Appendicular Skeletal A&P Lab Week #4 Skeletal System Part 4.B Appendicular Skeletal

Appendicular Skeleton Consists of bones of the limbs and supporting elements (or girdles) that connect them to trunk 126 bones Pectoral girdle (4) Upper limbs (60) Pelvic girdle (2) Lower limbs (60)

The bones of the appendicular skeleton SKELETAL SYSTEM 206 AXIAL SKELETON 80 Clavicle 2 Pectoral girdle 4 Scapula 2 Humerus 2 Radius 2 Ulna 2 Upper limbs 60 Carpal bones 16 Metacarpal bones 10 APPENDICULAR SKELETON 126 Phalanges (proximal, middle, distal) 28 Hip bone (coxal bone) 2 Pelvic girdle 2 Femur 2 Patella 2 Tibia 2 Fibula 2 Lower limbs 60 Tarsal bones 14 Metatarsal bones 10 Phalanges 28

Pectoral girdle Pectoral (shoulder) girdle Joins arm to trunk Consists of clavicle and scapula

The relationship of the clavicle to adjacent bones Jugular notch Scapula Humerus Anterior view

Pectoral girdle Clavicle Originates at superior, lateral border of manubrium Articulates with acromion of scapula Characteristics Sternal end Pyramid-shaped Acromial end Flatter, broader than sternal end Rough interior surface bearing lines and tubercles

Two views of the right clavicle Superior view LATERAL MEDIAL Acromial end Sternal end LATERAL Inferior view MEDIAL

Pectoral girdle Scapula Body Broad, smooth triangle Sides Superior border Medial border Lateral border Corners Superior angle Inferior angle Lateral angle

Pectoral girdle Scapula (continued) Subscapular fossa Glenoid cavity Anterior surface depression Glenoid cavity Cup-shaped Articulates with humerus Scapular spine Ridge on posterior surface

Pectoral girdle Scapula (continued) Supraspinous fossa (supra, above) Infraspinous fossa (infra, below) Acromion process End of spine Coracoid process Anterior, superior to glenoid cavity

Two views of the right scapula Scapular spine Acromion Coracoid process Superior border Superior angle Acromion Supraspinous fossa Subscapular fossa Process that supports the cup-shaped glenoid cavity Medial border Infraspinous fossa Lateral border Anterior view Posterior view Inferior angle

A lateral view of the right scapula Coracoid process Glenoid cavity Acromion

Humerus, radius, ulna Skeleton of upper limbs includes those of arms, forearms, wrists, and hands Arm = shoulder to elbow Forearm = elbow to wrist

Humerus, radius, ulna Humerus Head Lesser tubercle Greater tubercle Proximal end that articulates with glenoid cavity (scapula) Lesser tubercle Smaller projection on anterior, medial epiphyseal surface Greater tubercle Rounded projection on lateral epiphyseal surface Establishes lateral contour of shoulder Intertubercular groove Between tubercles Important for muscle attachment

Humerus, radius, ulna Humerus (continued) Anatomical neck Marks extent of joint capsule Surgical neck Fractures typically occur here Deltoid tuberosity Large, rough elevation on lateral surface Attachment of deltoid muscle Radial groove Crosses inferior end of deltoid tuberosity Depression marking path of radial nerve

Humerus, radius, ulna Humerus (continued) Radial fossa Condyle Accommodates portion of radial head Condyle Capitulum Lateral surface of condyle Trochlea (trochlea, pulley) Medial surface of condyle Extends from olecranon fossa (posterior) to coronoid fossa (anterior) These depressions accept projections of ulna

Surface features of the right humerus Anterior view Posterior view Head Greater tubercle Greater tubercle Lesser tubercle Intertubercular groove Anatomical neck Surgical neck Radial groove Shaft Deltoid tuberosity Radial fossa Coronoid fossa Olecranon fossa Lateral epicondyle Medial epicondyle Trochlea Capitulum Trochlea

Humerus, radius, ulna Ulna and radius Parallel bones that support forearm In anatomical position, ulna is medial to radius Shafts connected via interosseus membrane Proximal radio-ulnar joint Radial notch on ulna with radial head Distal radio-ulnar joint Lateral surface of ulnar head with distal end of radius

