3 Anatomy Lecture_Joints PDF

Faculty of Medicine Medical Education- Damietta University Level 1 Semester 1 PAH 101  Joints Dr. Gamal Elsayed Abdulsalam  Contact: Anatomy Department. Official email: [email protected] Mobile (optional): 0101493590...

Faculty of Medicine Medical Education- Damietta University Level 1 Semester 1 PAH 101  Joints Dr. Gamal Elsayed Abdulsalam  Contact: Anatomy Department. Official email: [email protected] Mobile (optional): 01014935906 Instructor Academic hours: information Sunday: 11:00-12:00 AM Monday: 11:00-12:00 AM  Types of the joints Lecture Characters of the joints topics  Identify different types of joints. Demonstrate characters of each type of Learning joints. Outcomes Recognize examples of each type of joints.  An 18-year-old student was doing part-time work delivering pizzas on his motorcycle. His boss insisted on Case quick delivery, so the student tended to weave in and out of traffic whenever there was a holdup. On one occasion, he scenario, misjudged the gap between two vehicles, and the outer surface of his left knee hit a car bumper. On examination in Clinical the emergency department, he was found to have extensive paralysis of the muscles of the anterior and lateral Correlate, compartments of the left leg. Practice As a result, the patient was unable to dorsiflex the ankle joint (which showed footdrop) and evert the foot. In points addition, there was evidence of diminished sensation down the anterior and lateral sides of the leg and t of the foot and toes, including the medial side of the big toe.  Two or more bones come together, whether movement occurs. Classified according to the tissues between the bones: Joints 1. Fibrous joints. 2. Cartilaginous joints. 3. Synovial joints.  The articulating surfaces of the bones are joined by fibrous tissue, and thus very little movement is possible. Fibrous Joints The sutures of the vault of the skull and the inferior tibiofibular joints are examples of fibrous joints.  Cartilaginous joints can be divided into: Cartilaginous a. Primary Joints b. Secondary.  Primary cartilaginous joint: a. The bones are united by a plate of hyaline cartilage. b. The union between the epiphysis and the diaphysis and between the 1st rib and the manubrium sterni are examples of such a joint. c. No movement is possible.  Secondary cartilaginous joint: The bones are united by a plate of fibrocartilage and the articular surfaces of the bones are covered by layer of hyaline cartilage. Examples are the joints between the vertebral bodies and the symphysis pubis. A small amount of movement is possible. Synovial Joints The articular surfaces are covered by a thin layer of hyaline cartilage separated by a joint cavity. Great degree of freedom of movement. The cavity of the joint is lined by synovial membrane, extends from the margins of one articular surface to those of the other.  The synovial membrane is protected on the outside by the capsule of the joint. The articular surfaces are lubricated by synovial fluid, which is produced by the synovial membrane.  In certain synovial joints, for example, in the knee joint, discs or wedges of fibrocartilage are interposed between the articular surfaces of the bones. These are referred to as articular discs.  Fatty pads are found in some synovial joints lying between the synovial membrane and the fibrous capsule or bone. Examples are found in the hip and knee joints  The degree of movement in a synovial joint is limited by a. The shape of the bones participating in the joint. b. The coming together of adjacent anatomic structures. c. The presence of fibrous ligaments uniting the bones. Most ligaments lie outside the joint capsule, but in the knee, the cruciate ligaments, lie within the capsule.  Synovial joints classified according to: a. The arrangement of the articular surfaces b. The types of movement that are possible. Plane joints In plane joints, the apposed articular surfaces are flat, and this permits the bones to slide on one another. Examples of these joints are the sternoclavicular and acromioclavicular joints.  Hinge joints resemble the hinge on a door, so that flexion and extension movements Hinge joints are possible. Examples of these joints are the elbow, knee, and ankle joints  In pivot joints, a central bony pivot is surrounded by a bony–ligamentous ring, and rotation is the only Pivot joints movement possible. The atlantoaxial and superior radioulnar joints are good example  Condyloid joints have convex surfaces that articulate with two concave surfaces. The movements of flexion, extension, abduction, Condyloid joints and adduction are possible together with a small amount of rotation. The metacarpophalangeal joints or knuckle joints are good examples.  