Tissues ppt. 2

∗ Group of cells having a common origin similar or related
structure which work together to perform a common function.
∗ HISTOLOGY – Study of Tissues
∗ Plants and animals have similar life processes but they do not
have similar tissues.
∗ Because of the differences in organisation,mode of living and
life style.
TISSUES

∗ Plants :
∗ Continue to grow throughout their life.
∗ Possess meristematic tissues in specific regions of body
for growth.
∗ Animals:
∗ Mobile, move in search of food, shelter, etc.
∗ Tissues are living.
∗ Living tissues require more energy for maintenance.
∗ Stop growing after maturity
∗ No meristematic tissues
∗ In having organ and organ system, structural
organisation of animals is far more specialised and
localised as compared to plants because of mobility and
Plants
Stationary, require supportive tissues for structural strength.
Most tissues are dead, provide mechanical strength and requires
less maintenance.

PLANT TISSUES (2 TYPES)
PLANT TISSUES
Meristematic Tissue
(i) Apical
(ii) Intercalary
(iii) Lateral
Permanent Tissue
Simple Permanent
(i) Parenchyma
(ii) Sclerenchyma
(iii) Collenchyma
Complex
Permanent
(i) Xylem
(ii) Phloem
Special
Tissue
(i)Protective
(ii) Glandular

∗ Thin walled, compactly arranged, immature cells -
have the potential to divide and form new cells.
∗ Meristem cells – Meristematic cells
∗ Region where present – functions as growth region.
∗ New cells produced by meristems – meristematic cells
- grow slowly, differentiate and mature into
components of various permanent tissues
MERISTEMATIC TISSUE (also called meristem)

∗ Shape and size – small, spherical or polygonal in outline.
∗ Cell wall – thin, elastic
∗ Intercellular space – absent, cells are compactly arranged.
∗ Cell contents:
∗ Nucleus is large.
∗ Cytoplasm is dense.
∗ Vacuoles are absent or very small.
∗ Activity:
∗ Respiration is rapid.
∗ High synthetic activity.
∗ Food supply is high but not stored.
∗ Cells grow and divide repeatedly.
CHARACTERISTICS OF MERISTEMATIC CELLS

∗ Parent tissue – Parent tissue from which other
tissues develop.
∗ Growth – takes part in growth by formation of
new cells.
∗ New Organs – plants continue to produce new
leaves, stem branches, flowers, fruits, root hairs
and root branches. They are formed by
meristematic cells.
∗ Injury – place of injury is healed by the formation
FUNCTIONS OF MERISTEMATIC
TISSUES

LOCATION OF
MERISTEMS
∗ Based on position in plant body, meristematic
tissues are of 3 types: (i) Apical, (ii) Intercalary, (iii)
Lateral
∗ Apical Meristem:
∗ Occurs in growing tips of stems and roots.
∗ Depending upon its occurrence, it is called:
∗ Root tips – root apical meristem
∗ Stem or shoot tips – stem or shoot apical meristem
∗ Produces growth in length of root and stem.
∗ Intercalary Meristem:
∗ Occurs in intermediate position:
∗ At the base of leaves,
∗ At the base of internodes (eg. Grasses), or,
∗ Below the nodes (eg. Mint)

LOCATION OF
MERISTEMS
∗ Intercalary Meristem:
∗ Helps in growth of leaves and internodes.
∗ Upward bending of lodged shoot is made
uptight due to intercalary meristem.
∗ It is the left out part of optical meristem.
∗ Lateral Meristem:
∗ Occurs on the sides of both stem and roots.
∗ Increases the girth of stem and root.
∗ Two types:
∗ Vascular Cambium – Produces secondary vascular
tissues, secondary phloem, secondary xylem.
∗ Cork Cambium – Produces protective cork on the
outside.

