Appendicular Skeleton Prof Abdulameer AlNuaimi a alnuaimisheffield ac

Appendicular Skeleton Prof. Abdulameer Al-Nuaimi a. alnuaimi@sheffield. ac. uk abdulameerh@yahoo. com

Hi Prof, It is great to hear from you, I really enjoyed your teaching last year. You taught me the hardest subject I have encountered so far in a manner that I understood and could remember. I hope you are enjoying your new job in Jordon. Are you still teaching anatomy? Many thanks for your teaching and best of luck in Jordon Sam Allison

Appendicular Skeleton Each upper limb skeleton consists of 32 bones, which form two distinct regions: ØThe pectoral girdle. § Clavicle. § Scapula. ØThe free upper limb. § Humerus. § Ulna § Radius. § Hand.

The pectoral girdle The clavicle is the anterior bone and the scapula is the posterior bone.

Clavicle • S - shaped bone. • Lies horizontally across the anterior part of the thorax superior to the first rib. • The medial half of the clavicle is convex anteriorly and the lateral half is concave anteriorly. • The medial end of the clavicle, called the sternal end, is rounded and articulates with the manubrium of the sternum to form the sternoclavicular joint. • The broad, flat, lateral end, the acromial end , articulates with the acromion of the scapula at the acromioclavicular joint. • The superior surface of the clavile (smooth), while the inferior surface (rough).

Clavicle

• • • Scapula scapula or shoulder blade, is a large, triangular, flat bone with a ridge on its posterior surface. The scapula occupies the superior part of the posterior thorax between the levels of the second and seventh ribs a few finger breadths lateral to the vertebral column. A prominent ridge called the spine across the posterior surface of the scapula. The lateral end of the spine projects as a flattened, expanded process called the Acromion Inferior to the acromion is a shallow depression, the glenoid cavity, that accepts the head of the humerus to form the glenohumeral joint, or shoulder joint. The thin edge of the scapula closer to the vertebral column is called the medial (vertebral) border.

Scapula

• • Scapula The thick edge of the scapula closer to the arm is called the lateral (axillary) border. The medial and lateral borders join at the inferior angle. The superior edge of the scapula, called the superior border, joins the vertebral border at the superior angle. The scapular notch is a prominent indentation along the superior border. At the lateral end of the superior border of the scapula is the coracoid process. Superior and inferior to the spine are two fossae: the supraspinous fossa and the infraspinous fossa. On the anterior surface is a slightly hollowed-out area called the subscapular fossa.

Scapula

Humerus The humerus or arm bone, is the longest and largest bone of the upper limb. It has a ball-like proximal end with two prominent projections of bone at the base of the ball, a cylindrical, tubular shaft that makes up the majority of its length, and an expanded flattened distal end.

• • Humerus It articulates proximally with the scapula and distally with both the ulna and the radius to form the elbow joint. The proximal end of the humerus features a rounded head that articulates with the glenoid cavity of the scapula to form the glenohumeral (shoulder) joint. Distal to the head is the anatomical neck, which is visible as an oblique groove. The greater tubercle is a lateral projection distal to the anatomical neck. The lesser tubercle projects anteriorly. Between both tubercles runs an intertubercular sulcus. The surgical neck is a constriction in the humerus just distal to the tubercles.

Humerus

Humerus Laterally, at the middle portion of the shaft, there is a roughened, V-shaped area called the deltoid tuberosity. This area serves as a point of attachment for the tendon of the deltoid muscle. The radial groove runs along the posterior surface of the humerus. This groove contains the radial nerve.

Humerus at the distal end of the humerus, rounded knob on the lateral aspect of the bone that articulates with the head of the radius (capitulum). The radial fossa is an anterior depression above the capitulum that articulates with the head of the radius when the forearm is flexed. The trochlea, located medial to the capitulum, that articulates with the ulna. The coronoid fossa, anterior depression that receives the coronoid process of the ulna when the forearm is flexed. The olecranon fossa is the large posterior depression that receives the olecranon of the ulna when the forearm is extended.

