STUDY OF CELLS - TISSUES

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10 Νοε 2013 (πριν από 3 χρόνια και 5 μήνες)

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STUDY OF CELLS
-

TISSUES

BIOLOGY 10TH GRADE

TISSUES

Tissues

:

Groups

of

cells

which

have

a

common

origin,

with

similar

structure

and

function
.

They

exhibit

great

variety

in

their

structure

including

shapes

of

cells
,

thickness

of

cell

walls

and

other

characteristics
.



Organ

:

Different

types

of

tissues

together

take

up

a

particular

function

and

form

an

organ
.


Organ

System

:

A

group

of

organs

performing

a

set

of

common

functions

is

called

an

organ

system
.


Histology

:

The

branch

of

biology

which

deals

with

the

study

of

tissues

and

their

organization

in

organs,

is

called

histology
.

As

we

go

higher

up

in

the

ladder

of

evolution,

the

body

organization

in

plants

and

animals

becomes

more

complex
.

The

body

consists

of

specialised

tissues

and

organs

to

perform

various

metabolic

activities
.

Thus,

specialisation

of

the

tissues

in

higher

organisms

has

enabled

them

to

perform

life

processes

more

efficiently
.


PLANT TISSUES

In

an

angiosperm

plant

body

there

are

different

types

of

tissues

to

perform

a

variety

of

functions

such

as

growth,

protection,

absorption,

photosynthesis

and

conduction

of

water

and

minerals
.


Plant Tissues


Different types of tissues

Meristematic Tissue

Permanent Tissue

These tissues have the capacity to divide.

These tissues have lost the capacity of
division.

They have thin cellulose wall

They have thick cellulose wall.

They produce permanent tissues.

They are produced by meristematic tissue

They contain many small vacuoles in their
cytoplasm

They contain only a single large vacuole in
their cytoplasm

They do not have intercellular spaces.

They have large intercellular spaces

They contain dense cytoplasm with
prominent nucleus

They contain thin cytoplasm with normal
nucleus

They are responsible for primary and
secondary growth of plants.


These tissues add to various growth.

Kindly paste the below link to watch the you tube
video on Plant tissues :


http
://www.youtube.com/watch?v=uN_vBFyu_
-
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PLANT TISSUES

In

an

angiosperm

plant

body

there

are

different

types

of

tissues

to

perform

a

variety

of

functions

such

as

growth,

protection,

absorption,

photosynthesis

and

conduction

of

water

and

minerals
.


PLANT TISSUES (SIMPLE PERMANENT TISSUE)

PARENCHYMA

COLLENCHYMA

SCLERENCHYMA

Location
: Stem, Root, Leaves,

Fruits and widely distributed

Location :
Below Epidermis

Location :
Outermost boundaries

of plants , parts, cortex, pit, hard
seeds etc.

Function :


Stores and Assimilates food


偲潶楤敳 M散桡湩h慬a卵灰潲琠
⡴畲杩摩uy⤠


Store

waste products like
tannin, gum, resins, etc.

Function :


Provides Mechanical

Support
and Elasticity


M慮畦慣t畲攠s畧慲u慮搠st慲a栠

Function :


Provides Mechanical Support

and Strength

Oval

and Sperical

Elongated


Long and Narrow

cells

Living

Cells

Thickened with Cellulose



Cells are thickened with Lignin



Simple
permanent tissues are composed of cells which are similar in structure and function.
There are three types of simple permanent
tissues

PLANT TISSUES (
COMPLEX

PERMANENT TISSUE)


Tissues
which are composed of two or more types of cells but contribute to a common
function are called
complex tissues
. Xylem and phloem are the complex permanent tissues.
They together form the vascular
bundle hence known as
Vascular tissues”

Phloem and xylem are complex tissues that perform transportation of
food and
water in
a plant. They are the vascular tissues of the plant and together form vascular bundles.
They work together as a unit to bring about
effective
transportation of food, nutrients,
Minerals
and water

PLANT TISSUES (
COMPLEX

PERMANENT TISSUE)

