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The Skeletal System

Chapter 5

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Objectives:

•List and describe the major functions of the skeletal system.•Describe the types of various bone tissues, their locations, and functions.•List, describe and give specific examples of the types of bones.•List and describe the two major divisions of the skeletal system and the bones which compose each.•Describe the process of bone formation.•List and describe the various types of joints.•List and describe various disorders and diseases of the skeletal system.

The Skeletal System

Click on the trunk's lid and then use the red knob to pull the object from the trunk.

What would you look like if you did not have any bones? Take a minute a make a sketch of what you think you might look like. Could you stand up? Could you walk? Without bones you would be just a puddle of skin and organs on the floor.

The human skeleton contains

206 bones!

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Functions of the Skeletal System

•Support of the body•Protection of soft organs•Movement due to attached skeletal muscles•Storage of minerals and fats•Blood cell formation (hematopoiesis)

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·The skeleton has 206 bones·Two basic types of bone tissue·Compact bone·Homogeneous·Located on the outside surface·Spongy bone·Small needle-like ·pieces of bone (trabeculae)·Many open spaces

Where marrow is located

Types of Bone Tissue

Diagram on p. 118

Compact Bone Spongy Bone- hard bone- surrounds spongy bone- made of osteon systems that contain blood vessels- made of osteocytes

(living bone cells)

- less dense bone- contains many holes and spaces

spongy

compact

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Classification of Bones by Shape

•Long bones –Typically longer than wide –Have a shaft (long, central cylinder) with heads at both ends –Contain mostly compact bone

•Examples: Femur, humerus•Short bones

–Generally cube-shape –Contain mostly spongy bone

•Examples: Carpals, tarsals

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•Flat bones –Thin and flattened –Usually curved –Thin layers of compact bone around a layer of spongy bone

•Examples: Skull, ribs, sternum•Irregular bones

–Irregular shape –Usually with projections (processes) or openings (foramen) –Do not fit into other bone classification categories

•Example: Vertebrae and pelvic bones

Classification of Bones by Shape

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Classification of Bones by Shape

Diagram on p. 117

Color in the types of bonesbased on the correct classifications.

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Microscopic Bone Anatomy

Diagram on p. 120

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Microscopic Bone Anatomy

•Osteon (Haversian System)–A unit of bone

•Central (Haversian) canal–Opening in the center of an osteon–Carries blood vessels and nerves

•Perforating (Volkman’s) canal–Canal perpendicular to the central canal–Carries blood vessels and nerves

Diagram on p. 120

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Microscopic Bone Anatomy

•Lacunae–Cavities containing bone cells (osteocytes)–Arranged in concentric rings

•Lamellae–Rings around the central canal–Sites of lacunae

•Canaliculi –Tiny canals–Radiate from the central canal to lacunae–Form a transport system between cells

Diagram on p. 120

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Bone Cell Types

•Osteocytes–Mature bone cells surrounded by matrix•Osteoblasts–Bone-forming cells produce new matrix•Osteoclasts–Bone-destroying cells–Break down bone matrix for remodeling and release of calcium•Bone remodeling is a process by both osteoblasts and osteoclasts. –During your life span the your skeleton is broken down and rebuilt completely on the average of seven times!

Sharpey's fibersPeriosteum

Lacunae

LamellaOsteocytes Haversian/central canal

Volkmann's canal Spongy boneCompact boneBlood vessel

Osteon

Canaliculi Lamella

Review! Bone ClassificationsLong Bones Flat Bones

Irregular Bones Short Bones

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Gross Anatomy of a Long Bone

•Diaphysis–Shaft–Composed of compact bone

•Epiphysis –Ends of the bone–Composed mostly of spongy bone–Contains red marrow

•Medullary cavity–Cavity of the shaft–Contains yellow marrow (mostly fat) in adults

•Articular cartilage–Covers the external surface of the epiphyses–Made of hyaline cartilage–Decreases friction at joint surfaces

Diagram on p. 118

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Gross Anatomy of a Long Bone

•Periosteum–Outside covering of the diaphysis–Fibrous connective tissue membrane

•Sharpey’s fibers–Secure periosteum to underlying bone

•Endosteum - Inner lining of the medullary cavity

•Arteries, veins, nerves–Found in the Haversian and Volkman canal systems within the compact bone.

