the skeletal systemcontents.kocw.or.kr/document/wcu/2012/anatomy_and... · •two thin layers of...

1

5The Skeletal System

Yong Jeong, MD, PhD

Department of Bio and Brain Engineering

© 2012 Pearson Education, Inc.

The Skeletal System

•Parts of the skeletal system

•Bones (skeleton)

•Joints

•Cartilages

•Ligaments

•Two subdivisions of the skeleton

•Axial skeleton

•Appendicular skeleton

2


Functions of Bones

• Support the body

• Protect soft organs

• Skull and vertebrae for brain and spinal cord

• Rib cage for thoracic cavity organs

• Allow movement due to attached skeletal muscles

• Store minerals and fats

• Calcium and phosphorus

• Fat in the internal marrow cavity

• Blood cell formation (hematopoiesis)


Bones of the Human Body

•The adult skeleton has 206 bones

•Two basic types of bone tissue

•Compact bone

•Homogeneous

•Spongy bone

•Small needle-like pieces of bone

•Many open spaces

3

© 2012 Pearson Education, Inc. Figure 5.1

Spongybone

Compactbone


Classification of Bones on the Basis of Shape

•Bones are classified as:

•Long

•Short

•Flat

• Irregular

4


Classification of Bones

•Long bones• Typically longer than they are wide• Shaft with heads situated at both ends• Contain mostly compact bone• All of the bones of the limbs (except wrist,

ankle, and kneecap bones)• Example:

• Femur• Humerus

© 2012 Pearson Education, Inc. Figure 5.2a

5



•Short bones•Generally cube-shaped•Contain mostly spongy bone• Includes bones of the wrist and ankle•Sesamoid bones are a type of short bone which form within tendons (patella)

•Example:•Carpals•Tarsals

© 2012 Pearson Education, Inc. Figure 5.2d

6



•Flat bones

•Thin, flattened, and usually curved

•Two thin layers of compact bone surround a layer of spongy bone

•Example:

•Skull

•Ribs

•Sternum


7



• Irregular bones

• Irregular shape

•Do not fit into other bone classification categories

•Example:

•Vertebrae

•Hip bones

© 2012 Pearson Education, Inc. Figure 5.2b

8


Anatomy of a Long Bone

•Diaphysis

•Shaft

•Composed of compact bone

•Epiphysis

•Ends of the bone

•Composed mostly of spongy bone


Distalepiphysis

Diaphysis

Proximalepiphysis

Articularcartilage

Spongy bone

EpiphyseallinePeriosteum

Compact boneMedullarycavity (linedby endosteum)

(a)

9



•Periosteum

•Outside covering of the diaphysis

•Fibrous connective tissue membrane

•Perforating (Sharpey’s) fibers

•Secure periosteum to underlying bone

•Arteries

•Supply bone cells with nutrients

© 2012 Pearson Education, Inc. Figure 5.3c

Yellowbone marrow

Compact bone

Perforating(Sharpey’s)fibers

Nutrientarteries

Periosteum

Endosteum

(c)

10



•Articular cartilage

•Covers the external surface of the epiphyses

•Made of hyaline cartilage

•Decreases friction at joint surfaces


Compact bone

Spongy bone

Articularcartilage

(b)

11



•Epiphyseal plate

•Flat plate of hyaline cartilage seen in young, growing bone

•Epiphyseal line

•Remnant of the epiphyseal plate

•Seen in adult bones


Distalepiphysis

Diaphysis

Proximalepiphysis

Articularcartilage

Spongy bone

EpiphyseallinePeriosteum

Compact boneMedullarycavity (linedby endosteum)

(a)

12



•Marrow (medullary) cavity

•Cavity inside of the shaft

•Contains yellow marrow (mostly fat) in adults

•Contains red marrow for blood cell formation in infants

• In adults, red marrow is situated in cavities of spongy bone and epiphyses of some long bones


Bone Markings

• Surface features of bones

• Sites of attachments for muscles, tendons, and ligaments

• Passages for nerves and blood vessels

• Categories of bone markings

• Projections or processes—grow out from the bone surface

• Terms often begin with “T”

