN CALCIUMOTHER FACTORS IN CALCIUM

HOMEOSTASIS:HOMEOSTASIS:

1. VITAMIN D—AIDS IN THE ABSORPTION1. VITAMIN D—AIDS IN THE ABSORPTION

OF BOTH CALCIUM AND PHOSPHORUS.OF BOTH CALCIUM AND PHOSPHORUS.

2. VITAMIN A—HELPS THE OSTEOBLASTS2. VITAMIN A—HELPS THE OSTEOBLASTS

PRODUCE BONY MATRIX.PRODUCE BONY MATRIX.


3. TESTOSTERONE AND ESTROGEN—3. TESTOSTERONE AND ESTROGEN—

STIMULATES BONE DEPOSITION OF STIMULATES BONE DEPOSITION OF

CALCIUM STARTING AT PUBERTY.CALCIUM STARTING AT PUBERTY.

HOMEOSTATIC IMBALANCES HOMEOSTATIC IMBALANCES OF THE SKELETAL SYSTEMOF THE SKELETAL SYSTEM

RICKETSRICKETS

1. DISEASE OF CHILDREN DUE TO1. DISEASE OF CHILDREN DUE TO

LACK OF VITAMIN D.LACK OF VITAMIN D.

2. CALCIUM IS NOT DEPOSITED.2. CALCIUM IS NOT DEPOSITED.

3. BOWING OF THE BONES.3. BOWING OF THE BONES.


OSTEOMALCIAOSTEOMALCIA

1. RICKETS IN ADULTS1. RICKETS IN ADULTS

2. DUE TO A LACK OF VITAMIN D2. DUE TO A LACK OF VITAMIN D

3. CALCIUM IS NOT DEPOSITED IN3. CALCIUM IS NOT DEPOSITED IN

BONE.BONE.

4. MAIN SYMPTOM IS PAIN WHEN WEIGHT IS PUT ON THE AFFECTED BONE.


OSTEOPOROSISOSTEOPOROSIS

1. BONE REABSORPTION IS GREATER 1. BONE REABSORPTION IS GREATER

THAN BONE DEPOSITION.THAN BONE DEPOSITION.

2. CAUSES:2. CAUSES:

A. LACK OF ESTROGEN A. LACK OF ESTROGEN

B. LACK OF EXERCISEB. LACK OF EXERCISE

C. INADEQUATE INTAKEC. INADEQUATE INTAKE

D. LACK OF VITAMIN DD. LACK OF VITAMIN D


OSTEOPOROSISOSTEOPOROSIS

3. SIGNS AND SYMPTOMS:3. SIGNS AND SYMPTOMS:A. SPONGY BONE OF THE SPINE IS MOST VULNERABLE.A. SPONGY BONE OF THE SPINE IS MOST VULNERABLE.B. OCCURS MOST OFTEN IN POSTMENOPAUSAL B. OCCURS MOST OFTEN IN POSTMENOPAUSAL WOMEN.WOMEN.C. BONES BECOME SO FRAGILE THAT SNEEZING OR C. BONES BECOME SO FRAGILE THAT SNEEZING OR STEPPING OFF A CURB CAN CAUSE FRACTURES.STEPPING OFF A CURB CAN CAUSE FRACTURES.

4. TREATMENT4. TREATMENTA. CALCIUM AND VITAMIN D SUPPLEMENTS.A. CALCIUM AND VITAMIN D SUPPLEMENTS.B. HORMONE REPLACEMENT TREATMENTB. HORMONE REPLACEMENT TREATMENTC. INCREAE WEIGHT BEARING EXERCISE.C. INCREAE WEIGHT BEARING EXERCISE.

skeletal system. the structures of the skeletal system include: bones, joints, and ligaments

Documents

long bone slide

long bones long bones

short bones short bones

appendicular skeleton

axial skeleton slide

flat bones flat bones

classification of bones

facial bones