the skeletal system: the appendicular skeleton. divisions of the skeletal system axial...
TRANSCRIPT
The Skeletal System: The The Skeletal System: The Appendicular SkeletonAppendicular Skeleton
Divisions of the Skeletal SystemDivisions of the Skeletal System
Axial skeletonAxial skeleton—protects and supports the —protects and supports the internal organsinternal organs
Appendicular skeletonAppendicular skeleton—facilitates —facilitates movementmovement
The appendicular skeleton consists of 126 The appendicular skeleton consists of 126 bones; it includes bones of the limbs and bones; it includes bones of the limbs and the girdlesthe girdles
Pectoral (Shoulder) GirdlesPectoral (Shoulder) Girdles
Attach the bones of the upper limbs to the Attach the bones of the upper limbs to the axial skeletonaxial skeleton
Each consists of 2 bones: Each consists of 2 bones: clavicleclavicle and and scapulascapula
ClavicleClavicle
CollarboneCollarbone An s-shaped bone that articulates with the An s-shaped bone that articulates with the
manubrium of the sternum and with the manubrium of the sternum and with the scapulascapula
One of the most frequently fractured bones One of the most frequently fractured bones of the bodyof the body
Fig. 08.02
ScapulaScapula
Shoulder bladeShoulder blade A triangular-shaped flat bone that A triangular-shaped flat bone that
articulates with the claviclearticulates with the clavicle The The acromionacromion is a process of the scapula is a process of the scapula
that can be felt as the high point of the that can be felt as the high point of the shouldershoulder
The The glenoid cavityglenoid cavity is a depression of the is a depression of the scapula that articulates with the humerus to scapula that articulates with the humerus to form the shoulder jointform the shoulder joint
Upper LimbsUpper Limbs
Each upper limb has 30 bones: Each upper limb has 30 bones: – HumerusHumerus (1) (1)– Radius Radius (1)(1)– UlnaUlna (1) (1)– CarpalsCarpals (8) (8) – MetacarpalsMetacarpals (5) (5)– PhalangesPhalanges (14) (14)
HumerusHumerus
Upper arm boneUpper arm bone The longest and largest bone of the upper limbThe longest and largest bone of the upper limb Articulates proximally with the scapula and Articulates proximally with the scapula and
distally at the elbow with the radius and ulna of distally at the elbow with the radius and ulna of the forearmthe forearm
The The headhead articulates with the articulates with the glenoid cavityglenoid cavity of the of the scapulascapula
The The capitulumcapitulum articulates with the articulates with the headhead of the of the radius; the radius; the trochleatrochlea articulates with the ulna articulates with the ulna
Radius and UlnaRadius and Ulna
Long bones of the forearmLong bones of the forearm The ulna is longer than the radius and is located on the The ulna is longer than the radius and is located on the
“little-finger” side of the forearm“little-finger” side of the forearm The The olecranonolecranon of the ulna forms the prominence of the of the ulna forms the prominence of the
elbowelbow The radius is located on the thumb side of the forearmThe radius is located on the thumb side of the forearm The elbow joint is formed by 2 articulations:The elbow joint is formed by 2 articulations:
– The The trochlear notchtrochlear notch of the ulna with the of the ulna with the trochlea trochlea of the humerusof the humerus– The The headhead of the radius with the of the radius with the capitulumcapitulum of the humerus of the humerus
CarpalsCarpals
The wrist consists of 8 small bones called The wrist consists of 8 small bones called carpalscarpals
These bones are arranged in two rows of These bones are arranged in two rows of four bones eachfour bones each
In most carpal fractures, only the In most carpal fractures, only the scaphoidscaphoid carpal bone is brokencarpal bone is broken
MetacarpalsMetacarpals
The palm of the hand consists of 5 long The palm of the hand consists of 5 long bones called bones called metacarpalsmetacarpals
Each of these bones consists of a Each of these bones consists of a basebase, , shaftshaft, and , and headhead
The metacarpals are numbered 1 through 5, The metacarpals are numbered 1 through 5, starting with the thumbstarting with the thumb
The “knuckles” are the heads of the The “knuckles” are the heads of the metacarpalsmetacarpals
PhalangesPhalanges
The long bones of the fingers (digits)The long bones of the fingers (digits) There are 14 There are 14 phalangesphalanges in each hand in each hand Each Each phalanxphalanx consists of a consists of a basebase, , shaftshaft, and , and
headhead There are 2 phalanges in the thumb, or There are 2 phalanges in the thumb, or
pollexpollex, and 3 phalanges in each of the other , and 3 phalanges in each of the other four digitsfour digits
Pelvic (Hip) GirdlesPelvic (Hip) Girdles
Consist of 2 hip bones, called Consist of 2 hip bones, called coxal bonescoxal bones These 2 bones unite anteriorly at a joint called the These 2 bones unite anteriorly at a joint called the pubic pubic
