Skeletal System, types of joints -1.pptx

This note is about skeletal system, its classification i.e axial and appendicular skeletal system and types of joints.
it is brief and short. enjoy it!

1. Skeletal System

2. Skeletal system The skeletal system consists of bones , joints and cartilage Bones Dense connective tissue Form the main skeletal framework of the body Functions of Skeletal System Support - serve as a firm framework for the entire body Protection - protect delicate structures Movement - serve as levers, working with attached muscles to produce movement Mineral Storage Hematopoiesis - blood cell formation in red marrow Energy Storage - lipids/fat stored in yellow marrow

3. Bone Structure Shape - the bones of the skeleton can be of several different shapes Long bones – considerably longer shaft with 2 ends (most limb bones, finger bones, etc.) Short bones – roughly cube shaped (wrist bones) Sesamoid bone – short bone within a tendon (patella) Flat bones – flattened, thin, and usually curved (most cranial bones, ribs, sternum, and scapula) Irregular bones – irregularly shaped (vertebrae, hip bones)

4. General anatomy of a long bone Diaphysis - main shaft of the bone Epiphysis - large end of the bone Metaphysis - where above meet during bone growth Articular Cartilage - covers epiphysis, reduce friction Periosteum - dense, white covering around the bone Fibrous layer - blood, lymph, nerves pass through Osteogenic layer - where bone cells originate Medullary (marrow) Cavity - adults, yellow marrow Endosteum - lines medullary cavity, houses bone cells The most familiar shape of bone that makes up almost all of the skeleton of the arms and legs. Has;

5. Bone Structure … Osteoprogenitor cells : give rise to osteoblasts :- found in periosteum , endosteum , and canals Osteoblasts : secrete proteins, ca, P:- found on bone surface where growth occurs Osteocytes : maintain bone integrity In the bone tissue, surounded by matrix Osteoclasts : degrade & absorb bone during growth (derived from WBCs) Bone Tissue (Osseous Tissue) Bones are organs, with their own system of osseous tissue, blood vessels, lymphatic vessels, and nerves Bone /Osseous tissue There are two types of bone tissue ( osseous tissue ) Bone tissue is composed of matrix and cells Compact/Dense Spongy / Cancellous Cells Matrix Osteocytes Gel-like ground substance calcified with inorganic salts Osteoblasts Collagen fibers Osteoclasts

6. Compact /dense bone General Features This tissue makes up the main shaft of a long bone and the outer layer of other bones Few empty spaces (dense) Thicker in diaphysis than epiphysis Concentric ring-like structures, Osteon Osteon ( Haversian system) Central ( haversian ) canal - containing nerves and blood vessels Osteocytes - mature bone cells (from osteoblasts ) Lacunae - spaces between the rings and extend out (where osteocytes reside) Lamellae - rings around canal, house lacunae Canaliculi - projections from lacunae + osteocytes Perforating ( volkmann ) canals – channels run perpendicular haversian canal

7. Haversian system

8. Spongy / cancellous bone General features Many spaces filled with red marrow (not yellow) Most of epiphysis of long bones in adult Found in short, flat, irregular bones Trabeculae - irregular, sponge-like network Lacunae - spaces within trabeculae for osteocytes Spaces - filled with red marrow ( hematopoiesis ) Trabecular structure

9. Bones are lined on both internal and external surfaces by layers of tissue containing osteogenic cells, Endosteum …. internally Periosteum …. externally Bone Membranes Bone marrow Found in the medullary cavities of long bones and within spaces in spongy bone There are two kinds of bone marrow, Red marrow Yellow marrow

10. Development and growth of bone (Ossification) Ossification : the process by which bone is formed Different cells involved 1. Mesenchymal cells – migratory embryonic connective tissue cells 2. Chondroblasts - cartilage forming cells 3. Osteoblasts - bone forming cells All bones are derived from mesenchyme by one of two processes : Intramembranous ossification The formation of bone directly on or within fibrous conn . tissue membranes Mesenchymal models of bone form during the embryonic period, and direct ossification of the mesenchyme begins in the fetal period Endochondral ossification The formation of bone within a cartilage model Cartilage models of bones form from mesenchyme during the fetal period, and bone subsequently replaces most of the cartilage The two methods do not lead to different structure of bone Both involve the replacement of a preexisting conn . tissue with bone