• Depressions or cavities—indentations

• Terms often begin with “F”

13


Microscopic Anatomy of Compact Bone

•Osteon (Haversian system)•A unit of bone containing central canal and matrix rings

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

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


CompactbonePeriostealblood vesselPeriosteum

Perforatingfibers

Central (Haversian) canal

Perforating(Volkmann’s) canalBlood vessel

Spongy bone

Blood vessel continues intomedullary cavity containing marrow

Lamellae

(a)

Osteon(Haversian system)

14


Microscopic Anatomy of Bone

•Lacunae

•Cavities containing bone cells (osteocytes)

•Arranged in concentric rings called lamellae

•Lamellae

•Rings around the central canal

•Sites of lacunae


Lamella

Canaliculus

Lacuna

Central (Haversian) canal(b)

Osteocyte

Osteon

Lacuna

Centralcanal

Interstitiallamellae

(c)

15


Microscopic Anatomy of Bone

•Canaliculi

•Tiny canals

•Radiate from the central canal to lacunae

•Form a transport system connecting all bone cells to a nutrient supply


Lamella

CanaliculusLacunaCentral (Haversian) canal

(b)

Osteocyte

16


Formation of the Human Skeleton

• In embryos, the skeleton is primarily hyaline cartilage

•During development, much of this cartilage is replaced by bone

•Cartilage remains in isolated areas

•Bridge of the nose

•Parts of ribs

•Joints


Bone Growth (Ossification)

•Epiphyseal plates allow for lengthwise growth of long bones during childhood

•New cartilage is continuously formed

•Older cartilage becomes ossified

•Cartilage is broken down

•Enclosed cartilage is digested away, opening up a medullary cavity

•Bone replaces cartilage through the action of osteoblasts

17


Bone Growth (Ossification)

•Bones are remodeled and lengthened until growth stops

•Bones are remodeled in response to two factors

•Blood calcium levels

•Pull of gravity and muscles on the skeleton

•Bones grow in width (called appositional growth)


In a fetusIn an embryo

Bone collar

Hyalinecartilagemodel

Bone startingto replacecartilage

In a child

Medullarycavity

New center ofbone growth

Hyalinecartilage

Epiphysealplate cartilage

Growthin bonelength

New boneforming

Invadingbloodvessels

Epiphysealplatecartilage

Articularcartilage

Spongybone

New boneforming

Growthin bonewidth

18


Bone growth

Bone grows inlength because:

Bone remodeling

Growing shaft isremodeled as:

Cartilagegrows here.

Cartilageis replacedby bone here.

Cartilagegrows here.

Cartilageis replaced by bone here.

1

2

3

4

1

2

3 Bone isresorbed here.

Epiphyseal plate

Articular cartilage

Bone isresorbed here.

Bone is addedby appositionalgrowth here.


Types of Bone Cells

•Osteocytes—mature bone cells

•Osteoblasts—bone-forming cells

•Osteoclasts—giant bone-destroying cells

•Break down bone matrix for remodeling and release of calcium in response to parathyroid hormone

•Bone remodeling is performed by both osteoblasts and osteoclasts

19


Bone Fractures

•Fracture—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


Common Types of Fractures

Table 5.2

20


Repair of Bone Fractures

•Hematoma (blood-filled swelling) is formed

•Break is splinted by fibrocartilage to form a callus

•Fibrocartilage callus is replaced by a bony callus

•Bony callus is remodeled to form a permanent patch

© 2012 Pearson Education, Inc. Figure 5.7, step 4

Internalcallus(fibroustissue andcartilage)

Hematomaforms.

Fibrocartilagecallus forms.

Bony callusforms.

Bone remodelingoccurs.

