Muscular and Nervous Tissue Lec 6 PDF

Muscular and nervous tissue lec 6 By Dr. shahad mansour MUSCULAR TISSUE  Muscles: are multi-cellular contractile units, Composed of muscle fibers supported by connective tissue. They are divided into three types: 1. Skeletal muscle 2. Smooth muscle 3. Cardiac muscle...

Muscular and nervous tissue lec 6 By Dr. shahad mansour MUSCULAR TISSUE  Muscles: are multi-cellular contractile units, Composed of muscle fibers supported by connective tissue. They are divided into three types: 1. Skeletal muscle 2. Smooth muscle 3. Cardiac muscle There are many similarities and differences between them in the structure, shape and function. 1. Skeletal muscle: 2. Smooth muscle: 3. Cardiac muscle: responsible for the Involuntary muscle Involuntary muscle movement of the Spindle shape of fiber Branches muscle fibers skeleton. Striated muscles Non-Striated muscles Voluntary muscle Single and Central One or two central Long and cylindrical nucleus nuclei fiber Have intercalated discs: Striated muscles Location: visceral organs cell junctions between the Multi-nucleated cells like stomach, urinary ends of adjacent muscle Location: Skeletal bladder, blood vessels. fibers muscles. Location: heart only. Nucleus Muscle fiber NERVOUS TISSUE The human nervous system is complex system in human body and is formed by network of more than 100 million nerve cells (neuron) Nervous system divided anatomically in to: Central nervous system (CNS) which include brain and spinal cord. Peripheral nervous system (PNS) which include nerve fibers and ganglia. 1. Neurons (nerve cells), which receive and transmit impulses. ❖ Consist of three parts: a. Cell body have central nucleus with nucleolus, cytoplasm, Nissl bodies, Golgi, endoplasmic reticulum b. Axon: single elongated process. c. Dendrites: Multiple elongated processes. d. Synapses: cell junctions between its axon and other cells to allow cell communication.  Neurons are classified according to its functions to: 1. Sensory neurons: Carry the signal from the body to the brain and spinal cord (input) such as touch, sound, or light 2. Motor neurons: Carry the signal away from the brain and spinal cord to cause everything from muscle contractions and glandular effects (output). 2. Interneurons: are communicating network between the sensory and motor neurons. 2. Glia cells: They are other type of cell found in nervous tissue which consider as supporting cells that occupy the inter- neuronal space. There are six types of glia cells, four of them are found in the CNS and two are found in the PNS.  Meninges The skull and the vertebral column protect the central nervous system. It is also encased in membranes of connective tissue called the meninges. There are three Meningeal layers: 1. Dura mater: the outer layer 2. Arachnoid: the medium layer 3. Pia mater: the inner layer