Xylem
Phloem
Function :
Transportation of food and nutrients such as
sugar and amino acids from leaves to storage organs and
growing parts of plant. This movement of substances is
called translocation.
Function :
Water and mineral transport from roots to aerial
parts of the plant.
Movement :
Bidirectional (Moves up or down the plant's
stem from "source to sink")
Movement :
Unidirectional (Moves up the plant's stem)
Occurrence :
Roots, stems and leaves. transports sucrose
to growth (roots and shoots) and storage regions of the plant
(seeds fruit and swollen roots)
Occurrence :
Roots, stems and leaves
Additional Functions :
Forms vascular bundles with xylem
Additional Functions
: Forms vascular bundles with
phloem and gives mechanical strength to plant due to
presence of lignin cells. The lignified secondary wall also
makes the xylem waterproof and prevent it from
collapsing under the pressure of water transpiration
Structure :
Elongated, tubular shape with thin walled sieve
tubes. The sieve tubes have pores at each end in the cross
walls and microtubules that extend between sieve elements
allowing longitudinal flow of material.
Structure
: Tubular shape with no cross walls which
allows a continuous column of water + facilitates more
rapid transport within the xylem vessels. There are two
types - protoxylem (first formed xylem) + metaxylem
(mature xylem) depending on pattern of lignin.
Elements :
Sieve tubes, companion cells, phloem
parenchyma (loosely packed resulting in intercellular spaces
which allows gas exchange), bast fibers, intermediary cells,
Elements :
Tracheids, vessel elements, xylem
parenchyma (loosely packed resulting in intercellular
spaces which allows gas exchange), xylem sclerenchyma
Nature of tissue :
Living tissue with little cytoplasm but no
nucleus/tonoplast.
Nature of tissue :
Dead tissue at maturity so it is hollow
with no cell contents
Shape
: Phloem is not star shaped.
Shape :
Xylem is star shaped.
PLANT TISSUES (
COMPLEX

PERMANENT TISSUE)

Xylem
Phloem
Function :
Transportation of food and nutrients such as
sugar and amino acids from leaves to storage organs and
growing parts of plant. This movement of substances is
called translocation.
Function :
Water and mineral transport from roots to aerial
parts of the plant.
Movement :
Bidirectional (Moves up or down the plant's
stem from "source to sink")
Movement :
Unidirectional (Moves up the plant's stem)
Occurrence :
Roots, stems and leaves. transports sucrose
to growth (roots and shoots) and storage regions of the plant
(seeds fruit and swollen roots)
Occurrence :
Roots, stems and leaves
Additional Functions :
Forms vascular bundles with xylem
Additional Functions
: Forms vascular bundles with
phloem and gives mechanical strength to plant due to
presence of lignin cells. The lignified secondary wall also
makes the xylem waterproof and prevent it from
collapsing under the pressure of water transpiration
Structure :
Elongated, tubular shape with thin walled sieve
tubes. The sieve tubes have pores at each end in the cross
walls and microtubules that extend between sieve elements
allowing longitudinal flow of material.
Structure
: Tubular shape with no cross walls which
allows a continuous column of water + facilitates more
rapid transport within the xylem vessels. There are two
types - protoxylem (first formed xylem) + metaxylem
(mature xylem) depending on pattern of lignin.
Elements :
Sieve tubes, companion cells, phloem
parenchyma (loosely packed resulting in intercellular spaces
which allows gas exchange), bast fibers, intermediary cells,
Elements :
Tracheids, vessel elements, xylem
parenchyma (loosely packed resulting in intercellular
spaces which allows gas exchange), xylem sclerenchyma
Nature of tissue :
Living tissue with little cytoplasm but no
nucleus/tonoplast.
Nature of tissue :
Dead tissue at maturity so it is hollow
with no cell contents
Shape
: Phloem is not star shaped.
Shape :
Xylem is star shaped.
ANIMAL TISSUES

Animal tissues are more complex in structure and function when compared
to plant tissues.

The
animal tissues can be broadly classified as follows.

ANIMAL TISSUES


Epithelial Tissue





EPITHELIAL

TISSUE

:

You

are

familiar

with

the

skin

which

is

the

outer

covering

of

the

body
.

