Overview of the Skeleton

Transcription

1 Skeleton & Joints

2 The Skeletal System Overview of the skeleton The skull The vertebral column and thoracic cage The pectoral girdle and upper limb The pelvic girdle and lower limb Adaptations to Bipedalism

3 Overview of the Skeleton Regions of the skeleton axial skeleton = central axis appendicular skeleton = limbs and girdles Number of bones 206 in typical adult skeleton

4 Surface Features of Bones

5 Axial and Appendicular Skeleton Axial skeleton Appendicular skeleton

6 Major Skull Cavities

7 The Skull 22 bones joined together by sutures Cranial bones surround cranial cavity 8 bones in contact with meninges Facial bones support teeth and form nasal cavity and orbit 14 bones with no direct contact with brain or meninges attachment of facial and jaw muscles

8 Frontal Bone Forms forehead Forms roof of the orbit

9 Parietal Bone Cranial roof and part of its lateral walls Temporal lines of temporalis muscle Temporal lines

10 Temporal Bone Lateral wall and part of floor of cranial cavity squamous part tympanic part mastoid part petrous portion

11 Petrous Portion of Temporal Bone Part of cranial floor Houses middle and inner ear cavities

12 Occipital Bone Rear and base of skull Foramen magnum Skull rests on atlas

13 Sphenoid Bone Body of the sphenoid Lesser wing Greater wing

14 Maxillary Bones Forms upper jaw Forms inferomedial wall of orbit Forms anterior 2/3 s of hard palate

15 Forms bridge of nose and supports cartilages of nose Nasal Bones

16 Only movable bone Mandible Holds the lower teeth Attachment of muscles of mastication Mandibular foramen Mental foramen

17 Ramus, Angle and Body of Mandible

18 The Vertebral Column

19 Newborn Spinal Curvature Spine exhibits one continuous C- shaped curve

20 Adult Spinal Curvatures S-shaped vertebral column with 4 curvatures Secondary curvatures develop after birth Cervical curvature Lumbar curvature

21 Abnormal Spinal Curvatures Scoliosis Kyphosis Lordosis

22 Typical Cervical Vertebrae Small body and larger vertebral foramen Transverse process short with transverse foramen for protection of vertebral arteries Bifid or forked spinous process in C2 to C6

23 Typical Thoracic Vertebrae Spinous processes pointed and angled downward Rib attachment

24 Lumbar Vertebrae Thick, stout body and blunt, squarish spinous process

25 Thoracic Cage Attachment site Protection Involved in respiration

26 True and False Ribs True ribs (1 to 7) False ribs (8-12) 12 pairs of ribs in both sexes

27 Pectoral Girdle Attaches upper extremity to the body Scapula and clavicle Clavicle attaches medially to the sternum and laterally to the scapula Scapula articulates with the humerus

28 Clavicle S-shaped bone, flattened dorsoventrally

29 Scapula Triangular plate overlies ribs 2 to 7

30 30 bones per limb Upper Limb Brachium Antebrachium Carpus Manus

31 Brachium and Antebrachium

32 Carpal Bones Form wrist 2 rows (4 bones each)

33 Metacarpals and Phalanges Phalanges are bones of the fingers Metacarpals are bones of the palm

34 Sesamoid Bone

35 Pelvic Girdle Girdle Pelvis Supports trunk on the legs and protects viscera

36 Os Coxae (Hip Bone) Acetabulum is hip joint socket Ilium Pubis Ischium

37 Comparison of Male and Female Female lighter, shallower pubic arch( >100 degrees), and pubic inlet round or oval Male heavier, upper pelvis nearly vertical, coccyx more vertical, and pelvic inlet heart-shaped

38 Femur and Patella

39 Tibia Tibia is thick, weightbearing bone (medial) Broad superior head with 2 flat articular surfaces

40 Fibula Slender lateral strut stabilizes ankle Does not bear any body weight Joined to tibia by interosseous membrane

41 The Ankle and Foot Tarsal bones are shaped and arranged differently from carpal bones Talus Calcaneus Distal row of tarsal bones

42 The Foot Remaining bones of foot are similar in name and arrangement to the hand Metatarsal I is proximal to the great toe (hallux) Phalanges 2 in great toe 3 in all other toes

43 Bipedalism and Limb Adaptations

44 Bipedalism and Upright Stance

45 Bipedalism and Head Position

46 The Skeletal System Summary Overview of the skeleton The skull The vertebral column and thoracic cage The pectoral girdle and upper limb The pelvic girdle and lower limb Adaptations to Bipedalism

47 Joints Joints Classification bony fibrous cartilaginous Synovial joints Types of Movement Anatomy of Some Joints Humeroscapular Elbow Coxal Knee Joint Disease

48 Joints Classification Arthrology Kinesiology

49 Joints Classification Classified by freedom of movement diarthrosis amphiarthrosis Synarthrosis Classified how adjacent bones are joined fibrous, cartilaginous, bony or synovial

50 Bony Joint Gap between two bones ossifies Can occur in either fibrous or cartilaginous joint

51 Fibrous Joints Collagen fibers span the space between bones sutures, gomphoses and syndesmoses

52 Fibrous Joint -- Sutures Immovable fibrous joints Serrate - interlocking lines

53 Fibrous Joint -- Sutures Lap - overlapping beveled edges Plane - straight, nonoverlapping edges

54 Types of Sutures

55 Fibrous Joint -- Gomphoses Attachment of a tooth to its socket Held in place by fibrous periodontal ligament Some movement while chewing