Surface features of the right ulna and radius Posterior view Anterior view Radial head Trochlear notch Olecranon Neck of the radius Coronoid process Proximal radio-ulnar joint Radial notch at proximal radio-ulnar joint Radial tuberosity Ulna Radius Radius Ulna Interosseous membrane Ulnar notch Distal radio-ulnar joint Ulnar head Styloid process of the radius Ulnar head Styloid process of the ulna

Humerus, radius, ulna Ulna Olecranon Ulnar head Superior end of ulna Point of elbow Ulnar head Distal, slender, rounded end Styloid process (styloid, long and pointed) Posterior, lateral surface of head Radial notch Accommodates head of radius

Humerus, radius, ulna Ulna (continued) Trochlear notch Articulates with trochlea of humerus at elbow joint Coronoid process Inferior lip of trochlear notch

Humerus, radius, ulna Radius Radial head Neck Radial tuberosity Articulates with capitulum of humerus During flexion, swings into radial fossa of humerus Neck From radial head to tuberosity Radial tuberosity Marks attachment site of biceps brachii muscle Ulnar notch Site of articulation with ulnar head Styloid process Distal radius that articulates with bones of wrist

Carpal bones, metacarpals, and phalanges Carpus Eight carpal bones arranged in two rows of four bones Proximal carpal bones Scaphoid (skaphe, boat) Lateral border of wrist Closest to styloid process of radius Lunate (luna, moon) Medial to scaphoid Articulates with radius Pisiform (pisum, pea) Anterior to triquetrum Triquetrum (triquetrus, three-cornered) Articulates with disc separating ulna from wrist

Carpal bones, metacarpals, and phalanges Carpus (continued) Distal carpal bones Trapezium (trapezion, four sided with no parallel sides) Lateral bone that articulates with scaphoid Trapezoid Medial to trapezium Proximal articulation with scaphoid Capitate (caput, head) Largest carpal bone Between trapezoid and hamate Hamate Medial carpal bone

The bones of the carpus (wrist) Proximal Carpal Bones Scaphoid Lunate Pisiform Triquetrum Right wrist and hand, anterior (palmar) view Radius Ulna I II III IV V Metacarpal bones Proximal phalanx Distal Carpal Bones Trapezium Trapezoid Capitate Hamate Middle phalanx Distal phalanx

Carpal bones, metacarpals, and phalanges Metacarpals (metacarpus, hand) Articulate with distal carpal bones and support hand Identified by Roman numerals I–V, from lateral to medial Distally articulate with proximal finger bones Phalanges 14 phalanges per hand Pollex (thumb) has 2 phalanges (proximal and distal) All other fingers have 3 phalanges (proximal, middle, and distal)

(designated I–V) and the phalanges of the hand Radius Ulna The metacarpal bones (designated I–V) and the phalanges of the hand Radius Ulna Proximal Carpal Bones Scaphoid Lunate Triquetrum Distal Carpal Bones Pisiform Trapezium Trapezoid Capitate Hamate I V IV III II Proximal phalanx of pollex Metacarpal bones Proximal phalanx Distal phalanx of pollex Middle phalanx Right wrist and hand, posterior (dorsal) view Distal phalanx

Pelvic girdle Pelvic girdle Consists of paired hip bones (coxal bones) Hip bone formed by fusion of three bones Ilium Ischium Pubis Acetabulum (acetabulum, vinegar cup) Concave socket formed by all three fused bones Articulates with head of femur Has smooth, cup-shaped surface (lunate surface) Has superior gap in bony rim (acetabular notch)

Pelvic girdle Ilium Iliac spines Gluteal lines Greater sciatic notch Attachment of important muscles and ligaments Gluteal lines Mark attachment of large hip muscles Greater sciatic notch Passage of sciatic nerve to lower limb Iliac crest Important ridge for muscle attachment

Pelvic girdle Ilium (continued) Iliac fossa Auricular surface Shallow depression that supports abdominal organs and some muscle attachment Auricular surface Surface that articulates with sacrum Iliac tuberosity Roughened area superior to auricular surface Has attached ligaments that stabilize sacro-iliac joint Arcuate line Continuous with pectineal line of pubis

Pelvic girdle Ischium Ischial spine Ischial tuberosity Ischial ramus Projects superior to sciatic notch Passage of blood vessels, nerves, and small muscle Ischial tuberosity Roughened projection Supports body weight when seated Ischial ramus Bony extension that borders obturator foramen

Pelvic girdle Pubis Pectineal line Pubic symphysis Ridge that ends in pubic tubercle Pubic symphysis Connects pubic bones via fibrous cartilage pad Superior and inferior pubic rami (singular, ramus) Bony extensions that border obturator foramen