Diagram on p. 118

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Bone Development and Growth•During development, cartilage is replaced by bone (ossification)•Cartilage remains in isolated areas–Bridge of the nose–Parts of ribs–Joints •Bones are remodeled and lengthened until growth stops–Bones change shape somewhat–Bones grow in width

Diagram on p. 121

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Bone Development and Growth

•Epiphyseal plates allow for growth of long bone during childhood–New cartilage is continuously formed–Older cartilage becomes ossified•Cartilage is broken down•Bone replaces cartilage

Diaphysis

Sharpey's fibers

Bone marrow

Spongy bone

Compact boneEpiphyseal lineCartilage

EpiphysisEpiphysisSpongy bone

Compact bonePeriosteumBlood vessels

Medullary Cavity CartilageCompact bonePeriosteum

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Divisions of the Skeleton

•The Skeleton is divided into two major regions:

a. Axial Skeleton b. Appendicular Skeleton

•Axial Skeleton - longitudinal part of the body

–Divided into three parts •Skull •Vertebral column •Bony thorax

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•Appendicular skeleton - appendages and joints –Limbs (appendages) –Pectoral girdle (shoulder, scapula, and clavicle) –Pelvic girdle (pelvis)

Divisions of the Skeleton

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Divisions of the Skeleton

Diagram p. 125

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Label Mr. Bones!

FibulaPatella

Cranium

Mandible

Metatarsals

Clavicle

Vertebra

Metacarpals

Radius

Scapula

Femur

Ulna

Sacrum

Humerus

Pelvic

Sternum

Ribs

Tibia

skull

clavicle

scapula

costals

humerus

radius

ulna

metacarpals

femur

patella

tibia

fibula

metatarsals

vertebra

pelvis

Boneyard Bill'sBody Parts

Can you drag all the bones to their correct locations?

C L A V I C L E

FE

MU

R

VERTEB

AR

LN

A

RANIUM

IB

UL

A

HUMERUS

J W B O N E

P AT E L LA

PELVIS

P

AL

ANGES

H

AD

IU

S

I B S

L AS C U PA

SPINE

S T E R N U M

IBIA

LN

A

AB

C D

E

F

G

A

E

H

Y

T

JM

N

S

Y

S

O

O

P

E

P

L L

ES C H O O L

T

A

T

T

K

DC

T AB

E

E

E

E

ML

NN

TTS

S

B

DRAGO

N

O G

T

U

RT

L

ES

ZX

V

M

RWR

A

A

A

AAS

S

E

E

A

OO

O

S

S SA

A

A

H

M

T

N

K

I

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EB O A

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AB

CD

F

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How fast can your class find the words?

SPINE

ULNA

FIBULAFEMUR

PATELLA

CLAVICLE

RADIUS

STERNUM

TIBIAPELVISPHALANGES

JAWBONE

CRANIUM

RIBSHUMERUS

VERTEBRA

SCAPULA

BONES, BONES, BONESAs you find the bones, identify them on Steve!

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Axial Skeleton: The Skull

•Two sets of bones –Cranium –Facial bones

•Bones are joined by sutures (fixed, non-movable joints)

•Only the mandible is attached by a freely movable joint

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Axial Skeleton: The Skull

Diagram p. 126

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Axial Skeleton: The SkullDiagram p. 129

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Axial Skeleton: The SkullDiagram p. 127

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Axial Skeleton: The Skull•Paranasal sinuses: Hollow portions of bones surrounding the nasal cavity –Functions •Lighten the skull •Give resonance and amplification to voice

Diagram p. 128

Parietal bone

Temporal bone Occipital bone

Frontal bone

MandibleSphenoid bone

Lacrimal boneEthmoid boneNasal bone

Zygomatic bone

Maxilla Suture

Suture Suture

Auditory meatus

Styloid process

Mastoid process

Mandibular ramusMental foramen

Suture

Frontal bone

Parietal boneTemporal bone

Sphenoid bone

Nasal bone

MaxillaMandible VomerLacrimal bone Ethmoid bone

Zygomatic boneInferior nasal concha

Alveolar margins

Optic canal

Middle nasal concha

Practice Makes Perfect!

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Axial Skeleton: Hyoid Bone

·The only bone that does not articulate with another bone·Serves as a moveable base for the tongue

Figure 5.12

Diagram p. 130

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Axial Skeleton: Vertebral Column

·Vertebrae are separated by intervertebral discs composed of fibrocartilage·The spine has a normal curvature·Each vertebrae is given a name according to its location

Diagram p. 131

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Axial Skeleton: Vertebral Column

Diagram p. 133

Cervical vertebrae

Thoracic vertebrae

Lumbar vertebrae

Sacrum Coccyx C1 Atlas

C2 Axis

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Appendicular Skeleton: Pectoral Girdle

