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TISSUES

TISSUES•Definition: A group of

closely associated cells that perform related functions and are similar in structure.

FOUR BASIC TYPES OF ANIMAL TISSUES

Epithelial tissueConnective tissue

• Connective tissue proper (examples: fat tissue, fibrous tissue of ligaments)

• Cartilage• Bone• Blood

Muscle tissueNervous tissue

EPITHELIAL TISSUE

• Epithelium: sheet of cells that covers a body surface or lines a body cavity; also form most of the body’s glands

• Roles: as interfaces and as boundaries• Functions:

Protection AbsorptionSensory reception Ion transportSecretion Filtration Formation of slippery surfaces for movement

SPECIAL CHARACTERISTICS SPECIAL CHARACTERISTICS OF EPITHELIAOF EPITHELIA

CellularityCellularity Specialized contactsSpecialized contacts PolarityPolarity

Free upper (apical) surfaceFree upper (apical) surface Lower (basal) surface contributing Lower (basal) surface contributing

basal lamina to basement membrane basal lamina to basement membrane Support by connective tissue Support by connective tissue A vascular but innervatedA vascular but innervated

Without vesselsWithout vessels With nerve endings With nerve endings

RegenerationRegeneration

CLASSIFICATION OF EPITHELIA

• According to thickness– “simple” - one cell layer– “stratified” – more than one layer of cells

(which are named according to the shape of the cells in the apical layer)

• According to shape– “squamous” – wider than tall– “cuboidal” – as tall as wide– “columnar” - taller than wide

Where diffusion is important.

Where tissues are involved in secretion and absorption: larger cells because of the machinery of production, packaging, and energy requirements.

SIMPLE SQUAMOUS EPITHELIUM

CUBOIDAL EPITHELIUM

COLUMNAR EPITHELIUM

CONNECTIVE TISSUECONNECTIVE TISSUE Originate from embryonic tissue called Originate from embryonic tissue called

mesenchyme.mesenchyme. Most diverse and abundant type of Most diverse and abundant type of

tissue.tissue. Many subclasses:Many subclasses:

EmbryonicEmbryonic

ProperProper

SpecialSpecial Cells separated from one another by Cells separated from one another by

large amount of nonliving extracellular large amount of nonliving extracellular matrixmatrix..

FUNCTIONS OF FUNCTIONS OF CONNECTIVE TISSUECONNECTIVE TISSUE

►Storage of energy.Storage of energy.►Protection of organs.Protection of organs.►Providing structural Providing structural

framework for the body.framework for the body.►Connection of body tissues.Connection of body tissues.

MESENCHYME

MESENCHYME

AREOLAR TISSUE

ADIPOSE TISSUE

RECTICULAR TISSUE

BONE & CARTILAGE

Bone is a very strong and non flexible tissue. The matrix of the bone is heavily coated with calcium salts. Cartilage is somewhat flexible. This type of tissue is present comparatively in very few parts of the body. The best example is the tip of nose and external ear.

HYALINE CARTILAGE

TENDONS & LIGAMENTSTENDONS & LIGAMENTS

Tendons and ligaments are thick Tendons and ligaments are thick network of fibres. The fibres are network of fibres. The fibres are loose and very elastic in nature. loose and very elastic in nature. These fibres are secreted by the These fibres are secreted by the surrounding connective tissue surrounding connective tissue cells. The tendons are strong and cells. The tendons are strong and connect the muscle to bone. The connect the muscle to bone. The ligaments are elastic and ligaments are elastic and connect bone to bone.connect bone to bone.

BLOOD

Blood is also a connective tissue. In this tissue the cells move in a fluid matrix or medium called blood plasma. The blood plasma contain cells called blood corpuscles. They are red blood corpuscles (RBC), white blood corpuscles (WBC) and platelets. Blood flows to all parts of the animal body and thus connects every part of the body.

BLOOD CELLS

MUSCULAR TISSUE

It consists of elongated cells called muscle fibres and is responsible for movement in our body. Muscles contain special proteins, which contract and relax to cause movement.

TYPES OF TYPES OF MUSCULAR MUSCULAR TISSUETISSUE

There are three types of muscular tissue:Skeletal musclesSmooth musclesCardiac muscles

STRIATED MUSCLES

These muscles are attached to the bones and help in body movement. The main characteristic features of this type of tissue are :

i. cells of the tissue are long cylindrical ,non-tapering and unbranched

ii. transverse alternate light and dark bands or striations can be seen

iii. there are many nuclei (multinucleated), which are situated towards the periphery of the muscle fibre.

STRIATED MUSCLES

UNSTRIATED MUSCLE

These tissue are found within the walls of all the tubular organs such as stomach, intestine, ureter, bronchi, etc. The smooth muscle tissue have following features:

i. The cells are long with pointed ends (spindle shape).

ii. The cells has only one nucleus (uninucleated) situated in the centre.

iii. It does not show any strips or striations across the muscle.

UNSTRIATED MUSCLES

CARDIAC MUSCLES

These type of muscles tissue is exclusively present the heart. The main features are:

i. composed of non-tapering cells with faint cross striations

ii. each cell contains one or two nuclei situated in the centre

iii. the function is rhythmic contraction and relaxation throughout life without fatigue under normal conditions

iv. the cells are cylindrical and branched.

