Study Guide Appendicular Skeleton
1. The skeleton of limbs (appendages) and their girdles form Appendicular Skeleton.
2. Pectoral Girdle on each side has 2 bones – clavicle and scapula.
3. Clavicle = collar bone is a membrane bone like most skull bones. It is a long bone with double curve.
It lies horizontally in front of shoulder and extends to the base of neck. It anchors Scapula to the
sternum. It acts like a brace for scapula when the arm is moved laterally.
4. Scapula = shoulder blade lies posterior to ribs on backside of shoulder. It has Acromian at the corner
of shoulder to which lateral end of clavicle articulates. It has Glenoid cavity for articulation of head
of Humerus. On posterior side an oblique large spine ends in Acromian. The spine divides the
Supraspinous and Infraspinous fossae. A coracoids process is also seen near acromian. Both clavicles
and scapulae provide attachment surfaces for muscles of neck, shoulder and arm.
5. Fore-limb = arm + forearm + wrist+ hand. Arm = Brachium; Forearm = antebrachium; Wrist = carpus;
Hand = manus. Skeleton of fore-limb includes Humerus in arm; Radius and Ulna in forearm; 8 carpals
in wrist; 5 metacarpals in palm; 14 phalanges in digits.
6. Brachium has single bone. Humerus is a typical long bone. Proximal humerus has a head to
articulate with glenoid cavity of scapula. Greater and lesser tubercles. Head is large and neck is not
well marked. Nearly in the middle, diaphysis has Deltoid tuberosity for attachment of deltoid
muscle. The distal humerus has 2 condyles, medial (on head side) Trochlea – spool like to articulate
with Ulna and lateral Capitulum to articulate with Radius. Both condyles have larger epicondyles.
Just above trochlea, on posterior side, olecranon fossa is present to articulate with olecranon
process.
7. Antebrachium has a lateral Radial and a median Ulna. Proximally radius is shorter and has a disc like
head that articulate with the capitulum condyle of humerus. Radical below the neck has radial
tuberosity for attachment of tendon of bicep muscles of arm. Distal radius is larger than distal ulna
and mainly carries the hand.
8. Carpus is formed of 8 carpals forming roughly forming 2 rows:
Medial side< Hamate, Capitate, Trapezoid, Trapezium > lateral side - Distal row of carpals
<Pisiform, Traquetral, Lunate , Scaphoid > Proximal row of carpals; Ulna articulate with
Lunate and Radius articulates with Scaphoid.
9. Palm has 5 metacarpals 1-5, starting with thumb metacarpal. Thumb has a distal and a proximal
phalanx but each finger has a distal, middle and a proximal phalanx. The 1st metacarpal is fixed lower
than the other 4 metatarsals and phalanges of the thumb are opposable to the phalanges of fingers.
This enabled making and using tools by humans possible. So our hands are clasping tools.
10. Do activity 2 in lab manual.
11. Pelvic or hip Girdle is formed of 2 coxal bones = ossa coxae. 2 coxal bones + sacrum + coccyx form
bony pelvis.
12. Coxal bone – Posterior/Superior wing like part is ilium bone having superiorly a thick Crest.
Anterior /lateral extension of ilium is Ischium. Medial part is Pubis. 2 pubis parts make a
cartilaginous Pubic Symphysis. All 3 surround Acetabulum the socket for articulation of head of
femur. Study the differences in male and female pelvis in table 9.1 in lab manual.
13. Thigh has 1 bone. Femur is the longest bone in human body. Proximal femur has a rounded head
with a distinct narrow neck. Greater Trochanter is present on lateral side and lesser trochanter on
medial side. Distal femur has a lateral and a median condyle on posterior side. Patellar surface is
seen on anterior side of epicondyles. Patella is a sesamoid bone also called knee cap.
14. Lower leg has a well built medial Tibia and a thin lateral Fibula. Proximal tibia has 2 articular
surfaces for the 2 condyles of femur. A tibial tuberosity is present on anterior side, observed just
below knee joint. Tibia has a ridge like anterior border commonly called shin. Distal tibia has
articular surface for Tallus tarsal and a median malleolus. Fibula does not articulate with femur.
Proximal and distal fibula articulate with tibia and make proximal and distal tibiofibular joints. Distal
fibula ends into Lateral malleolus. The 2 malleolus ends protrude on opposite sides of ankle joint.
15. Foot is formed of 7 tarsals, 5 metatarsals and 14 phalanges.
16. Tarsus has a large Calcaneum tarsal forming the heel. It has Talus in superior/ medial to it that
makes the articulation with distal tibia. Navicular lies in front of talus; and Cuboid is anterior to
calcaneum. The distal row of tarsals: Medial Cuneiform, middle Cuneiform, lateral Cuneiform and
Cuboid tarsal.
17. 5 metatarsals and 14 phalanges are similar to bones in hand. The metatarsal and phalanges of big
toe = Hallux lies parallel to other 4 metatarsals. Watch carefully the arch made by bones of foot and
placement of ankle joint. The arch of the foot helps to bear effectively the burden of body and
forward shifting of ankle joint helps to have better balance when bending backwards.
18. Do activity 5 lab manual.
19. Learn to identify left and right sides of limb bones and scapula by identifying medial and lateral
sides. Learn to identify anterior and posterior sides of scapula and pelvic girdle.
20. Total bones in Appendicular skeleton: Hind Limb = 2 X (coxal + femur + patella + tibia + fibula + 7
tarsals + 5 metatarsals + 14 phalanges) = 62; Fore Limb = 2 X (clavicle + scapula + humerus + ulna +
tibia + 8 carpals + 5 metacarpals + 14 phalanges) = 64. Total = 62 + 64 = 126
21. Go over the bones and important markings time and again. Do the review sheets to understand the
structures.