Week 28 PHA112 Joints 2023-24 Student Handout PDF

WEEK 28 MPharm Programme Normal Systems Musculoskeletal system - Joints PHA112 Dr Praveen Bhugra Slide 1 of 40 PHA112 Musculoskeletal System - Joints WEEK 28 Learning objectives From this lecture you should be able to: – Name the different classes of joint and give an example of each – Draw and labe...

WEEK 28 MPharm Programme Normal Systems Musculoskeletal system - Joints PHA112 Dr Praveen Bhugra Slide 1 of 40 PHA112 Musculoskeletal System - Joints WEEK 28 Learning objectives From this lecture you should be able to: – Name the different classes of joint and give an example of each – Draw and label a synovial joint – Describe and give named examples of different synovial joints – Describe the range of movements of different joints Slide 2 of 40 PHA112 Musculoskeletal System - Joints WEEK 28 Introduction Joints or articulations are sites where two or more bones meet Joints have two fundamental functions: – provide for skeletal mobility – hold the skeleton together Weakest parts of the skeleton, yet have a remarkable ability to resist the forces that tear them apart Slide 3 of 40 PHA112 Musculoskeletal System - Joints WEEK Classification of joints 28  Functional classification (Focuses on amount of movement)  Synarthroses (immovable joints)  Amphiarthroses (slightly movable joints)  Diarthroses (freely movable joints)  Structural classification (Based on the material binding them and presence or absence of a joint cavity)  Fibrous  Cartilagenous  Synovial Slide 4 of 40 PHA112 Musculoskeletal System - Joints WEEK Joint classes 28 Fibrous joints – Suture – Syndesmoses – Gomphoses Cartilaginous joints – Synchondroses – Symphyses Synovial – Gliding, hinge, pivot, condyloid, saddle, and ball and socket Slide 5 of 40 PHA112 Musculoskeletal System - Joints WEEK Fibrous joints 28 In fibrous joints the bones are joined by fibrous tissue; no joint is present The three types of fibrous joints are: Sutures – Dense fibrous connective tissue Syndesmosis – A cord or band of connective tissue Gomphosis – Peg-in-socket arrangement surrounded by fibrous tissue or peridontal ligament Slide 6 of 40 PHA112 Musculoskeletal System - Joints Fibrous joints - sutures WEEK 28 Occurs only between bones of the skull Wavy articulating bone edges interlock Junction is filled by connective tissue Rigid splices bind bones of the skull together tightly Slide 7 of 40 PHA112 Musculoskeletal System - Joints WEEK Fibrous joints - syndesmoses 28 The bones are connected exclusively by ligaments, cords or bands of fibrous tissue Longer fibrous tissue occurs as a sheet or membrane Longer fibrous tissue permits the joint to “give” or flex Slide 8 of 40 PHA112 Musculoskeletal System - Joints WEEK 28 Fibrous joints - gomphoses Is a “peg-in-socket” Only example is the articulation of a tooth with its bony alveolar socket Ligament is a short periodontal ligament Slide 9 of 40 PHA112 Musculoskeletal System - Joints WEEK 28 Cartilaginous joints Articulating bones united by cartilage Lack a joint cavity Not highly movable Two types Synchondroses (singular: synchondrosis) Sympheses (singular: symphesis) Slide 10 of 40 PHA112 Musculoskeletal System - Joints WEEK Cartilaginous joints - synchondroses 28 Literally: “junction of cartilage” Hyaline cartilage unites the bones Immovable (synarthroses) Examples: Epiphyseal plates Joint between first rib’s costal cartilage and manubrium of the sternum Slide 11 of 40 PHA112 Musculoskeletal System - Joints WEEK Cartilaginous joints - symphyses 28 Literally “growing together” Fibrocartilage unites the bones Slightly movable (amphiarthroses) Resilient shock absorber Provide strength and flexibility Hyaline cartilage on articular surfaces of bones to reduce friction Examples Intervertebral discs Pubic symphysis of the pelvis Slide 12 of 40 PHA112 Musculoskeletal System - Joints