Muscular System and Joint PDF

Types of Muscles 1- Skeletal muscles 2- Smooth (visceral muscles) 3- Cardiac muscles  Skeletal muscles -Large striated cells -With peripheral nuclei - Attached to origin& insertion by rounded tendon or flat aponeurosis - Controlled by voluntary...

Types of Muscles 1- Skeletal muscles 2- Smooth (visceral muscles) 3- Cardiac muscles  Skeletal muscles -Large striated cells -With peripheral nuclei - Attached to origin& insertion by rounded tendon or flat aponeurosis - Controlled by voluntary part of nervous system  Forms of Skeletal muscles A- Muscles with fibers parallel to the line of pull: -they are strap like -they give wide range of movements -Examples: Sartorius, rectus abdominis Sartorius Rectus abdominis B- Muscles with fibers oblique to line of pull: 1- Triangular (fan like) : e.g. Temporalis 2- Pennate Muscles (feather- like) a- Unipennate muscles: -Tendon is along one margin of muscle - Fibers slope into one side of tendon like half a feather - Example: flexor pollicis longus b- Bipennate Muscles: - Tendon is in the center - Fibers slope into two sides of tendon like a feather - Example: Rectus femoris c- Multipennate Flat type muscles: 1- Flat type which is a series of bipennate muscles alongside one another. E.g. middle fibers of deltoid  Circumpennate type 2- Circumpennate type in which muscle fibers converge from all sides into central tendon. E.g. tibialis anterior C- Spiral Muscles: -There is a twist between two groups of muscle fibers - Example: pectoralis major  Visceral (smooth) muscle -Spindle shaped cells - With central nuclei - They appear unstriated - Found in the wall of visceral organs and blood vessels -Controlled by involuntary part of nervous system  Cardiac muscle -polygonal finely striated branching cells -anastomose together - Controlled by involuntary part of nervous system  Cardiac muscle It is known as the myocardium and forms the middle layer of the heart. It is composed of finely striated branching anastomosing cells with central nuclei. intercalated discs are seen between the cells. Types of Joints 1- Fibrous Joints 2- Cartilagenous Joints 3-Synovial Joints  Fibrous Joints - Bony surfaces are joined by fibrous tissue - Bones are fixed together or very little movement is allowed -Types: 1- Suture 2-Syndesmosis 3- Gomphosis  Suture -limited to flat bones of the skull - Margins of bones are serrated and articulated with each other  Syndesmosis -the opposed surfaces are connected by interosseous ligament e.g. inferior tibiofibular joint  Gomphosis -Peg& socket joint - Restricted to the fixation of teeth to mandible and maxilla  Cartilagenous Joints 1- Primary Cartilagenous Joint: - The bones are connected by hyaline cartilage --they are quite immobile -they are very strong -It ossifies (temporary) - e.g. - Costo-chondral junction - The joint between the epiphyses and diaphysis of a growing long bone Primary Cartilagenous Joint (Costochondral junction Secondary Cartilagenous Joint - Articular surfaces of bones are covered by thin lamina of hyaline cartilage - The bones are united by fibrocartilagenous disc. - Limited degree of movement is possible - It does not ossify. -e.g. -Symphysis pubis - Intervertebral discs -Manubrio-sternal joint  Symphysis pubis cartilaginous lamina Intervertebral discs Secondary Cartilaginous Primary Joint Cartilaginous Joint  Synovial Joints Characters of the synovial joints: 1- The articular surfaces are in contact but not continuity. 2-They are covered by thin layer of hyaline cartilage to decrease friction. 3-The joint is surrounded by strong fibrous capsule. 4-The capsule encloses the joint completely except for the bursa. 5-The joint is strengthened by variable numbers of ligaments. 6-the fibrous capsule is lined by synovial membrane. 7- synovial membrane secretes synovial fluid. 8-synovial fluid acts as lubricant and is important in nutrition. 9- Some intra-articular structures as menisci, labrum, ligaments and fat pads Classification of synovial joints  Plane Joints - Allow simple sliding movement between two articular surfaces -Example: intercarpal & intermetacarpal joints Uniaxial Joints 1- Hinge Joint 2- Pivot Joint  Hinge Joint - Has a transverse axis -The movements are only flexion and extension - e.g. Elbow j.  Pivot Joint - Has a vertical axis - The movement is only rotation - e.g. atlanto- axial j. - superior& inferior radio- ulnar js. Biaxial Joints 1- Condyloid joint 2-Saddle joint  Condyloid joint - biconcave surface articulate with biconvex one - movements are; flexion- extension, abduction- adduction and rotation - e.g. metacarpo- phalangeal js.  Ellipsoid joint -A type of condyloid joint but no rotation allowed - e.g. Wrist joint  Saddle joint - concavo- convex surface in one bone fits in convexo- concave surface in the other - e.g. carpo- metacarpal joint of Polyaxial Joint (Ball& socket) 1- Shoulder joint 2- Hip joint  e.g. hip joint -movements are free and in all directions - Articular surface are hemispherical (ball) fits into cup shaped surface (socket) Thank You