Transcript Chapter_08_AppendicularSystemx

Anatomy and
Physiology I
BIOL 2401
Chapter 8
The Skeletal System
-Appendicular System
Skeletal System – Appendicular Skeleton
• Bones that make
up upper and
lower extremities
• Bones that make
up pectoral and
pelvic girdles
Appendicular Skeleton – Pectoral Girdle
Pectoral Girdle:
Attach upper extremities to
the axial skeleton
Bones include:
Clavicles: articulate with
scapula and sternum.
Scapulae: articulate with
the arm bone and the
clavicle.
Appendicular Skeleton – Pectoral Girdle
Clavicles:
S shaped bones.
Landmarks include:
Medial sternal end - articulates with the manubrium of sternum.
Forms sternoclavicular joint.
Lateral acromial end - articulates with the acromion of scapula.
Forms acromioclavicular joint.
Appendicular Skeleton – Pectoral Girdle
Scapula:
Flat, triangular shaped bone placed on the posterior surface of thorax.
Landmarks include:
Body: main part of scapula.
Spine: a bony ridge that runs obliquely across the posterior surface.
Acromion: a lateral, flat end of the spine; the high point of the shoulder.
Coracoid process: a projection of the body just below the acromion;
attachment site for muscles.
Glenoid cavity: a cavity on the lateral border of the scapula; for articulation
with head of humerus---forms glenohumeral joint (shoulder joint).
Appendicular Skeleton – Pectoral Girdle
Scapula
Appendicular Skeleton – Upper Extremities
30 bones in each
limb.
Total of 60 bones.
Consists of:
Humerus
Radius, Ulna
Carpals
Metacarpals
Phalanges
Appendicular Skeleton – Upper Extremities
Humerus
Proximal end:
Head: articulates with
glenoid cavity of scapula.
Greater and lesser
tubercles: lateral and
anterior projections just
distal to anatomical neck.
Intertubercular sulcus:
groove between greater
and lesser tubercles.
Appendicular Skeleton – Upper Extremities
Humerus
Body: shaft of the bone.
Anatomical neck: just
distal to head.
Surgical neck: area
distal to tubercles;
humerus narrows.
Deltoid tuberosity:
lateral projection;
attachment site for
tendon of deltoid
muscle
Appendicular Skeleton – Upper Extremities
Humerus
Distal end:
Medial and lateral
epicondyles: projections
on the distal humerus;
attachment points for muscles
of the forearm.
Capitulum: rounded structure
on distal humerus (lateral);
articulates with radius of
forearm.
Trochlea: medial to the
capitulum; shaped like an
hourglass on its side;
articulates with the ulna.
Olecranon fossa: posterior
fossa that receives the
olecranon process of the
ulna.
Appendicular Skeleton – Upper Extremities
Forearm
Composed of the radius and the ulna
Articulate with humerus to form elbow joint
Appendicular Skeleton – Upper Extremities
Radius (Forearm)
Lateral bone.
Radial head: disc
shaped; articulates with
the capitulum of
humerus.
Radial tuberosity:
bony projection
medially located;
attachment site for
biceps brachii muscle
Appendicular Skeleton – Upper Extremities
Ulna (Forearm)
Medial bone.
Trochlear notch:
articulates with
trochlea of humerus
Coronoid process:
anteriorly located; fits
in coronoid fossa of
humerus when elbow
flexed (bent).
Olecranon process:
posteriorly located;
forms the elbow point;
fits into olecranon
fossa of humerus
when arm is bent.
Styloid process:
located on distal end.
Appendicular Skeleton – Upper Extremities
Elbow
Capitulum of humerus articulates with the head of radius.
The trochlea of humerus articulates with the trocheal notch of ulna.
The olecranon of ulna fits into the olecranon fossa on posterior surface
of the humerus.
Appendicular Skeleton – Upper Extremities
Wrist
Made of 8 short bones called carpals.
Arranged in two rows of four bones:
Proximal: Scaphoid, Lunate, Triquetrum, Pisiform
Distal: Trapezium, Trapezoid, Capitate, Hamate
Appendicular Skeleton – Upper Extremities
Metacarpals
Five in each palm.
