Introduction: The structural and functional unit of life is called cell. There are various size and shape of the cells found in our environment.
When same or different types of cells comes to form a group to perform a specific function is known as tissue.
It may be also defined as the group of similar or dissimilar cells ordinating to perform a specific function is known as tissue.
Study of tissues is called histology.
Two types of tissues:
Simple tissue: Group of similar structure and embryonic origin to perform a particular function is known as simple tissue.
Complex or compound tissue: Group of cells, which differ in their structure and embryonic origin but perform a particular function is known as complex tissue.
Plant and animal tissue:You have already know about the basic difference of plant and animal cell which further makes tissue in both plant and animals, different types of cells are present in both plant and animals.
Difference between animal tissues and plant tissue:
Plant tissues: On the basis of nature and these are two types:-
A. Simple tissue B. Compound tissue
A. Simple tissue: Formed by similar cells, structure and functions.
On the basis of power of division simple tissue are of two types:-
(a) Meristematic tissue (b) Permanent tissue
(a) Meristematic tissue or Growing tissue: Capable of division in which zone of the plant, they are found called meristem.
Characteristics:-
Cells are thin walled, living, isodiametric in this tissue.
Oval, polygonal or rounded shaped.
Localised in certain region, division through life, cell wall is made of cellulose.
Cell are tightly packed, very active.
Types of meristem:On the basis of location
(i) Apical meristem: Found at apices of root, stem and branches for longitudinal growth called primary growth.
(ii) Lateral meristem (cambium): Found at lateral sides of stem and root,i.e increase the girth of plants.
(iii) Intercalary meristem: Found at base of leaves or internodes, primary growth of plants.
(b) Permanent tissue:-
Cells are thick or thin walled living or dead and mature.
Rounded, oval, polygonal and elongated.
Incapable of division, specialised for a specific function.
Two types of permanent tissue: On the basis of nature of cells
(A) Simple permanent tissue: Cells are similar in structure, origin and function.
On the nature of cell these are of three types:-
(a) Parenchyma: usually living cells, oval, round and polygonal,thin walled loosely packed.
Found at soft organs, lower plants, fruit pulp etc.
Store and assimilate food provide mechanical support.
(b) Collenchyma: living cells, oval and circular thick at the corners have chloroplast provide flexibility.
Found at stem axis leaf stalk etc.
Provide elasticity,manufacture carbohydrates.
(c) Sclerenchyma: dead cells, long, narrow, walls are thick and have pits (oblique thin area in the cell walls).
Located at at heard covering of seed,jute etc.
Provide mechanical support.
Some modification of parenchyma:-
(i) Chlorenchyma: Developed chloroplast perform photosynthesis found in mesophyll of leaves.
(ii) Arenchyma:Air cavities present, provide buoyancy for floating.
(B) Complex or Compound permanent tissue:-Two or more than two types of cells perform same function.
(1) Xylem (wood): formed of four types of cells.
(i) Trachieds (ii) Xylem parenchyma (iii) Trachea or Vessels (iv) Xylem fibres.
Function: tracheids and vessels help in long distance conduction of water and minerals also help in mechanical support.
Xylem parenchyma is a living cell which help in storage food and help in lateral conduction of water and minerals,where as xylem fibres are dead and lignified. Sclerenchymal tissue cells provide mechanical strength.
(2) Phloem (bast): formed by four types of cells
(i)Sieve tube cells (ii) Phloem parenchyma (iii) Companion cells (iv) Phloem fibre.
Functions: Mature seive tube cells are dead placed end to end, end walls are porous,i.e they are called seive plates.
Companion cells are living parenchymal cells, control the function of dead seive tube cells.
Phloem parenchyma are living cells, help in storage and short distance conduction of food.
Phloem fibres are dead cells provide mechanical support.
Phloem is chief food conducting tissues for both upward and downward direction .
Classification of plant tissue:-
Meristematic tissue on origin basis:
1. Primary Meristem 2. Secondary Meristem
Meristematic tissue on position basis:
1. Apical 2. Intercalary 3. Lateral
Permanent tissue:
(A) Simple permanent tissue:
1. Parenchyma 2. Collenchyma 3. Sclerenchyma.
(B) Compound permanent tissue:
1. Xylem 2. Phloem
Animal tissue:-
On the basis of their function, animal tissue are of four types:-
1. Epithelial tissues 2. Connective tissues
3. Muscular tissues 4. Nervous tissues
1. Epithelial tissue: Cover and protect body organ.e.g skin
2. Muscular tissue: Contractile so move the body parts.e.g movement of lungs
3. Connective tissue: Bind and transports the material in the body organs. e.g lymph, blood, cartilage and bone.
4. Nervous tissue: Conduction of nerve impulse.
Types of animal tissues:-
1. Epithelial or Covering or Protective tissues:-
Covers all the organs of body externally, lines the hollow organs internally.
