Transcript Appendicular Skeleton

Appendicular Skeleton
Appendicular Skeleton
• Contains 126 bones between 4 groups:
– Pectoral girdle (4)
– Arms (60)
– Legs (60)
– Pelvic girdle (2)
Pectoral Girdle: attaches the
upper appendage to the thorax
Pectoral Girdle
• Includes 2 bones (on each side)- clavicle
and scapula.
• Weaker girdle than the pelvic girdle
– Not designed to be weight bearing
– Small point of attachment with the axial
skeleton (at the sternoclavicular joint)
– Most of the girdle is supported by back
muscles.
Clavicle: the anterior bone of
the pectoral girdle
• S-shaped
• Collarbone
• Articulates with the manubrium of the
sternum (sternoclavicular joint). This is a
diarthrosis (gliding joint).
Clavicular Landmarks
• Sternal end: the thickened medial end of
the clavicle that articualtes with the
manubrium of the sternum.
• Acromial end: the thinner lateral end of the
clavicle that articulates with the acromion of
the scapula.
• Conoid tubercle: a small projection found on
the inferior surface of the lateral end of the
clavicle.
– This can help determine if it is the left/right
clavicle.
Scapula: the posterior bone of
the pectoral girdle.
• Larger than the clavicle
• Triangular shaped
• Attached to the axial skeleton through the
joint it forms with the clavicle
(acromioclavicular joint).
• Held in place by the larger muscles of the
back.
Anterior Scapular Landmarks
• Superior angle: the highest point on the
scapula.
• Superior border: the superior edge of the
scapula.
• Inferior angle: the lowest point on the
scapula.
• Medial (vertebral) border: a thin ridge of bone
found close to the vertebral column.
• Lateral (axillary) border: a thick ridge of bone
found close to the humerus and inferior to the
Glenoid fossa.
Anterior Scapular Landmarks cont…
• Scapular notch: a small “cut out” in the
superior border of the scapula, medial to the
coracoid process.
– Allows blood vessels to pass over the superior
border in order to feed and drain the arm. This
notch protects the vessels.
• Subscapular fossa: a large shallow
depression found on the anterior surface of
the scapula.
– In this case, “sub” means “underneath”.
Anterior Scapular Landmarks cont…
• Coracoid process: a long, tube-like
projection found medial to the Glenoid fossa.
– Where the pectoralis minor and biceps brachii
attach.
Posterior Scapular Landmarks
• Spine: a prominent ridge of bone found on
the posterior surface of the scapula.
• Acromion: a wide flat projection found on the
lateral end of the spine.
– Angled 90° anterior to the spine.
– Articulates with the acromial end of the clavicle at
the acromioclavicular joint.
• Supraspinous fossa: a shallow depression
found superior to the spine of the scapula.
– PFMA.
Posterior Scapular Landmarks
• Infraspinous fossa: a large shallow
depression found inferior to the spine of the
scapula.
– PFMA
• Glenoid (cavity) fossa: a shallow depression
found superior to the lateral (axillary) border.
– Articulates with the head of the humerus to form
the shoulder joint. This helps form the socket of
the “ball and socket”. This joint is not a tight fit
which allows a range of motion.
The Upper Appendages
• 30 bones in each arm
• Proximal  Distal:
Humerus Radius Ulna Carpals (8)
Metacarpals (5) Phalanges (14)
• Humerus: single bone of the upper arm.
– Largest bone of the arm
Proximal Humeral Landmarks
• Head: the rounded proximal end of the
humerus.
– Articulates with the glenoid fossa (not tightly
which allows for a wide range of motion)
• Anatomical neck: a small line found just
distal to the head of the humerus.
– Site of the epiphyseal line (where the growth
plate has completely ossified).
• Greater tubercle: a large blunt projection
found on the proximal end of the humerus,
lateral to the head.
Proximal Humeral Landmarks cont..
• Lesser tubercle: a small blunt projection
found on the proximal end of the humerus on
the anterior surface.
– This helps determine if it is the right/left humerus
because it is only on the anterior surface.
• Intertubercular (sulcus) groove: an elongated
channel (groove) found between the greater
and lesser tubercles.
– Allows the tendon of the biceps brachii muscle to
pass over the head on its way to the scapulawithout being bent.
Proximal Humeral Landmarks cont..
• Surgical neck: the constricted region found
inferior to the intertubercular sulcus.
– This is a term created by doctors.
– Most commonly fractured region of the humerus.
– Where the compact bone of the diaphysis thins
to transition to spongy bone of the epiphyses.
• Deltoid tuberosity: a large slightly rounded
projection found on the lateral surface of the
diaphysis.
– Point for the deltoid muscle attachment.
Distal Humeral Landmarks
• Capitulum: the rounded lateral condyle of
the humerus.
– Articulates with the head of the radius to help
stabalize the elbow joint.
• Trochlea: the pulley-shaped medial
condyle of the humerus.
– Articulates with the ulna to form the
“functional” part of the elbow that allows it to
be a hinge joint.
* Most condyles are specifically named but
these 2 are shaped so differently!
Distal Humeral Landmarks cont..