The

inner

wall

of

the

body

is

also

lined

with

a

similar

tissue
.

These

outer

and

inner

layers

are

made

up

of

a

type

of

tissue

called

epithelial

tissue
.




The

epithetial

tissue

consists

of

a

single

layer

of

cells

called

simple

epithelium
.

If

it

contains

more

than

one

layer
,

it

is

called

stratified

epithelium
.



Simple

epithelium

consisting

of

flat

plate

like

cells

is

called

squamous

epithelium
.

It

is

found

in

the

alveoli

of

lungs,

and

in

oesophagus
,

in

blood

vessels,

blood

capillaries

and

chambers

of

the

heart
.

This

tissue

is

referred

to

as

endothelium
.



It

permits

materials

to

diffuse

through

it
.

The

epithelial

tissue

containing

elongated

cells

is

called

columnar

epithelium
.

It

is

found

in

the

inner

layer

of

the

stomach,

small

intestine
,

pharynx
,

larynx

and

oviducts
.



Simple Epithelium
: A simple epithelium has a single layer of cells.


Stratified Epithelium
: A stratified epithelium has multiple layers of
cells.


Likewise, the shape of the cells on the free surface can be:


Cuboidal :
Analogous
to the shape of dice
.

Columnar :
Analogous
to the shape of bricks on an end
.

Squamous :
Analogous
to the shape of flat tiles on a floor.



By combining the terms for shape and layers, we can derive
epithelial types such as stratified squamous epithelium or simple
columnar epithelium.

ANIMAL TISSUES


Epithelial Tissue


The

mucus

secreted

by

the

cells

in

the

stomach

protects

the

wall

of

the

stomach

from

acidic

contents

and

digestive

enzymes
.

The

mucus

produced

in

the

intestine

lubricates

the

passage

of

food
.

The

epithelium

bearing

numerous

cilia

is

called

ciliated

epithelium
.


Epithelium

consisting

of

cube

shaped

cells

is

known

as

cuboidal

epithelium
.

It

forms

the

lining

of

many

ducts

such

as

pancreatic

duct,

salivary

duct

and

sweat

ducts
.
In

many

glands

like

salivary

glands

and

thyroid

gland,

cuboidal

epithelium

is

involved

in

secretion
.

ANIMAL TISSUES


Epithelial

Tissue


ANIMAL TISSUES
-

FUNCTIONS OF EPITHELIAL TISSUES



1.
The
epithelium forms a thick tough barrier and protects the
underlying tissues in the form of external skin. The epithelium
of the skin also helps in controlling the body temperature
constant
.


2. The ciliated epithelium helps in the movement of materials
.


3. The epithelium cells in glands facilitate secretion
.


4. Epithelium helps in absorption of nutrients and
excretion.


5. The epithelium in sense organs contain receptor cells.


ANIMAL TISSUES


Tissue and Muscles


Muscular Tissue


MUSCULAR
TISSUE


Muscular tissue is concerned with the movements of the body.

It is made up of muscle cells, which appear like fibres. Hence they are
called
muscle fibres
(
myofibres
). The muscle fibres are specialised cells
capable of contraction and relaxation. This property is responsible for
movement of limbs and bending of the body
.


The movements of internal organs like heart, stomach and alimentary
canal are caused by muscles. These muscles are not under the control
of the animal. Hence they are called
involuntary muscles.


The
muscles of organs like limbs which are under the control of the
animal, are called
voluntary muscles.


The
muscles are classified into three types based on the structure,
function and location.

They are (1)
Unstriped

muscles (2) Striped muscles (3) Cardiac muscles.

UNSTRIPED MUSCLES

STRIPED MUSCLES

CARDIAC MUSCLES

Made up of spindle
shaped elongated muscle
fibres without stripes
(cross bands).

They are also called
smooth muscles.

Made up of elongated
unbranched

cylindrical
fibres with striations are
called striped muscles.


The heart is made up of
special type of muscles
called Cardiac muscles

A number of muscle fibres
are held together by a
membrane to form
bundles called muscles

are usually attached to the
bones and hence, are also
known as skeletal
muscles.