Long bones with proximal and distal ends.
Proximal end: articulate with carpals.
Distal end (head): articulate with finger bones; form the
knuckles.
Appendicular Skeleton – Upper Extremities
Fingers
Composed of long bones called phalanges, each with
proximal and distal ends.
Three bones in each finger; two in thumb (pollex); a total
of 14 phalanges in each hand.
Skeletal System – Appendicular Skeleton
Lower extremities
Pelvic girdle
Appendicular Skeleton – Pevic Girdle
Pelvic Girdle:
Attach lower extremities
to the axial skeleton.
Made of two flat bones
called coxal bones.
They articulate with each
other and sacrum to form
a ring.
Appendicular Skeleton – Pevic Girdle
Coxal bone:
Each coxal bone is formed by fusion of three bones: ilium, ischium and pubis.
Appendicular Skeleton – Pevic Girdle
Coxal bone:
Lower extremities articulate with acetabulum - a depression on lateral surface.
Anteriorly, coxal bones articulate with each other – pubic symphysis.
Posteriorly, coxal bones articulate with sacrum.
Appendicular Skeleton – Pevic Girdle
Pelvic Girdle: Male vs. Female
Male:
Female:
Narrower
Wider—allows for childbirth
Pelvic arch less than 90 degrees
Pelvic arch greater than 90 degrees
Larger, heavier
Shallow, lighter
Larger acetabulum
Smaller acetabulum
Sacrum – longer, narrower
Sacrum – wider and shorter
Appendicular Skeleton – Lower Extremities
30 bones in each
limb.
Total of 60 bones.
Consists of:
Femur
Tibia, fibula
Tarsals
Metatarsals
Phalanges
Appendicular Skeleton – Lower Extremities
Femur
Proximal end:
Head: articulates with
acetabulum of coxal.
Greater and lesser
trochanter: lateral and
anterior projections for
muscle attachment.
Appendicular Skeleton – Lower Extremities
Femur
Neck- narrow area distal to
head (common fracture
site).
Shaft: body of the bone.
Linea aspera- attachment
site for thigh muscles.
Appendicular Skeleton – Lower Extremities
Femur
Distal end:
Medial and lateral
epicondylesattachment
sites for knee ligaments
Medial and lateral
condyles- articulate with
tibial condyles (held in
place with menisci)
Intercondylar fossafound between condyles
(posterior surface)
Patellar surface- found
on anterior surface
Appendicular Skeleton – Lower Extremities
Patella
Sesamoid bone.
Protects knee joint.
Appendicular Skeleton – Lower Extremities
Tibia
Medial bone.
Supports weight of body.
Proximal end:
Lateral and medial
condyles: articulate
with condyles of femurtibiofemoral (knee)
joint.
Tibial tuberosity: for
patellar ligament
attachment.
Distal end:
Medial malleolus - distal
end; medial ankle
Appendicular Skeleton – Lower Extremities
Fibula
Lateral bone.
Proximal end:
Head: articulate with
proximal end of tibia
(not femur).
Distal end:
Articulates with distal end
of tibia.
Lateral malleolus - distal
end; lateral ankle.
Appendicular Skeleton – Lower Extremities
Ankle/Foot
Tarsals: ankle and heel bones; 7 short bones.
Talus, calcaneous (heel bone), Navicular,
Cuneiforms (lateral, intermediate, and
medial), Cuboid.
Metatarsals: 5 long bones;
Proximal end: articulate with tarsals.
Distal end: articulate with toe bones.
Phalanges: make up toes.
Each with proximal and distal ends.
Three bones in each toe.
Two in big toe (hallex).
A total of 14 phalanges in each foot.
Appendicular Skeleton – Lower Extremities
Foot arches
Bones of foot are held in place by ligaments and tendons.
They are arranged to form two arches:
Longitudinal arch and transverse arch
Function: Distribute body weight, act as a spring, support the body and
provide leverage when walking.
Disorders
• Flat foot: Longitudinal arch decreased
• Club foot: Longitudinal arch increased
• Bunion: deformity of the big toe
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