General Anatomy for Dentistry Lecture 3: Joints PDF

General anatomy for Dentistry Lecture 3: Joints By: Rasha Mohamed Elshinety; MD. PhD Professor of Human Anatomy & Embryology  It is a point of meeting of two or more bones. What is a joint? Joints are divided according to...

General anatomy for Dentistry Lecture 3: Joints By: Rasha Mohamed Elshinety; MD. PhD Professor of Human Anatomy & Embryology  It is a point of meeting of two or more bones. What is a joint? Joints are divided according to the material (tissues) separating the bones into: fibrous, cartilaginous and synovial joints.  A- Fibrous joints The articulating bones are connected by fibrous tissue No movements Types of B- Cartilaginous joints The articulating bones are onnected by cartilage joints: No/ Limited movement C- Synovial joints It has a special structure Range of movement Fibrous joints:  It is the point of meeting of two bones or more.  The bones are connected by fibrous tissue.  There is No movement in fibrous joints. Fibrous joints (subtypes): 1- Sutures  The bones have serrated edges.  There is minimal amount of fibrous tissue.  Example: sutures of the skull. Fibrous joints (subtypes): 2- Peg and socket (gomphosis)  The bones are peg & socket.  There is moderate amount of fibrous tissue.  Example: roots of teeth & the jaw. Fibrous joints (subtypes): 3- Syndesmosis:  The bones are rough.  There is big amount of fibrous tissue (interosseous ligament).  Example: inferior tibio-fibular joint. Cartilaginous joints:  It is the point of meeting of two bones or more.  The bones are connected by cartilage.  There is No/ limited movement in cartilaginous joints. Cartilaginous joints (subtypes): 1. Primary cartilaginous joints 2. Secondary cartilaginous joints (synchondrosis): (synchondrosis):  The cartilage between the  The cartilage between the bones is articulating bones is temporary. permanent.  No movements.  Limited movements.  Example: the growing ends of long  Example: all joints in the median bones. plane as those present between bodies of vertebrae. 1ry cartilaginous joints 2ndry cartilaginous joints Synovial joints:  The bones are separated by synovial fluid.  Most of the joints of the limbs are synovial.  They permit considerable range of mobility. Synovial joint Synovial joints (subtypes):  According to the number of axes around which the synovial joint moves; the synovial joints are subdivided into 4 subtypes: 1. Uniaxial 2. Biaxial 3. Polyaxial 4. Plane 1. Uniaxial synovial joints:  They move around single axis. a. Hinge joint:  The joint moves around a horizontal axis.  Example: Elbow joint. b. Pivot joint:  There is a disc that rotates in a ring i.e. the axis is longitudinal (i.e. along the bone).  Example: Superior radio-ulnar joint. 2. Biaxial synovial joints:  They move around two axes.  Movements: flexion, extension, abduction & adduction. a. Ellipsoid joint:  Example: Wrist joint. b. Saddle joint:  Example: carpometacarpal joint of the thumb. c. Condyloid joint:  Example: metacarpophalangeal joints Ellipsoid joint 3. Polyaxial synovial joint:  A ball articulates with a socket.  Example: shoulder joint/ Hip joint.  Movements wide range (flexion, extension, abduction, adduction, medial rotation, lateral rotation and circumduction). 4. Plane synovial joint:  Two smooth flat surfaces.  Movements: Gliding movements  Example: Intercarpal joints. Factors affecting stability of the joints: 1- Bony factor: shape of articulating bone 2- Muscular factors: muscles that surround the joint 3- Ligamentous factor A 70 years old man would have all the following types of joints EXCEPT: a. Sutures b. Polyaxial synovial c. Primary cartilaginous d. Secondary cartilaginous The type of shoulder joint is: a. Sutures b. Polyaxial synovial c. Primary cartilaginous d. Secondary cartilaginous All of the following types of joints might be present in the upper limb EXCEPT: a. Uniaxial synovial b. Polyaxial synovial c. Primary cartilaginous d. Secondary cartilaginous The bones in the midline are commonly articulating through: a. Uniaxial synovial b. Polyaxial synovial c. Primary cartilaginous d. Secondary cartilaginous Which of the following joint types posses no mobility? a. Fibrous joints b. Cartilaginous joints c. Plane synovial joints d. Polyaxial synovial joints The fibrous joints with largest amount of fibrous tissue is: a. Sutures b. Gomphosis c. Syndesmosis d. Non of the above The skull cap (vault) bones are connected together through: a. Sutures b. Gomphosis c. Syndesmosis d. Plane synovial joint