• Medial epicondyle: a large projection
found proximal to the trochlea.
– PFMA
– This region is called the “funny bone”. The
sensation that you feel when you hit this is
actually due to the pressure put on the ulnar
nerve that runs posteriorly to this.
• Lateral epicondyle: a small projection
found proximal to the capitulum.
– PFMA
Distal Humeral Landmarks cont..
• Coronoid fossa: a small projection found
proximal to the capitulum.
– It accepts the coronoid process of the ulna when
the elbow is bent.
– If we didn’t have this, we wouldn’t be able to
bend the joint so far.
• Olecranon fossa: a large shallow depression
found proximal to the trochlea on the distal
posterior surface of the humerus.
– This accepts the olecranon of the ulna and allows
the elbow to straighten.
Radius
• The lateral bone of the forearm.
– On the thumb side
– Helps to stabilize the elbow joint.
• Head: the flattened proximal end of the
radius.
– Articulates with the capitulum of the humerus.
• Radial tuberosity: a small round projection
found on the anterior surface just distal to the
head.
– Where the biceps brachii attaches and pulls on
the radius.
Radius continued…
• Styloid process: a small triangular projection
found on the distal lateral surface.
– PFMA
– Can be felt as a bump on the distal, lateral
surface.
Ulna
• The medial bone of the forearm.
– On the pinky side
• Trochlear notch: a “C” shaped notch found on
the proximal anterior surface.
– Articulates with the trochlea to form the functional
part of the elbow. This is the pivot point for the
hinge joint.
• Coronoid process: a small triangular process
found on the anterior surface of the trochlear
notch.
– Fits into the coronoid fossa of the humerus when
the elbow is bent.
Ulna continued…
• Olecranon (process): a large blunt projection
found on the proximal posterior surface.
– PFMA
– The part of the elbow that “sticks out” when it is
bent.
• Head: the smaller distal end.
– The only bone that has the head at the distal end.
• Styloid process: a small triangular projection
on the distal medial surface.
Carpals
• A group of 8 short bones that form the wrist.
• Function:
– Evenly transfer forces from the palm to the
radius and ulna.
• Bones: Arranged in 2 rows of 4 bones
“Tell the children how scotties like to play”
• Distal row (lateral to medial)
• Trapezium-Trapezoid-Capitate-Hamate
• Proximal row (lateral to medial)
• Scaphoid-Lunate-Triquetrum-Pisiform
Metacarpals & Phalanges
• Metacarpals: A group of 5 long bones that
make up the palm of the hand.
– Numbered #1-5 from lateral (thumb) to medial
(pinky)
• Phalanges: A group of 14 long bones that
make up the digits of the hand.
– Digit #1 is the thumb- has 2 bones (proximal and
distal)
– Digits #2-5- each have 3 bones (proximal,
intermediate, and distal)
– Phalanx- Singular form of phalanges (each
individual finger bone)
Pelvic Girdle
• Attaches the lower appendages to the
sacrum of the vertebral column
• Immovable girdle
• Designed to be weight bearing
• Large bony point of attachment with the sacrum
at the sacroiliac joint
• Os coxae (coxa is singular)
• Two bones of the pelvic girdle
• Each is composed of 3 bones that are fused
together
Ilium
• Large, superior bone of the os coxa
• Forms the prominence of the hips
Illiac Landmarks: (#1-5 are PFMA)
• Anterior superior iliac spine (ASIS): a large
blunt projection that marks the beginning of
the iliac crest.
• Iliac crest: a prominent ridge of bone that
forms the superior border of the ilium.
• What you feel when you put your hands on your
hips.
Ilium
• Posterior superior iliac spine (PSIS): a large
blunt projection that marks the end of ht eiliac
crest.
• Anterior inferior iliac spine (AIIS): a smaller
blunt projection found inferior to the anterior
superior iliac spine
• Posterior inferior iliac spine (PIIS): a smaller
blunt projection found inferior to the posterior
superior iliac spine.
Ilium
• Greater sciatic notch: a large cut out area
found anterior to the posterior inferior iliac
spine.
• This allows the large branch of the sciatic nerve
to pass over the os coxa on its way to the leg.
Ilium
• Iliac fossa: a large shallow depression found
on the anterior surface of the ilium.
• Auricular surface: a roughened area found
anterior to the posterior inferior iliac spine.
• Articulates with the auricular surface of the
sacrum to form the sacroiliac joint
Ischium
• The inferior, posterior bone of the os coxa.
Ischial landmarks:
• Ischial spine: a sharp flat projection found
inferior to the greater sciatic notch.
• Lesser sciatic notch: a small cut area found
inferior to the ischial spine.
• Allows a small branch of the sciatic nerve to pass
over the ischium on its way to the leg.
• Ischial tuberosity: a large, flat, blunt projection
found inferior to the lesser sciatic notch.
Pubis
• The inferior, anterior bone of the os coxa.
Pubis landmarks:
• Pubic crest: a small ridge of bone found on the
anterior surface.
• Pubic tubercle: a small rounded projection found
on the medial end of the pubic crest.