11. Different Bone Markings - Essential Terminology Fissure:- cleft-like opening between adjacent parts of bones through which vessels & nerves pass Foramen:- hole through which blood vessels, nerves, ligaments can pass Meatus :- tunnel-like passageway through a bone Sinus:- cavity within a bone with narrow opening Sulcus :- groove or depression that accommodates a soft structure such as vessels, nerve, tendon Fossa :- depression in/on a bone; Openings and Depressions

12. Processes for attachment (tendons, ligaments, etc.) Tubercle :- small, rounded process Tuberosity :- large, rounded, usually rough process Trochanter :- large, blunt projection; only on the femur Line :- less prominent ridge than a crest Spine :- sharp, slender process Epicondyle :- prominence found "above" a condyle Process :- prominent projection or point of attachment Articular Processes (of the joints) Condyle :- large, rounded articular (joint) prominence Head :- rounded articular projection supported by a more constricted portion of a bone neck Facet :- smooth, flat surface on a bone

13. Divisions of the Skeletal System The Axial Skeleton The Appendicular Skeleton The Axial Skeleton The axial skeleton consists of bones arranged along the longitudinal axis The parts of the axial skeleton are the skull , hyoid bone , auditory ossicles , vertebral column , sternum , and ribs

14. Skull The skull bones consists of the skeleton of the cranium & face ( 8 cranial & 14 facial ) Sutures - are joints b/n the skull bones. They are Coronal suture Sagittal suture Lamdoid suture Squamosal suture Fontanels - are membrane-filled spaces b/n the cranial bones of fetuses & infants The major fontanels are Anterior Posterior Anterolaterals /Sphenoid Posterolaterals /Mastoid

15. Paired Maxilla Zygomatic Nasal Lacrimal Palatine Inf. Nasal Conchae The cranial bones include …. 8 Enclose and protect the brain and provide attachment to muscles Paired- --- temporal and parietal Unpaired- --- frontal, occipital, sphenoid and ethmoid The facial bones are …. 14 Form frame of the face Form cavities for sense organs (nose , eyes, oral, taste) Provide openings for air and food Provide cavities to hold teeth Provide attachment to the muscles Unpaired Mandible Vomer Facial bones

16. PARIETAL (2) FRONTAL (1) OCCIPITAL (1) SPHENOID (1) TEMPORAL (2) BONES OF CALVARIUM

17. Cranial bones Frontal - forms the forehead, the anterior of the skull’s roof, and the roof of the eye orbit (socket) Parietal - form most of the top and the side walls of the cranium Temporal –form the lower sides of the skull and some of the base of the skull Contain an external auditory meatus (ear canal), a middle ear cavity, and an inner ear labyrinth Occipital - forms the lower, posterior part of the braincase. Its foramen magnum is a large opening for the spinal cord, The two condyles (rounded projections) on either side articulate with the atlas, the first cervical vertebra

18. Sphenoid – forms the middle part of the floor of the brain. It looks like a bat , with A greater wing is visible on the side of the skull b/n the frontal and temporal bones A lesser wing hidden A body of the bat ( saddlelike ) which has a depression called the sella turcica , that holds and protects the pituitary gland Ethmoid - It forms a part of the medial wall of the eye orbit, a small portion of the cranial floor, and most of the nasal cavity roof It has a vertical upward projection the crista galli that anchors the cranial meninges A thin, platelike , downward extension of this bone ( perpendicular plate of ethmoid bone ) forms much of the nasal septum, a midline partition in the nose

19. Cranial Fossae Created by bony ridges Supports, encircles brain 3 Fossae Anterior Middle Posterior N.B All the bones visible from this view are the cranial bones!!