A lateral view of the right Os Coxa An Os Coxa, consists of an ilium, an ischium, and a pubis A lateral view of the right Os Coxa Ilium POSTERIOR ANTERIOR Pubis Ischium Iliac crest Gluteal Lines Anterior Inferior Anterior superior iliac spine Posterior Posterior superior iliac spine Lunate surface Posterior inferior iliac spine Greater sciatic notch Acetabulum Ischial spine Ischial ramus Ischial tuberosity Acetabular notch

A medial view of the right Os Coxa Ilium ANTERIOR POSTERIOR Pubis Ischium Iliac crest Iliac tuberosity Iliac fossa Auricular surface of the ilium Arcuate line of the ilium Greater sciatic notch Pectineal line Obturator foramen Superior pubic ramus Pubic symphysis Ischial ramus Inferior pubic ramus

Pelvis Region Consists of the two Os coxa, sacrum, and coccyx Has extensive network of ligaments connecting sacrum with: Iliac crest Ischial tuberosity Ischial spine Arcuate line Other ligaments tie ilia to lumbar vertebrae

The structures of the pelvis Sacrum Os Coxa Ilium Coccyx Pubis Ischium L5 Iliac crest Iliac fossa Ilium Sacrum Sacro-iliac joint Acetabulum Pubic tubercle Obturator foramen Ischium Pubic symphysis

Pelvis Region May be divided into: True (lesser) pelvis Encloses pelvic cavity Superior limit extends from base of sacrum, along arcuate line and pectineal line, to pubic symphysis = Pelvic brim Encloses pelvic inlet Pelvic outlet bounded by coccyx, ischial tuberosities, ischial spines, and inferior pubic symphysis False (greater) pelvis Consists of area enclosed by bladelike portions of ilia superior to pelvic brim

The locations and extents of the true (lesser) pelvis (in purple) and the false (greater) pelvis Superior view Inferior view Pelvic outlet False pelvis Ischial spine Pelvic inlet Pelvic brim Pelvic outlet

Pelvis Region Sexual differences in pelvic structure Most related to adaptations for childbearing Female (compared to male) Generally smoother and lighter with less prominent markings Enlarged pelvic outlet Broader pubic angle, greater than 100° Less curvature on sacrum and coccyx Wider, more circular pelvic inlet Relatively broad, low pelvis Ilia project farther laterally but not as far superiorly

The shapes of the pelvis in females and males The pelvis of a female The pelvis of a male Female Male Ischial spine Ischial spine 100° or more 90° or less

Femur, tibia, and fibula Skeleton of lower limb consists of: Femur (thigh) Patella (kneecap) Tibia and fibula (leg) Connected with interosseus membrane Metatarsal bones and phalanges (foot) Same number of bones as upper limb Functional anatomy is different due to weight- bearing properties

Femur, tibia, and fibula Femur: Longest and heaviest bone in body Articulates with hip at hip joint Articulates with tibia at knee joint Characteristics Femoral head Articulates with pelvis at acetabulum Fovea capitis Small pit containing ligament attaching head to acetabulum Neck Joins shaft at about 125°

Femur, tibia, and fibula Femur: (continued) Characteristics Greater trochanter Large, rough projection that extends laterally Attachment site for large tendons Lesser trochanter Smaller process that projects posteriorly and medially Intertrochanteric line Marks edge of articular capsule on anterior femur Gluteal tuberosity Attachment of gluteus maximus muscle

Femur, tibia, and fibula Femur: (continued) Characteristics Linea aspera (aspera, rough) Attachment of powerful hip muscles Popliteal surface (poples, hollow of knee) Flattened triangular area on posterior Medial and lateral condyles Participate in knee joint at distal end Separated by: Patellar surface (anterior) Intercondylar fossa (posterior)

Landmarks of the right femur Neck Fovea capitis Greater trochanter Greater trochanter Femoral head Intertrochanteric crest Gluteal tuberosity Intertrochanteric line Linea aspera Lesser trochanter Anterior view Posterior view Shaft Lateral supracondylar ridge Popliteal surface Adductor tubercle Patellar surface Lateral epicondyle Medial epicondyle Intercondylar fossa Lateral condyle Medial condyle Lateral epicondyle Lateral condyle