Hematoma

Bonycallus ofspongybone

Spongybonetrabecula

Newbloodvessels

Externalcallus

Healedfracture

1 2 3 4

21


The Axial Skeleton

•Forms the longitudinal axis of the body

•Divided into three parts

•Skull

•Vertebral column

•Bony thorax

© 2012 Pearson Education, Inc. Figure 5.8a(a) Anterior view

Phalanges

Metatarsals

Tarsals

Fibula

Tibia

Patella

Femur

Metacarpals

Phalanges

Carpals

UlnaRadius

Vertebra

Humerus

Rib

Sternum

Scapula

Clavicle

Facial bones

Cranium

Skull

Thoracic cage(ribs andsternum)

Vertebralcolumn

Sacrum

22

© 2012 Pearson Education, Inc. Figure 5.8b(b) Posterior view

Fibula

Tibia

Femur

Metacarpals

Phalanges

Carpals

RadiusUlna

Vertebra

Humerus

Rib

Scapula

Clavicle

Cranium

Bones ofpectoralgirdle

Upperlimb

Bones ofpelvicgirdle

Lowerlimb


The Skull

•Two sets of bones

•Cranium

•Facial bones

•Bones are joined by sutures

•Only the mandible is attached by a freely movable joint

23


Coronal suture

Parietal bone

Lambdoidsuture

Temporal bone

Squamous suture

Occipital bone

Zygomatic process

External acoustic meatus

Mastoid process

Styloid process

Mandibular ramus

Frontal bone

Sphenoid bone

Ethmoid bone

Lacrimal bone

Nasal bone

Zygomatic bone

Maxilla

Alveolarprocesses

Mandible (body)Mental foramen


Sphenoidbone

Temporal bone

Internalacoustic meatus

Parietal bone

Occipital bone

Foramen magnum

Jugular foramen

Foramen ovale

Sella turcica

Optic canal

Frontal bone

Cribriform plate

Crista galliEthmoidbone

24


Maxilla(palatine process)Hard

palatePalatine bone

Zygomatic bone

Temporal bone(zygomatic process)

Vomer

Mandibular fossa

Styloid process

Mastoid process

Temporal bone

Parietal bone

Occipital boneForamen magnum

Occipital condyle

Jugular foramen

Carotid canal

Foramen ovale

Sphenoid bone(greater wing)

Maxilla


Coronal suture

Parietal bone

Nasal bone

Sphenoid bone

Ethmoid bone

Lacrimal bone

Zygomatic bone

Maxilla

Mandible

Alveolar processes

Vomer

Inferior nasal concha

Middle nasal conchaof ethmoid bone

Temporal bone

Optic canal

Superior orbital fissure

Frontal bone

25


Paranasal Sinuses

•Hollow portions of bones surrounding the nasal cavity

•Functions of paranasal sinuses

•Lighten the skull

•Give resonance and amplification to voice


Frontal sinus

Ethmoid sinus

Sphenoidal sinus

Maxillary sinus

(a) Anterior view

26


Frontal sinus

Ethmoid sinus

Sphenoidal sinus

Maxillary sinus

(b) Medial view


The Hyoid Bone

•The only bone that does not articulate with another bone

•Serves as a moveable base for the tongue

•Aids in swallowing and speech

27


Greater horn

Lesser horn

Body


The Fetal Skull

•The fetal skull is large compared to the infant’s total body length•Fetal skull is 1/4 body length compared to adult skull which is 1/8 body length

•Fontanels—fibrous membranes connecting the cranial bones•Allow skull compression during birth•Allow the brain to grow during later pregnancy and infancy

•Convert to bone within 24 months after birth

28


Frontal bone

Parietalbone

(a)

Occipitalbone

Anteriorfontanel

Posterior fontanel


Anterior fontanel

Frontalbone

SphenoidalfontanelParietal bone

Posteriorfontanel

OccipitalboneMastoidfontanel

Temporal bone

(b)

29


The Vertebral Column

•Each vertebrae is given a name according to its location

•There are 24 single vertebral bones separated by intervertebral discs

•Seven cervical vertebrae are in the neck

•Twelve thoracic vertebrae are in the chest region

•Five lumbar vertebrae are associated with the lower back



•Nine vertebrae fuse to form two composite bones

•Sacrum

•Coccyx

30


Anterior Posterior1st cervicalvertebra (atlas)2nd cervical vertebra (axis)