20. Facial bones Maxillae - are the two upper jaw bones, which also form the anterior portion of the hard palate (roof of the mouth) Sockets for the roots of the teeth are found in the maxillae and the mandible Mandible (lower jaw) - the only movable bone of the face It forms a condyloid joint ( temporomandibular joint (TMJ)) with each temporal bone Nasal bones - form the bridge of the nose where they articulate with the frontal bone (the rest of the nose is supported by cartilage)

21. Lacrimal bones they form the medial side of each orbit Lacrimal fossa contains the lacrimal sac (tears from the eye collect in this sac) Zygomatic bones - forms the point of a cheek, and articulates with the maxilla, frontal bone, and temporal bone Palatine bones - are the posterior portion of the hard palate. Vomer - a plow-shaped bone forms the lower part of the nasal septum It articulates with the ethmoid bone Conchae - On either side of the vomer , six scrolllike bones that curl downward from the sides of the nasal cavities They increase the surface area of nasal mucosa

22. Paranasal sinuses Paranasal sinuses are cavities in bones of the skull that communicate with the nasal cavity They are lined by mucous membranes There are 4 paranasal air sinuses Frontal Ethmoidal cells sphenoidal maxillary

23. Hyoid bone U-shaped bone in the neck between the larynx and the mandible It has an anterior body and two large greater horns two small conical lesser horns The hyoid bone is a key bone in the neck Because it connects the floor of the oral cavity in front with the pharynx behind and the larynx below Axial Skeleton …

24. The vertebral column is divided into 5 major regions 7 Cervical vertebrae … found in the neck 12 Thoracic vertebrae ... found in the thoracic region & have ribs attached to them 5 Lumbar vertebrae … in the lower back 5 Fused sacral vertebrae … large triangular, attached laterally with the hip bones 3-5 Fused coccygeal vertebrae ... found in the terminal portion of the vertebra column Bones of the trunk Include the vertebral column , and the bones of the chest , or thorax

25. Vertebrae - General structure With few exceptions it has a body , vertebral arch , and seven processes Body The most obvious feature of a vertebra and it is the weight-bearing portion Its rough superior and inferior surfaces provide firm attachment to the intervertebral discs Vertebral foramen A triangular canal dorsal to the body of each vertebra It is bordered by a bony vertebral arch composed of two parts on each side: a pillarlike pedicle and plate like lamina Collectively form the vertebral canal, a passage for the spinal cord

26. Processes Pedicle Lamina Spinous process A downward projection from the apex of the arch, formed by the two laminea Transverse process Extends laterally from the point where the pedicle and lamina meet The spinous & trans. processes provide attachment points for spinal muscles Superior articular processes (SAP) A pair of processes project upward from one vertebra and meet a similar pair of IAP that project downward from the vertebra just above Inferior articular processes (IAP) Intervertebral foramen- opening b/n the pedicles when two vertebrae are joined The spinous processes can felt as a row of bumps along the spine

27. Typical Vertebrae 29

28. Curvature of the vertebral column The vertebral column in the adult has curves Cervical, thoracic, lumbar, and pelvic curvatures These curves are so named as either primary curves (thoracic and pelvic/sacral) or secondary curves (cervical and lumbar ) They give strength, support, and balance Normal curves in vertebral column 1 . Cervical curve - concave posteriorly 2. Thoracic curve - convex posteriorly 3. Lumbar curve - concave posteriorly 4. Sacral- coccygeal curve - convex posteriorly

29. Structure Composed of two components Annulus fibrosus Outer ring of concentric lamellae surrounds the outer margin Composed of fibrocartilage Nucleus pulposus Central/inner core structure, Highly elastic and semi fluid substance Shock absorber Herniation of disk Intervertebral Disc

30. The Thoracic Cage The thoracic cage consists of the thoracic vertebrae , sternum & ribs The inferior border of the cage is formed by a downward arc of the ribs called the costal margin Has a broad base and a somewhat narrower superior apex

31. Sternum The sternum (breastbone) is in the anterior midline of the thorax Subdivided into 3 parts: manubrium , body & xiphoid process Manubrium It is the broad superior portion Has a superior suprasternal notch (jugular notch), which can easily be palpated between the clavicles Has a superolateral right and left clavicular notches, where it articulates with the clavicles

32. Ribs 12 pairs of ribs form the main portion of the thoracic cage The upper seven are true ribs because they form complete arch between the vertebrae and the sternum. The true ribs progressively longer. The lower five ribs fail to reach the sternum and are called false ribs. The false ribs become progressively shorter .