In ellipsoid joints, an elliptical convex articular surface fits into an elliptical concave articular surface. Ellipsoid joints The movements of flexion, extension, abduction, and adduction can take place, but rotation is impossible. The wrist joint is a good example.  In saddle joints, the articular surfaces are reciprocally concavoconvex and resemble a saddle on a horse’s back. Saddle joints These joints permit flexion, extension, abduction, adduction, and rotation. The best example of this type of joint is the carpometacarpal joint of the thumb. Ball-and-socket joints In ball and socket joints, a ball shaped head of one bone fits into a socket like concavity of another. This arrangement permits free movements, including flexion, extension, abduction, adduction, medial rotation, lateral rotation, and circumduction.  The shoulder and hip joints are good examples of this type of joint. Stability of Joints The stability of a joint depends on three main factors: The shape, size, and arrangement of the articular surfaces The ligaments The tone of the muscles around the joint. Joint stability ligaments muscle tone  The ball and socket arrangement of the hip joint and the arrangement of the ankle joint Articular Surfaces are good examples of how bone shape plays an important role in joint stability.  Other examples of joints in which the shape of the bones contributes little or nothing to the stability include the acromioclavicular joint, the calcaneocuboid joint, and the knee joint Ligaments Fibrous ligaments prevent excessive movement in a joint, but if the stress is continued for an excessively long period, then fibrous ligaments stretch. For example, the ligaments of the joints between the bones forming the arches of the feet will not by themselves support the weight of the body.  Should the tone of the muscles that normally support The arches become impaired by fatigue, then the ligaments will stretch, and the arches will collapse, producing flat feet. Elastic ligaments return to their original length after stretching.  The elastic ligaments of the auditory ossicles play an active part in supporting the joints and assisting in the return of the bones to their original position after movement. Muscle Tone In most joints, muscle tone is the major factor controlling stability. For example, the muscle tone of the short muscles around the shoulder joint keeps the hemispherical head of the humerus in the shallow glenoid cavity of the scapula. The knee joint is very unstable without the tonic activity of the quadriceps femoris muscle. The joints between the small bones forming the arches of the feet are largely supported by the tone of the muscles of the leg, whose tendons are inserted into the bones of the feet. Nerve Supply of Joints The capsule and ligaments receive an abundant sensory nerve supply. A sensory nerve supplying a joint also supplies the muscles moving the joint and the skin overlying the insertions of these muscles, a fact that has been codified as Hilton’s law.  Remember that more than one joint may receive the same nerve supply. For example, both the hip and knee joints are supplied by the obturator nerve. Thus, a patient with disease limited to one of these joints may experience pain in both. Tempromandibular joint  An 18-year-old student was doing part-time work delivering pizzas on his motorcycle. His boss insisted on quick delivery, so the student tended to weave in and out of traffic whenever there was a holdup. On one occasion, he misjudged the gap between two vehicles, and the outer surface of his left knee hit a car bumper. On examination in the emergency department, he was Case found to have extensive paralysis of the muscles of the anterior and lateral compartments of the left leg. discussion As a result, the patient was unable to dorsiflex the ankle joint (which showed footdrop) and evert the foot. In addition, there was evidence of diminished sensation down the anterior and lateral sides of the leg and t of the foot and toes, including the medial side of the big toe.  1- Synovial joints allow movement between their bony elements. A- Free B- Limited C- No Questions D- Unstable 2- Synovial joints are classified into multiple subtypes according to: A- Shape of the articulating surfaces B- Degree of movement allowed C- Composition of the joint cavity D- Size of the articulating surfaces 3- primary cartilaginous joint: A. The bones are united by a plate of hyaline cartilage B. The union between the epiphysis and diaphysis C. Union between ribs and sternum D. No movement is possible. 4- stability of joints depends on: A. The shape of articulating bones B. Arrangement of the articulating bones C. Ligaments D. Acromioclavicular joint is an example of stable joints  http://www.innerbody.com/image/ skel07.html https://courses.lumenlearning.com /wm-biology2/chapter/types-of- References synovial-joints/