University of Debrecen Anatomy, Histology & Embryology Practical Guide PDF

 Joints I. – Connections between bones (lecture!) Synarthrosis – Uninterrupted connections Synovial joint = articulation = diarthrosis Synarthrosis: these joints normally do not allow movements (or Joint cavity between ar...

 Joints I. – Connections between bones (lecture!) Synarthrosis – Uninterrupted connections Synovial joint = articulation = diarthrosis Synarthrosis: these joints normally do not allow movements (or Joint cavity between articulating bones movement is limited) between the articulating bones. These joints are classified based on the tissue type that holds the bones together. Fibrous joints (dense connective tissue) Cartilage or bone Suture: a thin layer of dense connective tissue, which Synchondrosis (cartilaginous joint): bones are held together unites the bones of the skull; e.g. coronal or lambdoid by hyaline cartilage. E.g. sphenopetrosal synchondrosis suture Symphysis: bones are held together by fibrous cartilage; e.g. Gomphosis: microscopic ligaments in the dental intervertebral disks alveoli that attach teeth to their sockets Hemidiarthrosis: a specialised form when there is a gap in the Syndesmosis (fibrous joint): a dense connective fibrous cartilage, representing a transition towards synovial tissue ligament or sheet holds bones together, joints; e.g. pubic symphysis enabling very limited movements; Synostosis: fusion of two or more bones into a single bone; e.g. coracoclavicular ligament, interosseous e.g. hip bone, sacrum membrane between tibia and fibula Joints II. – Connections between bones (lecture!) Synovial joint = articulation = diarthrosis Joint cavity between articulating bones The most typical types of joints. Most synovial joints enable a wide range of movements. Main components of a typical synovial joint: - articular cartilage on the articular surface of bones - ligaments - joint capsule - synovial membrane and the fluid it produces (synovia), which fills the joint cavity Accessory components (for some joints only): - articular disks and menisci (singular: meniscus) - articular labrum (lip) - bursae and synovial tendon sheaths Joints III. – Connections between bones (lecture!) Synovial joint = articulation = diarthrosis Joint cavity between articulating bones One or more axis NO definite axis for movements -> Plane joint = -> Uniaxial joint Amphiarthrosis -> Biaxial joint -> Multiaxial joint The axis of a joint is always perpendicular to the plain of its movement. Movement in a joint always takes place around an axis. Joints IV. – Connections between bones (lecture!) Uniaxial joints - Hinge (L: ginglymus) - Pivot (L: trochoid) - Special case: combination of the above in a complex joint: trocho- ginglymus Biaxial joints - Ellipsoid (or condyloid) - Saddle (L: sellaris) Multiaxial - Ball and socket (L: spheroid) - Special case: enarthrosis (the socket covers the sphere beyond its equator)  Joints of the shoulder girdle Sternoclavicular and acromioclavicular joints Movements of the sternoclavicular joint and the shoulder girdle Movements: - elevation – depression - protraction – retraction - rotation The two joints form a “bridge” that attaches the upper limb to the elevation-depression protraction-retraction trunk. The sternoclavicular joint is a saddle type of joint by shape, but a ball-and-socket joint by function; the sternal end of the clavicle articulates with the clavicular notch of the sternum. An articular disk splits the joint cavity. Movements are mainly limited by the costoclavicular ligament. The acromioclavicular joint is a plane joint; the distal end of the clavicle is held to the scapula by the coracoclavicular syndesmosis (fibrous joint) Key structures relevant to this page are shown in red boxes.  Shoulder joint Articular head (humeral head) and socket (glenoid cavity) This is a ball and socket joint. The main limiting factor for the lateral elevation (abduction around a sagittal Movements axis) is the humeral fornix (coracoacromial ligament). abduction – adduction flexion – extension sagittal axis horizontal axis The tendon of long head of biceps brachii muscle passes through the joint cavity. external rotation – internal rotation vertical axis Key structures relevant to this page are shown in red boxes.  Elbow joint I. Articulating surfaces Ligaments The elbow is a compound joint. It consists of: - humeroulnar joint (hinge or ginglymus) trochlea of humerus -> trochlear notch of ulna - humeroradial joint (ball and socket) capitulum of humerus -> radial head - proximal radioulnar joint (pivot or trochoid) articular circumference of radius -> radial notch of ulna The elbow joint is a hinge and pivot (trochoginglymus) type of joint. The annular ligament of the radius tightly Movements holds the radial head in its socket, stabilising it. flexion – extension supination – pronation horizontal axis constructional axis of forearm Collateral ligaments characteristic to hinge joints are present. Key structures relevant to this page are shown in red boxes.  Elbow joint II. Elbow joint and forearm The red line in the figure represents the constructional axis of the forearm (between the radial head and the ulnar styloid process). Rotation around this axis takes place by the movement (rotation) of the articular circumference of the radius in the radial notch. The distal radioulnar joint is a plane type of joint. The distal extremities of both bones passively follow supination-pronation. The interosseous membrane is a fibrous joint (syndesmosis). Movements flexion – extension supination – pronation horizontal axis constructional axis of forearm Key structures relevant to this page are shown in red boxes.  Radiographic image of wrist and hand Movements of wrist joint palmarflexion – dorsalflexion ulnar abduction – horizontal axis radial abduction The radiocarpal (wrist) joint is an ellipsoid (or sagittal axis condyloid) type of joint. Articulating surfaces include the carpal articular surface of radius, and three carpal bones (triquetrum, lunate, scaphoid) of the proximal row. The space between ulna and carpal bones is filled up by an articular disk. Joint socket – distal end of radius seen from the carpal bones Key structures relevant to this page are shown in red boxes. Intercarpal joints (between the carpal bones) Articulatio radiocarpea The carpometacarpal (CMC) joint of the thumb is a are plane type of joints, held together by a saddle type of joint (keep in mind the articular common joint capsule. surface of trapezium). The carpometacarpal (CMC) joints are situated between the carpal bones and the bases of the Movements: abduction – adduction (sagittal axis); Articulationes intercarpeae metacarpal bones. Also plane type of joints. opposition – reposition (at a plane horizontal to the “saddle”) Volar view Dorsal view Key structures relevant to this page are shown in red boxes.  Joints of the fingers Metacarpophalangeal joints (ellipsoid or condyloid type of joints) are Movements of digits located between the heads of the metacarpal bones and the bases of the proximal phalanges. flexion – extension Ligaments of the digital joints horizontal axis Interphalangeal joints are located between the phalanges. These are hinge types of joints with strong collateral ligaments. Metacarpophalangeal joints are also widely used as MCP, the proximal interphalangeal joints as PIP, and the distal interphalangeal joints as DIP joints. Bones in the joints of the fingers Metacarpophalangeal joints also enable spreading the fingers Key structures relevant to this page are shown in red boxes. (abduction – adduction).  References and image sources Sobotta: The Atlas of Human Anatomy Gray’s Basic Anatomy Szentágothai – Réthelyi: Functional Anatomy Internet