33. Head - vertebral end of ribs Ribs 2 to 9 have crest heads that come to a point between a superior articular facet above and an inferior articular facet below Neck – narrow region lateral to the head Tubercle – a posterior projection lateral to the head Ribs 1 to 10 each have a head and tubercle, neck ( ribs 11 and 12 have a head only) Shaft - an spiral elongated blade of the ribs ( Rib 1 is a flat in horizontal plat) Ribs 2 to 10 have a sharp turn called the angle, distal to the tubercle

34. Intercostal spaces Are spaces between the ribs They contain muscles, blood vessels , & nerves Arteries , veins , and nerves pass in the costal groove in the plane b / n the inner two layers of muscles in a V A N order from above-down

35. Appendicular skeleton The appendicular skeleton consists of the bones of The upper division of the appendicular skeleton The lower division of the appendicular skeleton The upper division on each side includes The shoulder girdles The bones of the upper extremities The lower division includes The hip (part of the pelvic girdle) The bones of the lower extremities

36. Contains the pectoral girdle and the free part of the upper limb form the superior appendicular skeleton Pectoral girdle Clavicle and scapula Free part of the upper limb Humerus (arm) Ulna and radius (forearm) Carpal bones (wrist) Metacarpals (hand) Phalanges (fingers) The upper division of the appendicular skeleton

37. Pectoral (Shoulder) Girdles The pectoral girdle (shoulder girdle) supports the arm It consists of : the clavicle (collarbone) and the scapula (shoulder blade ) The medial end of the clavicle articulates with the sternum at the sternoclavicular joint The lateral end of the clavicle articulates with the scapula at the acromioclavicular joint The scapula also articulates with the humerus at the humeroscapular joint These are loose attachments that make the shoulder joint easy to dislocate

38. Clavicle Is a slightly S-shaped bone, Easily seen and palpated on the upper thorax Its superior surface is relatively smooth Its inferior surface is marked by grooves and ridges for muscle attachment Near the acromial end is a rough tuberosity called the conoid tubercle For ligament attachment Also called collarbones

39. Scapula Triangular flat bone Lies on the posterolateral aspect of the thorax, overlying the 2nd-7th ribs Has three angles (lateral, superior, and inferior); Three borders (superior, lateral, and medial); Two surfaces (costal and posterior); and Three processes (acromion, spine, and coracoid process) Appendicular skeleton …

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41. Humerus It is a long bone, it is the only bone of the arm Proximally has head, shaft Neck Surgical and anatomical neck Greater and lesser tubercle Separated by intertubercular groove Distal end has Medial and lateral condyle Capitulum and trochlea For the insertion of the muscles that surround and move the shoulder jnt Shaft Deltoid tuberosity Radial grove

42. ULNA The medial and longer of the two forearm bones Its proximal end has two prominent projections Olecranon posteriorly Coronoid process anteriorly The two form the walls of the trochlear notch Trochlear notch articulates with the trochlea of the humerus Radial notch on the lateral side of the coronoid process articulates with the head of radius 45 05/08/2024 08:53

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44. Shaft (body) proximally it is thick, but it tapers distally Head narrow distal end rounded with small, conical ulnar styloid process The ulna does not reach, and therefore does not participate in the wrist (radiocarpal) joint 47 05/08/2024 08:53

45. RADIUS The lateral and shorter of the two forearm bones Its proximal end consists of a cylindrical head, a short neck, a projection from the medial surface (radial tuberosity) Head superior surface is concave for articulation with capitulum of humerus medially articulate with radial notch of ulna 48 05/08/2024 08:53

46. Neck narrow part between head and radial tuberosity Shaft (body) gradually enlarges distally Distal end medially - ulnar notch for head of ulna laterally - radial styloid process 49 05/08/2024 08:53

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48. Carpal Bones 8 bones, form the wrist (carpus) Arranged in two transverse rows of 4 bones Carpus is convex from side to side posteriorly and concave anteriorly Proximal row articulate with radius and articular disc of wrist joint proximally and distal row of carpals distally Proximal row from lateral to medial : “ S he L ike T o P lay ” Scaphoid : boat-shaped with scaphoid tubercle, largest bone in proximal row Lunate : moon-shaped Triquetrum : pyramidal Pisiform : pea-shaped; lies on palmar surface of triquetrum 05/08/2024 08:53 51

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50. Distal row Articulate with proximal row of carpals proximally and metacarpals distally Distal row from lateral to medial: “ T ry T o C hase H er ” Trapezium : four sided Trapezoid : wedge-shaped Capitate : head like; largest in distal row Hamate : wedge-shaped, has hooked process (hook of hamate) 05/08/2024 08:53 53