∗ Group A
∗ Q 1. Name the different types of meristematic tissues.
∗ Q 1. What type of meristematic tissue is observed in the
roots of the onion?
∗ Group B
∗ Q 1. Consider the meristem being experimented with in
the activity. Mention the functions of this meristem
performed in a plant.
∗ Group C
∗ Q 1. What do you expect the end result of the activity to
WORK SHEET

PERMANENT TISSUES
Permanent Tissue
Simple Permanent
(i) Parenchyma
(ii) Sclerenchyma
(iii) Collenchyma
Complex
Permanent
(i) Xylem
(ii) Phloem
Special Tissue
(i)Protective
(ii) Glandular

∗ Differentiation of Meristematic tissues:
∗ Meristematic tissues have lost the ability to divide, and have
assumed a permanent shape, size and function –
DIFFERENTIATION.
∗ Permanent tissues are formed due to differences in their
specialisation.
∗ Permanent tissues are:
∗ Simple Permanent
∗ Complex Permanent
∗ Special Permanent
PERMANENT TISSUES

∗ Shape and Size: Cells have definite shape and size,
which do not alter afterwards.
∗ Specific functions: Permanent cells come to have
specific functions.
∗ Wall: Thin or thick. Thickening can be regular or
irregular.
∗ Division: Normally do not divide.
∗ Life: May be living or dead.
CHARACTERISTICS OF PERMANENT TISSUES

Meristematic Tissue Permanent Tissue
• Nature: Cells are small,
isodiametric and undifferentiated.
• Cells are large, differentiated with
different shapes.
• Spaces: Intercellular space absent. • Intercellular places often present.
• Vacuoles: Nearly absent. • Large central vacuole in living
permanent cells.
• Nucleus: Large and prominent. • Less conspicuous.
• Wall: Cell wall is thin. • Cell wall is thin or thick.
• Division: Cells undergo regular
divisions.
• Cells do not normally divide.
• Tissue: Meristematic tissue is a
simple tissue.
• Can be simple, complex or special.
• Organelles: Cell organelles are
simple.
• Cell organelles are well developed.
DIFFERENCES

∗ Cells of Simple Permanent tissues are similar in structure,
origin and function.
∗ Three types of Simple Permanent tissues:
 Parenchyma
 Collenchyma
 Sclerenchyma
SIMPLE PERMANENT TISSUE

∗ Parenchyma:
∗ Thin walled, made up of cellulose.
∗ Relatively unspecialised.
∗ Isodiametric
∗ Living cells
∗ lying in between specialised tissues.
∗ Most abundant tissue.
∗ Found in all non-woody parts like stem, root, flowers, fruits.
∗ Cells are oval, spherical or polygonal in outline.
∗ Central vacuole, peripheral cytoplasm and nucleus.
∗ Loosely packed with small and large intercellular space.

∗ Functions of Parenchyma:
∗ Storage: Stores food and water.
∗ Cells are specially enlarged to store nutrients and water.
∗ Support: Cells remain turgid and provide rigidity to softer parts.
∗ Gaseous exchange: Intercellular spaces present, allows
movement of gases and gaseous exchange.
∗ Waste Products: Certain cells store waste products like tanning
resins , gums, crystals, etc.

∗ Functions of Parenchyma (cont.)
∗ Transport: Parenchyma in xylem and phloem takes part
in slow, lateral movement of materials.
∗ Chlorenchyma: Parenchyma containing chloroplast -
seat of photosynthesis.
∗ Aerenchyma:
∗ A network of parenchyma cells encloses large air
cavities
∗ Store gases and provides buoyancy to acquatic plants.
∗ Epidermis: Specialised parenchyma present on the
surface of plant organs.

∗ Collenchyma:
∗ Simple permanent, living, mechanical tissue.
∗ Provides flexibility to soft aerial parts that bend without breaking
(Eg. Leaves, young stems).
∗ Cell wall is thickened unevenly at the corners
∗ Thickening made up of pectin and cellulose.
∗ Intercellular spaces are little.
∗ Cells are elongated but appear oval,
circular or angular in T.S section.
∗ Occurs below the epidermis in leaf stalks, leaf mid ribs and
herbaceous dicot stems.
∗ Absent in monocots

∗ Functions of Collenchyma:
∗ Strength: Provides mechanical strength and flexibility.
Because of Collenchyma plant organs can bend without
breaking.
∗ Growth: allows growth and elongation of organs.
∗ Storage: being a living tissue, it stores food.
∗ Photosynthesis: cells may contain chloroplast and take
part in photosynthesis.

∗ Sclerenchyma:
∗ Long, narrow, dead and highly thick-walled with little lumen
(internal space)
∗ Thickening is made of – Lignin
∗ Lignin functions as cement and hardens the cells.
∗ The walls contain certain unthickened areas – pits.
∗ Sclerenchyma occurs in – stems of monocot plans, around vascular
bundles – xylem and phloem.
∗ Hard covering of nuts, husk of coconut,
grit of apple, pear and guava.

