Muscle Nerve Endings (1) PDF

 -Classification of Muscular tissue: It is classified according to ‫شكل العضلة‬ Morphology Function Striated muscles Non- striated muscles Voluntary as s...

 -Classification of Muscular tissue: It is classified according to ‫شكل العضلة‬ Morphology Function Striated muscles Non- striated muscles Voluntary as striated Involuntary as cardiac skeletal muscles. and smooth muscles. (Skeletal and Cardiac). (Smooth muscles). --------------------------------------------------------------------------------------------------------------------- Skeletal muscle: 1-The whole muscle is covered by a C.T. covering, the epimysium. 2. Consists of parallel skeletal muscle fibers, arranged in bundles, separated by C.T. septa, the perimysium. 3-The individual fibers (muscle cells) are separated by C.T. called endomysium. --------------------------------------------------------------------------------------------------------------------- Skeletal Muscle Fibers in Microscope (L.M. Picture) - Cylindrical in shape. - Non-branched. - Multinucleated: nuclei are multiple and are peripherally located. -Cytoplasm (sarcoplasm) is acidophilic and shows clear transverse striations. ‫الصفحه ده عبارة عن مراجعة علي خدناه السنة الي فاتت مفهوش حاجة جديدة‬ ---------------------------------------------------------------------------------------------------------------------  Afferent sensory NERVE ENDINGS IN MUSCULAR TISSUE Efferent motor - Sensory nerve endings: 1-Simple spiral terminations of nonmyelinated nerves around the 2-muscle fiber. 3-Muscle spindles (neuromuscular spindles). 4-Tendon spindles. 5-Pacinian corpuscles. --------------------------------------------------------------------------------------------------------------------- ‫ لحد لما يروح لاللياف العضلية بيتفرع وبيبقي‬Myelinated ‫النيرف بيبقي‬ Muscle Spindles (Neuromuscular Spindles) Unmyelinated 1- Site: They are present in between the skeletal muscle fibers and are numerous in the small muscles that need fine control (e.g.small muscles of the hand). 2- Shape & structure:-Light microscope (LM): They are fusiform bodies (1-5 mm long & 0.2 mm wide) consist of: Capsule: Thin and made of C.T. cells and fibers. Preaxial (subcapsular) lymphatic space: contains tissue fluids, nerve fibers and 2-12 intrafusal muscle fibers, to distinguish them from ordinary muscle fibers (extrafusal fibers. ‫ بيوجد مكان اسمه‬Capsule , ‫ جوه ال‬Connective tissue ‫ مكون من‬Capsule ‫ بيكون فيها من بره‬Fusiform ‫ بتكون علي شكل‬Muscle spindles intrafusal muscle fibers ‫ المكان ده بيبقي فيه الياف عضلية اسمها‬Preaxial (subcapsular) lymphatic space Intrafusal muscle fibres The nuclear bag type The nuclear chain type thick, long & few in number. The thinner, shorter and more numerous. central is non-contractile and They have a regular diameter with a row contains numerous nuclei. The of nuclei centrally located and arranged peripheral parts are striated and in a chain form. contractile.  Nerve fibres Motor nerve fibers Sensory nerve fibres -small, gamma nerve fibers penetrate the C.T. capsule, to terminate around the intrafusal -spiral on intrafusal muscle muscle fibers. fibers ‫بيلف علي االلياف العضلية الداخلية‬ Annulospiral endings Flower spray endings spirally around the central terminate mainly around parts of both kinds of the the peripheral ends of intrafusal muscle fibers.(The the nuclear chain muscle nuclear bag type and The fibers. nuclear chain type) ‫بيلف علي النوعين‬ --------------------------------------------------------------------------------------------------------------------- Function Spinal cord ‫ الي‬Impulses ‫بيبعت‬ Intrafusal muscle fibres stretch occur tension ‫اإلشارات‬Spinal cord ‫بعدين بيعكس ال‬ Reversed action‫عن طريق عملية ال‬ Intrafusal muscle fibres‫اشارات فبيبعت‬ Stretch on tendon contraction ln muscle fiber contraction ‫انها تعمل‬ Contraction on tendon relax on muscle fiber ‫ بتعمل‬firing impulses ‫بيحصل حاجة اسمها‬ stretch ‫ انها تعمل‬Intrafusal muscle fibres ‫إشارات لل‬ firing impulses contraction tension Tendon spindles (Golgi tendon organs) Site: They are found in tendons. They are formed of collaginous bundles, covered by a C.T. capsule. The sensory naked nerve fibers penetrate the capsule to end around the collagen bundles (similar to muscle Spindles). Tendon spindles are similar to muscle spindles but differ in: Intrafusal fibers are collaginous. It has no efferent (motor) supply. Motor impulses‫ ولكن ميستقبلش إشارات‬Sensory impulses ‫ بيبعت اشارارت عادي خالص‬Tendon spindles Tendon spindles (Golgi tendon organs) Intrafusal muscle fibres Connective tissue capsule Connective tissue capsule intrafusal collaginous fibers Intrafusal muscle fibres The nuclear bag type The nuclear chain type extrafusal collaginous fibers Intrafusal muscle fibres Sensory only Sensory and motor nerve endings Pacinian corpuscles 1- Sites: High Sensation ‫مناطق فيها‬ a- Subcutaneous tissue of fingertips, palm, sole and penis. b- Also in tendons, ligaments, joints, muscles, walls of blood vessels and pancreas ‫شكلها عامل زي البصله كده فيها‬ fibroblast‫طبقات كتير كل طبقة تتكون من‬ Sensory nerve ending‫وفي النص يوجد‬