Slide 1: T I S S U E S Slide 2: A group of cells similar in structure that work together to perform a particular function forms a tissue.All cells of a Tissue have common origin. For Example ,human nervous tissue (present in brain,spinal cord and nerves) has nerve cells or neurons which are basically same structurally and functionally.
All nerve cells basically has a cell body or soma which has two types of branches namely Dendrites (to receive messages) and an axon (to convey messages away from the soma). TISSUES Slide 3: Most of the tissues of the plants are supportive as they do not require much energy,thus they provide them with structural strength.
Most of the plant tissues are non-living;they do not have living protoplasm.
There are some tissues in plants which divide throughout their life.
Various plant tissues can be classified as Meristematic and permanent tissues. Animal Tissue Plant Tissue As animals are heterotrophic they require more energy than plants.
Most of the animal tissues are living as they do have living protoplasm.
Growth in animals is uniform.There is no demarcation between dividing and non dividing regions. Types of Tissues Slide 4: PLANT TISSUES Meristematic Tissue
Xylem : Meristems divide continuously and help in increasing the length and girth of the plant.
Location : Meristematic tissues are growth tissues and are found in those regions of the plants that grow.
Structure : Meristematic cells may be spherical,oval,polygonal or rectangular in shape.
Function : Their main function is to continuously form a number of new cells.
According to their position in plants they can be classified as -
Intercalary MERISTEMATIC TISSUES Slide 6: APICAL Location: These are situated at the growing tip of stems and roots ,i.e. at shoot apex and root apex.
They are also found at apices of leaves.
Function : It brings about the elongation of root and stem.
It results in increase in the height of the plant (primary growth). Slide 7: Location : These are found beneath the bark and in vascular bundles of dicot roots and stems.
They occur in thin layers.
Cambium is the region which is responsible for growth in thickness.
Function : It causes the organ to increase in diameter and girth (secondary growth). LATERAL Slide 8: Location : they are located at the base of leaves or internodes.eg. Stems of grasses and other monocots.
Function :It produces an increase in length of organ. INTERCALARY Slide 9: These tissues are derived from Meristematic tissues but their cells have lost the power of division and have attained their definite forms.
They can be classified into two types – simple and complex.
Simple permanent tissues are composed of cells which are structurally and functionally similar.
They can be classified as parenchyma,collenchyma and sclerenchyma.
Complex permanent tissues consist of more than one type of cells.All these cells coordinate to perform a common function.
They can be classified as xylem and phloem. PERMANENT TISSUES Slide 10: Nature : Parenchyma cells forms the bulk of plant body.They are living and possess the power of their division .
Structure : They are rounded or isodiametric i.e. equally expanded on all sides.
Location : The parenchyma is widely distributed in plant body such as stem,roots,leaves flowers and fruits.The parenchyma is found in the soft parts of the plant such as cortex of roots,ground tissues in stems and mesophyll of leaves.
The main function is to store and assimilate food.Parenchyma serves as food storage tissue.
It serves as a packing tissue to fill the spaces between other tissues and maintain the shape and firmness of the plant due to its turgid cells. PARENCHYMA COLLENCHYMA : COLLENCHYMA Nature :Collenchyma tissue also consists of living cells cells.
It shows many features of parenchyma but is characterized by the deposition of extra cellulose at the corners of the cells.
Structure :These cells are elongated in shape.
They often contain a few chloroplasts.
Location :The cells of Collenchyma are located
below the epidermis of dicotyledon stem and petiole.
The cells also occur in midribs of dicot leaves.
It provides mechanical support and elasticity
It provides easy bending in various parts of a
plant without actually breaking it. SCLERENCHYMA : SCLERENCHYMA Nature :Sclerenchyma cells are dead cells and they are devoid of protoplasm.
The cell walls of Sclerenchyma are composed of lignin.
Location : They are found in stems,roots,veins of leaves ,hard coverings of seeds and nuts.
The sclerenchyma is mainly mechanical and protective in function.
It gives strength,rigidity,flexibility and elasticity to the plant body and thus enables it to withstand various strains. Slide 13: Nature : Xylem is a vascular and mechanical tissue.It is a conducting tissue.
The main function of xylem is to carry water and mineral salts upward from the root to different parts of shoots .