∗ Functions of Sclerenchyma:
∗ Mechanical Strength: Chief mechanical tissue providing strength to
the plants - enables them to bear various stresses.
∗ Protection: Forms a protective covering around seeds and nuts.
∗ Commercial fibres: Sclerenchyma fibres of some plants are
commercially exploited, e.g. Flax, Hemp, Jute, Coconut.

Identify the Figures
1 2 3
Group A :
Identify the above figures
Group B:
In the above figures, name the living and non living tissues
Group C:
Name the tissue present in the bark of the tree. How is it useful to
the plant?

∗ Protective Tissue
∗ Outer layer of cells (stem, root, leaves, flowers, fruits,
etc.)
∗ Providing protection against adverse environmental
factors and pathogens.
∗ Performs specialized functions – like exchange of gases.
∗ Types: EPIDERMIS AND CORK
∗ Epidermis:
∗ Outermost, protective layer in plant organs.
∗ Commonly single layers
∗ Cells are elongated and closely packed.
SPECIAL TISSUE

∗ Epidermis (cont.)
∗ In aerial parts, the outer thick walls (Cellulose) covered by a layer of
water impermeable fatty substance – CUTIN
∗ Cutin and Wax form a separate non-cellular coating – CUTICLE
∗ At some places (like leaves), aerial parts bear minute pores called
stomata.
∗ Each stoma is enclosed by a pair of specialised epidermal cells called
guard cells.
∗ Guard cells – are kidney shaped (dicot) or dumb-bell shaped (monocot)
∗ Guard cells are thicker on the inside and thinner on the outside
∗ The pores are helpful in exchange of gases
∗ Pores are seat of transpiration
∗ In roots, epidermal cells give rise to tubular outgrowths called root
hairs.
SPECIAL TISSUE

∗ Epidermis (cont.)
∗ Root hairs increase the absorption by increasing the surface area of the
root.
SPECIAL TISSUE

∗ Functions of Epidermis:
∗ Protection – against pathogens and pests
∗ Water loss – checks water loss because of the cuticle
∗ Epidermal Hair – produces insulating stationary layer of air.
∗ Stomata – Regulate exchange of gases
Seat of major water loss in transpiration
Transpiration keeps aerial parts cool
∗ Epidermis of the root along with root hairs absorb water and
minerals
SPECIAL TISSUE

∗ Cork:
∗ Outer protective tissue of older stems and roots
∗ Formed by secondary lateral meristem called cork cambium
∗ Rectangular in outline
∗ Compactly arranged in several layers
∗ Intercellular space – absent
∗ Older cells – dead and filled with tannins, resins and air
∗ Their walls become impermeable due to deposition of Suberin
∗ Commercial cork – obtained from stems of Cork Oak
SPECIAL TISSUE

∗ Functions of Cork:
∗ Protection against loss of Water
∗ Protection from microbes
∗ Insulation against mechanical injury, extremes of
temperature, fire and browsing animals
∗ Commercial use – stoppers for bottles, shock
absorber insulation boards, sports goods, etc.
SPECIAL TISSUE

∗ Permanent tissues made of more than one type of cells
∗ Work together to perform one particular function
∗ Conducting or Vascular tissues – survival of the plant is
possible as they carry materials inside the plant
∗ Types
∗ Xylem
∗ Phloem
COMPLEX PERMANANENT
TISSUE

∗ Xylem:
∗ Takes part in conduction of water and mineral salts
∗ Provides mechanical strength
∗ Also called wood
∗ Four elements: (a) tracheids, (b) vessels, (c) xylem
fibres, (d) xylem parenchyma
∗ Tracheids:
∗ Long, tubular dead cells with lignified walls and tapering ends
∗ Possess various types of thickening for mechanical strength
∗ Unthickened areas help in movement of water from one
tracheid to another
COMPLEX PERMANANENT
TISSUE

∗ Xylem (cont.)
∗ Vessels:
∗ Long tubules
∗ Walls are lignified
∗ Occur in flowering plants
∗ More efficient than tracheids
∗ Formed by end to end union of large number of dead cells
∗ Vessels and tracheids are conducting elements of xylem. They
conduct water and minerals vertically
∗ Xylem fibres:
∗ Sclerenchyma fibres found in xylem
∗ Have thick pitted walls, narrow lumen and tapering ends
COMPLEX PERMANANENT
TISSUE