51. Metacarpals Forms the skeleton of the palm Composed of five metacarpal bones They count from lateral to medial Each metacarpal consists of a base, shaft, and head The proximal bases of the metacarpals articulate with the carpal bones The distal heads of the metacarpals articulate with the proximal phalanges and form the knuckles 05/08/2024 08:53 54

52. Phala n ges 14 bones; form the fingers Each digit has three phalanges (proximal, middle, and distal) except for the first (thumb), which has only two (proximal and distal) Each phalanx has a base proximally, a shaft (body), and a head distally The distal phalanges are flattened and expanded at their distal ends, which underlie the nail beds 05/08/2024 08:53 55

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54. Pelvic girdle a basin-shaped ring of bones that connects the vertebral column to femurs pelvic girdle is strong and rigid, especially compared to the pectoral (shoulder) girdle. 8/5/2024 8:53:45 AM 57

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56. Pelvic bones The bones of the pelvis consist of the right and left pelvic (hip) bones, the sacrum, and the coccyx . The sacrum artic­ulates superiorly with vertebra LV at the lumbosacral joint . The pelvic bones articulate posteriorly with the sacrum at the sacroiliac joints and with each other anteriorly at the pubic symphysis . 8/5/2024 8:53:45 AM 59

57. ilium The ilium is the superior, fan-shaped part of the hip bone . The Ala (wing) of the ilium represents the spread of the fan, and the body of the ilium, the handle of the fan. On its external aspect, the body participates in formation of the acetabulum. The iliac crest, the rim of the fan, has a curve that follows the contour of the Ala between the anterior and posterior superior iliac spine. 8/5/2024 8:53:45 AM 60

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59. pubis pubis is an angulated bone with a superior ramus, which helps form the acetabulum, and an inferior ramus, which helps form the obturator foramen. A thickening on the anterior part of the body of the pubis is the pubic crest, which ends laterally as a prominent swelling, the pubic tubercle. The lateral part of the superior pubic ramus has an oblique ridge, pectineat line. 8/5/2024 8:53:45 AM 62

60. Femur longest and heaviest bone in the body It is the second long bone to start ossification is approximately a quarter of the person’s height The femur consists of a shaft two ends , superior/proximal inferior/distal 8/5/2024 8:53:49 AM kebere D (MSc student) 63

61. F emur 8/5/2024 8:53:49 AM kebere D (MSc student) 64

62. Femur….. proximal end consists of a head, neck, and two trochanters Proximal end has Head is neck is trapezoidal, with its narrow end supporting the head and its broader base being continuous with the shaft Trochanter lesser and greater Shaft Distal end 8/5/2024 8:53:49 AM kebere D (MSc student) 65

63. Trochanters are two Lesser trochanter abrupt , conical and rounded projection extends medially from the posteromedial part give tendinous attachment to the primary flexor of the thigh 8/5/2024 8:53:49 AM kebere D (MSc student) 66

64. Femur con’t… shaft slightly bowed (convex) anteriorly anteriorly smooth rounded posteriorly has a broad, rough line, the linea aspera provides aponeurotic attachment for adductors of the thigh has medial and lateral lips 8/5/2024 8:53:49 AM kebere D (MSc student) 67

65. The linea aspera superiorly, lateral lip blends with the broad, rough gluteal tuberosity , medial lip continues as a narrow , rough spiral line Inferiorly , divided into medial and lateral supracondylar lines , which lead to the medial and lateral femoral condyles pectineal line prominent intermediate ridge extends from the central part of the linea aspera to the base of the lesser trochanter 8/5/2024 8:53:49 AM kebere D (MSc student) 68

66. Distal end of the femur Formed by the medial and lateral femoral condyles Lies on the same horizontal level when the bone is in the anatomical position articulate with menisci and tibial condyles to form the knee joint are separated posteriorly and inferiorly by an intercondylar fossa anteriorly merge, forming a shallow longitudinal depression, the patellar surface 8/5/2024 8:53:54 AM kebere D (MSc student) 69

67. Distal end of the femur has lateral and larger and more prominent medial epicondyle superior to which another elevation , the adductor tubercle , to a tendon attachment provide proximal attachment for the medial and lateral collateral ligaments of the knee joint 8/5/2024 8:53:55 AM kebere D (MSc student) 70

