skeletal system

WELCOMEWELCOME

TOTO

HUMAN HUMAN SKELETAL SKELETAL SYSTEMSYSTEM

PRESENTEPRESENTED BYD BY

MR.ATUL MANKARMR.ATUL MANKARP.G.T. (BIOLOGY)P.G.T. (BIOLOGY)Kendriya Vidyalaya DIPHUKendriya Vidyalaya DIPHU

OBJECTIVESOBJECTIVES

To impart To impart knowledge about knowledge about human human skeletal systemskeletal system

To make the To make the viewers realize viewers realize their body their body frameworkframework

CONTENTSCONTENTS

INTRODUCTIONINTRODUCTION

DIVISIONS OF SKELETONDIVISIONS OF SKELETON

FUNCTIONSFUNCTIONS

The human skeletal system consists The human skeletal system consists of frame work of of frame work of

Cartilages Cartilages Bones Bones

(206) (few)(206) (few)

INTRODUCTIONINTRODUCTION

Bones & Cartilages are specialized connective Bones & Cartilages are specialized connective tissues tissues

BONES CARTILAGEBONES CARTILAGE

Has hard matrix Has slightly pliable Has hard matrix Has slightly pliable

matrixmatrix

Presence of Ca salts Presence of chondroitin Presence of Ca salts Presence of chondroitin

saltssalts

Human SkeletonHuman Skeleton

Grouped into 2 main divisionsGrouped into 2 main divisions

Axial skeleton Appendicular skeletonAxial skeleton Appendicular skeleton

HUMAN SKELETONHUMAN SKELETON

AXIAL SKELETONAXIAL SKELETON Comprises of 80 bones distributed Comprises of 80 bones distributed

along the main axis of the body along the main axis of the body Comprises of –Comprises of –

SkullSkull Vertebral column Vertebral column Sternum Sternum RibsRibs

SKULL SKULL Cranial bones (8)Cranial bones (8)

Skull Skull

Facial (14)Facial (14)

Cranial bones form the hard protective Cranial bones form the hard protective outer covering of the brainouter covering of the brain

Facial bones form front part of the skullFacial bones form front part of the skull

HyoidHyoid

It is a single U shaped bone present at It is a single U shaped bone present at the base of buccal cavity the base of buccal cavity

Also included in the skullAlso included in the skull

Our each middle ear contain 3 tiny Our each middle ear contain 3 tiny bones-bones-

Mallaeus ,Incus & StapesMallaeus ,Incus & Stapes

Called ear ossiclesCalled ear ossicles

Human skull is Human skull is dicondylicdicondylic as it as it

articulates with the superior region of articulates with the superior region of

vertebral column with the help of 2 vertebral column with the help of 2

occipital condyles.occipital condyles.

VERTEBRAL COLUMNVERTEBRAL COLUMN Formed of 26 serially arranged units Formed of 26 serially arranged units

called vertebraecalled vertebrae

It is dorsally placedIt is dorsally placed

Extends from base of the skullExtends from base of the skull

Constitutes main framework of the trunkConstitutes main framework of the trunk

The spinal cord passes through the The spinal cord passes through the central hollow neural canal of the central hollow neural canal of the vertebraevertebrae

11st st vertebra - Atlasvertebra - Atlas

It articulates with the occipital condylesIt articulates with the occipital condyles

7 cervical vertebrae - make up the neck 7 cervical vertebrae - make up the neck partpart

12 thoracic vertebrae12 thoracic vertebrae

5 lumbar vertebrae5 lumbar vertebrae

1 fused sacral vertebrae1 fused sacral vertebrae

1 fused coccygeal vertebrae1 fused coccygeal vertebrae

Function of Vertebral Function of Vertebral ColumnColumn

Protects the spinal cordProtects the spinal cord

Supports the headSupports the head

Serves as point of attachment for the Serves as point of attachment for the ribs & musculature of the backribs & musculature of the back