CARDIAC MUSCLES

NERVOUS NERVOUS TISSUETISSUE

• It is composed of brain , spinal cord and It is composed of brain , spinal cord and nerves. The cells of this tissue are called nerves. The cells of this tissue are called neurons. neurons.

• A neuron has a single long part , called A neuron has a single long part , called the axon, and many short ,branched the axon, and many short ,branched parts called dendrites.parts called dendrites.

• Neurons are highly specialized for being Neurons are highly specialized for being stimulated and then transmitting the stimulated and then transmitting the stimulus very rapidly from one place to stimulus very rapidly from one place to another. another.

NEURON

PLANT TISSUE

The plant body is made up of different kinds of tissues. These tissues may primarily be classified into two groups:

a) Meristematic tissues andb) Permanent tissues.

(A)MERISTEMATIC TISSUES (MERISTEMS)

The meristematic tissue are present only at the growing regions like shoot tip, root tip and cambium (region which is responsible for growth in thickness). These cells divide continuously thus helping in increasing the length and the girth of the plant.

CHARACTERISTIC FEATURES OF MERISTEMS The cells of this tissue are similar in structure

and have thin walls. The cells may be spherical, oval, polygonal or

rectangular. They are compactly arranged without any

intercellular spaces between them. They contain dense or abundant cytoplasm and

single large nucleus. They contain few vacuoles or no vacuoles at all.

CLASSIFICATION ON THE BASIS OF LOCATIOIN

Apical meristems: at the growing tips of the stem and roots.

Lateral meristems: around the stem and root.

Intercalary meristems: at the base of the leaves or internodes (on either side of the node) on twings.

(B) PERMANENT TISSUE

Permanent tissue are derived from meristematic tissues till they loose the ability to divide.

Permanent cells have definite shape.They may be living or dead, and thin

walled or thick walled.The cells are large having vacuolated

cytoplasm.

SIMPLE PERMANENT TISSUE

A simple tissues is a group of one type of cells only. The common simple tissue of plant body are:

a) Parenchymab) Collenchymac)Sclerenchyma

(A) PARENCHYMA

It is widely distributed in plant body like stem, roots, leaves, flowers and fruits.

Cells are isodiametric. Cells may be oval, round, polygonal or elongated

and have thin walls. There may or may not be intercellular spaces

between them. They are usually living and contains dense

cytoplasm. A large central vacuole is present in the cell.

FUNCTIONS OF PARENCHYMATOUS

TISSUEto store assimilate foodto provide mechanical strength( as

they maintain the turgidity of cells)they also store waste products such as

tannin, gum, crystals, resins of inorganic waste, etc.

PARENCHYMA

Aerenchyma 1.bulliformcell 2.mesophyll3.vascular bundle 4.air cavity 5.midrib

Absorption parenchyma

Assimilation parenchyma

Storage parenchyma

(B) COLLENCHYMA

A living tissue like parenchyma.Located below the epidermis. Consists of thin walled cells

which are thickened at the corners.

Intercellular spaces are absent. Cells may be oval, circular or

polygonal.

FUNCTIONS OF COLLENCHYMA

Provide mechanical supportProvide elasticityManufacture sugar and

starch when they contain chloroplasts

COLLENCHYMA

TRASVERSE AND LONGITUDINAL SECTION OF COLLENCHYMAS

(C) SCLERENCHYMA Dead cells devoid of protoplasm. Length varies from 1mm to 550mm in

different plants. They are long, narrow, thick and lignified. Closely packed without intercellular spaces. They are pointed at the ends. Cell walls are so thick so that the cell cavity

or lumen is nearly absent. They provide mechanical support to plants.

COMPLEX PERMANENT COMPLEX PERMANENT TISSUETISSUE

Complex tissue is made up of more Complex tissue is made up of more than one type of cells and they work than one type of cells and they work together as a unit. Complex tissues together as a unit. Complex tissues transport water, salt and food transport water, salt and food material to various parts of plant material to various parts of plant body. They are of following types: body. They are of following types:

• XylemXylem• Phloem or bastPhloem or bast Xylem and phloem are also called Xylem and phloem are also called

vascular tissue and together they vascular tissue and together they constitute vascular bundles. constitute vascular bundles.

(1) XYLEM

• Xylem is a conducting tissue. It is composed of cells, i.e. elements of four different kinds- tracheids, vessels or tracheae, xylem parenchyma and xylem sclerenchyma. Important one is tubular vessel. They carry water from root to different parts of shoot. Xylem gives mechanical strength to the plant body.

(2) PHLOEM• Phloem is a living conducting tissue.

It is composed of four elements- a) sieve tubes b) companion cells c) phloem parenchyma d) phloem fibres The most important are the sieve

tubes. These tubular cells have perforated walls, which translocate food materials from leaves to other parts of the plant.

PHLOEM

SIEVE TUBE AND COMPANION CELL

I. Longitudinal section II.Transverse section

1.sieve plate 　 2.sieve tube 　 3.companion cell 　 4.leucoplast 5.phloem parenchyma

THANK YOU !

MADE BY :- VAIBHAV KUMAR SHRAWAN CLASS:- 9th