Chapter 9 Joints 9 1 Famous Quotes I

Chapter 9 -- Joints 9 -1

Famous Quotes • I figured my body always would be able to repair itself. I think all of us believe that – until you begin to age and get hit with deteriorating joints. Lee Majors • It had not occurred to me that marriage requires the same effort as a career. And unlike a career, marriage requires a joint effort. Jessica Savitch (1947 -1983) 9 -2

Ch. 9 (Joints) Study Guide 1. Critically read Chapter 9 pp. 278 -297 before 9. 3 (Anatomy of selected diarthroses). Study all figures in the Power. Point slides as well. 2. Comprehend Terminology (those in bold in the textbook) within the reading scope above 3. Study-- Figure questions, Think About It questions, and Before You Go On (section-ending) questions (within the reading scope above) 4. Do end-of-chapter questions— – Testing Your Recall— 1 -4, 6 -7, 9, 11 -16, 18 – True or False– 2, 4, 5, 9, 10 5. Review/study review sheet document (4 pages) posted on Blackboard 9 -3

I. Overview of the joints 9 -4

Figure 9. 1 –a gymnast and joint flexibility 9 -5

§ Why Knuckles Crack and Joints Creak • Some peoples' bodies play a percussive symphony of cracking and creaking, thanks to the large orchestra of noise-making human joints. • What's behind it all? 9 -6

§ Joints and their names 1. What are joints? • Arthrology = study of the joints • Kinesiology = study of musculoskeletal movement (motion of human body) 2. How joints are named? • From the names of the bones involved • Ex. The atlantoccipital joint • Ex. The humeroscapular joint 9 -7

II. Functional classification of joints 9 -8

1. Are all joints able to move? – Immovable joints– where? Why? – Less movable– ex. vertebral column; why? – Moveable—shoulder, elbow, knee 2. Functional classification (freedom of movement) – synarthrosis (little/no movement) (“Syn”-together) – amphiarthrosis (slightly movable) – diarthrosis (freely movable) (‘Dia”– through) 9 -9

III. Structural classification of joints 9 -10

§ Structural classification How adjacent bones are joined? 1. Bony joints (synostosis; synarthrosis)– two bones fused 2. Fibrous joints (synarthrosis)—held together by collagen fibers; lack a synovial cavity 3. Cartilaginous joints (amphiarthrosis)– held together by cartilage; lack a synovial cavity 4. Synovial joints (diarthrosis)– having synovial (joint/articular) cavity (Fig. 9. 5 next slide) 9 -11

Fig. 9. 5 Synovial Joint • Joint in which two bones are separated by a space called a synovial (joint) cavity • Most are freely movable 9 -12

§ 1. Bony Joints (Synostosis) A. Gap between “two bones ossify”– become a single bone • TWO frontal/mandibular bones in infants B. Can occur in either fibrous joints or cartilaginous as well; Examples: • • Aging: cranial sutures (fibrous joints) destroyed (ex. Parietal bones fuse) in elderly Aging: attachment of first rib to the sternum (cartilaginous joint) becomes a synostosis with age 9 -13

§ 2. Fibrous Joints (Synarthrosis. Amphiarthrosis) • Collagen fibers span the space between bones • Three kinds of fibrous joints – A. Sutures— the fibers are short and allow for little movement – B. Gomphoses— the fibers are also _____ and allow for little movement; between teeth and the jaw – C. Syndesmoses—longer fibers and more movable • Figure 9. 2 9 -14

Fibrous Connective Tissue Fig. 9. 2 R. Tibia A Suture B Syndesmosis Gomphosis 9 -15

Fibrous Joint – A. Sutures • Immovable fibrous joints – Bind bones together; only in skull • 3 types— (Fig. 9. 3 next slide) • Serrate sutures - interlocking lines – coronal, sagittal and lambdoid sutures • Lap sutures - overlapping beveled edges – Between temporal and parietal bones; Name the suture? • Plane sutures - straight, nonoverlapping edges – palatine processes of the maxillae Suture 9 -16