∗ Xylem (cont.)
∗ Xylem parenchyma:
∗ Consists of living cells
∗ Present inside xylem
∗ Stores food
∗ Helps in lateral conduction
∗ Functions of Xylem:
∗ Conducts water and minerals from roots to the top of
plants. Movement is unidirectional
∗ Provides mechanical strength because of the occurrence of
thick walled lignified components
COMPLEX PERMANANENT
TISSUE

∗ Phloem:
∗ Takes part in conduction of organic food
∗ Living conducting tissue because of the living cells in its transport
channels
∗ Four elements –
∗ (a) Sieve tubes
∗ (b) Companion cells
∗ (c) Phloem parenchyma
∗ (d) Phloem fibres
COMPLEX PERMANANENT
TISSUE

∗ Sieve Tubes:
∗ Elongated, living, tubular conducting channels
∗ Transverse end walls between adjacent sieve tubes cells are perforated –
sieve plates
∗ Have vacuolated cytoplasm
∗ Nucleus degenerates
∗ Cytoplasmic strands are continuous between adjacent sieve tubes
COMPLEX PERMANANENT
TISSUE

∗ Companion cells:
∗ Thin walled, small and elongated
∗ Has dense cytoplasm and nucleus
∗ Nucleus controls the sieve tubes and keeps them living
∗ Phloem parenchyma:
∗ Parenchyma present in phloem
∗ Thin walled and living
∗ Function – storage and slow lateral conduction of food
COMPLEX PERMANANENT
TISSUE

∗ Phloem fibres:
∗ Only non-living component of phloem
∗ Thick walled, elongated, spindle shaped
∗ Dead cells, which possess narrow lumen
∗ Provide mechanical strength to the tissues
COMPLEX PERMANANENT
TISSUE

∗ Phloem (cont.)
∗ Functions:
∗ Transports organic food throughout the plant
∗ Conduction occurs in both directions
∗ Phloem fibres of some plants are sources of commercial
fibres (E.g. Jute, Hemp, Flax)
COMPLEX PERMANANENT
TISSUE

∗ Differences between xylem and phloem
COMPLEX PERMANANENT
TISSUE
Xylem Phloem
• Conduction: Conducts water and
minerals
• Conducts organic solutes or food
materials
• Direction: Mostly unidirectional • Can be bidirectional
• Components: Tracheids, vessels, xylem
parenchyma, xylem fibres
• Sieve tubes, companion cells, phloem
parenchyma, phloem fibres
• Channels: Conducting channels are
tracheids and vessels
• Conducting channels are sieve tubes
• Dead / Living parts: Tracheids, vessels
and xylem fibres are dead elements.
Only xylem parenchyma is a living
element
• Sieve tubes, companion cells and
phloem parenchyma are living elements.
Phloem fibres are the only dead
elements
• Mechanical Strength: In addition to
conduction, xylem provides mechanical
strength to the plant
• There is no mechanical function

∗ Occur in holozoic organisms.
∗ On the basis of structure and functions
ANIMAL TISSUES
Animal Tissues
Epithelial Tissue Connective
Tissue
Muscular Tissue
Nervous
Tissue

∗ Fundamental animal tissue.
∗ Forms a continuous sheet of closely packed cells.
∗ Covers the entire external and internal surface of the animal
body.
∗ Intercellular space is absent
∗ Cells are tightly held together by small amount of cementing
material.
∗ Epithelium rests over an extra cellular layer of collagen fibres
and dense matrix – BASEMENT MEMBRANE.
EPITHELIAL TISSUE(Epithelium-Plural)

∗ Basement membrane connects the epithelial tissue to the
underlying connective tissue.
∗ A direct vascular supply is absent.
∗ Forms a barrier for separating the different body system.
∗ Anything entering the body must cross atleast one layer of
epithelium.
∗ Permeability of various epithelial cells determines the passage
of substances between different body parts and between
body and external environment.
∗ Occurs over – skin, lining of mouth,parts of alimentary canal,
lung alveoli, lining of respiratory tract, reproductive tract,
blood vessels and different types of glands.

∗ FUNCTIONS:
∗ 1.Protection:Epithelium lying over the skin protects the body
from drying up, microbes and chemical injury.Similar
protection is carried out by in in the lining of the mouth, nasal
tract, and alimentary canal.
∗ 2.Absorption: Some epithelium have become specialized for
absorption. Eg. Intestinal mucosa.
∗ 3. Excretion: Epithelium lining the different parts of kidney
tubules take part in ultra filtration, secretion and reabsorption
to produce urine.
∗ 4.Exchange of gases: In the lining of the lung alveoli allows
diffusion of gases between blood and alveolar air.

