BONES JOINTS AND MUSCLES

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BONES JOINTS AND MUSCLES

• DR. VINIT.K.ASHOK
• ADJUNCT FACULTY

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INTODUCTION/FUNCTION

• INTRODUCTION-BONES FORM THE SKELETAL SYSTEM
  ,BONES ARE FORMED OF MANY TISSUES, CONTAIN NERVES
  AND BLOOD VESSELS.BONES ARE ATTACHED TO EACH
  OTHER AT JOINTS.THE COMBINATION OF BONES, JOINTS
  AND RELATED CONNECTIVE TISSUE FORM THE SKELETAL
  SYSTEM.THERE ARE A TOTAL OF 206 BONES IN THE
  SKELETON
• FUNCTIONS
• -BONES GIVE SHAPE TO THE BODY AND FORM A FIRM
  FRMEWORK
• TO SUPPOT THE WEIGHT OF THE BODY
• -TO PROTECT DELICTE STRUCTURES( BRAIN, SPINAL
  CORD, LUNGS)
• -WORK AS LEVERS, ALONG WITH THE ATTACHED MUSCLES
  BRING ABOUT MOVEMENT
• -STORE MINERALS LIKE CALCIUM AND PHOSPHATE. THESE
  ARE RELEASED INTO THE BLOOD WHEN NEEDED
• -SITE OF ERYTHROPOIESIS( RED BLOOD CELLFORMATION)

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CLASSIFICATION OF BONESACCORDING TO THEIR SHAPE

• LONG BONES-
• -LONGER THAN WIDER. EACH LONG BONE HAS A
  SHAFT,UPPER( PROXIMAL END) AND A LOWER( DISTAL
  END)
• -MOST OF THE BONES OF THE LIMBS ARE LONG BONES(
  HUMERUS,FEMUR)
• -SHORT LONG BONES ARE PRESENT IN THE HAND AND
  FEET( PHALANGES)
• SHORT BONES-
• -THESE BONES ARE CUBE SHAPED( CARPAL BONES OF THE
  WRIST)
• -SESAMOID BONES ARE ANOTHER TYPE OF SHORT BONE,
  THEY ARE FORMED WITHIN A TENDON( PATELLA)
• FLAT BONES-
• THIN FLAT AND CURVED BONES
• -SKULL BONES, RIBS , STERNUM( BREAST BONE)
• IRREGULAR BONES-
• THEY HAVE DIFFERENT SHAPES
• EXAMPLES ARE VETEBRAE, HIP BONES

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stucture of long bone
spongy bone
EPIPHYSIS
SPONGY BONE
epiphysis
ARTICULAR CARTILAGE
compact bone
COMPACT BONE
medullary cavity
MEDULLARY CAVITY
articular cartilge
diaphysis
YELLOW BONE MARROW
DIAPHYSIS
SHARPEY'S FIBRES
PERIOSTEUM
epiphysis
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ANATOMY OF BONES

• COMPACT BONE-THIS IS HARD AND DENSE BONE,FORMS
  THE OUTER LAYER OF BONES , FORMS THE SHAFT OFLONG
  BONES.THE OSTEOCYTES IN THIS ARE IN RINGS AROUND
  A CANAL( HAVERSIAN CANAL)
• SPONGY BONE- THIS HAS MORE SPACES THAN COMPACT
  BONES(HONEYCOMB).MADE UP OF A MESHWORK OF BONY
  PLATES FILLED WITH RED MARROW AND IS FOUND AT THE
  END OF LONG BONES AND THE CENTER OF OTHER BONES
• RED MARROW- IS THE SITE WHERE RED BLOOD CELLS
  ARE FORMED
• YELLOW MARROW WHERE NO RED BLOOD CELLS ARE
  FORMED. FILLED WITH FAT