These are arranged in one or more layers, there is no intercellular space and very small amount of matrix between them so form a continuous sheet.
Covering and protective tissue, barriers between different body organs.
Two types of epithelial tissue:
(I) Simple epithelial tissue: unilaminar, found in areas less wear and tear.
Further different types of simple epithelial tissue :
(i) Squamous epithelial tissue: discoidal, thin, flat and polygonal fit like tiles in a floor.
Nuclei are flat and oval.
Function: found in alveoli for exchange of gases etc.
(ii) Cuboidal epithelial tissue: cells are polygonal and cuboidal.
Nuclei are rounded and centric.
Function: in retina of eye, in gonads ( testis and ovary ) produce sperm and ova respectively.
Cells of microvilli for absorption of useful materials.
(iii) Columnar epithelial tissue: pillar like, oval shaped,found in basal part of cells.
Function: in fallopian tube of female, hair like cilia for movement of ovum/ zygote.
Line ducts of mammary glands.
(II) Compound epithelial tissue: multilaminar
Further two types of compound epithelial tissue:
(i) Stratified epithelial tissues: less stretchable
Function:protects from entry of germs,loss of water,mechanical wear and tear,formed epidermis of skin.
(ii) Transitional epithelial tissue stretchable
Function: help in dilution of urinary bladder to store urine, found in uterus and urinary bladder.
Modification of columnar epithelial tissue:
(i) Glandular columnar epithelial tissue: develop unicellular glands are called goblet cells,secrete mucus,found in mucous membrane of stomach, lubricates the food.
(ii) Ciliated columnar epithelial tissue: have hair like cilia found in trachea and bronchi to expel any dust or food or pollutant particle.
2.Connective tissue: loosely- arrange, large sized,intercellular spaces filled with matrix (protein fibres).
Binding and packing tissue between internal organ of body,protection,mechanical support etc.
Three types of connective tissue:
(i) Connective tissue proper: (soft matrix)
Further divided into four types:
(a) Areolar connective tissue: matrix is transparent, and sticky,loosely arrange between two fibre with spaces airoli in between fibres with spaces (areolae) in between fibres, also called loose connective tissue.
This two fibres are
(1) White fibres
(2) Yellow fibres
Function: binding tissue between the organs, packing tissue, repair the tissues.
(b) White fibre connective tissue (tendon): matrix is with large number of bundles of thick white fibres, highly strong but less elastic.
Function: join muscles to bone.
(c) Yellow fibrous connective tissue ( ligament):
Matrix with yellow fibres, highly elastic.
Function: joins bone to bone.
(d) Adipose connective tissue:oval and rounded fat cell matrix,lies between internalorgans and beneath the skin of body.
Function:Shock absorber,fat reservior etc.
(ii) Skeletal connective tissue: dense and mineralised matrix, forms endoskeleton, protect vital organ,provide a framework of body.
Two types of skeletal connective tissues:
(a) Cartilage: basic structure of hyaline cartilage, hard but flexible, solid matrix external covered by white fibrous tissue called perichondrium,unidirectional growth.
Function: found in ear, trachea and bronchi, provides mechanical support and shock absorber.
(b) Bone or osseous tissue: matrix is formed both organic and inorganic matter minerals provide hardness,strongest and inflexible.
Have bone marrow cavity, growth is bi-directional.
Function form major part of endoskeleton of bony fishes.
Supporting framework and safe to the body and provide surface for attachment of muscle to help in locomotion.
Act as a store house of calcium and phosphorus and protect vital organs.
(iii) Vascular tissue:fluidy and fibre free matrix with free floating cells. Their matrix is not secreted by the cells.
There are two types of vascular tissue:
(a) Blood and (b) Lymph
(a) Blood: Red vascular connective tissue, opaque, alkaline (pH 7.4) and bright red (when oxygenated) form 7 - 8% of body weight.
It is form of two components
(1) plasma (2) Blood corpuscles.
(1) Plasma: light yellow colour liquid part 55 to 60% of blood its component are 90 to 92% water 1 to 2% minerals and 6 to 8% proteins.
Sodium chloride is the main salt and albumin, globulins etc are main protein.
Function:transportation of nutrients, waste, gases, hormones etc.
Are bullet water balance,pH and body temperature.
(2) Blood corpuscles: cells floating in the blood plasma.