∗ FUNCTIONS:
∗ 5.Movement:Epithelium having cilia help in movement of
various types of materials. Eg. Dust particles and mucus in
respiratory tract, ovum in oviduct, urine in urineferous
tubules, etc.
∗ 6.Secretion: Glandular epithelium produces secretions. Eg.
Tear, gastric juice, mucus, intestinal juices.
∗ 7.Germinal Epithelium: Produces male and female sex cells.
∗ 8. Sensations: Sensory epithelium is specialised to receive
sensations.Eg. Nasal epithelium, taste buds.

∗ On the basis of arrangement of layers, cell shapes and
functions Epithelial tissues are classified as:
Epithelium
Arrangement of
Layers
1.Simple Epithelium
2.Stratified
Epithelium
Cell Shape
1.Squamous
Epithelium
2.Cuboidal Epithelium
3.Columnar Epithelium
Functions
1.Ciliated Epithelium
2.Glandular
Epithelium
3.Sensory epithelium
4.Germinal
Epithelium

∗ Simple epithelial tissues- cells are arranged in single layer
∗ Stratified epithelial tissues- cells are arranged in more than one
layer
∗ Squamous epithelial tissues
-also called – Pavement
Epithelium – cells are arranged
like the tiles of the floor.
-cells are thin, flat, polygonal with bulging centre and flat nuclei.
- Margins my be smooth or wavy.

Simple Squamous epithelium :
- Functions as selectively permeable barrier allowing diffusion,
filtration, and secretion.
-occurs in Lung alveoli, blood capillaries, Bowman's capsules.
Stratified Squamous epithelium :
-occurs in areas where there is wear and tear of tissues.
Eg. buccal cavity, Pharynx, oesophagus, skin.
The basal layer lying in contact with basement membrane
continues to add new cells as the older surface are torn away.

∗ Cuboidal Epithelium :
∗ Compactly arranged cells
∗ Cuboidal in shape
∗ Nucleus is rounded and centrally placed
∗ Occurs in salivary ducts, kidney tubules, pancreatic ducts, thyroid
vescicles , endocine glands – providing mechanical support.
∗ Acquire additional specialization as gland cells for secretion,
absorption and excretion
∗ Sometimes aportion of the cuboidal epithelium gets folded inwards
to form multicellular gland – Glandular epithelium.

∗ Columnar Epithelium :
∗ Consists of tall, pillar like, compactly arranged cells, oval nucleus
lying near the base.
∗ Facilitates movement across the epithelial barrier
∗ Takes part in secretion and absorption in the lining of the
stomach, intestine and their glands.
∗ Columnar epithelial cells in the respiratory tract have cilia –
CILIATED EPITHELIUM
∗ Cilia pushes the mucus forward
∗ and clears it.

∗ Fundamental animal tissue
∗ Embedded in an abundant matrix
∗ Matrix helps in connecting, binding, packing
and supporting different structures of the
animal body.
∗ Matrix may be jelly like, fluid , solid- dense or
rigid.
∗ On the basis of nature of matrix types of
connective tissue are:
CONNECTIVE TISSUE

Connective tissue
CONNECTIVE TISSUE
1. Areolar Tissue
2. Adipose Tissue
3. Ligament
4. Tendon
Skeletal Tissues
1.Cartilage
2.Bone
Vascular
Tissues
1.Blood
2.Lymph

Areolar Tissue:
∗ Connective tissue found between skin and muscles, around
blood vessels and nerves in bone marrow.
∗ Fills the space inside the
organs.
FUNCTIONS:
1. Supports internal organs
2. Helps in repair of tissues
3. Produces antibodies and
other chemicals to combat microbes.
CONNECTIVE TISSUE

Adipose Tissue: Connective tissue found below the skin and
between the internal organs.
∗ Cells of the tissues are filled with fat globules.
FUNCTIONS:
1. Stores fat it is kept as a reserve
and used when required.
2. Storage of fat makes it act as
an insulator.
3. Forms shock absorbing cushions
around the organs.
4.Rounds of body contours and provides shape to various parts
of the body
CONNECTIVE TISSUE