• Superior pubic ramus: the short horizontal portion
of the pubis found lateral to the pubic tubercle.
• Inferior pubic ramus: the longer vertical portion of
the pubis found inferior to the pubic tubercle.
Os coxa Landmarks
• Acetabulum: a large cup shaped depression
found on the lateral surface of the os coxa.
• Formed by all 3 bones of the os coxa.
• Articulates with the head of the femur to form the ball
and socket hip joint.
• Obturator foramen: a large opening through the
os coxa formed by the joining of the ischium and
the pubis.
• PFMA
Lower Appendages
• 60 total bones (30 per leg)
Proximal to Distal:
femurpatellatibiafibulatarsals (7)
Metatarsals (5)phalanges (14)
• Femur: single bone of the upper leg.
• Longest, largest and strongest bone of the body.
• Articulates with the acetabulum of the os coxa.
Femoral Landmarks
• Head: the rounded proximal end of the
femur.
• Fits better with the acetabulum than the
humerus does with the glenoid cavity. This
gives it less range of motion but more weight
bearing.
• Fovea capitis: a small opening in the head of
the femur that allows blood vessels to enter
the proximal end of the femur.
• Can only be seen when viewing the medial
surface of the head.
Femoral Landmarks
• Neck: the constricted region of the femur just
distal to the head.
• Most commonly fractured site on the femur.
• Greater trochanter: a large blunt, irregular
projection found on the proximal lateral
surface.
• Largest bone landmark in the body.
• Lesser trochanter: a smaller blunt projection
found on the proximal, medial posterior
surface.
Femoral Landmarks
• Intertrochanteric line: a small ridge of bone
found between the greater and lesser
trochanters on the proximal anterior surface.
• Intertrochanteric crest: a large prominent
ridge of bone found between the greater and
lesser trochanters on the proximal posterior
surface.
• Gluteal tuberosity: a short vertical ridge of
bone found inferior to the intertrochanteric
crest.
• Where the gluteus maximus tendon attaches.
Femoral Landmarks
• Linea aspera: a long vertical ridge of bone
found inferior to the gluteal tuberosity on the
posterior surface of the diaphysis.
• Medial epicondyle: a small projection found
proximal to the medial condyle.
• Lateral epicondyle: a small projection found
proximal to the lateral condyle.
• Medial and lateral condyles: the rounded
distal ends of the femur.
• Articulate with the condyles of the tibia to form
the knee joint.
Femoral Landmarks
• Intercondylar fossa: a large shallow
depression found between the medial and
lateral condyles of the femur.
• Where ligaments attach that hold the knee joint
together.
Patella
• Small triangular bone located anterior to the
knee joint.
• Sesamoid bone: bone that develops inside a
tendon.
• Function: protects the tendon of the quadriceps
femoris muscle group as it crosses over the
knee joint.
• Landmarks:
• Base: the blunt superior portion.
• Apex: the pointed inferior portion.
Tibia
• Large, medial weight bearing bone of the
lower leg.
• Articulates with the condyles of the femur to
form the knee joint.
• Articulates with the talus to form the ankle joint.
Tibial landmarks:
• Medial and lateral condyles: the concave
proximal ends.
• Start out rounded and they flatten when the
person starts walking.
• Articulate with the condyles of the femur.
Adult tibia
Tibial Landmarks cont…
• Intercondylar eminence: a paired triangular
projection found between the medial and lateral
condyles.
• Point for ligament attachment- PCL and ACL attach
to this and the intercondylar fossa of the femur.
• Tibial tuberosity: a small rounded projection
found on the proximal anterior surface.
• PFMA
• Anterior (crest) border: a sharp ridge of bone
found on the anterior surface of the shaft.
• PFMA
Tibial Landmarks cont…
• Medial malleolus: a large blunt projection
found on the distal medial surface.
• Forms the prominence of the ankle on the medial
side.
• Helps prevent medial dislocation of the ankle.
Fibula
• The smaller, lateral, non-weight bearing bone of
the lower leg.
• Point of attachment for the muscles that act on the
foot.
• This is why it is difficult to walk if the fibula is
broken.
Fibular landmarks:
• Head: the rounded proximal end.
• Lateral malleolus: the pointed distal end.
• Forms the prominence of the ankle on the lateral
side and helps prevent lateral dislocation.
Tarsals
• A group of 7 short bones that form the
posterior arch of the foot.
• Function to transfer force from the foot to the
tibia when walking.
Tarsal bones:
Calcaneuscuboidlateral
cuneiformintermediate cuneiformmedial
cuneiformnaviculartalus
“Crazy couples love introducing many new
things”
Metatarsals & Phalanges
• Metatarsals: a group of 5 long bones that
form the anterior arch of the foot.
• Numbered 1st-5th (medial to lateral)
• Phalanges: a group of 14 long bones that
form the digits of the foot.
• Great toe (hallux) has 2 phalanges (proximal
and distal)
• 2nd-5th have 3 phalanges (proximal,
intermediate/middle and distal)
ACT - UP
The term
condyles” is used
to describe the
proximal end of
the tibia. Is this
term being used
correctly?
Defend your
answer.