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ANATOMY OF A LONG BONE

• DIAPHYSIS-THIS IS THE SHAFT OF THE BONE AND
  CONTAINS THE MARROW CAVITY
• EPIPHYSIS- THE IRREGULAR ENDS OF THE LONG BONE
• EPIPHYSEAL LINE- THIS IS PRESENT BETWEEN THE
  DIAPHYSIS AND EPIPHYSIS OF AN ADULT LONG BONE
• EPIPHYSEAL PLATE- THIS IS A PLATE OF HAYLINE
  CARTILAGE PRESENT IN CHILDREN BETWEEN THE
  EPIPHYSIS AND DIAPHYSIS( ALLOWS GROWTH OF THE
  BONE)
• ARTICULAR CARTILAGE- IT COVERS THE ENDS OF THE
  LONG BONES(EPIPHYSIS)
• PERIOSTEUM-BONES ARE COVERED ON THE OUTSIDE
  EXCEPT AT THE JOINT REGION BY THIS MEMBRANE.
• a) PROVIDES NOURISHMENT
• b) ATTACHMENT FOR LIGAMENTS AND TENDONS
• c) OSTEOGENESIS
• -MEDULLARY CAVITY- IT IS IN THE DIAPHYSIS OF THE
  LONG BONES, AND THERE IS NO BONE TISSUE. IT IS
  FILLED WITH YELLOW BONE MARROW
• ENDOSTEUM- THE MEMBRANE THAT LINES THE INNER
  SURFACE OF THE BONE.HAS OSTEOBLASTS( FORM NEW
  BONE), OSTEOCLASTS( BONE RESORPTION),NOURISHMENT
  

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ANATOMY OF SHORT /IRREGULAR/FLAT BONES

• LOOK SIMILAR TO EACH OTHER HISTOLOGICALLY
• PRESENCE OF PERIOSTEUM EXTERNALLY AND ENDOSTEUM
  INTERNALLY
• DO NOT HAVE DIAPHYSIS
• HAVE NO MARROW CAVITY BUT HAVE BONE MARROW IN THE
  SPACES INSIDE THE BONE
• IN THE FLAT BONES( SKULL) THE SPACES INSIDE ARE
  CALLED DIPLOE AND THESE CONTAIN BONE MARROW

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HISTOLOGY OF BONE (OSSEOUS TISSUE)

• CONNECTIVE TISUE ,HAVING CELLS AND INTERCELLULAR
  SUBSTANCE( MATRIX)
• CELLS ARE OSTEOBLASTS,OSTEOCYTES AND OSTEOCLASTS(
  GIANT CELLS)
• MATRIX HAS COLLAGEN FIBRES AND HYDRXYAPATITES(
  MINERAL SALTS CALCIUM AND PHOSPHATE)
• HISTOLOGICALLY COMPACT BONE LOOKS DIFFERENT FROM
  THE SPONGY BONE
• OSSIFICATION---- FORMATION OF BONE TISSUE( 2ND
  -3RD MONTH OF IUL)

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HISTOLOGY OF COMPACT BONE
OSTEON
CENTRAL CANAL
OSTEOCYTE
INTERSTITIAL LAMELLAE
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HISTOLOGY OF COMPACT BONE

• HAVERSIAN SYSTEM( OSTEON)FORMS THE MAIN
  HISTOLOGICAL COMPONENT
• OSTEONS ARE PLACED ALONG THE LONG AXIS OF THE
  BONE
• MICROSCOPICALLY AN OSTEON LOOKS LIKE A CROSS
  SECTION OF A TREE TRUNK AND IT HAS CONCENTRIC
  CIRCLES( CONCENTRIC LAMELLAE)
• PRESENT IN THE MIDDLE OF EACH OSTEON IS A CANAL(
  HAVERSIAN CANAL). IT IS LINED WITH ENDOSTEUM HAS
  HAS BLOOD VESSELS AND NERVES WHICH SUPPLY THE
  BONE
• OSTEOCYTES ARE THE MATURE BONE CELLS AND LOOK
  LIKE SPIDERS AND ARE PRESENT IN A SPACE CALLED A
  LACUNA. THE SPIDER LEGS OCCUPY THIN TUBES CALLED
  CANALICULI.( THESE HELP IN DIFFUSION). THE MAIN
  FUNCTION OF THE OSTEOCYTE IS TO MAINTAIN THE BONE
  MATRIX