symphysissymphysis and posteriorly with the sacrum at the and posteriorly with the sacrum at the sacroiliac jointssacroiliac joints
The 2 coxal bones and the sacrum form the The 2 coxal bones and the sacrum form the pelvispelvis; the ; the pelvis supports the vertebral column and pelvic organs and pelvis supports the vertebral column and pelvic organs and attaches the lower limbs to the axial skeletonattaches the lower limbs to the axial skeleton
In an adult, each coxal bone consists of three bones that In an adult, each coxal bone consists of three bones that fused together after birth:fused together after birth:– IliumIlium– Ischium Ischium – Pubis Pubis
Pelvic (Hip) Girdles (continued)Pelvic (Hip) Girdles (continued)
The ilium is the largest and most superior of the three hip The ilium is the largest and most superior of the three hip bone components; it articulates with the sacrum to form bone components; it articulates with the sacrum to form the the sacroiliac jointsacroiliac joint
The ischium is located inferior and posterior; the pubis is The ischium is located inferior and posterior; the pubis is located inferior and anterior; together, they surround the located inferior and anterior; together, they surround the obturator foramenobturator foramen, the largest foramen of the skeleton, the largest foramen of the skeleton
All three of these bones make up the All three of these bones make up the acetabulumacetabulum, a deep , a deep fossa that accepts the round head of the fossa that accepts the round head of the femurfemur
The two coxal bones meet anteriorly at a joint called the The two coxal bones meet anteriorly at a joint called the pubic symphysispubic symphysis; this joint contains a cartilage disc that ; this joint contains a cartilage disc that gives the joint flexibilitygives the joint flexibility
The pelvis of a female is wider and shallower than that of a The pelvis of a female is wider and shallower than that of a male to allow for childbirthmale to allow for childbirth
Lower LimbsLower Limbs
Each lower limb has 30 bones:Each lower limb has 30 bones:– Femur Femur (1)(1)– Patella Patella (1)(1)– Tibia Tibia (1)(1)– Fibula Fibula (1)(1)– Tarsals Tarsals (7)(7)– Metatarsals Metatarsals (5)(5)– Phalanges Phalanges (14)(14)
FemurFemur
Thigh boneThigh bone Longest, heaviest, and strongest bone in the Longest, heaviest, and strongest bone in the
bodybody Its proximal end consists of a Its proximal end consists of a head head that that
articulates with the hip bone at the articulates with the hip bone at the acetabulum; its distal end articulates with acetabulum; its distal end articulates with the tibia and patellathe tibia and patella
PatellaPatella
KneecapKneecap A small, triangular bone located anterior to A small, triangular bone located anterior to
the knee jointthe knee joint It is a It is a sesamoid bonesesamoid bone, which develops in the , which develops in the
tendon of the “quadriceps” muscletendon of the “quadriceps” muscle Articulates with the femurArticulates with the femur
Tibia and FibulaTibia and Fibula
The tibia is the shinbone The tibia is the shinbone It is the larger, medial, weight-bearing bone of the It is the larger, medial, weight-bearing bone of the
lower leglower leg At is proximal end, the tibia articulates with the At is proximal end, the tibia articulates with the
femur and fibula; at its distal end, it articulates femur and fibula; at its distal end, it articulates with the fibula and the with the fibula and the talustalus bone of the ankle bone of the ankle
The fibula is the smaller bone of the lower legThe fibula is the smaller bone of the lower leg It lies parallel and lateral to the tibiaIt lies parallel and lateral to the tibia
TarsalsTarsals
The ankle consists of 7 bones called The ankle consists of 7 bones called tarsalstarsals The The calcaneuscalcaneus is the largest and strongest is the largest and strongest
tarsal bone; it is located in the posterior heel tarsal bone; it is located in the posterior heel part of the footpart of the foot
The The talustalus is the uppermost tarsal bone; it is the uppermost tarsal bone; it articulates with the fibula and tibiaarticulates with the fibula and tibia
MetatarsalsMetatarsals
The main part of the foot consists of 5 long The main part of the foot consists of 5 long bones called bones called metatarsalsmetatarsals
Each of these bones consists of a Each of these bones consists of a basebase, , shaftshaft, and , and headhead
The metatarsals are numbered 1 through 5, The metatarsals are numbered 1 through 5, from the medial to lateral position from the medial to lateral position
PhalangesPhalanges
The long bones of the toesThe long bones of the toes There are 14 There are 14 phalangesphalanges on each foot on each foot Each Each phalanxphalanx consists of a consists of a basebase, , shaftshaft, and , and
headhead There are 2 phalanges in the big toe, or There are 2 phalanges in the big toe, or
halluxhallux, and 3 phalanges in each of the other , and 3 phalanges in each of the other four digitsfour digits