Ch 7 – The Skeleton - PowerPoint Presentation

Slide1

Ch 7 – The Skeleton

Part A: The Axial Skeleton

Section 1 – Axial Skeleton Overview (pp. 198-200)Slide2

Consists of 80 bonesDivided into 3 main parts

:

1) Skull 2) Vertebral column 3) Bony ThoraxFunctions of Axial Skeleton: 1) Forms longitudinal axis 2) Supports head, neck, & trunk 3) Protects brain, spinal cord, heart, & lungs

The Axial SkeletonSlide3

Ch 7 – The Skeleton

Part A: The Axial Skeleton

Section 2 – The Skull (pp. 200-216)Slide4

Skull - Two sets of bones 1) Cranial bones

(Cranium) - enclose & protect brain - provide attachment sites for head/neck muscles 2) Facial bones - provide framework for the face - contain cavities for sight,

taste, & smell sense organs

- provide attachments sites for facial

expression

muscles

The Axial Skeleton – SkullSlide5

Skull - Most are flat bones & are joined together by sutures

-

Mandible only bone attached w/ freely movable joint - Many bones have air-filled sinuses to reduce weight - About 85 openings providing passageways for major blood vessels & nerves

The Axial Skeleton – SkullSlide6

There are 8 cranial bones:

Frontal bone

Parietal bone (left & right)Occipital boneTemporal bone (left & right)Sphenoid boneEthmoid boneCranial BonesSlide7

Frontal BoneMost anterior portion of cranium…

foreheadContains frontal sinusForms superior wall of orbitsSupports frontal lobes of brainCranial Bones – Frontal boneSlide8

Parietal Bone (x2)Most

superior

(top) & lateral (side) parts of cranial cavityBulk of cranial cavityCranial Bones – Parietal bonesSlide9

Occipital BoneForms posterior

wall of cranium

Attachment site for many neck/back musclesOccipital condyles - form joint w/ vertebral columnForamen magnum - large opening for spinal

cord to attach to

brain

Cranial Bones – Occipital boneSlide10

Temporal Bone (x2)

Inferior

to parietal bonesForms lower sides of cranium & part of cranial floorExternal acoustic meatus - surrounds external ear canalMandibular fossa

- forms the temporomandibular

joint

w/

mandible

Zygomatic

process

- part of cheek

bone nearest your ear

Cranial Bones – Temporal boneSlide11

Four sutures form major joints of the cranium: 1) Coronal

suture

- between parietal & frontal bones 2) Squamous suture - between parietal & temporal bones 3) Lamboid suture - between parietal &

occipital bones 4)

Sagittal suture

- between left & right

parietal

bones

Cranial Bones –

Major SuturesSlide12

Sphenoid BoneComplex, bat

-shaped bone

“Keystone” of the cranium - forms joints w/ all other cranial bonesSella turcica - small enclosure for pituitary gland

Cranial Bones – Sphenoid boneSlide13

Ethmoid Bone

Deepest

skull boneSuperior part of nasal septumCribiform plates - roof of nasal cavitiesCrista galli - between cribiform plates attaches to covering of brain to help

secure it to cranial cavity

Cranial Bones – Ethmoid boneSlide14

Frontal BoneLeft & Right Parietal Bones

Occipital Bone

Left & Right Temporal BonesSphenoid BoneEthmoid BoneCranial BonesSlide15

There are 14 facial bones:

Mandible

Maxillary bones (x2)Zygomatic bones (x2)Nasal bones (x2)Lacrimal bones (x2)Palatine bones (x2)VomerInferior nasal conchae (x2)Facial BonesSlide16

Mandible Lower jaw

Largest,

strongest facial bone Temporomandibular joint - only freely movable joint in skull Alveolar margin - contains sockets for teethFacial Bones – MandibleSlide17

Maxillary Bones Two bones fused medially

Form

upper jaw & central portion of face “Keystone” of face - form joints w/ all other facial bonesFacial Bones – Maxillary BonesSlide18

Zygomatic Bones Cheekbones

Form

lateral borders of orbitsFacial Bones – Zygomatic BonesSlide19

Nasal Bones Form bridge of

nose

Facial Bones – Nasal BonesSlide20

Lacrimal Bones Form medial

walls of

orbits Houses lacrimal sac - part of passageway that allows tears to drain into nasal cavityFacial Bones – Lacrimal BonesSlide21

Palatine Bones Form back 1/3 of roof of

mouth

… hard palate Form back walls of nasal cavityFacial Bones – Palatine BonesSlide22

Vomer Plow-shaped Lower part of nasal

septum

Facial Bones – VomerSlide23

Inferior nasal conchae

Form

lateral walls of nasal cavity Force inhaled air to swirl so that it can pick up moisture before traveling to lungsFacial Bones – Inferior nasal conchaeSlide24