Lower end of humerus

Humerus The medial epicondyle and lateral epicondyle are rough projections on either side of the distal end of the humerus to which the tendons of most muscles of the forearm are attached. The ulnar nerve passes posterior to the medial epicondyle. Lat Epicond Med Epicond Ventral surface Dorsal surface

Ulna • The ulna is located on the medial aspect of the forearm and is longer than the radius. • The ulna is thick and notched at its proximal end, and its wide triangular shaft tapers to become more narrow and cylindrical distally. • At the proximal end of the ulna is the olecranon, which forms the prominence of the elbow.

• • • Ulna The coronoid process an anterior projection distal to a large notch, the trochlear notch. This notch, on the anterior side of the olecranon, receives the trochlea of the humerus to form part of the elbow joint. It is called the trochlear notch The radial notch is a depression that is lateral and inferior to the trochlear notch and articulates with the head of the radius. Just inferior to the coronoid process is the ulnar tuberosity. The distal end of the ulna consists of a head that is separated from the wrist by a disc of fibrocartilage. A styloid process is located on the posterior side of the ulna’s distal end.

Upper end of ulna

• • • Radius The radius, the shorter of the two forearm bones, is located on the lateral aspect of the forearm. In contrast to the ulna, the radius is narrow at its proximal end and widens at its distal end. The proximal end of the radius has a disc-shaped head that articulates with the capitulum of the humerus and the radial notch of the ulna. Inferior to the head is the constricted neck. A roughened area inferior to the neck on the anteromedial side, called the radial tuberosity, is a point of attachment for the tendon of the biceps brachii muscle. The shaft of the radius widens distally to form a styloid process on the lateral side.

Radius and Ulna

Radius • The ulna and radius articulate with the humerus at the elbow joint. • The articulation occurs in two places: where the head of the radius articulates with the capitulum of the humerus, and where the trochlear notch of the ulna receives the trochlea of the humerus. • The ulna and the radius connect with one another at three sites. First, a broad, flat, fibrous connective tissue called the interosseous membrane, joins the shafts of the two bones. • The ulna and radius articulate at their proximal and distal ends.

Radius • Proximally, the head of the radius articulates with the ulna’s radial notch, a depression that is lateral and inferior to the trochlear notch. This articulation is the proximal radioulnar joint. • Distally, the head of the ulna articulates with the ulnar notch of the radius. This articulation is the distal radioulnar joint. • Finally, the distal end of the radius articulates with three bones of the wrist—the lunate, the scaphoid, and the triquetrum to form the radiocarpal (wrist) joint.

Upper and lower ends of Radius and Ulna

Bones of the hand Carpals. (8), Metacarpals. (5), Phalanges. (14)

Carpals • The carpus (wrist) is the proximal region of the hand consists of eight small bones, the carpals, joined to one another by ligaments. • Articulations between carpal bones are called intercarpal joints. • The carpals are arranged in two transverse rows of four bones each.

Metacarpals • The metacarpus or palm, is the intermediate region of the hand; it consists of five bones called metacarpals. • Each metacarpal bone consists of a proximal base, an intermediate shaft, and a distal head. • The metacarpal bones are numbered I to V (1 -5), starting with the thumb, from lateral to medial. • The bases articulate with the distal row of carpal bones to form the carpometacarpal joints. • The heads articulate with the proximal phalanges to form the metacarpophalangeal (MP) joints.

Phalanges • The phalanges or bones of the digits, make up the distal region of the hand. • There are 14 phalanges in the five digits of each hand. • Like the metacarpals, the digits are numbered I to V (or 1– 5), beginning with the thumb from lateral to medial. • Each phalanx consists of a proximal base, an intermediate shaft, and a distal head. • The thumb has two phalanges, and there are three phalanges in each of the other four digits. • In order from the thumb, these other four digits are commonly referred to as the index finger, middle finger, ring finger, and little finger.

Bones of the Hand

Lower Limb q Each lower limb skeleton consists of 31 bones, which form two distinct regions: Ø The pelvic girdle. § consists of the two hip bones, also called coxal (pelvic) bones. • The hip bones unite anteriorly at a joint called the pubic symphysis. • They unite posteriorly with the sacrum at the sacroiliac joints. • The complete cylinder composed of the hip bones, pubic symphysis, and sacrum forms a deep, basin like structure called the bony pelvis. • pelvis also connects the bones of the free lower limbs to the axial.

