Alka Singh 9th E

PRESENTATION BY ALKA SINGH9th EDigital LibraryTopic:- Tissuse(Biology)What is Tissue?Tissueis a cellular organizational level intermediate betweencellsand a completeorganism. A tissue is an ensemble of similar cells from the sameoriginthat together carry out a specific function.Organsare then formed by the functional grouping together of multiple tissues.The study of tissue is known ashistologyor, in connection with disease,histopathology. The classical tools for studying tissues are theparaffin blockin which tissue is embedded and then sectioned, thehistological stain, and theoptical microscope. In the last couple of decades, developments inelectron microscopy,immunofluorescence, and the use offrozen tissue sectionshave enhanced the detail that can be observed in tissues. With these tools, the classical appearances of tissues can be examined in health and disease, enabling considerable refinement of clinical diagnosis andprognosis.

Microscopic View of Human Lung Tissue

How Many Types of Tissue?Two Types Of Tissue :- Animal Tissue Plant TissueWhat is Animal Tissue?Animal tissues can be grouped into four basic types:connective,muscle,nervous, andepithelial. Multiple tissue types compose organs and body structures. While all animals can generally be considered to contain the four tissue types, the manifestation of these tissues can differ depending on the type of organism. For example, the origin of the cells comprising a particular tissue type may differ developmentally for different classifications of animals.Theepitheliumin all animals is derived from theectodermandendodermwith a small contribution from themesoderm, forming theendothelium, a specialized type of epithelium that composes thevasculature. By contrast, a trueepithelial tissueis present only in a single layer of cells held together via occluding junctions calledtight junctions, to create a selectively permeable barrier. This tissue covers all organismal surfaces that come in contact with the external environment such as theskin, the airways, and the digestive tract. It serves functions of protection, secretion, and absorption, and is separated from other tissues below by abasal lamina.

Animal Tissue

How Many Types of Animal Tissue?Four Types Of Tissue:- Connective Tissue Muscle Tissue Nervous Tissue Epithelial Tissue

Connective TissueConnective tissues are fibrous tissues. They are made up of cells separated by non-living material, which is calledextracellular matrix. Connective tissue gives shape to organs and holds them in place. Both blood and bone are examples of connective tissue. As the name implies, these support and bind other tissues. Unlike epithelial tissue, connective tissue typically has cells scattered throughout an extracellular matrix2.Connective Tissue

Functions of Connective Tissue

Storage of energyProtection of organsProvision of structural framework for the bodyConnection of body tissuesConnection of epithelial tissues to muscle tissues

Characteristics of Connective Tissue Cells are spread through an extracellular fluid.Ground substance - A clear, colorless, and viscous fluid containing glycosaminoglycans and proteoglycans to fix the bodywater and the collagen fibers in the intercellular spaces. Ground substance slows the spread of pathogens.Fibers. Not all types of CT are fibrous. Examples include adipose tissue and blood. Adipose tissue gives "mechanical cushioning" to our body, among other functions.[6][7]Although there is no dense collagen network in adipose tissue, groups of adipose cells are kept together by collagen fibers and collagen sheets in order to keep fat tissue under compression in place (for example, the sole of the foot). The matrix of blood is plasma.Both the ground substance and proteins (fibers) create the matrix for CT.

Disease of Connective Tissue

Aconnective tissue diseaseis any disease that has theconnective tissuesof the body as a target of pathology. Connective tissue is any type ofbiological tissuewith an extensiveextracellular matrixthat supports, binds together, and protectsorgans. These tissues form a framework, or matrix, for the body, and are composed of two major structural protein molecules:collagenandelastin. There are many different types of collagen protein in each of the body's tissues. Elastin has the capability of stretching and returning to its original lengthlike a spring or rubber band. Elastin is the major component of ligaments (tissues that attach bone to bone) and skin. In patients with connective tissue disease, it is common for collagen and elastin to become injured by inflammation. Many connective tissue diseases feature abnormal immune system activity with inflammation in tissues as a result of an immune system that is directed against one's own body tissues.Muscle TissueMuscle cellsform the active contractile tissue of the body known asmuscle tissueor muscular tissue. Muscle tissue functions to produce force and cause motion, either locomotion or movement within internal organs. Muscle tissue is separated into three distinct categories: visceral orsmooth muscle, which is found in the inner linings of organs;skeletal muscle, in which is found attached to bone providing for gross movement; andcardiac musclewhich is found in theheart, allowing it to contract and pump blood throughout an organism.Muscle Tissue

Types of Muscle

Skeletal muscleor "voluntary muscle" is anchored bytendons(or byaponeurosesat a few places) toboneand is used to effectskeletalmovement such aslocomotionand in maintaining posture. Though this postural control is generally maintained as an unconscious reflex, the muscles responsible react to conscious control like non-postural muscles. An average adult male is made up of 42% of skeletal muscle and an average adult female is made up of 36% (as a percentage of body mass).[2]It also has striations unlike smooth muscle.Smooth muscleor "involuntary muscle" is found within the walls of organs and structures such as theesophagus,stomach,intestines,bronchi,uterus,urethra,bladder,blood vessels, and thearrector piliin the skin (in which it controls erection of body hair). Unlike skeletal muscle, smooth muscle is not under conscious control.Invertebrates, there is a third muscle tissue recognized:Cardiac muscleis also an "involuntary muscle" but is more akin in structure to skeletal muscle, and is found only in the heart.Cardiac and skeletal muscles are "striated" in that they containsarcomeresand are packed into highly regular arrangements of bundles; smooth muscle has neither. While skeletal muscles are arranged in regular, parallel bundles, cardiac muscle connects at branching, irregular angles (called intercalated discs). Striated muscle contracts and relaxes in short, intense bursts, whereas smooth muscle sustains longer or even near-permanent contractions.