Not a bone of the skull

Only bone that

does not articulate w/ another bone Attachment site for muscles of swallowing & speech Acts as a moveable base for tongueHyoid BoneSlide25

Found in frontal, sphenoid, ethmoid, & maxillary

bones

Mucosa-lined, air-filled spaces Enhance resonance of voice Lighten the skullParanasal SinusesSlide26

Ch 7 – The Skeleton

Part A: The Axial Skeleton

Section 3 – The Vertebral Column (pp. 216-223)Slide27

Vertebral columnTransmits weight of trunk

to

lower limbsSurrounds & protects spinal cordProvides attachment points for ribs & muscles of back/neckFlexible due to its curved constructionThe Axial Skeleton – Vertebral columnSlide28

Vertebral columnComposed of 26 irregular bones & divided into 5

segments

1) Cervical vertebrae (7) - vertebrae of the neck 2) Thoracic vertebrae (12) - vertebrae of thoracic cage 3) Lumbar vertebrae (5)

- vertebrae of lower back

4) Sacrum

5)

Coccyx

The Axial Skeleton – Vertebral columnSlide29

Natural CurvaturesIncrease flexibility of spine

Function like

spring instead of rodWhen viewed from side, S-shapedTwo posteriorly concave curvatures 1) Cervical curvature 2) Lumbar curvatureTwo posteriorly convex curvatures

1) Thoracic curvature 2)

Pelvic curvature

The Axial Skeleton – Vertebral columnSlide30

The Axial Skeleton – Vertebral columnSlide31

Scoliosis (abnormal lateral curvature)

The Axial Skeleton – Vertebral columnSlide32

Kyphosis (“Hunchback”)

The Axial Skeleton – Vertebral columnSlide33

Lordosis (“Swayback”)

The Axial Skeleton – Vertebral columnSlide34

Ligaments - Give added strength,

support

to spine 1) Anterior & posterior longitudinal ligaments - run entire length of spine *Anterior = front side; prevents bending too far backward *Posterior = back side; prevents bending too far forward 2)

Ligamentum flavum

- Connects 2 adjacent

vertebrae

3)

Short

ligaments - Connects each vertebrae to the one

above

&

below

it

The Axial Skeleton – Vertebral columnSlide35

Intervertebral Discs - cushion-like pads between vertebrae

- shock absorbers during walking, jumping, & running - thickest in lumbar/cervical regions; enhances flexibility - flatten during course of day; always a few millimeters shorter at night

The Axial Skeleton – Vertebral columnSlide36

Herniated Disc - “slipped disc

”

- rupture of the disc caused by compression of vertebrae - disc “squeezes” out from between vertebrae - if pressing on spinal cord, causes numbness or pain - usually treated w/ exercise, massage, heat, painkillers

- may have to be surgically removed

; vertebrae fused

The Axial Skeleton – Vertebral columnSlide37

General Structure of Vertebrae 1) Body or centrum

- anterior;

weight-bearing region 2) Vertebral foramen - opening for spinal cord 3) Intervertebral foramina - openings between vertebrae for spinal nerves to leave spinal cord

4) Spinous process

- project out the posterior

side;

protection

The Axial Skeleton – Vertebral column

Animation: Rotatable Spine (horizontal)

Animation: Rotatable Spine (vertical

)Slide38

Cervical Vertebrae (C1-C7

)

- smallest, lightest vertebrae - found in the neckC1 vertebra = Atlas - articulates with base of the skull - allows you to nod “yes”C2 vertebra = Axis

- knoblike “dens” projects up

- Atlas pivots

around “

dens

”

- allows you to shake head “no”

The Axial Skeleton – Vertebral columnSlide39

Thoracic Vertebrae (T1-T12

)

- All form joints with ribs - All have long, downward-pointing spinous processesThe Axial Skeleton – Vertebral columnSlide40

Lumbar Vertebrae (L1-L5

)

- “small of the back” - receives most stress - each has large centrum to handle extra stress The Axial Skeleton – Vertebral columnSlide41

Sacrum - shapes posterior wall of

pelvis

- lateral borders form joints with hipsCoccyx - tailbone - nearly uselessThe Axial Skeleton – Vertebral columnSlide42

Ch 7 – The Skeleton

Part A: The Axial Skeleton

Section 4 – The Thoracic Cage (pp. 223-225)Slide43

Thoracic cage - aka “Bony thorax

”

- Made up of 3 parts: 1) Sternum 2) Ribs & costal cartilage 3) Thoracic vertebraeThe Axial Skeleton – Thoracic cageSlide44

