Ex. 11 & 13

1. Ex. 11 & 13 The Appendicular Skeleton, Articulations and Movement

2. Important figures & quiz knowledge • All figures and tables are important to know & understand • Don’t forget: next week is the practical exam • Practical review: • Friday, 10/2 • SC 115 • 2-5 PM • 3 classes overlapping (I will be going back and forth)

3. Appendicular skeleton: 126 bones • 64 bones in upper limbs and pectoral girdle • Shoulder girdle functional aspects • Attachment of the upper limbs to the axial skeleton • Attachment points for many trunk and neck muscles • Clavicle/ collarbone – sternal end attaches to sternal manubrium.  (Figure 11.2, p147) • Acromial end - articulates with scapula & holds arm away from the top of the thorax • Scapulae/ shoulder blades – have no directs attachment to the axial skeleton but is loosely held in place by the trunk muscles. (Figure 11.2, p147) • Spine - deltoid muscle attachment • Acromion process – connects with the clavicle • Coracoid process – serves as attachment point for some of the upper limb muscles • Glenoid cavity – a shallow socket that receives the head of the arm bone – humerus • The Arm • Humerus – long bone. (Figure 11.3, p148) • Head – fits into the shallow glenoid cavity of the scapula • Greater and lesser tubercles - attachemnt for biceps muscles • The Forearm (Figure 11.4, page 149) • Radius - lateral bone of the forearm • Ulna - medial bone of the forearm • Radial notch – articulates with the head of the radius • The Hand – manus (Figure 11.5, page 150) • Three groups of bones: • Carpus – wrist.  8 carpal bones • Metacarpals – palm: numbered 1 to 5 from the thumb.   • Phalanges – fingers: numbered 1 to 5 from the thumb • 14 bones • Each finger contains three phalanges except for the thumb which has only two

10. Appendicular skeleton: 126 bones • 62 bones in lower limbs and pelvic girdle • The Pelvic (Hip) Girdle (Figure 11.6, pages 151-2) • Formed by two coxal bones (2 fused bones) • Bones are heavy and massive, and attach securely to the axial skeleton • Sockets for the heads of the femurs (thigh bones) are deep and heavily reinforced by ligaments to ensure a stable, strong attachment • Ability to bear weight is more important than mobility and flexibility • Combined weight of the upper body rests on the pelvis • Each coxal bone is a result of the fusion of three bones: • Ilium – large flaring bone • Ischium – “sit – down” bone • Pubis - anterior poertion of the coxal bone • All three bones fuse at the deep hemispherical socket – acetabulum, which receives the head of the thigh bone • Comparison of the Male and Female Pelves  (Table 11.1, page 153) • Bones of males: usually larger, heavier, and have more prominent bone markings • Female pelvis reflects modifications for childbearing • Wider, shallower, lighter, and rounder • The Leg (Figure 11.8, page 155) • Tibia - larger & medial bone • Fibula - parallel to the tibia • The Foot (Figure 11.9, page 156) • 7 tarsal bones, 5 metatarsals (instep), 14 phalanges (toes) • Body weight is concentrated on two largest tarsals • Calcaneus  - heel bone • Talus – b/n tibia and calcaneus • Each toe has three phalanges except the great toe, which has two • The Arches • The foot has two important functions: weight bearing and propulsion. These functions require a high degree of stability and flexibility • The foot has three arches • Medial longitudinal arch is the highest and most important of the three arches. It is composed of the calcaneus, talus, navicular, cuneiforms, and the first three metatarsals • Lateral longitudinal arch is lower and flatter than the medial arch. It is composed of the calcaneus, cuboid, and the fourth and fifth metatarsal • Transverse arch is composed of the cuneiforms, the cuboid, and the five metatarsal bases • Arches are maintained by the shapes of the bones as well as by ligaments and tendons

18. Articulations • Articulations – joints, bone – bone contact • Function: • Hold bones together • Allow flexibility so that body movements can occur • Functional classification (based on amount of movement) (p. 170, Fig 13.1) • Synarthroses – immovable joints, ex.: sutures in the axial skeleton • Amphiarthroses – slightly movable joints, ex.: vertebral disc, in the axial skeleton • Diarthroses – freely movable joints, ex.: synovial joints in the limbs

19. Structural classifications (based connective tissue type • Fibrous joint– joined by fibrous c.t., little or no movement • Suture – edges of bone interlock (ex.: skull) • Syndesmoses – bones connected by short ligaments (ex.: between distal ends of tibia and fibula) • Cartilaginous joint– articulating bone ends joined by cartilage plate or pad, slightly movable • Symphysis – fibrocartilage (ex.: pubic symphysis) • Synchondrosis – hyaline cartilage (ex.: epiphyseal plate) • Synovial joint – joined by joint cavity containing synovial fluid, freely movable (p. 171, Fig 13.2)

21. Subclassifications of synovial joints • Based on # of axes, joint shape, & allowable motion type • Classification of synovial joints by shape of joint, and type of motion allowed (p.172; 13.3): • Plane/gliding joint: the wrist • Bone surfaces slide across each other, allowing a wide range of movements • Hinge joint: elbow and ankles • Allow for flexion and extension • Pivot joint: the skull on its spinal axis • Movement is limited to rotation • Condyloid/ Ellipsoid joint: structurally similar to a ball and socket joint but without rotation • Saddle joint: the thumb • Bone surfaces are concave, allowing movement in all direction but only limited rotation • Ball and Socket joint: the rounded head of one bone fits into a socket-like cavity of another, such as the hip and shoulder joints • Allow free rotation • Classification of synovial joints by the number of axes • Nonaxial joint - movement tends to be linear rather than angular • Joint surfaces flat and glide over one another instead of around • ex.: carpal bones • Uniaxial joint - movement in one plane around one axis • Move like a door hinge • ex.: elbow joint and interphalangeal joints of hand and foot • Pivot joint - bone pivots around another bone • ex.:  radius pivots around stationary ulnar, also atlantoaxial joint C1 (atlas) pivots around stationary C2(axis) on the odontoid process • Biaxial joint - motion occurs in two different axis in two planes • Condyloid (ellipsoidal) –metacarpophalangeal joints of fingers or toes • Saddle – carpometacarpal joints at thumb • Triaxial/ multiaxial joint - motion in all three axes • ex.: ball and socket - hip and shoulder • More motion than any other type of joint

24. Movements of synovial joints • Flexion • Sagittal plane • Decreases joint angle & distance betw. articulated bones • Extension • Opp. flexion • Increases joint angle & distance betw. bones • Abduction • Frontal plane • Movement of limb away from midline or median plane • Adduction • Opp. abduction • Movement toward midline or median plane • Rotation • Movement of bone around its own logitudinal axis w/o lateral or medial displacement • Circumduction: combination of previously listed movements (except rotation) • Pronation: movement of palm from anterior or superior position to a posterior or inferior position • Supination: opp. of pronation • Inversion: medial turning of sole of foot • Eversion: opp. of inversion • Dorsiflextion: movement of ankle joint dorsally • Plantar flexion: movement of ankle joint ventrally