Since walls of tracheids,vessels and sclerenchyma of xylem are lignified they give mechanical strength to the plant body. XYLEM Slide 14: Nature : Like xylem ,it contains tubes but has no mechanical function.
Phloem is composed of foll. Four elements or cells.
Function : Phloem transport photosynthetically prepared food materials from the leaves to the storage organs and later from storage organs to the growing regions of the plant body. PHLOEM Slide 15: The animal tissues can be classified as – ANIMAL TISSUES Slide 16: Nature: Epithelial Tissue is the simplest tissue.It is the
protective tissue of the animal body.The cells of this tissue
are tightly packed and it forms a continuous sheet.
Functions : The cells of the body surface form the outer
layer of the skin .These cells protect the underlying cells
from drying,injury and chemical effects.Epithelial tissues
help in absorption of water and nutrients.
Ciliated EPITHELIAL TISSUE Slide 17: SQUAMOUS
Nature : It is made up of thin ,flat,irregular-shaped cells which fit together like floor tiles to form a compact tissue.
Occurrence : It forms the delicate lining of cavities (mouth,oesophagus,nose,pericardium,alveoli etc.) and of blood vessels and of covering of tongue and skin.
Function : it protects the underlying parts of the body from mechanical injury,entry of germs,chemicals and drying.It also forms a selectively permeable surface through which filtration occurs. Slide 18: CUBOIDAL
Nature : It consists of cube like cells which are square in section but the free surface appear hexagonal .
Occurrence : It is found in Kidney tubules.thyroid vesicles and in glands(e.g.salivary glands,sweat glands and exocrine pancreas).It forms germinal epithelium of gonads.
Functions : It helps in absorption ,excretion and secretion.It also provides mechanical support. Slide 19: COLUMNARNature : it consists of cells which are taller than broad(I.e. pillar like).The nuclei are towards the base and sometimes the free ends of cells has a border containing microvilli.
Occurrence : it forms the lining of stomach,small intestine and colon ,forming mucous membrane.It also forms lining of gall bladder and oviduct.
Functions : Its main function includes absorption and secretion . Slide 20: CILIATED
Nature : Certain cuboidal or columnar cells have a free border which bear thread like cytoplasmic outgrowths called cilia.such cells form the ciliated epithelium.
Occurrence : It is found in sperm ducts.The ciliated columnar epithelium lines the trachea ,bronchi ,kidney tubules and oviducts.
Function : The rhythmic concerted beating of the cilia moves the solid particles in one direction through the ducts. GLANDULAR
The columnar epithelium is often modified to form glands which secrete chemicals. Slide 21: MUSCULAR TISSUE
The muscle Tissue or the muscles form the contractile tissue and are made of muscle cells.Muscle cells are elongated and large sized so they are also called muscle fibres. The movement of the body or the limbs are brought about by the contraction and the relaxation of the contractile proteins which are present in muscle cells.The movements of the internal organs such as heart and the alimentary canal are all caused by muscle tissues .
There are three types of muscle tissues –
Cardiac Muscles Slide 22: STRIATED
Nature : These muscles are also known as striped,skeletal or voluntary muscles.the striated muscle cells are long or elongated .non-tapering and cylindrical,unbranched.These cells have a number of nuclei.Each muscle cell is enclosed in a thin but distinct plasma membrane called sarcolemna.
Occurrence : Striated muscles occur in muscles of limbs.Striated muscles present in tongue ,pharynx,diaphragm and upper part of oesophagus are called visceral striated muscles.
Striated muscles are powerful and undergo rapid contraction.these muscles can be tired and need rest.
They provide the force for locomotion and all other voluntary activities. Slide 23: SMOOTH MUSCLES
Nature:These are also known as unsriated,visceral or involuntary muscles.These are held together by loose connective tissue.Each muscle cell is enclosed in a plasma membrane.
Occurrence:They are found in the walls of the hollow visceral organs,except that of the heart.
Functions : They do not work according to our will so they are also called involuntary muscles.Movement of food in the alimentary canal,opening and closing of tubes are involuntary muscles. Slide 24: CARDIAC
Nature : Cardiac muscles show characteristics of both smooth and striated muscles.They are composed of branched fibres ,the branches join to form a network.
Occurrence : The cardiac muscles occur in the heart (i.e. in the walls of the heart)
Cardiac muscles contract and relax rapidly,rhythmically and tirelessly throughout our life.