STERNUMSTERNUM

It is a flat It is a flat

bone on bone on

the the

ventral ventral

midline of midline of

the thoraxthe thorax

RIBSRIBS 12 pairs of ribs12 pairs of ribs

Each rib is a thin flat bone connected dorsally to the Each rib is a thin flat bone connected dorsally to the vertebral column & ventrally to the sternumvertebral column & ventrally to the sternum

Has 2 articulation surface on it’s dorsal end (dicephalic)Has 2 articulation surface on it’s dorsal end (dicephalic)

11st st 7pairs of ribs -true ribs. attached dorsally to the 7pairs of ribs -true ribs. attached dorsally to the vertebral column & ventrally to the sternum with the vertebral column & ventrally to the sternum with the help of hyaline cartilagehelp of hyaline cartilage

88thth ,9 ,9thth& 10& 10thth pairs of ribs called false ribs. Do not pairs of ribs called false ribs. Do not articulate directly with the sternum but join the 7articulate directly with the sternum but join the 7thth rib rib with the help of hyaline cartilage (vertebrochondral rib)with the help of hyaline cartilage (vertebrochondral rib)

1111thth & 12 & 12thth pairs of ribs called floating ribs. They are not pairs of ribs called floating ribs. They are not connected ventrallyconnected ventrally

RIB CAGE --- THORACIC VERTEBRAE + RIBS+ STERNUMRIB CAGE --- THORACIC VERTEBRAE + RIBS+ STERNUM

APPENDICULAR SKELETONAPPENDICULAR SKELETONLimb bones + GirdlesLimb bones + Girdles

LIMB - Each limb made of 30 bonesLIMB - Each limb made of 30 bones

Forelimb - Bones are humerus , radius + ulna Forelimb - Bones are humerus , radius + ulna

carpals (wrist- 8) metacarpals (palm -8), carpals (wrist- 8) metacarpals (palm -8),

phalanges (fingers- 14)phalanges (fingers- 14)

Hind limb - Bones are femur (thigh bone - longest)Hind limb - Bones are femur (thigh bone - longest)

tibia + fibulatibia + fibula

tarsals (ankle-7), metatarsals (sole -5),tarsals (ankle-7), metatarsals (sole -5), phalanges(toes - 14) phalanges(toes - 14)

Knee - covered by a cup shaped bone called Knee - covered by a cup shaped bone called

patellapatella

PectoralPectoral

GIRDLES GIRDLES Pelvic Pelvic

Girdle bones helps in the articulation of the Girdle bones helps in the articulation of the

upper & lower limbs with the axial skeletonupper & lower limbs with the axial skeleton

Each half of pectoral girdle consists of a CLAVICLE & a Each half of pectoral girdle consists of a CLAVICLE & a SCAPULASCAPULA

Scapula-large triangular flat boneScapula-large triangular flat bone

Situated in the dorsal part of the thorax between the 2Situated in the dorsal part of the thorax between the 2ndnd & 7& 7thth ribs ribs

Dorsal side has a slightly elevated ridge called spine Dorsal side has a slightly elevated ridge called spine which extends as a flat expanded which extends as a flat expanded acromian processacromian process

It articulates with the clavicleIt articulates with the clavicle

Below acromian a depression called glenoid cavity Below acromian a depression called glenoid cavity which atriculates with head of humerus to form which atriculates with head of humerus to form shoulder joint (ball & socket joint)shoulder joint (ball & socket joint)

Clavicle - called collar boneClavicle - called collar bone

- Long slender bone with 2 curvatures- Long slender bone with 2 curvatures

Pelvic girdle consists of 2 coxal bones:Pelvic girdle consists of 2 coxal bones:

= Each coxal bone formed by fusion of 3 bones= Each coxal bone formed by fusion of 3 bones

= Ilium ,Ischium & Pubis= Ilium ,Ischium & Pubis

= At the point of fusion of the 3 bones is a = At the point of fusion of the 3 bones is a cavity , acetabulum to which femur cavity , acetabulum to which femur articulates (ball& socket joint)articulates (ball& socket joint)

= The 2 halves of the pelvic girdle meet = The 2 halves of the pelvic girdle meet ventrally to form pubic symphysis containing ventrally to form pubic symphysis containing fibrous cartilagefibrous cartilage