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• HISTOLOGY OF SPONGY ( CANCELLOUS ) BONE
• PRESENCE OF BONY TRABACULAE
• THEY ENCLSE THE MARROW SPACES
• PERIPHERALLY THESE TRABACULAE MERGE WITH THIN
  SHELL OF COMPACT BONE WHICH HAVE OSTEONS
• WITHIN THE MARROW SPACES ARE THE BLOOD FORMING
  CELLS ( HEMOPOETIC) AND FAT CELLS ( ADIPOSE
  CELLS)
• THERE ARE ALOS BLOOD VESSELS WITHIN THE MARROW
  SPACES

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FORMATION OF BONE(OSSIFICATION)

• THIS BEGINS IN THE EMBRYO AND GOES ON THROUGH
  CHILHOOD AND ADOLESCENCE , AS THE SKELETON KEEPS
  GROWING AND OCCURS AT A SLOWER RATE IN ADULTS(
  REMODELLING)
• THERE ARE 2 TYPES OF OSSIFICATION
• a)Intramembranous ossification-
• b)Enchondral ossification-

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OSSIFICATION
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INTRAMEMBRANOUS OSSIFICATION

• MEMBRANE BONES DEVELOP LIKE THIS ( SKULL BONES,
  CLAVICLE)
• DURING THE 8TH WEEK OF EMBRYONIC DEVELOPMENT
  CERTAIN CELLS IN THE MESENCHYMAL MEMBRANE BECOME
  OSTEOBLASTS( BONE FORMING CELLS)
• THESE CELLS SECRETE OSTEOID( ORGANIC PART OF THE
  BONE MATRIX), THIS GETS CALCIFIED AND THE
  OSTEOBLASTS FORM THE MATURE OSTEOCYTES.

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SKULL BONES
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INTRMEMBRANOUS OSSIFICATION
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ENCHONDRAL OSSIFICATION

• ALL THE REST OF THE BONES EXCEPT THE SKULL BONES
  AND THE CLAVICLE DEVELOP LIKE THIS
• FIRST A CARTILAGE MODEL IS FORMED WHICH IS THEN
  REPLACED WITH BONE TISSUE
• BEGINS IN THE 2ND MONTH OF THE EMBRYO, AND GOES
  ON TO EARLY ADULHOOD

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FORMATION OF A LONG BONE
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DIVISION OF THE SKELETON

• AXIAL/ APPENDICULAR
• AXIAL---SKULL,VERTEBRAL COLUMN ,THORACIC CAGE( 80
  BONES)
• APPENDICULAR SHOULDER GIRDLE,PELVIC GIRDLE AND
  LIMB BONES( 126 BONES)

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MUSCLES

• MUSCLES ATTACHED TO THE SKELETON ARE CALLED
  SKELETAL MUSCLES AND THEY FORM THE BULK OF THE
  MUSCULATURE IN THE HUMAN BODY
• FUNCTIONS-
• -BRING ABOUT MOVEMENT IN THE BODY
• -RESPONSIBLE FOR FACIAL EXPRESSIONS( FACIAL
  MUSCLES)
• -GIVES SHAPE TO THE BODY

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DIFFERENCES BETWEEN SKELETAL,SMOOTH AND CARDIAC
MUSCLES

• SKELETAL MUSCLES
• VOLUNTARY MUSCLE
• STRIATED
• NOT BRANCHED
• MULTINUCLEATED( NUCLEUS PRESENT PERIPHERALLY)
• NOT BRANCHED
• CYLINDRICAL IN SHAPE
• PRESENT INRELATION TO BONES

• SMOOTH MUSCLES
• -INVOLUNTARY MUSCLE
• -NOT STRIATED
• -SPINDLE SHAPED
• -SINGLE CENTRAL NUCLEUS
• -PRESENT IN RELATION TO ORGANS( GIT)

• CARDIAC MUSCLES
• -INVOLUNTARY MUSCLE
• -STRIATED
• -BRANCHED
• -SINGLE CENTRAL NUCLEUS
• -CYLINDRICAL IN SHAPE
• -PRESENT ONLY IN THE HEART

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CLASSIFICATION OF SKELETAL MUSCLES

