chapter 8: the appendicular skeleton
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Chapter 8: The Appendicular Skeleton. BIO 210 Lab Instructor: Dr. Rebecca Clarke. Appendicular Skeleton. Allows us to move and manipulate objects Includes all bones besides axial skeleton: the limbs the supportive girdles Pectoral (shoulder) Pelvic. Appendicular Skeleton. Figure 8–1. - PowerPoint PPT PresentationTRANSCRIPT
BIO 210 LabInstructor: Dr. Rebecca Clarke
Chapter 8:The Appendicular Skeleton
Appendicular Skeleton Allows us to move and manipulate objectsIncludes all bones besides axial skeleton:
the limbs the supportive girdles
Pectoral (shoulder)Pelvic
Appendicular Skeleton
Figure 8–1
Pectoral Girdle Also called the shoulder girdlePositions shoulder jointsConnects the arms to the body Provides base for muscle attachmentHelps move upper limbs
Pectoral Girdle
Figure 8–2a
Pectoral Girdle Consists of:
2 clavicles 2 scapulae
Connects with axial skeleton only at the manubrium (clavicle articulations)
ClavicleAlso called collarboneLong, S-shaped boneOriginates at manubrium (sternal end)Articulates with scapula (acromial end)Relatively fragile so fractures common
ClavicleSternal End:
Square, flat surfaceArticulates with
manubrium; only ones between axial skeleton and pectoral girdle
Acromial End:Flatter, broader
endArticulates with
acromion of scapula
Figure 8–2b, c
Scapula Also called shoulder bladeBroad, flat triangleArticulates with arm and collarboneSkeletal muscles support/position
Extreme mobilityNot much strength
Scapula: Posterior SurfaceBody
Broad, flat, triangular area
Has 3 borders/ marginsSuperiorMedialLateral
Figure 8–3c
Scapula: Posterior Surface
SpineLarge ridge across
posterior surfaceShoulder blade
Supraspinous fossaDepression superior to
spineInfraspinous fossa
Depression inferior to spine
Figure 8–3c
Scapula: Posterior SurfaceAcromion
Large, posterior extension at lateral end of spine
Articulates with clavicle (acromial end)
Figure 8–3c
Scapula: Lateral ViewGlenoid fossa (cavity)
Cup-shaped, lateral depression
Articulates with humerus
Forms shoulder joint
Figure 8–3c
Scapula: Lateral ViewCoracoid process
Smaller, anterior projection superior to glenoid cavity
Near clavicle vs coronoid process on mandible near nose)
Figure 8–3c
Scapula: Anterior SurfaceSubscapular fossa
Depression on smooth, anterior side of body
Figure 8–3a
Bones of the Upper LimbsBrachium (arm)Antebrachium (forearm)
UlnaRadius
Carpals (wrist)Metacarpals (hand)Phalanges (fingers)
HumerusOnly bone in brachium (arm)Extends from scapula to elbowArticulates with pectoral girdle
on proximal end (head) – with glenoid fossa of scapula
on distal end – with radius and ulna (bones of antebrachium)
Humerus
HeadLarge, ball-shaped
structure on proximal endGreater tubercle
Larger, rounded projection on lateral/posterior surface of epiphysis
Lesser tubercleSmaller projection on
medial/anterior surfaceIntertubercular groove
Separates tubercles
Figure 8–4
Humerus
Anatomical neckNarrow groove between
base of head and tuberclesMargin of joint capsule
Surgical neckAt metaphysisWhere fractures often occur
Deltoid tuberosityRough ridge on-anterior
surface of shaftWhere deltoid muscle
attaches
Figure 8–4
Humerus
Condyle= rounded projection for
muscle attachmentDistal epiphysis where
humerus articulates with radius and ulna
“Knuckles” on anterior surface of humerus
Figure 8–4
Humerus
Lateral epicondyleMedial epicondyle
More prominent than lateral one
Trochlea (“pulley” or “spool”)In center of condyle (middle
“knuckle)Where trochlear notch of ulna
rotates during forearm flexionCapitulum
Forms a “cap” over the radius
Figure 8–4
Humerus
Coronoid fossaOn anterior surfaceArticulates with coronoid
process of ulnaOlecranon fossa
On posterior surfaceArticulates with
olecranon of ulna
Figure 8–4
Antebrachium (Forearm)
Consists of 2 long bones:Ulna (medial)Radius (lateral)
“Rotates”Site of radial pulse
Figure 8–5
Ulna
Olecranon (process)Large, curved
projection (like cobra head) on proximal end
“U” for ulnaArticulates in
olecranon fossa of humerus
Superior lip of trochlear notch
Point of elbow
Figure 8–5
Ulna
Trochlear notchAnterior curved surface
of proximal epiphysisArticulates with trochlea
of humerusCoronoid process
Inferior lip of trochlear notch
Articulates in coronoid fossa of humerus
Figure 8–5
Ulna
HeadMuch smaller, distal
epiphysis (near wrist)Articulates with radium
and carpal (wrist) bonesStyloid process
Medial pointed extension at distal epiphysis
On posterior, lateral surface of head
Figure 8–5
Ulna: Articulations with the HumerusForearm extended:
Olecranon enters olecranon fossa Forearm flexed:
Coronoid process enters coronoid fossa
Radius
HeadDisc-shaped proximal
epiphysisArticulates with humerus
NeckNarrow region between
head and tuberosityRadial tuberosity
Structure at proximal end of diaphysis below neck
Marks attachment site of biceps brachii muscle
Figure 8–5
Radius
ShaftCurves and
broadensDistal portion much
larger than distal portion of ulna
Styloid processLateral pointed
extension at distal epiphysis
Stabilizes wrist joint
Figure 8–5
Carpal Bones Allow wrist to bend and twist
8 bones“Sam likes to push the toy car hard.”