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69. Pattella A Disc shaped, roughly triangular sesamoid bone A type of bone that forms within the tendon of the knee as a child begins to walk It has A broad superior base A pointed inferior apex A pair of shallow articular facets on its post. surface where it articulates with the femur The lateral facet is usually larger than the medial Leg ( crura ) The leg has two bones A thick, strong tibia and a slender, lateral fibula Appendicular skeleton …

70. Bone of leg and foot Leg Tibia Fibula Foot 7 Tarsal bones 5 Metatarsal bones 14 Phalanges 73 8/5/2024 8:54:05 AM kebere D (MSc student)

71. Tibia Large, weight bearing bone Articulate in three parts proximally with condyles of femur at knee joint distally with the talus of ankle laterally at its proximal and distal ends with fibula has three parts Proximal end The shaft Distal end 74 8/5/2024 8:54:19 AM kebere D (MSc student)

72. Tibia Features of proximal end The two condyles The two superior articular surface  Tibial plateau Intercondylar eminence and tubercle Fibular articular facet Tibial tuberosity Shaft of tibia:- It is somewhat triangular in cross-section, having three surfaces and borders: On posterior surface, proximal part of the tibial shaft, there is a rough diagonal ridge called soleal line, Which runs inferomedially to the medial border Immediately distal to the soleal line is an obliquely directed vascular groove, which leads to large nutrient foramen 75 8/5/2024 8:54:21 AM kebere D (MSc student)

73. 76 8/5/2024 8:54:27 AM kebere D (MSc student)

74. anterior border of the tibia is the most prominent border. It and the adjacent medial surface are subcutaneous throughout their lengths and are commonly known as the “ shin Their periosteal covering and overlying skin are vulnerable to bruising Distal end of tibia Fibular notch-it is formed when the sharp interosseous boarder is replaced by groove inferiorly Inferior Tibial articular surface Medial malleolus Groove fore tibialis posterior posteriorly 77 8/5/2024 8:54:30 AM kebere D (MSc student)

75. Fibula fibula lies posterolateral to the tibia and is firmly attached to it by the tibiofibular syndesmosis, Serves mainly for muscle attachment than for support ( it doesn’t bear body weight ) The proximal end of the fibula consists of an enlarged head superior to a small neck . The head has a pointed apex (styloid process). The common fibular nerve lies against the posterolateral aspect of the neck 78 8/5/2024 8:54:43 AM kebere D (MSc student)

76. Fibula Like tibia , the shaft of fibula is triangular in cross-section, having three borders (anterior, interosseous, and posterior) and three surfaces (medial, posterior, and lateral ). Fractures commonly occur just proximal to lateral malleolus and often are associated with dislocation of ankle joint Also at neck of the fibula is common site of fracture Fibula is a common source of bone for grafting 79 8/5/2024 8:54:43 AM kebere D (MSc student)

77. 80 8/5/2024 8:54:43 AM kebere D (MSc student)

78. Bones of Foot Tarsal Bones 7 bones which form the ankle joint; talus, calcaneus, navicular, 3 cuneiforms & cuboid Only talus articulate with leg bones Calcaneus Heel bone Largest and strongest bone Articulate with talus and cuboid 81 8/5/2024 8:54:54 AM kebere D (MSc student)

79. 82 8/5/2024 8:54:56 AM kebere D (MSc student)

80. Metatarsal Bones 5 bones which form middle part of the foot Each bone has base, body & head Bases articulate with cuneiform and cuboid bones Heads articulate with proximal phalanges Phalanges 14 bones Lateral four digits have proximal, middle & distal phalanx Great toe (hallux) has only proximal & distal phalanx Each phalanx has base, body & head 83 8/5/2024 8:54:57 AM kebere D (MSc student)

81. 84 8/5/2024 8:54:59 AM kebere D (MSc student)

82. 85 8/5/2024 8:54:59 AM kebere D (MSc student)