• BASED ON THE DIRECTION OF MUSCLE FIBRES.
• RECTUS-( STRAIGHT) MUSCLE WHERE THE FIBRES ARE
  RUNNING PARALLEL TO AN IMAGINARY LINE ALONG THE
  LONG AXIS OF A LIMB BONE OR MIDLINE OF THE BODY(
  RECTUS ABDOMINIS)
• TRANVERSE- FIBRES RUNNING AT RT ANGLES TO AN
  IMAGINARY LINE( TRANVERSUS ABDOMINIS)
• OBLIQUE-FIBRES RUN OBLIQUELY( EXTERNAL OBLIQUE)
• BASED ON SIZE OF MUSCLE FIBRES.
• MAXIMUS-LARGEST( GLUTEUS MAXIMUS)
• MINIMUS SMALLEST( GLUTEUS MINIMUS)
• LONGUS-LONG( ADDUCTOR LONGUS)
• BREVIS-SHORT( ADDUCTOR BREVIS)

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CLASSIFICATION-2

• BASED ON THE LOCATION
• -FRONTALIS( PRSENT IN THE FRONTAL REGION)
• BASED ON THE NUMBER OF ORIGINS
• BICEPS( 2 ORIGINS, 2 BELLIES)
• TRICEPS( 3 ORIGINS , 3 BELLIES)
• QUADRICEPS( 4 ORIGINS ,4 BELLIES)
• BASED ON THE LOCATION OF ORIGIN AND INSERTION
• -STRENOCLIEDOMASTOID.( ORIGIN ON THE STERNUM AND
  CLAVICLE AND INSERTION ON THE MASTOID PROCESS)
• BASED ON SHAPE OF THE MUSCLE
• DELTOID( SHAPE OF A TRIANGLE)
• TRAPEZIUS( TRAPEZOID IN SHAPE)
• BASED ON ACTION OF THE MUSCLE
• EXTENSORS( CAUSE EXTENSION)

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BONE MUSCLE RELATIONSHIPLEVER SYSTEMS

• LEVER SYSTEM-CONSISTS OF A RIGID BAR ( LEVER)
  WHICH MOVES ON A FIXED PONIT ( FULCRUM) WHEN A
  FORCE IS APPLIED( EFFORT) TO MOVE A RESISTANCE(
  LOAD)
• THE BONES AND MUSCLES IN THE BODY ACT AS LEVER
  SYSTEMS
• BONESLEVERS
• JOINTS---FULCRUM
• MUCLES CONTRACTING ---EFFORT
• RESISTNCE(LOAD)-----BONE ITSELF ALL RELATED
  STRUCTURES

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LEVER SYSTEM
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TYPES OF LEVERS

• FIRST CLASS LEVERS-
• -FULCRUM LIES BETWEEN THE EFFORT AND THE LOAD(
  SEE-SAW)
• EFFORT IS APPLIED AT ONE END AND LOAD LIES ON THE
  OTHER END
• SECOND CLASS LEVERS
• -LOAD LIES BETWEEN EFFORT AND FULCRUM(
  WHEELBARROW)
• GREATER STRENGTH, LESS SPEED AND RANGE OF ACTION
• THIRD CLASS LEVERS
• EFFORT LIES BETWEEN LOAD AND FUNCTIONFAST LARGE
  MOVEMENTS WITH LITTLE EFFORT
• MOST SKELETAL MUSCLES ARE OF THIS TYPE

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Second class levers
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THIRD CLASS LEVERS
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OPERATION OF SKELETAL MUSCLES

• ORGIN VS INSERTION
• MORE FIXED ATTACHMENT IS THE ORIGIN
• THE LESS FIXED ATTACHMENT IS TH INSERTION
• FUNCTION TYPES BASED ON ACTIONS
• -PRIME MOVER ( AGONIST)- THE MUSCLE THAT IS
  RESPONSIBLE FOR A SPECEFIC ACTION ( BICEPS FLEXES
  THE FOREARM AT THE ELBOW)
• ANTAGONIST MUSCLES THAT OPPSE A PARTICULAR
  ACTION( RELXED WHEN AGONIST ARE ACTING( TRICEPS
  ARE RELAXED WHEN BICEPS ACT)
• SYNERGISTS- THESE ACT ALONG WITH AGONISTS ADD A
  LITTLE EXTRA FORCE TO THE ACTION
• FIXATORS- THEY HELP THE AGONIST BY HOLDING A BONE
  IN PLACE