the differences between epithelial tissue, connective tissue, muscular tissue and nervous tissue?

Answer 1

Hello,

-The epithelial tissue or epithelium in dermatology is a tissue composed of a layer of cells. In humans, it is one of four primary body tissues. Epithelium lines both the outside (skin) and the inside cavities and lumen of bodies. The outermost layer of our skin is composed of dead stratified squamous epithelial cells, as are the mucous membranes lining the inside of mouths and body cavities. Other epithelial cells line the insides of the lungs, the gastrointestinal tract, the reproductive and urinary tracts, and make up the exocrine and endocrine glands.

Functions of epithelial cells include secretion, absorption, protection, transcellular transport, sensation detection, and selective permeability. Endothelium (the inner lining of blood vessels) is a specialized form of epithelium.


-Connective tissue: is one of the four types of tissue in traditional classifications (the others being epithelial, muscle, and nervous tissue.) It is largely a category of exclusion rather than one with a precise definition, but all or most tissues in this category are similarly:
Involved in structure and support.
Derived from mesoderm (there are exceptions).
Characterized largely by the traits of non-living tissue.
Blood, cartilage, and bone are usually considered connective tissue, but because they differ so substantially from the other tissues in this class, the phrase "connective tissue proper" is commonly used to exclude those three. There is also variation in the classification of embryonic connective tissues; on this page they will be treated as a third and separate category. Also, labrums, facia, tendons, & ligaments are connective tissues.


Muscular tissue: provides for all body movement. Contracting muscles cause body parts to move. The three types of muscle tissue are skeletal, smooth, and cardiac. Skeletal Muscle Tissue Skeletal (voluntary) muscle fiber is striated, or striped, and is under the control of the individual's will (fig. 1-9). For this reason, it is often called “voluntary” muscle tissue. Skeletal muscle tissues are usually attached to bones. When muscle fibers are stimulated by an action of a nerve fiber, the fibers contract and relax. This interaction between muscle and nervous fibers produces movement

Smooth Muscle Tissue These muscle fibers are smooth, or nonstriated, and are not under the control of the individual's will . For this reason, this type of muscle tissue is called “involuntary.” Smooth muscle tissue is found in the walls of hollow organs, such as the stomach, intestines, blood vessels, and urinary bladder. Smooth muscle tissues are responsible for the movement of food through the digestive system, constricting blood vessels, and emptying the bladder.

General
All living cells have the ability to react to stimuli. Nervous tissue is specialised to react to stimuli and to conduct impulses to various organs in the body which bring about a response to the stimulus. Nerve tissue (as in the brain, spinal cord and peripheral nerves that branch throughout the body) are all made up of specialised nerve cells called neurons. Neurons are easily stimulated and transmit impulses very rapidly. A nerve is made up of many nerve cell fibres (neurons) bound together by connective tissue. A sheath of dense connective tissue, the epineurium surrounds the nerve. This sheath penetrates the nerve to form the perineurium which surrounds bundles of nerve fibres. blood vessels of various sizes can be seen in the epineurium. The endoneurium, which consists of a thin layer of loose connective tissue, surrounds the individual nerve fibres.

Although the system forms a unit it can be divided into the following parts: the central nervous system (CNS) which consists of the brain and spinal cord, the nervous system consists of the nerves outside the CNS which connect the brain and spinal cord to the organs and muscles of the body and the automatic or involuntary nervous system consists of nerve centres and fibres inside as well as outside the central nervous system.

There are three main types of neurons, which are classified according their function: Those that conduct impulses from the sensory organs to the central nervous system (brain and spinal cord) are called sensory (or afferent) neurons; those that conduct impulses from the central nervous system to the effector organs (such as muscles and glands) are called motor (or efferent) neurons. Interneurons (also known as connector neurons or association neurons) are those that connect sensory neurons to motor neurons.

Structure of a Motor Neuron
A motor neuron has many processes (cytoplasmic extensions), called dendtrites, which enter a large, grey cell body at one end. A single process, the axon, leaves at the other end, extending towards the dendrites of the next neuron or to form a motor endplate in a muscle. Dendrites are usually short and divided while the axons are very long and does not branched freely. The impulses are transmitted through the motor neuron in one direction, i.e. into the cell body by the dendrites and away from the cell body by the axon . The cell body is enclosed by a cell (plasma) membrane and has a central nucleus. Granules, called Nissl, bodies are found in the cytoplasm of the cell body. Within the cell body, extremely fine neurofibrils extend from the dendrites into the axon. The axon is surrounded by the myelin sheath, which forms a whitish, non-cellular, fatty layer around the axon. Outside the myelin sheath is a cellular layer called the neurilemma or sheath of Schwann cells. The myelin sheath together with the neurilemma is also known as the medullary sheath. This medullary sheath is interrupted at intervals by the nodes of Ranvier.


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Answer 2

Connective Tissue Vs Epithelial Tissue

Answer 3

Epithelial And Connective Tissue

Answer 4

This Site Might Help You.

RE:
the differences between epithelial tissue, connective tissue, muscular tissue and nervous tissue?

Answer 5

The most significant difference between tissue types is what is happening BETWEEN the cells (i.e. the extracellular matrix and cell-cell interactions).

Answer 6

thanx people