Three types of suture-- Serrate suture Lap suture Plane suture Miter joint Butt joint Bone Wood Dovetail joint 9 -17

Fibrous Joint – B. Gomphoses • Attachment of a tooth to its socket • Held in place by fibrous periodontal ligament – Consisting of collagen fibers attach teeth to jawbones (which bones? ) • Little movement (Synarthrosis) while chewing Gomphoses 9 -18

Fibrous Joint – C. Syndesmosis • Two bones bound by broad fibrous sheet called – Interosseous membrane • More/less movable than that of sutures/gomphoses • Examples: radius to ulna (a more movable one, Amphiarthrosis) allow supination and pronation (next slide); tibia to fibula (less movable one) Tibia & fibula Syndesmosis 9 -19

Supination and Pronation • For example: In the forearm • Supination – rotation of forearm so that the palm faces forward • Pronation – rotation of forearm so the palm faces to the rear A B Supine means up. In order to carry a bowl of soup, your hand must be in the supine position 9 -20

Check point question #1 - • Functionally, why are sutures classified as synarthroses, and syndesmoses as amphiarthroses? 9 -21

§ 3. Cartilaginous Joints (amphiarthrosis) Two bones are linked by cartilage Two types– A. synchondroses and B. symphyses 9 -22

Cartilaginous Joint – A. Synchondrosis • Bones are joined by hyaline cartilage • Examples: – First rib attachment to sternum (A on the right) – Temporary joint between epiphysis and diaphysis in growing bones: called Epiphyseal ? _____ A B, next 9 -23

Cartilaginous Joint – B. Symphyses • 2 bones joined by fibrocartilage • Examples: – See figure at right 2 • Only slight amount of movement is possible • Examples– 1 & 2 on the right 1 9 -24

Check point question #2 - • What is the structural difference in histology between a synchondrosis and a symphysis? 9 -25

IV. Focusing on synovial joints 9 -26

§ 4. Synovial Joint • Most are freely movable; two bones in fact Do / Do not touch each other • Two bones are separated by a space called A. _____ cavity (with fluid in it) and a soft tissue called B. _______ • B. Articular cartilage -hyaline cartilage covering the joint surfaces • Synovial fluid —a lubricant; feeds cartilages A B Next slide 9 -27

§ Synovial joints 1. Joint (Articular) capsule encloses joint cavity – (Outer) Fibrous capsule: continuous with periosteum – (Inner) synovial membrane; secretes ______ 2. Articular discs or menisci: cartilage grows inward and forms pads (Fig. 9. 29 c-d; 8. 39) – jaw, wrist, sternoclavicular and knee joints – absorbs shock, guides bone movements and distributes forces • • Tendon: attaches muscle to bone Ligament: attaches bone to bone 9 -28

Knee Joint 9 -29

Right Knee Joint – Superior View • Medial meniscus & lateral meniscus absorb shock and shape joint PCL ACL Lateral condyle of tibia ? Medial condyle of tibia 9 -30

Anterior view Posterior view 9 -31

§ Tendon Sheaths and Bursae • Bursa = a sac filled with synovial fluid • Tendon sheaths = elongated bursae lined with synovial membrane and wrapped around a tendon Ulnar bursa Tendons (flexor digitorum) Tendon sheaths 9 -32

Tendon Sheaths and Bursae • Bursa = a sac filled with synovial fluid – (Locations) between muscles or between a tendon & a bone etc. ; Good examples– Shoulder joint etc. Fig. 9. 24 • Tendon sheaths = elongated bursae – (Locations) where there is considerable friction; such as the hand, wrist, fingers, the ankle, foot, toes etc. • Functions of bursa and tendon sheaths: – Reduce friction in joints (such as the shoulder), – Cushion the movement of one body part over another 9 -33

Fig. 9. 24 Humeroscapular joint 9 -34

Check point question #3 - • A) What is the functional classification of synovial joints? • B) Why is a meniscus in an interphalangeal joint unnecessary? 9 -35