83. Joints /Articulations Where parts of skeleton meet Allows varying amounts of mobility Classified by structure or function By function Synarthroses = no/little movement Amphiarthroses = slight movement Diarthroses = great movement Arthrology : study of joints Type Movement Example Synarthrosis None (minimal) Sutures, Teeth, Epiphyseal plates, 1 st rib and costal cart. Amphiarthrosis Slight Distal Tibia/fibula, Intervertebral discs Pubic symphysis Diarthrosis Great Glenohumeral joint, Knee joint, TMJ & others

84. Joint Classification … By Structure Fibrous Sutures : connected by short strands of dense CT ( synarthroses ) Syndesmoses : connected by ligaments (varies) Gomphosis : peg in socket w/short ligament ( synarthroses ) Cartilagenous Synchondrosis : connected by hyaline cartilage ( synarthroses ) Symphysis : connected by fibrocartilage ( amphiarthroses ) Synovial ( diarthroses ); by synovial structures

85. I . Fibrous Joints A. Sutures Between cranial bones Very tight, thin layer of conn . tissue Synostoses - bone replaces conn . tissue in adult Skeletal system … Articulations (Joints) C. Gomphoses One part fit tightly into the other Periodontal tissue holds parts firmly together Example : teeth in the mandible and maxillae B. Syndesmoses Very little freedom for movement Interosseous membrane or ligament present Example : distal joint of the tibia and fibula

86. Immovable Joints (synarthrosis) Fibrous Joints Bones united by ligament suture 89

87. Immovable Joints ( synarthrosis ) Fibrous Joints Bones united by ligament ( syndesmosis ) 90 Interosseous membrane ( syndesmosis )

88. Gomphosis Ligaments hold tooth in bony socket Immovable joint enamel dentin gum root of tooth pulp Socket of alveolar process Peridontal ligament (membrane) 91

89. II. Cartilaginous Joints A. Synchondrosis Hyaline cartilage --> bone over time Example : between epiphysis & diaphysis of bone, between ribs and sternum B. Symphysis Bones connected by disc of fibrocartilage Allows for slight movement ( amphiarthrotic ) Example : pubic symphysis , intervertebral discs Skeletal system … Types of joints

90. Immovable Joint (synchondrosis) Cartilagenous Joints 93

91. Slightly Movable Joint (ampharthrosis) Cartilagenous Joints pubic symphysis symphysis 94

92. Any joint where there is a space between bones Articular cartilage : hyaline; covers ends of both bones articulating Synovial cavity : space between the bones holding synovial fluid Articular capsule : made of 2 layers Fibrous capsule : external dense CT for strength- attached to periosteum Synovial membrane : internal layer of capsule Produces synovial fluid which reduces friction Synovial fluid : viscous; lubricates and nourishes; contained in capsule and articular cartilages Ligaments : extracapsular / intracapsular Meniscus (some): articular discs (menisci) – fibrocartilage pads between bones; improves the fit of 2 bones to increase stability Bursae - sac-like structures that reduce friction Between tendons, muscle, ligaments: and bone III. Synovial joints Components of synovial joints freely moveable joints ( diarthrotic ) Nerves + vessels : Highly innervated & vascular

93. Plane/ gliding : articular surface in flat plane ( nonaxial movement) Short side-to-side; back-and forth movement in gliding manner ( eg ) Intercarpals , intertarsal , scapula-clavicle, articular processes of vertebrae Hinge: cylindrical end of 1 bone fits into trough shape of other ( nonaxial ) Angular movement occurs in a single plane ( eg ) elbow, ankle, interphalangal Pivot : round end fits into ring of bone + ligament ( nonaxial ) Rotation on long axis ( eg ) . atlas-axis (C1-C2), proximal radius-ulna Condyloid : egg-shape articular surface + oval concavity (biaxial) One bone "sits" in the saddle of another side-to-side , back -and-forth movement ( eg ) radius-carpal joint in the wrist, metacarpophalangeal (knuckle) Saddle : articular surface concave + convex (biaxial) Side-to-side, back-forth movement ( eg ) carpometacarpal jt of thumb Ball + Socket : spherical head + round socket ( triaxial or multiaxial ) Works just like a joy-stick in all directions ( eg ) shoulder, coxal (hip) joint Types of synovial Joints

94. Types of Synovial Joints 97

95. Planar Joint Bone surfaces are slightly curved Side to side movement only Rotation prevented by ligaments Examples: intercarpal to intertarsal joints sternoclavicular joint vertebrocostal joints 98

