Joints PDF

Joints Dr. Ahmed Elsaeed Ayad Lecturer of human anatomy and embryology Faculty of medicine, Alexandria university Faculty of dentistry, Pharos university Faculty of pharmacy, AASTMT Joints: Def.: It is a point of meeting of two or more bones. Joints are divide...

Joints Dr. Ahmed Elsaeed Ayad Lecturer of human anatomy and embryology Faculty of medicine, Alexandria university Faculty of dentistry, Pharos university Faculty of pharmacy, AASTMT Joints: Def.: It is a point of meeting of two or more bones. Joints are divided according to the material separating the bones into 3 types: 1. Fibrous joint, 2. cartilagenous joint, 3. synovial joint. I- Fibrous Joints: point of meeting of two bones or more, bones are separated by fibrous tissue. There is no movement in fibrous joints. 1. Sutures. 2. Gomphosis (Peg & Socket). 3. Syndesmosis.  1. Sutures: The bones have serrated edges. The bones are separated by minimal amount of fibrous tissue. Example: sutures of the skull. 2-Gomphosis (Peg & Socket). The bones are separated by moderate amount of fibrous tissue. Example: roots of teeth & of maxilla or mandible. 3- Syndesmosis: The bones are separated by big amount of fibrous tissue. Example: inferior tibio-fibular joint. II- Cartilagenous Joints: The bones are separated by cartilage. 1.Primary Cartilagenous. 2. Secondary Cartilagenous Primary Cartilagenous joint : The cartilage between the bones is temporary. The bones are separated by hyaline cartilage. No movements. Example: the growing ends of long bones.  Secondary Cartilagenous joint: The cartilage between the bones is permanent The bones are separated by fibrocartilage. Limited movements. Example: symphysis pubis and disc between vertebrae. IlI- Synovial Joints: Most of the joints of the limbs are synovial. They permit considerable mobility. 1-uniaxial 2-biaxial 3- Poly axial 4-plane 1. Uniaxial joint: The joint moves around one axis. Example: Elbow joint and knee joint, 2. Biaxial joint: The joint moves around two axes. Example: Wrist joint. 3. Polyaxial joint "Ball & Socket": It has multiple axes of movements Ball articulates with a socket. Example: Hip joint and shoulder joint. 4-plane joint: Two flat surfaces. Example: intercarpal joint. The muscles -Muscles make up about 40% of our body weight. - Muscle Tissue has the property of contractility which means the capacity of becoming short in response to stimulus. There are 3 types of muscles 1.skeletal, 2.smooth and 3.cardiac.  The skeletal muscles: - They are attached to bones of the skeleton. - Voluntary muscles. - Under conscious control.  The smooth muscles: -They are found in the wall of the alimentary canal, urinary bladder and vessels. -Involuntary muscles because they are not under conscious control. The cardiac muscle is only found in the heart. types of muscles Parts of a Skeletal Muscle: the belly: a middle reddish fleshy part of skeletal muscle. the tendons: rounded whitish fibrous ends. Attachments of a Skeletal Muscle: -The muscle is attached from both sides to bones. - One of the attachments is called an origin ‫ ة‬and the other is an insertion. -The Origin is the fixed and the proximal part of the muscle. -The Insertion is the mobile and the distal part of the muscle. Thank you