Nervous Tissue

Cells comprising thecentral nervous systemandperipheral nervous systemare classified as neural tissue. In the central nervous system, neural tissue forms thebrainandspinal cordand, in the peripheral nervous system forms thecranial nervesandspinal nerves, inclusive of themotor neurons. Nervous tissue functions to transmit messages in form of impulse.

Nervous Tissue

Neuronal CommunicationNerve cells are functionally made to each other at a junction known as asynapse, where the terminal branches of an axon and the dendrites of another neuron lie close to each other but normally without direct contact. Information is transmitted across the gap by chemical secretions calledneurotransmitters. It causes activation in the post-synaptic cell. All cells possess the ability to respond to stimuli. The messages carried by the nervous system are electrical signals called impulses.Classification of NeuronsNeurons are classified both structurally and functionally.Structural Classification Neurons are grouped structurally according to the number of processes extending from their cell body. Three major neuron groups make up this classification: multipolar (polar = end, pole), bipolar and unipolar neurons.Multipolar Neurons (3+ processes)These are the most common neuron type in humans (more than 99% of neurons belong to this class) and the major neuron type in the CNSBipolar NeuronsBipolar neurons are spindle-shaped, with a dendrite at one end and an axon's at the other. An example can be found in the light-sensitive retina of the eye. They also rapidly grow.Unipolar NeuronsSensory neurons have only a single process or fibre which divides close to the cell body into two main branches (axon and dendrite)This type of nerve fibre is present only in embryonic stage in human beings.Cancer

Tumorsin nervous tissue include:Gliomas(glial celltumors)Gliomatosis cerebri,Oligoastrocytoma,Choroid plexus papilloma,Ependymoma,Astrocytoma(Pilocytic astrocytoma,Glioblastoma multiforme),Dysembryoplastic neuroepithelial tumour,Oligodendroglioma,Medulloblastoma,Primitive neuroectodermal tumorNeuroepitheliomatoustumorsGanglioneuroma,Neuroblastoma,Atypical teratoid rhabdoid tumor,Retinoblastoma,EsthesioneuroblastomaNerve sheath tumorsNeurofibroma(Neurofibrosarcoma,Neurofibromatosis),Schwannoma,Neurinoma,Acoustic neuroma,NeuromaEpithelial Tissue

The epithelial tissues are formed by cells that cover the organ surfaces such as the surface of theskin, theairways, thereproductive tract, and the inner lining of thedigestive tract. The cells comprising an epithelial layer are linked via semi-permeable,tight junctions; hence, this tissue provides a barrier between the external environment and the organ it covers. In addition to this protective function, epithelial tissue may also be specialized to function insecretionandabsorption. Epithelial tissue helps to protect organisms from microorganisms, injury, and fluid loss.Epithelial Tissue

Functionsthe cell of the body surface form the outer layer of skin.inside the body,epithelial cells forms lining of mouth & alimentary canal & protect these organ.epithelial tissues help in absorption of water & nutrient.epithelial tissues help in elimination of waste product.The Different Types Of Epithelial TissuesSquamous epithelium,Cuboidal epithelium,Columnar epithelium,Glandular epithelium,Ciliated epithelium.

Plant Tissues

Examples of tissue in othermulticellularorganisms arevascular tissueinplants, such asxylemandphloem. Plant tissues are categorized broadly into three tissue systems: theepidermis, theground tissue, and thevascular tissue. Together they are often referred to asbiomass.Epidermis- Cells forming the outer surface of theleavesand of the young plant body.Vascular tissue- The primary components of vascular tissue are thexylemandphloem. These transport fluid and nutrients internally.Ground tissue- Ground tissue is lessdifferentiatedthan other tissues. Ground tissue manufactures nutrients byphotosynthesisand stores reserve nutrients.

Plant Tissue

Plant Tissues Can Also Be Divided Differently Into Two Types Meristematic Tissues Permanent Tissues

31Meristematic Tissues

Meristematic tissue consists of actively dividing cells, and leads to increase in length and thickness of the plant. The primary growth of a plant occurs only in certain, specific regions, such as in the tips of stems or roots. It is in these regions that meristematic tissue is present. Cells in these tissues are roughly spherical or polyhedral, to rectangular in shape, and have thin cell walls. New cells produced bymeristemare initially those of meristem itself, but as the new cells grow and mature, their characteristics slowly change and they become differentiated as components of the region of occurrence of meristimatic tissues, they are classified as:a)ApicalMeristem- It is present at the growing tips of stems and roots and increases the length of the stem and root. They form growing parts at the apices of roots and stems and are responsible for increase in length,also called primary growth.Thismeristemis responsible for the linear growth of an organ.b)LateralMeristem- This meristem consist of cells which mainly divide in one plane and cause the organ to increase in diameter and growth. LateralMeristemusually occurs beneath the bark of the tree in the form of Cork Cambium and in vascular bundles of dicots in the form ofvascular cambium. The activity of this cambium results in the formation of secondary growth.c)IntercalaryMeristem- Thismeristemis located in between permanent tissues. It is usually present at the base of node, inter node and on leaf base. They are responsible for growth in length of the plant.

Permanent Tissues

The meristematic tissues that take up a specific role lose the ability to divide. This process of taking up a permanent shape, size and a function is calledcellular differentiation. Cells of meristematic tissue differentiate to form different types of permanent tissue. There are 3 types of permanent tissues:1. simple permanent tissues2. complex permanent tissues3. special or secretory tissues (glandular).