Cervical curvature(concave)7 vertebrae,C1 – C7

1st thoracicvertebra

TransverseprocessSpinousprocess

Intervertebraldisc

Intervertebralforamen

Thoracic curvature(convex)12 vertebrae,T1 – T12

1st lumbarvertebra Lumbar curvature

(concave)5 vertebrae,L1 – L5

Sacral curvature(convex)5 fused vertebrae

Coccyx4 fused vertebrae



•Primary curvatures are the spinal curvatures of the thoracic and sacral regions•Present from birth•Form a C-shaped curvature as in newborns

•Secondary curvatures are the spinal curvatures of the cervical and lumbar regions•Develop after birth•Form an S-shaped curvature as in adults

31



A Typical Vertebrae

•Body

•Vertebral arch

•Pedicle

•Lamina

•Vertebral foramen

•Transverse processes

•Spinous process

•Superior and inferior articular processes

32


PosteriorLamina

Transverseprocess

Superiorarticularprocessandfacet

Spinousprocess

Vertebralarch

Pedicle Vertebralforamen

Body

Anterior


(a) ATLAS AND AXIS

Transverseprocess

Posteriorarch

Anteriorarch

Superior view of atlas (C1)

SpinousprocessTransverse

process Facet onsuperiorarticularprocessDens

Body

Superior view of axis (C2)

33


(b) TYPICAL CERVICAL VERTEBRAE

Facet on superiorarticular process

Spinousprocess

Vertebralforamen

Transverseprocess

Superior view

BodySuperiorarticularprocess

Spinousprocess Transverse

processFacet on inferiorarticular process

Right lateral view

© 2012 Pearson Education, Inc. Figure 5.20cRight lateral view

Spinousprocess

Costal facetfor rib

Facet onsuperiorarticularprocess

Facet ontransverseprocess

Body

Superior viewBody


Facetfor rib

(c) THORACIC VERTEBRAE

Transverseprocess

Vertebralforamen

Spinous process

34


(d) LUMBAR VERTEBRAE

Spinous process

Transverseprocess

Vertebralforamen

Body


Superior view

BodySuperiorarticularprocess

Spinousprocess

Facet on inferiorarticular process

Right lateral view


Sacrum and Coccyx

•Sacrum

•Formed by the fusion of five vertebrae

•Coccyx

•Formed from the fusion of three to five vertebrae

•“Tailbone,” or remnant of a tail that other vertebrates have

35


Superiorarticularprocess

AuricularsurfaceSacral

canalAla

Sacrum

Body

Mediansacralcrest

Posteriorsacralforamina

SacralhiatusCoccyx


The Bony Thorax

•Forms a cage to protect major organs•Consists of three parts

•Sternum•Ribs

•True ribs (pairs 1–7)•False ribs (pairs 8–12)•Floating ribs (pairs 11–12)

•Thoracic vertebrae

36


T1 vertebraJugular notch

ManubriumSternal angleBodyXiphisternaljoint

Xiphoidprocess

Sternum

Intercostalspaces

Costal cartilageFloatingribs (11, 12)

Falseribs(8–12)

Trueribs(1–7)

L1 Vertebra

(a)

Clavicular notch


T2

T3

T4

T9

Jugularnotch

Sternalangle

Heart

Xiphisternaljoint

(b)

37


The Appendicular Skeleton

•Composed of 126 bones

•Limbs (appendages)

•Pectoral girdle

•Pelvic girdle

© 2012 Pearson Education, Inc. Figure 5.8a(a) Anterior view

Phalanges

Metatarsals

Tarsals

Fibula

Tibia

Patella

Femur

Metacarpals

Phalanges

Carpals

UlnaRadius

Vertebra

Humerus

Rib

Sternum

Scapula

Clavicle

Facial bones

Cranium

Skull

Thoracic cage(ribs andsternum)