96. Ankle Joint 99

97. Hinge Joint Convex surface of bone fits in concave surface of 2 nd bone Unixlateral like a door hinge Examples: Knee, elbow, ankle, interphalangeal joints Movements produced: flexion extension hyperextension 100

98. Elbow 101

99. Knee Joint 102

100. Knee Joint 103

101. Knee Joint Fig. 9.13 The cruciate ligaments prevent undesirable movements at the knee joint. a) when the knee is flexed or extended, the anterior cruciate prevents anterior slipping movements of the tibia Cruciate Ligaments 104

102. Pivot Joint Rounded surface of bone articulates with the ring formed by the 2 nd bone & ligament Monoaxial since it only allows rotation around longitudinal axis Examples: proximal radioulnar joint supination pronation atlanto-axial joint Turning head side to side “no” 105

103. Condyloid Joint Oval-shaped depression fits into oval depression Biaxial= flex/extend or adduct/abduct is possible Examples: Wrist and metacarpophelangeal joints for 2 to 5 digits 106

104. Saddle Joint One bone saddle-shaped, other bone fits like a person riding on the saddle Biaxial circumduction allows the tip of the thumb to travel in a circle Opposition allows thumb to touch tip of other fingers Examples: Trapezium of carpus and metacarple of thumb 107

105. Synovial Joints Shoulder joint 108

106. Shoulder joint 109

107. Ball & Socket Joint Ball fitting into a cup-like depression Multiaxial flexion/extension abduction/adduction rotation Examples: shoulder joint hip joint 110

108. femur hyaline cartilage synovial cavity Synovial Joints 111

109. Joints of head and neck Joints of thorax

110. Joints of upper limb Joints of back

111. Joints of Lower Limb

112. Vasculature and Innervation of Joints Joints receive blood from articular arteries that arise from vessels around the joint They often anastomose to form networks ( periarticular arterial anastomoses ) Articular veins are communicating veins that accompany the arteries Like the arteries, they are located in the joint capsule, mostly in the synovial membrane Joints have a rich nerve supply --- Hilton's Law Most articular nerves are branches of nerves that supply the muscles that cross and move the joint In some case branches of the cutaneous nerves supplying the overlying skin The nerve endings are numerous in the joint capsule

113. Fracture Fracture of a bone is accompanied by a considerable hemorrhage of blood between the bone ends and into the surrounding soft tissue Immediately after a fracture, the patient suffers severe local pain and unable to use the injured part Deformity may be visible if the fragments have been displaced relative to each other Applied anatomy - Clinical application Fractures of the clavicle The most frequently fractured bone Usually occurs as a result of a fall on the shoulder or outstretched hand The fracture is mostly at its weakest point , the junction of the middle & lateral thirds After the fracture, the lateral fragment is depressed by the weight of the arm, and pulled medially and forward by pect . major The medial end is tilted upward by the sternocleidomastoid muscle

114. Abnormal curves of the vertebral column Kyphosis - exaggerated thoracic curve (hunchback) Can be caused by muscular weakness or by structural changes in the vert. bodies or IV discs Lordosis - exaggerated lumbar curve (slumping) May be caused by an increase in the weight of the abdominal contents Scoliosis - lateral deviation (out of midsagittal plane) Most commonly found in the thoracic region and may be caused by muscular or vertebral defects Paralysis of muscles caused by poliomyelitis can cause severe scoliosis Herniated disk - Protrusion of the gelatinous nucleus pulposus through the anulus fibrosus Compressed anteriorly & stretching/tension posteriorly Squeezing the nucleus pulposus posteriorly toward the thinnest part of the anulus fibrosus Applied anatomy - Clinical application Herniation of disk

115. Over age 45, occurs in: • 29% of women • 18% of men Osteoporosis Bones decrease in mass due to demeneralzation which leads to weak and thin bone cause aches and pains Such bones tend to fracture easily Bursitis Pain and inflammation of a bursa Arthritis Pain and inflammation of a joint and embraces more than a hundred different diseases Osteoarthritis Also called “wear-and-tear arthritis” because it is apparently a normal consequence of years of wear on the joints Rheumatoid arthritis The synovial membrane becomes inflamed and grows thicker cartilage, possibly due to an autoimmune reaction Applied anatomy - Clinical application Age-Related