Femur, tibia, and fibula Patella: Large sesamoid bone that forms in quadriceps tendon Characteristics Base Attachment of quadriceps tendon Apex Attachment of patellar ligament (patella to tibia) Lateral facet For lateral condyle of femur Medial facet For medial condyle of femur

The surface features of the patella Base of patella Lateral facet, for lateral condyle of femur Attachment area for quadriceps tendon Medial facet, for medial condyle of femur Attachment area for the patellar ligament, which attaches the patella to the tibia Articular surface of patella Apex of patella Anterior view Posterior view

Femur, tibia, and fibula Tibia: Large medial bone of leg Characteristics Intercondylar eminence Ridge separating lateral and medial tibial condyles Tibial tuberosity Attachment of patellar ligament Anterior margin Ridge beginning at tibial tuberosity, extending along anterior surface Medial malleolus (malleolus, hammer) Medial projection of ankle that supports joint

Femur, tibia, and fibula Fibula: Attachment of muscles that move foot and toes Provides lateral stability to ankle joint Characteristics Head Articulates with tibia proximally Lateral malleolus

Features of the right tibia and fibula Superior tibiofibular joint Articular surface of medial tibial condyle Intercondylar eminence Lateral tibial condyle Articular surface of lateral tibial condyle Medial tibial condyle Head of the fibula Lateral tibial condyle Tibial tuberosity Head of fibula Interosseous membrane Anterior view Posterior view Anterior margin of the tibia Tibia Fibula Fibula Medial malleolus of the tibia Inferior tibiofibular joint Lateral malleolus of the fibula Lateral malleolus (fibula) Inferior articular surface

Tarsals, metatarsals, and phalanges Angle bones accept body weight from leg and transfer to the ground, distributing through foot bones Need to be strong yet flexible to deal with locomotive movements

Tarsals, metatarsals, and phalanges Tarsals (7 bones) Calcaneus (heel bone) Largest of tarsal bones Most weight transmitted from tibia to ground through it Posterior portion is attachment site for calcaneal tendon (Achilles tendon) Talus Transmits weight from tibia toward toes Trochlea of talus bone forms articulation between tibia and talus

Tarsals, metatarsals, and phalanges Tarsals: (continued) Navicular Articulates with talus and three cuneiform bones Cuboid Articulates with anterior surface of calcaneus 5–7. Cuneiform bones Medial, intermediate, lateral

Tarsals, metatarsals, and phalanges Articulate with distal surfaces of cuboid and cuneiforms and phalanges Form distal portion of foot Identified by Roman numerals I–V from medial to lateral I–III articulate with cuneiform bones IV & V articulate with cuboid Phalanges (toe bones) Same anatomical organization as fingers (14 bones) Hallux (great toe) has two bones (proximal and distal) All other toes have three bones (proximal, middle, distal)

The bones of the ankle and foot The Ankle (Tarsus) The bones of the ankle and foot The ankle consists of seven tarsal bones. Calcaneus Talus Navicular Trochlea Cuboid Cuneiform bones Metatarsals Articulations of the cuboid and the cuneiform bones with the metatarsal bones V IV III II I Metatarsal bones (designated I–V) Proximal phalanx Phalanges Distal phalanx Proximal, middle, and distal phalanges Hallux

Tarsals, metatarsals, and phalanges Arches of the foot: Longitudinal arch: Transfers weight between toes and calcaneus Present because of ligaments and tendons connecting calcaneus to distal portions of metatarsals Lateral (calcaneal) portion has much less curvature than medial (talar) portion Therefore, medial plantar surface elevated to allow passage of inferior surface muscles, blood vessels, and nerves Creates transverse arch

A lateral view of the right ankle and foot Cuboid bone Navicular bone Cuneiform bones Metatarsal bones (I–V) Lateral surface of the trochlea Phalanges Lateral view I II Attachment site for the calcaneal tendon (Achilles tendon) III IV V

A medial view of the right ankle and foot Phalanges Metatarsal bones Medial cuneiform bone Navicular bone Talus Medial view I Calcaneus Longitudinal arch Transverse arch

Tarsals, metatarsals, and phalanges Arches of the foot: (continued) Congenital talipes equinovarus (clubfoot) Arches fail to develop properly due to abnormal muscle development Tibia, ankle, and foot are affected Longitudinal arches are exaggerated Feet turn medially and inverted Affects 1 in 1000 births Twice as common in boys Prompt treatment with casts or other supports can alleviate