•Composed of two bones –Clavicle – collarbone –Scapula – shoulder blade•These bones allow the upper limb to have

exceptionally free movement

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Appendicular Skeleton: Pectoral Girdle (Shoulder)

Diagram p. 139

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Appendicular Skeleton: Brachium Region

·The arm is formed by a single bone·Humerus

Diagram p. 140

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Appendicular Skeleton: Antebrachium Region

•The forearm has two bones •Ulna (side adjacent to little finger) •Radius (side adjacent to thumb)

Diagram p. 140

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Appendicular Skeleton: Carpus, Manus, and Digits Region

·The hand ·Carpals – wrist

·Metacarpals – palm ·Phalanges – fingers

Diagram p. 141

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Appendicular Skeleton: Pelvic Girdle

•Hip bones•Composed of three pair of fused bones

–Ilium –Ischium –Pubic bone•The total weight of the upper body rests on the

pelvis•Protects several organs

–Reproductive organs –Urinary bladder –Part of the large intestine

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Appendicular Skeleton: Pelvic Girdle

The sacrum and coccyx are part of the axial skeleton not appendicular skeleton.

Diagram p. 142

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Appendicular Skeleton: Pelvic GirdleCoxal Bone Structure

Diagram p. 142

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Appendicular Skeleton: Pelvic GirdleMale and Female Pelvis Comparison

Diagram p. 142

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Appendicular Skeleton: Femoral Region

·The thigh has one bone·Femur – thigh bone

Diagram p. 144

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Appendicular Skeleton: Patellar and Crural Regions

·The leg has two bones·Tibia·Fibula

Diagram p. 144

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Appendicular Skeleton: Tarsal, Pes, and Digits Regions

·The foot·Tarsus – ankle·Metatarsals – sole·Phalanges – toes

Diagram p. 145

Word Sort! Arrange the words into categories!

Compact

Spongy

Lacunae

Lamella Osteoclast

Osteoblast

Central canal

Volkmann's canal

Diaphysis

Epiphysis

MarrowHumerus

Cartilage Ossification

Femur

Phalanges

Costals

Scapula

Vertebra

Pelvis

CarpalsSternum

Patella

Cranium

Mandible

Suture

Nasal bone

Zygomatic bone

Ethmoid bone

Maxilla

Parietal bone

Occipital bone

Sphenoid bone

Temporal bone

Frontal bone

Lumbar

Cervical

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Articulations: Joints•A joint is a location where two or more bones

meet.•Functions of joints

–Hold bones together –Allow for mobility

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Types of Joints

•Ways joints are classified structurally: –Fibrous joints •Generally immovable (sutures of skull) –Cartilaginous joints •Immovable or slightly moveable (vertebral disc) –Synovial joints •Freely moveable (shoulder, pelvis, knee, elbow, digits) •Articulating bones are separated by a joint cavity •Synovial fluid is found in the joint cavity

•Ways joints are classified functionally: •Synarthroses – immovable

•Amphiarthroses – slightly moveable •Diarthroses – freely moveable

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Anatomy of Synovial Joints

•Articular cartilage – (hyaline) covers ends of bones•Fibrous articular capsule – enclose joint surfaces; lined with synovial membrane •Joint cavity – cavity between bones of a joint containing a lubricating fluid called synovial fluid•Ligaments – reinforce the joint

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Structure of a Synovial Joint

Figure 5.28

Diagram p. 149

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Type of Synovial Joints

Diagram p. 151

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Types of Synovial Joints

Diagram p. 151

HingePivotGliding

Identify the type of joint in the diagrams.

Ball and Socket

Ball and Socket

Gliding

Hinge & Pivot

What joint(s) is she using?

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Diseases and Disorders of the Skeletal System

•A fracture is a break in a bone•Types of bone fractures

–Closed (simple) fracture – break that does not penetrate the skin –Open (compound) fracture – broken bone penetrates through the skin•Bone fractures are treated by reduction and

immobilization –Realignment of the bone

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•Open reduction – surgery is needed to secure the bones together with pins or wires. •Closed reduction – bone ends coaxed back into position by physician

Diseases and Disorders of the Skeletal System

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Diseases and Disorders of the Skeletal System Diagram p. 123

ComminutedFracture radius

CompoundFracture tibia and fibula

SimpleSpiral fibula

SimpleGreenstick

radius

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Diseases and Disorders of the Skeletal System: Fractures

Identify the fractures.

X - Ray NQ

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Diseases and Disorders of the Skeletal System

•Osteoporosis: afflicts both men and women but most common in post menopausal women–Bone tissue becomes brittle and breaks easily with little applied stress–Cause - loss of calcium from bone matrix