The contraction and relaxation of the heart muscles help to pump and distribute blood to various parts of the body. Slide 25: CONNECTIVE TISSUE
The connective tissue is specialized to connect and anchor various body organs.As such it can connect bones to each other,muscles to bones,bind tissues and give support to various parts of body by forming packing around organs so that they do not get displaced by body movements.
Thus its main function is binding,supporting and packing together different organs of the body.
Types of connective Tissue –
Areolar connective tissue
Dense regular connective tissue
Fluid connective tissue Slide 26: AREOLAR LOOSE CONNECTIVE TISSUE
Nature : It is a loose and cellular connective tissue.Its matrix consists of two kinds of fibres-
White collagen fibres(which changes into gelatin on boiling in water)
Yellow elastic fibres or elastin
Occurrence : It is the simplest and most widely distributed connective tissue.It joins skins to muscles ,fills spaces inside the organs,is found around muscles,blood vessels and nerves.
It helps in repairs of tissues.
Helps in combating foreign toxins.
It fixes skin to underlying muscles. Slide 27: Tendons
Tendons are cord like strong,elastic structures that join skeletal muscles to bones.
It is a white fibrous tissue.
It has great strength but its flexibility is limited. DENSE REGULAR CONNECTIVE TISSUE
It is a fibrous connective tissue.it is characterized by ordered and densely packed collection of fibres and cells.Dense connective regular Tissue is the principal component of tendons and ligaments. Ligaments
They are elastic structures which join/connect bones to bones.
It is made up of white as well as yellow fibres.
A ligament is highly elastic and has great strength but contains very little matrix. Slide 28: ADIPOSE TISSUE
Nature : It Is basically an aggregation of fat cells or adipocytes.Each fat cell is rounded or oval and contains a large droplet of fat that almost fills it.The aft cells are arranged into lobules separated by partitions of collagen and elastin fibres.
Occurrence : The adipose tissue is abundant below the skin,between the internal organs and in yellow bone marrow.
It serves as a fat reservoir.
It provides shape to the limbs and body.
It acts an insulator.Being a poor conductor of heat it reduces heat loss from body,i.e. it regulates body temperature. Slide 29: Cartilage
It is a specialized connective tissue which is compact and less vascular.
It has widely spaced cells.
It is located in the foll body parts:ear pinna ,nose tip,epiglottis,intervertebral disks
It provides support and flexibility to the body parts. SKELETAL TISSUE
The skeletal or supporting tissue includes Cartilage and bone which forms the endoskeleton of the vertebrate body. Bone
It is very strong and non flexible tissue.
It is porous,highly vascular, hard , mineralized and rigid.
It provides shape and skeletal support to the body.
It protects viral organs such as brains,heart,lungs etc. Slide 30: Blood
Blood is a fluid connective tissue.The blood plasma does not contain protein fibres but contain cells called blood corpuscles.
These blood corpuscles are-RBC’s or erythrocytes,WBC’s or leucocytes and platelets.
Blood occurs in blood vessels called arteries,veins and capillaries.
It transports nutrients,hormones and vitamin to the tissues and transports excretory products from the tissues to the liver and kidney. Lymph
It is a colourless fluid that has filtered out of the blood capillaries.Since it is part of blood,its composition is similar to that of blood except that RBC's and some proteins are absent in it.
It transports the nutrients that may have filtered out of blood.
It brings CO2 and nitrogenous wastes from tissue fluid to blood.
Being loaded with WBC’s it protects the body against infection.It forms the defence immune system of the body. FLUID CONNECTIVE TISSUE
It links the different parts of the body and maintains a continuity in the body.it includes blood and lymph. Slide 31: NERVOUS TISSUE
Nature : A tissue which is specialized to transmit messages in our body is nervous tissue.Brain,spinal cord and nerves are all composed of nervous tissue.
Nervous tissue contains highly specialized unit cells called nerve cells or neurons.
Each neuron has foll three parts :
The cyton or cell body which contains a central nucleus and cytoplasm with characteristic deeply stained particles,called Nissl’s granules.
The dendrons which are short processes arising from the cyton and further branching into dendrites.
The axon is a single ,long cylindrical process of uniform diameter.It forms fine branches terminally.
The Dendrites receive pulses and the axon takes impulses away from the cell body. Slide 32: THANK YOU