WEEK 28 Synovial joints Include most of the body’s joints All are diarthroses (freely movable) All contain fluidfilled joint cavity Slide 13 of 40 PHA112 Musculoskeletal System - Joints WEEK Synovial joints 28 1. Articular cartilage Hyaline Spongy cushions absorb compression Protects ends of bones from being crushed 2. Joint (synovial) cavity Potential space Small amount of synovial fluid Slide 14 of 40 PHA112 Musculoskeletal System - Joints Synovial joints WEEK 28 3. Articular (or joint) capsule Two layered Outer: fibrous capsule of dense irregular connective tissue Inner: synovial membrane of loose connective tissue (makes synovial fluid) Lines all internal joint surfaces not covered by cartilage Slide 15 of 40 PHA112 Musculoskeletal System - Joints WEEK 28 4. Synovial fluid Synovial joints Filtrate of blood Contains special glycoproteins Nourishes cartilage and functions as slippery lubricant Weeping lubrication squeezes synovial fluid into and out of the cartilage nourishing the cells. Slide 16 of 40 PHA112 Musculoskeletal System - Joints Synovial joints WEEK 28 5. Reinforcing ligaments (some joints) Intracapsular Three possible types of reinforcing ligaments: Capsular (intrinsic)—part of the fibrous capsule Extracapsular—outside the capsule Intracapsular—deep to capsule; covered by synovial membrane Slide 17 of 40 PHA112 Musculoskeletal System - Joints WEEK Synovial joints 28 6. Nerves Detect pain Monitor stretch (one of the ways of sensing posture and body movements) 7. Blood vessels Rich blood supply Extensive capillary beds in synovial membrane (produce the blood filtrate) Slide 18 of 40 PHA112 Musculoskeletal System - Joints WEEK Some joints 28 Articular disc or meniscus (literally “crescent”) – Only some joints – Those with bone ends of different shapes or fitting poorly – Some to allow two kinds of movement (e.g. jaw) – Examples: – knee TMJ (temporomandibular joint) Slide 19 of 40 PHA112 Musculoskeletal System - Joints WEEK Bursae and Tendon sheaths 28 Contain synovial fluid Not joints but often associated with them Act like ball bearings Bursa means “purse” in Latin Flattened sac lined by synovial membrane Where ligaments, muscles, tendons, or bones overlie each other and rub together Tendon sheath Only on tendons subjected to friction Slide 20 of 40 PHA112 Musculoskeletal System - Joints Humerus resting Humerus moving Bursa rolls and lessens friction. WEEK 28 Factor influencing joint stability Articular surfaces Shape usually plays only minor role Some deep sockets or grooves do provide stability Ligaments Usually the more, the stronger the joint Can stretch only 6% beyond normal length before tear Once stretched, stay stretched Muscle tone Constant, low level of contractile force Keeps tension on the ligaments Especially important at shoulders, knees, arches of foot Slide 21 of 40 PHA112 Musculoskeletal System - Joints WEEK 28 Movements allowed by synovial joints Gliding Angular movements: ↑ or ↓ the angle between two bones – Flexion – Extension – Abduction – Adduction – Circumduction Rotation Special movements Slide 22 of 40 PHA112 Musculoskeletal System - Joints WEEK 28 Special movements Slide 23 of 40 Pronation Supination Dorsiflexion Plantar flexion Inversion Eversion PHA112 Musculoskeletal System - Joints Protraction Retraction Elevation Depression Opposition WEEK Gliding 28 One flat bone surface glides or slips over another similar surface Examples: Intercarpal joints Intertarsal joints Between articular processes of vertebrae Slide 24 of 40 PHA112 Musculoskeletal System - Joints WEEK Angular movements 28 Movements that occur along the sagittal plane: Flexion: decreases the angle of the joint Extension: increases the angle of the joint Hyperextension: excessive extension beyond normal range of motion Slide 25 of 40 PHA112 Musculoskeletal System - Joints Neck WEEK Angular movements 28 Vertebral