Skeletal Tissues:
1.Bones: forms the frame work supporting the body
∗ Anchors the muscles and supports the main organs of the
body.
∗ Strong, non-flexible tissue.
∗ Cells are embedded in a
hard matrix.
∗ Matrix is composed of
calcium and phosphorous.
CONNECTIVE TISSUE

Skeletal Tissues:
Bones:
FUNCTIONS:
1. Forms the frame work
2. Protects the vital organs like
heart, lungs, brain, etc.
3. Takes part in body movements
including locomotion
CONNECTIVE TISSUE

Skeletal Tissues : 2.Cartilage:
∗ Has widely spaced cells, solid matrix composed of
proteins and sugars.
∗ Smoothens bone surfaces at joints.
∗ Present in nose, ear, trachea, larynx, etc.
CONNECTIVE TISSUE

Skeletal Tissues: 2.Cartilage:
FUNCTIONS:
1. Provides support and flexibility to various body parts.eg. Ears
2. Prevents frictional wear and tear of the bones.
3. Acts as a cushion against stresses in the vertebral discs.
CONNECTIVE TISSUE

LIGAMENT:
∗ Two bones are connected to each other by ligament.
∗ Elastic in nature.
∗ Has considerable strength.
∗ Contain very little matrix.
∗ Over stretching causes sprain.
TENDONS:
∗ Connects muscles to bones
∗ Fibrous tissue, has great strength,limited flexibility
CONNECTIVE TISSUE

Vascular Tissues: 2 types.
1.Blood: has fluid matrix – Plasma
∗ RBC, WBC and platelets – suspended in plasma
∗ Plasma contains salts, proteins and hormones.
FUNCTIONS:
1. Blood flows and transports gases, digested food, hormones and
waste products to various parts of the body.
2. Conducts heat and regulates the body temperature.
3. Keeps the tissue moist.
4. WBC fight against microbes by producing antibodies.
VASCULAR TISSUE

2.Lymph:
∗ Fluid lying in the empty spaces.
∗ Light yellow fluid connective tissue.
∗ Brings in CO2 and wastes from tissues to blood.
∗ Carries O2, nutrients and hormones from blood to
tissues.
∗ Returns proteins and excess fluid to the circulation.
∗ Picks bacteria and brings them to lymph nodes and
destroy them.
∗ Transports fat from digestive system.
VASCULAR TISSUE

∗ Consists of elongated cells
∗ Also called as muscle fibers
∗ Responsible for movements in our body
∗ Contains special proteins - contractile protein
∗ Contractile protein – causes movement by contracting and
relaxing.
MUSCULAR TISSUE

Striated / Voluntary Muscles:
∗ Voluntary Muscles - moves by our consciouswill. Eg. Limb
Muscles.
∗ Also called as Skeletal muscles – attached to bones for
movement.
∗ Have light and dark bands or striations – Striated muscles.
∗ Striated muscle tissues – cells are long, cylindrical,
unbranched, multi nucleated.
MUSCULAR TISSUE

Smooth / involuntary Muscles:
∗ Movement cannot be controlled by us.
∗ Also called smooth or unstriated muscles as there are no
striations.
∗ Occurs in alimentary canal, blood vessels, ureters, iris of the
eye, bronchi of lungs.
∗ Cells are long with pointed ends, spindle shaped, uni nucleated
MUSCULAR TISSUE

Cardiac Muscles:
∗ Muscles of heart show rhythmic contraction and relaxation
through out the life.
∗ Involuntary muscles- movement cannot be controlled by us.
∗ Cardiac muscles – cylindrical, branched , uninucleated, faint
striations are seen
MUSCULAR TISSUE

∗ Cells possess the ability to respond to stimuli.
∗ Highly specialized - Being stimulated and transmitting the
stimulus very rapidly in the body.
∗ Also called as neurons.
∗ Occurs in brain, spinal cord, and nerves.
NERVOUS TISSUE

Structure of neuron:
∗ Consists of a cell body, nucleus and
Cytoplasm.
∗ Long hair like structures arise from
cytoplasm .
∗ Axon - single long part .
∗ Dendrites – many short branched parts.
∗ Individual cells - 0ne metre long.
∗ A nerve - Many nerve fibers bound
together by connective tissue.
∗ Nerve impulses allow us to move our
muscles when we want to.
∗ Combination of nerve and muscle tissue enables
animals to move rapidly in response to stimuli.
NERVOUS TISSUE

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