56 Fibrous Joint -- Syndesmosis Two bones bound by ligament only Most movable of fibrous joints

57 Cartilaginous Joint Bones are joined by hyaline cartilage

58 Cartilaginous Joint -- Symphysis 2 bones joined by fibrocartilage Only slight amount of movement is possible

59 Synovial Joint Joint in which two bones are separated by a space called a joint cavity

60 General Anatomy Articular capsule encloses joint cavity Synovial fluid = slippery fluid; feeds cartilages

61 General Anatomy Articular cartilage = hyaline cartilage covering the joint surfaces Articular discs and menisci Tendon Ligament

62 Tendon Sheaths and Bursae Bursa Tendon sheaths

63 Components of a Lever A lever is a rigid object that rotates around a fixed point called a fulcrum Rotation occurs when effort overcomes resistance

64 Mechanical Advantage of a Lever Two kinds of levers lever that helps increase output of force lever move object further and faster

65 Mechanical Advantage Mechanical advantage is calculated from the length of the effort arm (Muscle moment) divided by the length of the resistance arm (Joint moment)

66 First-Class Lever Has fulcrum in the middle between effort and resistance

67 Second-Class Lever Resistance between fulcrum and effort

68 Third-Class Lever Effort between the resistance and the fulcrum

69 Range of Motion Degrees through which a joint can move Determined by structure of the articular surfaces strength and tautness of ligaments, tendons and capsule action of the muscles and tendons

70 Axes of Rotation Shoulder joint has 3 degrees of freedom = multiaxial joint Other joints monoaxial or biaxial

71 Types of Synovial Joints

72 Types of Synovial Joints

73 Ball-and-Socket Joints Smooth hemispherical head fits within a cuplike depression Multiaxial joint

74 Condyloid (ellipsoid) Joints Oval convex surface on one bone fits into a similarly shaped depression on the next Biaxial joints

75 Saddle Joints Each articular surface is shaped like a saddle, concave in one direction and convex in the other Biaxial joint

76 Gliding Joints Flat articular surfaces in which bones slide over each other Limited monoaxial joint

77 Hinge Joints One bone with convex surface that fits into a concave depression on other bone Monoaxial joint

78 Pivot Joints One bone has a projection that fits into a ringlike ligament of another First bone rotates on its longitudinal axis relative to the other

79 Types of Movement

80 Flexion, Extension and Hyperextension Flexion Extension Hyperextension

81 Flexion, Extension and Hyperextension

82 Abduction and Adduction Abduction Hyperabduction Adduction

83 Elevation and Depression Elevation Depression

84 Protraction and Retraction Protraction Retraction

85 Circumduction

86 Medial rotation Rotation Lateral rotation

87 Supination and Pronation In the forearm and foot Supination Pronation

88 Movements of Head and Trunk Flexion, hyperextension and lateral flexion of vertebral column

89 Rotation of Trunk and Head Right rotation of trunk; rotation of head

90 Movements of Mandible Lateral excursion Medial excursion Protraction

91 Movement of Hand and Digits Radial and ulnar flexion Abduction of fingers and thumb Opposition is movement of the thumb to approach or touch the fingertips Reposition is movement back to the anatomical position

92 Movements of the Foot Dorsiflexion is raising of the toes as when you swing the foot forward to take a step (heel strike) Plantarflexion is extension of the foot so that the toes point downward as in standing on tiptoe Inversion is a movement in which the soles are turned medially Eversion is a turning of the soles to face laterally

93 Shoulder Joint

94 The Humeroscapular Joint Most freely movable joint in the body shallowness and looseness Supported by ligaments and tendons 3 glenohumeral, coracohumeral, transverse humeral and biceps tendon

95 The Humeroscapular Joint Supported by rotator cuff musculature 4 Bursae associated with shoulder joint

96 Stabilizers of the Shoulder Joint

97 Tendons of Rotator Cuff Muscles

98 Dissection of Shoulder Joint

99 Elbow Joint

100 Single joint capsule enclosing the humeroulnar and humeroradial joints The Elbow Joint

101 Elbow Joint

102 Hip Joint

103 The Coaxal (hip) Joint Head of femur articulates with acetabulum

104 Hip Joint

105 Dissection of Hip Joint

106 Knee Joint

107 The Knee Joint Most complex diarthrosis Patellofemoral Tibiofemoral

108 The Knee Joint Joint capsule anteriorly consists of patella and extensions of quadriceps femoris tendon

109 Knee Joint Sagittal Section

110 Knee Joint Anterior and Posterior Views Anterior and lateral cruciate ligaments Medial and lateral collateral ligaments

111 Knee Joint Superior View Medial and lateral meniscus absorb shock and shape joint

112 Dissection of Knee Joint

113 Joint Disease

114 Arthritis Arthritis is a broad term for pain and inflammation

115 Arthritis Osteoarthritis results from years of joint wear

116 Arthritis Rheumatoid arthritis is autoimmune attack on joint

117 Rheumatoid Arthritis

118 Summary Joints Classification bony fibrous cartilaginous Synovial joints Anatomy of Some Joints Humeroscapular Elbow Coxal Knee Joint Disease