column At the shoulder and knee Slide 26 of 40 PHA112 Musculoskeletal System - Joints WEEK Angular movements 28 Movements that occur along the frontal plane: Abduction: movement away from the midline Adduction: movement toward the midline Circumduction: flexion + abduction + extension + adduction of a limb so as to describe a cone in space Slide 27 of 40 PHA112 Musculoskeletal System - Joints the upper limb at the shoulder WEEK Rotation 28 The turning of a bone around its own longitudinal axis Examples: Between C1 and C2 vertebrae Rotation of humerus and femur Slide 28 of 40 PHA112 Musculoskeletal System - Joints Rotation of the head, neck, and lower limb Special Movements WEEK 28 Movements of radius around ulna: Supination: turning hand backward Pronation: turning hand forward Slide 29 of 40 PHA112 Movements of the foot: Dorsiflexion: upward movement Plantar flexion: downward movement Musculoskeletal System - Joints Special Movements WEEK 28 Movements of foot: Inversion: turn sole medially Eversion: turn sole laterally Slide 30 of 40 PHA112 Movements in a transverse plane: Protraction: anterior movement Retraction : posterior movement Musculoskeletal System - Joints Special Movements WEEK 28 Elevation: lifting the body part superiorly Depression: moving a body part inferiorly Slide 31 of 40 PHA112 Opposition of the thumb Movement in the saddle joint so that the thumb touches the tips of the other fingers Musculoskeletal System - Joints WEEK 28 Slide 32 of 40 Classification of Synovial Joints PHA112 Musculoskeletal System - Joints WEEK 28 Slide 33 of 40 Bones of the hand PHA112 Musculoskeletal System - Joints Plane joint WEEK 28 Articular surfaces are essentially flat Allow only short slipping or gliding movements No rotation around an axis Examples – Intercarpals – Intertarsals – Vertebrae Slide 34 of 40 PHA112 radius Musculoskeletal System - Joints ulna 28 In hinge joints a WEEK cylindrical shaped projection of bone fits into a trough shaped surface of another bone Motion is within a single plane Joint components resemble that of a mechanical hinge E.g. elbow & knee joints It allows for movement (flexion and extension) in only one plane Slide 35 of 40 PHA112 Musculoskeletal System - Joints Hinge joints WEEK Pivot joints 28 The rounded end of a bone protrudes into a ring of bone and ligaments on another bone Only movement allowed is rotation of bone around long axis Slide 36 of 40 PHA112 radius Musculoskeletal System - Joints ulna Condyloid joints WEEK 28 In condyloid joints the oval articular surface of one bone fits into a complementary concavity in another Both articulating surfaces are oval shaped Example Metacarpophalangeal (MCP) joints Slide 37 of 40 PHA112 Musculoskeletal System - Joints Saddle joints WEEK 28 Resemble condyloid joints, but allow greater freedom of movement Each surface has both a concave and a convex surface that fit together Each surface is shaped like a saddle The best example of a saddle joint in the body are the carpo-metacarpal joints of the thumb Slide 38 of 40 PHA112 Musculoskeletal System - Joints WEEK 28 Ball and socket joints The spherical head of one bone articulates with the cuplike socket of another These joints are multiaxial and the most freely moving synovial joints Movements in all planes is allowed All axis and planes Examples – Shoulder – Hip Slide 39 of 40 PHA112 Musculoskeletal System - Joints Further Reading Refer to the Following Textbooks WEEK 28 Ross and Wilson Anatomy and Physiology in Health and illness 13th Edition Gerard J. Tortora and Byran H. Derrickson Principles of Anatomy and Physiology 13th Edition Frederic H. Martini Fundamentals of Anatomy & Physiology 7th Edition Elaine N. Marieb and Katja Hoehn Human Anatomy & Physiology 8th Edition VanPutte, Regan and Russo Seeley’s Anatomy and Physiology 12th Edition Slide 40 of 40 PHA112 Musculoskeletal System - Joints