Vertebralcolumn

Sacrum

38

© 2012 Pearson Education, Inc. Figure 5.8b(b) Posterior view

Fibula

Tibia

Femur

Metacarpals

Phalanges

Carpals

RadiusUlna

Vertebra

Humerus

Rib

Scapula

Clavicle

Cranium

Bones ofpectoralgirdle

Upperlimb

Bones ofpelvicgirdle

Lowerlimb


The Pectoral (Shoulder) Girdle

•Composed of two bones•Clavicle—collarbone

•Articulates with the sternum medially and with the scapula laterally

•Scapula—shoulder blade•Articulates with the clavicle at the acromioclavicular joint

•Articulates with the arm bone at the glenoid cavity

•These bones allow the upper limb to have exceptionally free movement

39


Acromio-clavicularjoint

Scapula

(a) Articulated right shoulder (pectoral) girdleshowing the relationship to bones of thethorax and sternum

Clavicle


PosteriorSternal (medial) end

Acromial (lateral) end

Superior view

Acromial end

Anterior

Anterior

Sternal end

Posterior

Inferior view

(b) Right clavicle, superior and inferior views

40


Suprascapular notch

Superior angle

Spine

Medial border

Lateral border

Glenoid cavity at lateral angle

(c) Right scapula, posterior aspect

Coracoid process

Acromion


Acromion

Coracoidprocess

Glenoidcavity

Lateral(axillary)border

(d) Right scapula, anterior aspect

Medial(vertebral)border

Inferior angle

Suprascapular notch

Superior border

Superior angle

41


Bones of the Upper Limbs

•Humerus

•Forms the arm

•Single bone

•Proximal end articulation

•Head articulates with the glenoid cavity of the scapula

•Distal end articulation

•Trochlea and capitulum articulate with the bones of the forearm


Greater tubercle

Lesser tubercle

Head of humerus

Anatomical neck

Intertubercular sulcus

Medial epicondyle

Trochlea(a)

Capitulum

Coronoid fossa

Radial fossa

Deltoid tuberosity

Head of humerus

Anatomical neck

Radial groove

Deltoid tuberosity

Medial epicondyle

Trochlea(b)

Olecranon fossa

Lateral epicondyle

Surgical neck

42



•The forearm has two bones•Ulna—medial bone in anatomical position

•Proximal end articulation•Coronoid process and olecranon articulate with the humerus

•Radius—lateral bone in anatomical position•Proximal end articulation

•Head articulates with the capitulum of the humerus


Head

Neck

Radial tuberosity

Radius

Radial styloid process

Distal radioulnar joint

Ulnar styloid process

(c)

Inter-osseous membrane

Ulna

Proximal radioulnar joint

Coronoid process

Olecranon

Trochlear notch

43



•Hand•Carpals—wrist

•Eight bones arranged in two rows of four bones in each hand

•Metacarpals—palm•Five per hand

•Phalanges—fingers and thumb•Fourteen phalanges in each hand• In each finger, there are three bones• In the thumb, there are only two bones


Phalanges (fingers)

Distal

Middle

Proximal

Metacarpals (palm)

Carpals (wrist)

Hamate

Pisiform

Triquetrum

Lunate

UlnaRadius

Capitate

Scaphoid

Trapezoid

Trapezium

1

2345

44


Bones of the Pelvic Girdle

•Formed by two coxal (ossa coxae) bones•Composed of three pairs of fused bones

• Ilium• Ischium•Pubis

•Pelvic girdle = 2 coxal bones, sacrum•Bony pelvis = 2 coxal bones, sacrum, coccyx


Bones of the Pelvic Girdle

•The total weight of the upper body rests on the pelvis

• It protects several organs

•Reproductive organs

•Urinary bladder

•Part of the large intestine

45


Coxal bone (or hip bone)

llium

Pubis

Ischium

(a)

Pubic arch

Coccyx

Sacrum

lliac crest

Sacroiliac joint

Pelvic brim

Ischial spine

Acetabulum

Pubic symphysis


Posterior superior iliac spine

Posterior inferior iliac spine

Greater sciatic notch

Ischial body

Ischial spine

Ischial tuberosity

Ischium

Ischial ramus

(b)