These are of three types:-
(i) Erythrocytes (ii) Leukocytes and (iii) Platelets.
(i) Erythrocytes or red blood corpuscles / cells RBCs.: Human RBC are biconcave, circular and denucleated when mature. Lifespan 115 to 120 days.
Hemoglobin of RBCs help in transportation of O2 (97-98%) as well as CO2 (23%).
(ii) Leukocytes or white blood corpuscles (WBCs): amoeboid nucleated and white blood corpuscles larger in size, but less in number than RBCs. Life span 12 to 14 days.
WBCs are of two types on the basis of cytoplasmic granules:-
(a) Granulocytes: lobed necklace with cytoplasmic granules.
(b) Agranulocytes:non lobed nucleus and no cytoplasmic granules.
Granulocytes are of three types:- (i) Neutrophils (ii) Acidophils (esinophils) and (iii) Basophils.
Agranulocytes are of two types:- (i) Monocytes and (ii) Lymphocytes (or Immunocytes).
Function:-
(i) Neutrophils: chief phagocytic cells,known as soldier of the body.
(ii) Acidophils:act against allergy and parasitic infections, help in healing of wounds.
(iii) Basophils: in anticoagulation play important role.
(iv) Monocytes: natural scavenger remove damage and dead cells.
(v) Lymphocytes:provide immunity by secreting antibodies.
(iii) Blood platelets: smallest size, oval at injury these are help in clot formation for preventing excess bleeding.
(b) Lymph: white vascular connective tissue, present in lymph vessels,form tissue fluid.
Component:formed of two components plasma and corpuscles (especially lymphocytes), but differ from blood.
3. Muscular or contractile tissue: muscle cells (commonly called muscle fibres) two peculiar property i.e excitability, conductivity and contractability.( YouTube presence of contractile protein myosin and actin protein).
Muscles are highly elongated and contractile called muscle fibres, large number of contractile protein threads called myofibrils, and contractile cytoplasm called sarcoplasm.
Function: help in various types of movement and locomotion.
It is of three types:-
(i) Striated muscular tissue
(ii) Smooth muscular tissue
(iii) Cardiac muscular tissue
(i) Striated muscular tissue: found in limbs, tongue, body wall etc.
Muscle fibres are arranged in bundles, called fasciculi.
Long cylindrical, unbranched, special covering called sarcolemma, multinucleated, nuclei are oval and peripheral in position.
Myofibril has alternating dark and light band, so they are called striated or stripped muscle fibres.
Dark band (A band ) has centralite Jones called h those where is its light band iPad has dark zone at its centre is called that line the space between two adjoining z lines is known as sarcomere.
(ii) Smooth muscular tissue:- In wall of visceral organs (example intestine, blood vessels, ureter etc) so called visceral muscles.
Arrange in layers, small sized,spindle shaped with pointed ends,covered with plasma membrane,uninucleate, nucleus is a spherical and centric in position, also called non-skeletal muscles.
Help in peristaltic (involuntary) movement of gut ureters and genital ducts to move food, urine and sex cells respectively.
(iii) Cardiac muscular tissue:- found in myocardium of the heart.
Cylindrical with light and dark bands more mitochondria and covered with sarcolemma Uninucleate and involuntary.
Rapid and rhythmic contraction throughout life help in pumping and distributing blood to various parts of the the body.
4. Nervous tissue:- Compound tissue, formed four types of cells neurones are most important types of cells.
Power of excitation and conduction of nerve impulse.
Components: 4 types of cells.
(i) Neurones or nerve cell:- Longest cell, structural and functional unit of nervous system.
It is formed of two parts:-
(a) Cyton or Cell body (b) Nerve processes
(a) Cyton or Cell body:- Nucleated part of neuron, granular cytoplasm called neuro plasma, fine threads called neurofibrils (for conduction of nerve impulse).
Rough endoplasmic reticulum rich Nissl's granules (for protein synthesis).
(b) Nerve processes:-These are protoplasmic processes arising from the cyton and are two types:- axon dendron
(ii) Neuroglia:-Irregular cells present between the neurones in brain, spinal cord, ganglia and retina of eye.
Excess packing sale between the neurons, phagocytes.
This is also provide nutrition to the neurons.
(iii) Neuro-secretory cells:- in brain secrete neurohormones.
(iv) Ependymal cells:- Ciliated cuboidal cells which line the cavities of brain and spinal cord .
Move the cerebrospinal fluid present in their cavities.
Function:-Neurones co-ordinate senseense organs and muscles of body by conduction of nerve impulse for rapid responding to stimuli.
Some differences:-
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Thank you sir
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Thanku sir for great notes
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