Thoracic cage - Forms cage to protect major

organs

of chest - Supports pectoral girdle & upper limbs - Provides multiple muscle attachment sitesThe Axial Skeleton – Thoracic cageSlide45

Sternum - “breastbone”

- Composed of 3 fused bones:

1) Manubrium - articulates w/ clavicles & ribs 1-2 2) Body - articulates w/ ribs 2-7 3) Xiphoid process - site of muscle attachment - cartilage until age 40

The Axial Skeleton – SternumSlide46

The Axial Skeleton – Ribs

Ribs

- 12

pairs - True ribs

* Top

7

ribs

* Attach

directly

to sternum via costal cartilage

-

False

ribs

* Ribs

8-10

* Attach

indirectly

to sternum

-

Floating

ribs

* Ribs

11-12

*

No

attachment

to sternumSlide47

Ch 7 – The Skeleton

Part B: The Appendicular Skeleton

Section 5 – Appendicular Skeleton Overview (p. 225)Slide48

Everything attached to the axial skeleton -

Limbs

(arms/legs) - Pectoral girdle - Pelvic girdle Enables us to carry out all body movementsThe Appendicular SkeletonSlide49

Ch 7 – The Skeleton

Part B: The Appendicular Skeleton

Section 6 – The Pectoral Girdle (pp. 225-228)Slide50

Pectoral (shoulder) girdle - Composed of two bones 1) Clavicle

2)

Scapula - Attaches arms to axial skeleton - Provides arm w/ exceptionally free movementThe Appendicular Skeleton

A&P Flix™: Bones of the pectoral girdleSlide51

Clavicle - known as the “collarbone”

- acts as a

brace; holds scapula & arm out laterally - transmits compression forces of upper limb to axial skeleton - usually fracture anteriorly; posterior fractures very dangerous b/c of major blood vessels just behind clavicle

Pectoral Girdle – ClavicleSlide52

Scapula - known as the “shoulder blade” - attaches to

spine

by way of muscles; exceptional movementGlenoid cavity - articulates with humerus of arm, forming shoulder jointAcromion process - articulates with claviclePectoral Girdle – ScapulaSlide53

Ch 7 – The Skeleton

Part B: The Appendicular Skeleton

Section 7 – The Upper Limb (pp. 228-233)Slide54

Upper Limb - 30 bones in each upper limb

3 main components

1) Arm - Humerus 2) Forearm - Radius & ulna 3) Hand - 8 carpal (wrist) bones - 5 metacarpal (palm) bones - 14 phalanges (finger bones)The Upper LimbSlide55

Humerus - only bone of the arm

-

largest bone of upper limb - proximal end articulates w/ glenoid cavity of scapulaGreater & lesser tubercles - attachment sites for rotator cuffTrochlea - articulates w/ ulnaCapitulum - articulates w/ radius

The Upper Limb – ArmSlide56

The Upper Limb – Forearm

Ulna

- medial bone in forearm - main function is forming elbow joint w/ humerusRadius - lateral bone in forearm - main function is forming wrist joint w/ carpal bones

*Interosseous membrane - flat, flexible

ligament running

entire length

between

both bonesSlide57

Carpals - form “wrist” - 8 total bones laid out in

2 rows

Proximal row (from lateral to medial) - scaphoid, lunate, triquetrum, & pisiformDistal row (from lateral to medial) - trapezium, trapezoid, capitate, & hamate*Only the scaphoid

& lunate articulate w/ the radius to form the wrist joint

The Upper Limb – HandSlide58

Metacarpals - form “palm” - 5 total bones

-

#1-5 starting w/ thumbPhalanges - finger #1 (thumb) = 2 phalanges (distal & proximal) - fingers #2-5 = 3 phalanges (distal, middle, & proximal)

The Upper Limb – HandSlide59

Ch 7 – The Skeleton

Part B: The Appendicular Skeleton

Section 8 – The Pelvic Girdle (pp. 233-237)Slide60

Pelvic girdle Attaches lower limbs to

axial

skeleton using some of the strongest ligaments in the body- Lacks mobility of pectoral girdle but far more stable Supports total weight of upper body Protects pelvic organs: 1) Reproductive organs 2) Urinary

bladder 3) Part of large intestine

The Appendicular Skeleton – PelvisSlide61

Pelvic girdle formed by a pair of hip bones

each hip bone is made of 3 fused bones: 1) Ilium 2) Ischium 3) Pubis“Bony pelvis” - the 2 hip bones plus the sacrum & coccyx

Acetabulum = deep socket that receives the head of the femur

The Appendicular Skeleton – Pelvis

Animation: Rotatable

pelvisSlide62

Gender differences in pelvic girdle:

The Appendicular Skeleton – PelvisSlide63

Gender differences in pelvic girdle:

The Appendicular Skeleton – PelvisSlide64

Gender differences in pelvic girdle:

The Appendicular Skeleton – PelvisSlide65

Ch 7 – The Skeleton

Part B: The Appendicular Skeleton

Section 9 – The Lower Limb (pp. 237-241)Slide66

The Lower Limb - bones thicker &

stronger

than upper limb bones - carries weight of the body - subjected to exceptional forces 3 main components 1) Thigh -

Femur 2

) Leg

-

Tibia & fibula

3

)

Foot

-

7 tarsal

(ankle)

bones

-

5

metatarsal

(foot)

bones

-

14 phalanges

(toe bones

)

The Lower LimbSlide67

Femur - forms the “thigh

”

- largest, strongest bone in body - “neck” is weakest part & often fractured; “broken hip”Patella - “kneecap” - purpose is to protect knee jointThe Lower Limb – ThighSlide68

Tibia - medial leg bone

- receives

weight from femur; transmits it to footFibula - not weight-bearing - muscle attachment site - does not contribute to knee joint; only stabilizes ankle

*Bound together by interosseous membrane

The Lower Limb – LegSlide69

Tarsals - form “ankle” & posterior ½

of foot

- 7 total bones 1) talus 2) calcaneus 3) cuboid 4) navicular 5) medial cuneiform 6) intermediate cuneiform 7) lateral cuneiform

*Talus transfers weight from tibia to calcaneus (heel)

The Lower Limb – FootSlide70

Metatarsals - form anterior ½ of foot - 5 total bones

-

#1-5 starting w/ big toePhalanges - toe #1 (big toe) = 2 phalanges (distal & proximal) - toes #2-5 = 3 phalanges (distal, middle, & proximal)

The Lower Limb – Foot

Animation: Rotatable bones of the

footSlide71

Foot Arches - maintained by interlocking foot

bones,

ligaments, & tendons - allow foot to bear weight - “give” or stretch when weight is applied; spring back when weight is removedArches of the FootSlide72

Ch 7 – The Skeleton

Section 10 – Developmental Aspects

(pp. 242-244)Slide73

Fetal Skull - very large compared to infant’s total body length - more bones

than

adult skull; unfused sutures - mandible is proportionally very small Developmental AspectsSlide74

Fontanelles

- fibrous membranes

connecting cranial bones in infants - provide brain room to grow - convert to bone within 24 months after birthDevelopmental AspectsSlide75

Developmental AspectsSlide76

Developmental AspectsSlide77

Growth Rates: - at birth, cranium is

huge

relative to face - at 9 months, cranium is ½ adult size - mandible & maxilla lengthen w/ age - arms & legs grow at faster rate than head & trunkDevelopmental AspectsSlide78

Spinal Curvature: - thoracic &

sacral

curvatures obvious at birth - this gives the spine a C shapeDevelopmental AspectsSlide79

Spinal Curvature: - cervical &

lumbar

curvatures appear as child develops (lifts head, learns to walk, etc.) - positions weight over center of gravityDevelopmental Aspects

The

Girl

…

The

Boy

…

Men

are from Mars,

Women are from Venus…

He’s cute! I think

I’m in love!!!

Hey Mike! Come see

what the dog left!!!

Typical guy…Slide80

As you Age… - intervertebral discs become

thin

& less elastic - risk of disc herniation increases - loss of height (by several cm) is common by age 55 - costal cartilages ossify; thorax becomes rigid (breathing becomes more difficult) - all bones lose

mass

Developmental AspectsSlide81

Ch 7 – The Skeleton

Section 11 – Homeostatic Imbalances

(pp. 244-245)Slide82

Cleft Palate: - right & left halves of hard palate (maxilla) fail to

fuse

- opening between oral & nasal cavities - very difficult for babies to drink from bottles - can lead to aspiration (inhalation) of food into lungsHomeostatic ImbalancesSlide83

Clubfoot: - congenital defect where soles of feet face

medially

& toes point inferiorly - affects 1 in 700 babies - may be genetic defect or the result of abnormal position of the foot in the womb during developmentHomeostatic ImbalancesSlide84

Spina bifida: - congenital defect of the vertebral

column - 1 or more of the vertebral arches incomplete - ranges in severity…may not cause any problem or may severely impair neural function depending on locationHomeostatic ImbalancesSlide85

Spinal fusion: - surgical procedure involving insertion of

bone

chips to immobilize/stabilize specific region of vertebral column - used often with fractures involving the vertebrae & injuries involving herniated discsHomeostatic Imbalances