AlaIIium

IIiac crest

Anterior superior iliac spine

Anterior inferior iliac spine

Acetabulum

Body of pubis

Pubis

Inferior pubic ramus

Obturator foramen

46


Gender Differences of the Pelvis

•The female inlet is larger and more circular

•The female pelvis as a whole is shallower, and the bones are lighter and thinner

•The female ilia flare more laterally

•The female sacrum is shorter and less curved

•The female ischial spines are shorter and farther apart; thus the outlet is larger

•The female pubic arch is more rounded because the angle of the pubic arch is greater


False pelvis

Inlet of true pelvis

Pelvic brim

Pubic arch (less than 90°)

False pelvis

Inlet of true pelvis

Pelvic brim

Pubic arch (more than 90°)

(c)

47


Bones of the Lower Limbs

•Femur—thigh bone

•The heaviest, strongest bone in the body

•Proximal end articulation

•Head articulates with the acetabulum of the coxal (hip) bone

•Distal end articulation

•Lateral and medial condyles articulate with the tibia in the lower leg


Neck

Inter-trochanteric line

Lateral condyle

Patellar surface

(a)

Lesser trochanter

Head Head

Lesser trochanter

Gluteal tuberosity

Greater trochanterInter-trochanteric crest

Intercondylar fossa

Medial condyle

Lateral condyle

(b)

48



•The lower leg has two bones•Tibia—Shinbone; larger and medially oriented•Proximal end articulation

•Medial and lateral condyles articulate with the femur to form the knee joint

•Fibula—Thin and sticklike; lateral to the tibia•Has no role in forming the knee joint


Intercondylar eminence

Lateral condyleHead

Proximal tibiofibular joint

Fibula

Distal tibiofibular joint

Lateral malleolus

(c)

Medial malleolus

Tibia

Anterior border

Interosseous membrane

Tibial tuberosity

Medial condyle

49



•The foot

•Tarsals—seven bones

•Two largest tarsals

•Calcaneus (heel bone)

•Talus

•Metatarsals—five bones form the sole of the foot

•Phalanges—fourteen bones form the toes


Tarsals:

Medial cuneiform

Intermediatecuneiform

Navicular

Talus

Calcaneus

Cuboid

Lateral cuneiform

Tarsals:

Metatarsals

Proximal

MiddleDistal

Phalanges:

50


Arches of the Foot

•Bones of the foot are arranged to form three strong arches

•Two longitudinal

•One transverse


Medial longitudinal arch

Transverse arch

Lateral longitudinal arch

51


Joints

•Articulations of bones

•Functions of joints

•Hold bones together

•Allow for mobility

•Two ways joints are classified

•Functionally

•Structurally


Functional Classification of Joints

•Synarthroses

• Immovable joints

•Amphiarthroses

•Slightly moveable joints

•Diarthroses

•Freely moveable joints

52


Structural Classification of Joints

•Fibrous joints

•Generally immovable

•Cartilaginous joints

• Immovable or slightly moveable

•Synovial joints

•Freely moveable


Fibrous Joints

•Bones united by collagenic fibers•Types

• Sutures• Immobile

• Syndesmoses• Allows more movement than sutures but

still immobile• Example: Distal end of tibia and fibula

• Gomphosis• Immobile

53


Fibrous joints

Fibrous connective tissue

(a) Suture

Fibrous joints

Tibia

FibulaFibrousconnective tissue

(b) Syndesmosis


Cartilaginous Joints

•Bones connected by cartilage

•Types

•Synchrondrosis

• Immobile

•Symphysis

•Slightly movable

•Example: Pubic symphysis, intervertebral joints

54


Cartilaginous joints

First rib

Hyaline cartilage

Sternum

(c) Synchondrosis



Vertebrae

Fibrocartilage

(d) Symphysis

55

© 2012 Pearson Education, Inc. Figure 5.30e


Pubis

Fibro-cartilage

(e) Symphysis


Synovial Joints

•Articulating bones are separated by a joint cavity

•Synovial fluid is found in the joint cavity

56

© 2012 Pearson Education, Inc. Figure 5.30f

Synovial joints

Scapula

Articular capsule

Articular (hyaline) cartilage

Humerus

(f) Multiaxial joint(shoulder joint)