These muscle fibres are
striped and branched.

The peristaltic movements
of the
oesophagus
,
intestine and stomach are
due to these muscles.
Smooth muscles are
found in the wall of the
body cavity

They are voluntary
muscles and are
responsible for locomotion

The branches are
connected with one
another in a
criss
-
cross

form. They are involuntary
muscles.
Physical
exercises and games are
necessary

to keep the muscles in
good working condition

They are also found in
kidneys, blood vessels
and glands

They do not fatigue easily.
They are responsible for
the continuous heart beat
throughout one’s life.

ANIMAL TISSUES


Tissue and Muscles

Muscular Tissue


ANIMAL TISSUES


Tissue and Muscles

Connective Tissue


CONNECTIVE
TISSUES


The tissues which connect various other tissues of the body and provide support
are called connective tissues. They occur in all parts of the body
. Connective
tissues basically consist of cells and fibres enclosed in a ground substance.

The non
-
living substances like fibres and other materials surrounding the living cells
form the matrix. It may be soft or hard or liquid.

The connective tissues are identified on the basis of the nature of the matrix and
classified into three types. They are (1) Loose connective tissues (2) Dense
connective tissues (3) Fluid connective tissues.


LOOSE CONNECTIVE TISSUES :

The fibres in the matrix are loosely arranged is called loose connective tissue.
The
areolar tissue, adipose tissue and reticular tissue are included under this group.


Areolar

Tissue

Adipose Tissue

Reticula
r Tissue

Found below the skin. The fibres are loosely
connected with one another. Air spaces are
found in between the fibres. Hence, it is
called areolar tissue.

The tissue consists of closely
packed fat cells. The cells

are surrounded by fine
reticular fibres.

Tendons are made up of
fibrocytes

and
collagen fibres.

It binds the other tissues and provides a
frame work. It consists of a particular type of
cells which engulf bacteria and foreign bodies
that enter the body



This tissue stores nutrients
which are

used as and when the body
requires.

Reticular tissue provides framework for
important organs such as liver, spleen,
bone marrow, tonsils and mucous
membrane lining in the respiratory tract
and alimentary canal.

The nutrients and oxygen present in the
blood pass through areolar tissue and reach
other tissues.

It also provides insulation
against cold and protects the
body like a shock absorber.


It consists of reticular
fibre



They also digest toxic substances and destroy
them. Thus, they help in body defence.


ANIMAL TISSUES


Tissue and Muscles

Connective Tissue


ANIMAL TISSUES


Tissue and Muscles

Dense Connective Tissue



DENSE CONNECTIVE TISSUE :


The connective tissues consisting of hard
matrix are
called dense connective tissues.
The cells are embedded in a dense matrix
.


The major functions of dense connective tissues are
:



They
form the skeletal system of the body providing an internal
supporting frame
work.


They
enclose the internal organs. The skull protects the brain, ears,
eyes,nose

and other organs in the face.


The rib cage protects heart and lungs.


The
vertebral column protects
the spinal
cord. The organs of digestion, excretion,
reproduction and many
other organs
in the abdomen are protected by the pelvic
girdle and limbs are
provided with
support.

ANIMAL TISSUES


Tissue and Muscles

Dense Connective Tissue



CARTILAGE TISSUE :
BONE TISSUE :
Cartilage takes up different functions depending on the type of
matrix. The ‘C’ shaped cartilage rings in the trachea, bronchi and
the cartilage in the rib cage help in their movement by binding
the surrounding organs. The cartilages present in larynx,
epiglottis, wall of the eustachian tube and pinna contains
elastic fibres in the matrix. They are elastic and flexible. The
cartilages found in between the vertebrae in the vertebral
column chiefly contains collagen fibres. They bring about
bending and stretching movements.
The bone tissue is the most abundant skeletal material found
in the body. A large part of the body weight is due to the
bone tissue. The bone tissue consists of cells embedded in a
firm calcified matrix. The matrix chiefly consists of collagen
fibres, proteins and inorganic salts like calcium phosphate,
chlorides of potassium, sodium and magnesium. The
structure of the bone is designed to withstand stress and
strain. The long and strong bones of the limbs are filled with
a fluid called bone marrow. which consists of fat and blood
vessels. It produces blood cells.
Cartilage Tissue

Bone Tissue

ANIMAL TISSUES


Tissue and Muscles

Fluid Connective Tissue



FLUID CONNECTIVE TISSUES :
The blood
and the
lymph are the liquid
connective tissues of
the body
. They have a fluid matrix.