Hip bones are parts of the pelvis

Each of the two hip bones of a newborn consists of three bones separated by cartilage: a superior ilium, an inferior anterior pubis, and an inferior posterior ischium. By age 23, the three separate bones fuse together.

The free lower limb (extremity) has 30 bones in four locations: the femur in the thigh; the patella (knee cap); the tibia and fibula in the leg; the 7 tarsal bones in the tarsus (ankle), the 5 metatarsal bones in the metatarsus, and the 14 phalanges (bones of the digits) in the foot.

Ilium • The ilium is the largest of the three components of the hip bone. • It is thick near the hip joint and expands into a large curved plate of bone superiorly. • A superior ala (wing) and an inferior body comprise the ilium. The body is one of the components of the acetabulum, the socket for the head of the femur. • The superior border of the ilium, the iliac crest, ends anteriorly in a blunt anterior superior iliac spine. • The medial surface of the ilium contains the iliac fossa, a concavity where the tendon of the iliacus muscle attaches.

Parts of the Hip bone

Ischium • The ischium the inferior and posterior portion of the hip bone, is situated between the body of the ilium and the inferior ramus of the pubis. • The ischium is a arched or U-shaped structure, with its concave, notched margin contributing to the posterior two thirds of the obturator foramen (the large hole on the hip bone). • The ischium is comprised of a superior body and an inferior ramus.

Hip bone

Pubis The pubis is the inferior, anterior portion of the hip bone and, like the ischium, has the form of a sideways arch or a Ushape. It composed of a superior ramus, an inferior ramus, and a body between the rami. The anterior, superior border of the body is the pubic crest, and at its lateral end is a projection called the pubic tubercle. The pubic symphysis is the joint between the pubes of the two hip bones. The acetabulum is a deep fossa formed by the ilium, ischium, and pubis. It functions as the socket that contains the rounded head of the femur. Together, the acetabulum and the femoral head form the hip (coxal) joint.

Hip bone

Bony Pelvis The portion of the bony pelvis superior to the pelvic brim is the false (greater) pelvis. It is bordered by the lumbar vertebrae posteriorly, the upper portions of the hip bones laterally, and the abdominal wall anteriorly. It contains the superior portion of the urinary bladder and lower intestines in both genders and the uterus, ovaries, and uterine tubes of the female, The portion of the bony pelvis inferior to the pelvic brim is the true (lesser) pelvis. It is bounded by the sacrum and coccyx posteriorly, inferior portions of the ilium and ischium laterally, and the pubic bones anteriorly. It contains the rectum and urinary bladder in both genders, the vagina and cervix of the uterus in females, and the prostate in males.

Pelvis False Pelvis True pelvis

Bony Pelvis The superior opening of the true pelvis, bordered by the pelvic brim, is called the pelvic inlet; The inferior opening of the true pelvis is the pelvic outlet. difference between male and female pelves Oval and Wider transversely Round Shallow Cylindrical Rounded Heart shape Oval Long Funnel Angular

The femur, or thigh bone, is the longest, heaviest, and strongest bone in the body. Its proximal end articulates with the acetabulum of the hip bone. Its distal end articulates with the tibia and patella. The shaft of the femur directed medially and, as a result, the knee joints are closer to the midline than Femur

Femur The proximal end of the femur consists of a rounded head that articulates with the acetabulum of the hip bone to form the hip joint. The head contains a small, central depression called the fovea capitis. The neck of the femur is a constricted region distal to the head.

Femur • The greater trochanter and lesser trochanter are projections that serve as points of attachment for the tendons of some of the thigh and buttock muscles. • The greater trochanter is the prominence felt and It is a landmark commonly used to locate the site for intramuscular injections into the lateral surface of the thigh. The lesser trochanter is inferior and medial to the greater trochanter. • Between the anterior surfaces of the trochanters is a narrow intertrochanteric line. • A ridge called the intertrochanteric crest appears between the posterior surfaces of the greater trochanter and lesser trochanter.

