Tissue Types

II. Neural Tissue Two Types of Cells: 1)Neurons: Longest cells in the body Highly branched into many short DENDRITES- that receive information from the environment and long AXONS that carry or relay information to other nerve cells. At the end of the axon is an intercellular junction called a SYNAPSE The cell body or SOMA contains the nucleus.

Neural Tissue 1)Neuron (continued) Function: –Carries impulses from one part of the body to another rand to the brain –Makes up the brain and spinal cord

Neuron

Neural Tissue 2)Neuroglia Four different types support and protect the NEURONS by Surrounding them Lining the spinal chord and brain chambers Providing a chemical barrier Phagocytizing disease causing agents in the nervous system.

IV. Muscle Tissue Tissue specialized for contraction 1.STRAITED VOLUNTARY MUSCLE SKELTAL MUSCLE –STRUCTURE: Fibers have a band-like appearance created by the protein filaments of actin and myosin Cells are large, long and multinucleated Separate cells are hard to see Is held together by MUSCLE FASCIA –FUNCTION: Moves bones and other structures VOLUNTARILY when stimulated by nerves Has the ability to respond to stimuli has “Irritability” –LOCATION: arms, legs, any other muscle that you have control over.

2. NON STRIATED INVOLUNTARY Structure: –Fibers do not have a band like appearance. –Are not connected to bone –Cells have a single nucleus –Individual cells are visible Function: –May contract on their own or be stimulated by the involuntary nervous system. Location: –In the walls of blood vessels –In the iris of the eye –In the gastrointestinal tract

3) STRIATED INVOLUNTARY MUSCLE –CARDIAC MUSCLE Structure: actin and myocin give the cells a striped (striated) appearance. –muscle cells are called CARDIOCYTES and are a branched “network” of interconnected cells. –Cells are multinucleated –Individual cells are hard to see –Are not connected to bone. Function: –Internal regulator cells “pacemaker cells” causes rhythmic contractions without stimulation that serve to circulate blood through the body Location: ONLY IN THE HEART

Membranes At the tissue level (basement membrane) Form a barrier Four Types ( are a combination of epithelial and connective tissue) –1. Mucous –2. Serous –3. Cutaneous –4. Synovial

Mucous Membrane Structure: –Simple, stratified or transitional epithelium –May contain goblet cells: unicellular exocrine glands or multicellular exocrine glands Function: –Line cavities that communicate with the exterior environment e.g. digestive, respiratory, reproductive and urinary tract

Serous Membrane Structure: –Simple epithelium –Loose connective tissue –Very thin and tightly connected to the body wall and organs the cover. –Has parietal and visceral portions: Parietal: line the outer wall of the internal chamber Visceral: covers the organs within the body cavity

Serous Membrane (cont) A transudate or serous fluid covers the parietal and visceral surfaces and minimizes friction between the opposing surfaces. Function: –To reduce friction between the body wall and internal organs A) Pleura- lines the pleural cavity and covers lungs B) Peritoneum- lines the peritoneal cavity and covers the enclosed organs. C) Pericardium- lines the pericardial cavity and covers the heart. (Pleurisy, Pericarditis, Peritonitis)

Cutaneous Membrane The skin Structure: –Stratified squamous epithelium –Underlying connective tissues –Adipose, dense irregular, connective –And accessory organs (glands) –Thick, relatively waterproof and usually dry

Synovial Membranes Structure: –Loose connective tissue –An incomplete epithelium of squamous or cuboidal cells There is no basement membrane Gaps exist between adjacent cells Function: –Surrounds joints –Regulates the production and composition of SYNOVIAL FLUID which fills the joint cavity and… Prevents direct contact of bones Prevents abrasion and damage by impact to the ends of bones Allows for smooth movement.