V. Types of synovial joints 9 -36

§ 6 Types of Synovial Joints—in descending order of mobility 1. 9 -37

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1. Ball-and-Socket Joints • Features: Smooth hemispherical head fits within a cuplike depression • Examples: – (shoulder) head of humerus into glenoid cavity of scapula – (hip) head of femur into acetabulum of hip bone • Type: only multiaxial joints in the body • Demonstration: (next slide) 9 -39

Planes of movement (A-C) & axes of rotation • Shoulder joint has 3 degrees of freedom = multiaxial joint; • Other joints – monoaxial or biaxial • Axis of rotation– Def. --perpendicular to the plane of movement; examples— A, B, C The arm moves through the sagittal plane A The arm rises in the frontal plane C B 9 -40 The arm rotates in the transverse plane

Planes of movement & axes of rotation • A—Abduction (away from midline) vs. adduction • B—Flexion (decreases a joint angle) vs. extension • C—Medial (internal) rotation vs. lateral rotation 9 -41 It moves through the _____ plane A The arm rises in the frontal plane C B The arm rotates in the ______ plane

2. 9 -42

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2. Condyloid (ellipsoid) Joints • Features: Oval convex surface on one bone fits into a similarly shaped depression on the next • Examples: – radiocarpal joint of the wrist – metacarpophalangeal joints at the bases of the fingers • Type: Biaxial joints– why? • Demonstration: index finger (or 2 nd - 5 th digits) and Fig. 9. 21 9 -44

When someone is abducted, they are taken away, just as abduction takes the limb away from the body. During adduction, the limb is added to the body. Metacarpophalangeal joints 9 -45

3. 9 -46

Condyloid joint 9 -47

3. Saddle Joints • Features: Each articular surface is shaped like a saddle, concave in one direction and convex in the other bone (like a sitting rider) • Examples: trapeziometacarpal joint at the base of the thumb • Type: Biaxial joint (see demo below) • Demonstration: – A) frontal plane (palmar abduction) – B) sagittal plane (opposition) primates’ anatomical hallmark: _____ Fig. 1. 5 & 9. 21 c-d 9 -48

Monkey Primate adaptations: The thumbs became opposable; they made the hands prehensile Human 9 -49

Figure 9. 21 d ID this movement of thumb 9 -50

Figure 9. 21 e ID this movement of thumb 9 -51

4. 9 -52

4. Gliding (plane) Joints • Features: Flat articular surfaces in which bones slide over each other • Examples: Fig. Z tarsal bones – between the carpal bones of the wrist, – the tarsal bones of the ankle, – articular processes of the vertebrae • Type: Biaxial joints • Demonstration: head is tilted side-toside and back-and-forth, the vertebrae slide accordingly 9 -53

Can Talented Naval Medics Interest Lazy Cubs? Calcaneus Talus Cuboid (Intermediate) (Lateral) Gliding Medial cuneiform 9 -54

5. 9 -55

Anterior view Capitulum Funny bone 9 -56

5. Hinge Joints • Features: One bone with convex surface that fits into a concave depression on other bone • Examples: – ulna and humerus at elbow joint (trochlea of the humerus fits into the trochlear notch of the ulna) – femur and tibia at knee joint (tibiofemoral) – finger and toe joints (interphalangeal) • Type: Monaxial (uniaxial) joints • Fig. 9. 25 b 9 -57

A hinge joint --the elbow (Trochlear notch) 9 -58

6. 9 -59

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6. Pivot Joints • Features: One bone rotates on its longitudinal axis relative to the other • Examples: – proximal radioulnar joint; the radius pivots during pronation and supination – atlantoaxial joint (dens of axis to atlas); Fig. 8. 24 (rotation of the atlas) • Type: Monaxial joints • Demonstration: see next 3 slides 9 -61

Supination and Pronation • For example: In the forearm • Supination – rotation of forearm so that the palm faces forward • Pronation A B – rotation of forearm so the palm faces to the rear 9 -62

of the atlas (the next slide) 9 -63

Anterior arch ? (C 1) (C 2) 9 -64

Check point question #4 - • Which of the 6 type of synovial joints are biaxial? • Give one specific example for each biaxial synovial joint. 9 -65

Questions (muddiest points)? 9 -66