Femur

Femur • Inferior to the intertrochanteric crest on the posterior surface of the body of the femur is a vertical ridge called the gluteal tuberosity. It blends into another vertical ridge called the linea aspera. • The expanded distal end of the femur includes the medial condyle and the lateral condyle. These articulate with the medial and lateral condyles of the tibia. • A depressed area between the condyles on the posterior surface is called the intercondylar fossa. • Superior to the condyles are the medial epicondyle and the lateral epicondyle.

Femur The patellar surface is located between the condyles on the anterior surface. Just superior to the medial epicondyle is the adductor tubercle, a roughened projection that is a site of attachment for the adductor magnus muscle.

Patella The patella (kneecap), is a small, triangular bone. located anterior to the knee joint. It is a sesamoid bone. The broad proximal end of the patella is called the base. • The pointed distal end is the apex. • The posterior surface contains two articular facets. • •

Patella

• • • Tibia The tibia is the larger, medial, weight-bearing bone of the leg. The tibia is the second longest bone of the body. The tibia articulates at its proximal end with the femur and fibula and at its distal end with the fibula and the talus bone of the ankle. The tibia and fibula, are connected by an interosseous membrane. The proximal end of the tibia is expanded into a lateral condyle, medial condyle and Intercondylar Eminence Tibial condyles articulate with the condyles of the femur forming knee joint. The inferior surface of the lateral condyle articulates with the head of the fibula.

The Leg

Tibia • The tibial tuberosity on the anterior surface is a point of attachment for the patellar ligament. • Inferior to and continuous with the tibial tuberosity is a sharp ridge that can be felt below the skin and is known as the anterior border. • The medial surface of the distal end of the tibia forms the medial malleolus. This structure articulates with the talus of the ankle and forms the prominence that can be felt on the medial surface of the ankle. • Laterally, the fibular notch articulates with the distal end of the fibula to form the distal tibiofibular joint.

Fibular notch Tibia and Fibula

• • • Fibula The fibula is a slender bone that is slightly expanded at both ends. The fibula is parallel and lateral to the tibia, but is considerably smaller. Unlike the tibia, the fibula does not articulate with the femur and is non-weight-bearing, but it does help stabilize the ankle joint. The head of the fibula, the proximal end, articulates with the inferior surface of the lateral condyle of the tibia below the level of the knee joint to form the proximal tibiofibular joint. The distal end has a projection called the lateral malleolus that articulates with the talus of the ankle. This forms the prominence on the lateral surface of the ankle.

Tibia and Fibula

Fibula The fibula also articulates with the tibia at the fibular notch to form the distal tibiofibular joint. The fibula is a common source for bone grafting Tibia

Tarsals • The tarsus (ankle) is the proximal region of the foot and consists of seven tarsal bones. • Joints between tarsal bones are called intertarsal joints. • The tarsal bones include the talus and calcaneus, located in the posterior part of the foot. The calcaneus is the largest and strongest tarsal bone. • The anterior tarsal bones are: • Navicular bone. • Three cuneiform bones called the lateral, intermediate and medial. • Cuboid.

Foot

• • • Metatarsals The metatarsus is the intermediate region of the foot and consists of five metatarsal bones They are convex dorsally and concave on their plantar surfaces. Like the metacarpals of the palm, each metatarsal consists of a proximal base, an intermediate shaft, and a distal head. The metatarsals articulate proximally with the first, second, and third cuneiform bones and with the cuboid to form the tarsometatarsal joints. Distally, they articulate with the proximal row of phalanges to form the metatarsophalangeal joints. The first metatarsal is thicker than the others because it bears more weight.

Foot

Phalanges • The phalanges comprise the distal component of the foot. • The toes are numbered I to V (or 1– 5) beginning with the big toe (great toe) medially. • Each phalanx consists of a proximal base, an intermediate, shaft, and a distal head. • The great or big toe has two large, thick phalanges called proximal and distal phalanges. • The other four toes each have three phalanges proximal, middle, and distal. • Joints between phalanges of the foot, like those of the hand, are called interphalangeal joints.

Foot

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