© 2012 Pearson Education, Inc. Figure 5.30g

Synovial joints

Humerus


Articular capsule

Radius

Ulna(g) Uniaxial joint

(elbow joint)

57

© 2012 Pearson Education, Inc. Figure 5.30h

Synovial joints

Ulna

Radius

Articular capsule

(h) Biaxial joint(intercarpal joints of hand)

Carpals


Features of Synovial Joints

•Articular cartilage (hyaline cartilage) covers the ends of bones

•Articular capsule encloses joint surfaces and lined with synovial membrane

•Joint cavity is filled with synovial fluid

•Reinforcing ligaments

58


Structures Associated with the Synovial Joint

•Bursae—flattened fibrous sacs

•Lined with synovial membranes

•Filled with synovial fluid

•Not actually part of the joint

•Tendon sheath

•Elongated bursa that wraps around a tendon


Acromion of scapula

Ligament

Bursa

Ligament

Tendon sheath

Tendon of biceps muscle

Humerus

Fibrous layer of the articular capsule

Synovial membrane


Joint cavity containing synovial fluid

59


NonaxialUniaxialBiaxialMultiaxial

(a) Plane joint

(a)



(b)

HumerusUlna

(b) Hinge joint

60



(c)

(c) Pivot joint

UlnaRadius



(d)

MetacarpalPhalanx

(d) Condylar joint

61

© 2012 Pearson Education, Inc. Figure 5.32e


(e)

Carpal

(e) Saddle joint

Metacarpal #1

© 2012 Pearson Education, Inc. Figure 5.32f


(f)

Head of humerus

Scapula

(f) Ball-and-socket joint

62


Inflammatory Conditions Associated with Joints•Bursitis—inflammation of a bursa usually caused by a blow or friction

•Tendonitis—inflammation of tendon sheaths•Arthritis—inflammatory or degenerative diseases of joints•Over 100 different types•The most widespread crippling disease in the United States

• Initial symptoms: pain, stiffness, swelling of the joint


Clinical Forms of Arthritis

•Osteoarthritis•Most common chronic arthritis•Probably related to normal aging processes

•Rheumatoid arthritis•An autoimmune disease—the immune system attacks the joints

•Symptoms begin with bilateral inflammation of certain joints

•Often leads to deformities

63


Clinical Forms of Arthritis

•Gouty arthritis

• Inflammation of joints is caused by a deposition of uric acid crystals from the blood

•Can usually be controlled with diet

•More common in men


Developmental Aspects of the Skeletal System

•At birth, the skull bones are incomplete

•Bones are joined by fibrous membranes called fontanels

•Fontanels are completely replaced with bone within two years after birth

64


Frontal bone of skull

Mandible

RadiusUlna

Humerus

Femur

Tibia

Hip bone

Vertebra

Ribs

Scapula

Clavicle

Occipital bone

Parietal bone


Skeletal Changes Throughout Life

•Fetus

•Long bones are formed of hyaline cartilage

•Flat bones begin as fibrous membranes

•Flat and long bone models are converted to bone

•Birth

•Fontanels remain until around age 2

65



•Adolescence•Epiphyseal plates become ossified and long bone growth ends

•Size of cranium in relationship to body•2 years old—skull is larger in proportion to the body compared to that of an adult

•8 or 9 years old—skull is near adult size and proportion

•Between ages 6 and 11, the face grows out from the skull


66




•Curvatures of the spine

•Primary curvatures are present at birth and are convex posteriorly

•Secondary curvatures are associated with a child’s later development and are convex anteriorly

•Abnormal spinal curvatures (scoliosis and lordosis) are often congenital

67




•Osteoporosis•Bone-thinning disease afflicting

•50 percent of women over age 65 •20 percent of men over age 70

•Disease makes bones fragile and bones can easily fracture

•Vertebral collapse results in kyphosis (also known as dowager’s hump)

•Estrogen aids in health and normal density of a female skeleton

68



the skeletal systemcontents.kocw.or.kr/document/wcu/2012/anatomy_and... · •two thin layers of...

Documents