BLOOD TISSUE

LYMPH TISSUE




The fluid matrix of the blood tissue is
called plasma
. The red
blood cells, white blood cells and platelets are found floating
in it. The liquid nature of the plasma facilitates easy transport
of the various substances from one part of the body to
another.




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ev敲礠c敬氠楮⁴i攠扯摹.


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瑲慮獰潲琠楴it漠瑨攠汵l杳g


周攠eh楴攠扬潯d c敬汳⁨敬e 楮⁢潤礠摥f敮c攠慮e 慲攠e映
different types.


Some of them destroy the bacteria and enable the body to
fight against infections.


周攠灬et敬e瑳t慲攠瑩t礠c敬氠晲慧a敮瑳t睨楣h b物湧⁡扯畴 瑨攠
c汯t瑩t朠潦 b汯潤






L祭ph
楳⁡i
c潬潵牬敳o
晬u楤i獩浩污爠s漠o汯潤o楮⁳瑲tc瑵r攮e
坨敮 瑨攠b汯潤op慳a敳e瑨r潵杨 c慰楬污i楥猬i潮汹or敤 b汯潤o
c敬汳⁣慮 獱s敥z攠楮t漠瑨攠c慰楬污i楥献 周攠e敳琠潦 瑨攠e汵楤 楳i
called lymph tissue.



Lymph
enters another set of capillaries known as
lymphatic capillaries.


周敳攠
c慰楬污i楥猠f潲m 汹lph 杬慮d猠潲 汹lph n潤敳o


周攠
c潭o潳楴楯渠潦 汹lph 楳⁳業楬慲it漠瑨a琠潦 b汯潤o
exc数琠瑨a琠楴id潥猠n潴⁣潮t慩a r敤 b汯潤oc敬汳⁡ed
pr潴敩e献


The
lymphatic vessels empty lymph into the circulatory
system. Lymph produces antibodies which form an
essential part of immune system of the body.


I琠
c潮t慩a猠愠瑹灥 潦 睨楴攠扬潯d c敬汳
ph慧潣ot敳e
睨楣h r敭潶攠b慣t敲楡e慮d f潲敩杮 b潤楥猠晲潭o瑨攠
瑩獳u敳e

ANIMAL TISSUES


Tissue and Muscles

Nervous Tissue



Nervous Tissue is
one of the basic
characteristics of
living
organisms. This property is very
well developed
in nervous tissue.
The nervous
tissue responds
to external and internal stimuli of
the body
. It transmits nerve impulses from all
parts of
the body to
nerve
centres

very quickly
and brings
back the responses.


The
structural and functional unit of
nervous tissue
is the ‘
nerve
cell
’ or
neuron
.
The part consisting of a
prominent nucleus
is the
cell body. The short brush
like structures
arising from the cell
body are
called dendrites
.
The long extension of the cell body
is
the
axon.
The axon ends in a bunch of branches
. The
axon is
covered by a fatty sheath
called myelin
sheath
.


Dendrites carry the impulses towards
the cell
body. Axons carry
the messages away
from the
cell body. There is a tiny gap
between
two successive
neurons. This gap is known as synapse
.


The impulses are transmitted from the axon
of one
neuron to the
dendrite of
another neuron across
the synapse through chemical
substances

Did you know ????



Bone consists of
30%
organic
substances
,
collagen fibres
and
glycoprotein
. 70%
is made
up of
salts
out of which 85%
is
calcium
phosphate.

The muscles can
contract nearly

100 times per
second, when
a
person
is doing hard
work
.

The fastest
nerve
impulses in

humans
travel at 8
metres

per

second