Carpal BonesScaphoidLunateTriquetrumPisiform
TrapeziumTrapezoidCapitateHamate
Wrist and Hand Bones
Figure 8–6
Metacarpal Bones5 long bones of the hand Numbered I–V from lateral (thumb) to
medialArticulate with proximal phalanges
Phalanges (Phalanx=singular)Finger bones
I (lateral)Pollex (thumb):2 phalanges (proximal, distal)
II - V3 phalanges (proximal, medial or middle, distal)
Pelvic GirdleFunctions
Weight-bearingLocomotion
Bones more massive than those of pectoral girdle
Strong to bear body weight
Pelvic GirdleMade up of 2 hip bones (coxal bones or
pelvic bones)Each hip bone is made up of 3 fused bones:
Ilium (articulates with sacrum)IschiumPubis
Pelvic Girdle
Figure 8–7
Pelvic Girdle: Ilium
Largest hip boneSuperior part of
coxaeFused to ischium
(posteriorly) and pubis (anteriorly)
Articulates with sacrum – attaches pelvic girdle to axial skeleton
Figure 8–7
Pelvic Girdle: Ilium
Iliac crestSuperior border
Anterior superior iliac spine (ASIS)
Anterior inferior iliac spine (AIIS)
Posterior superior iliac spine (PSIS)
Posterior inferior iliac spine (PIIS)
Figure 8–7
Pelvic Girdle: Ilium
Iliac fossaDepression on anterior
aspectSacroiliac joint
Between posterior superior and inferior spines; where ilium and sacrum articulate
Greater sciatic notchInferior to PIISPassageway for large
sciatic nerve
Figure 8–7
Pelvic Girdle: Ischium
Posterior-inferior part of coxae
Ischial spineInferior to greater
sciatic notchAt posterior-superior
end Lesser sciatic notch
Inferior to ischial spine Ischial tuberosity
Thickened posterior-inferior part
Bears body weight when seated (“sit bone”)
Figure 8–7
Pelvic Girdle: Pubis
Anterior-inferior part of coxae
Pubic symphysisJoint where anterior
medial surfaces of pubic bones are interconnect by fibrocartilage pad
Limits movement between pubic bones of left and right hipbones
Figure 8–7
Pelvic Girdle: Acetabulum
Also called the hip socket
Large, concave socket on lateral surface of os coxae
Meeting point of ilium, ischium, and pubis
Articulates with head of femur
Figure 8–7
Pelvic Girdle: Obturator Foramen
Large space encircled by pubis and ischium
Closed by sheet of collagen fibers
Provides base for hip muscles
Figure 8–7
PelvisConsists of:
2 hip bonesSacrumCoccyx (of axial skeleton)
Stabilized by ligaments of pelvic girdle, sacrum, and lumbar vertebrae
Pelvis
Figure 8–8
Pelvic OpeningsPelvic inlet – (anterior) space enclosed by
pelvic brim Pelvic outlet – opening bounded by coccyx and
ischial tuberosities
Figure 8–9
Pubic AngleInferior angle between pubic bones
Figure 8–10
Bones of the Lower LimbsFemur (thigh)Patella (kneecap)Tibia and fibula (leg)Tarsals (ankle)Metatarsals (foot)Phalanges (toes)
Femur
Longest, heaviest boneTransfers body weight
to groundArticulates with:
coxae at acetabulumtibia at knee joint
Figure 8–11
Femur
HeadLarge, round proximal endArticulates at acetabulum
NeckNarrow connector between
head and shaftJoins shaft at angle
Figure 8–11
Femur
Greater trochanterLarge process at superior
end of shaftLesser trochanter
Smaller process inferior to neck on medial /posterior side
Figure 8–11
Femur
Lateral condyleLarge, rounded, lateral
projection at distal epiphysis
Articulates with lateral condyle of tibia
Medial condyleLarge, rounded, medial
projection at distal epiphysis
Articulates with medial condyle of tibia
Figure 8–11
Femur
Intercondylar fossaDepression between
condyles on posterior side
Figure 8–11
Femur
Patellar surfaceFlattened area between
condyles on anterior side
Figure 8–11
PatellaLarge sesamoid boneForms within tendon of quadriceps femoris
(extends/straightens the knee)
Figure 8–12
TibiaLarger, medial bone; supports body weightAlso called the shinbone
Figure 8–13
Tibia
Lateral condyleLateral projection at
proximal epiphysisArticulates with lateral
condyle of femurMedial condyle
Medial projection at proximal epiphysis
Articulates with medial condyle of femur
Figure 8–13
Tibia
Tibial tuberosityRoughened area on
anterior surfaceInferior to condylesAttachment for
patellar ligament
Figure 8–13
Tibia
Anterior marginRidge that begins at
tibial tuberosity and extends distally along anterior surface (“shin bone”)
Medial malleolus (“little mallet”)Projection on medial
side at distal epiphysis
Figure 8–13
FibulaSlender, lateral bone of lower leg
Figure 8–13
Fibula
HeadArticulates with
proximal tibiaLateral malleolus
Projection on lateral side at distal epiphysis
Articulates with distal tibia
Provides lateral stability to ankle
Figure 8–13
Tarsal Bones Allow ankle to bend and twist
7 bones
Ankle and Foot Bones
Figure 8–14a
Tarsal BonesTalusCalcaneousNavicularCuboid
Cuneiforms (3)
Note: movement more restricted than wrist/hand
Metatarsal Bones5 long bones of the foot Numbered I–V from medial (big toe) to
lateralArticulate with proximal phalanges
PhalangesToe bones
I (lateral)Hallus (big toe):2 phalanges (proximal, distal)
II - V3 phalanges (proximal, medial or middle, distal)