Basic Tissues of Body

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Basic Tissues of Body Powered By Docstoc
Enumerate of Basic Tissues
Define and mention the Epithelium
Define and discuss the Connective
Define and discuss the Muscular Tissues
Define and describe the Nervous Tissues
  Basic Tissues of Body
2.Connective Tissues
3.Muscular Tissues
4.Nervous Tissues
Definition: Layered
 collection of closely
 packed cells with
 very little
 material, usually
 covering the
 external or internal
 surface of body.
Epithelial cells
 also modified to
 form the glands
 which may be
 exocrine glands
 or endocrine
Epithelium is
  avascular, but
  supported by
  membrane, called
  as Basement
  Membrane, which
  made up of loose
  connective tissues
  with blood vessels.
    Simple cuboidal Epithelium
Cuboidal Cell

           Basement Membrane
Epithelium may
 covered the body
 surfaces like outer
 surface of body, the
 Skin or they line the
 luminal surface of
 hollow tubes or
 viscera, for e.g.
 blood vessels or
 Urinary Bladder.
Epithelium can be classified in three ways:
I- Shape
         1. Squamous
         2. Cuboidal
         3. Columnar
         4. Transitional
II- Stratification
         1. Simple
         2. Stratified
         3. Pseudostratified
III- Specializations
         1. Keratinized
         2. ciliated
Classification Description       Location          Drawing
                                 /Function         /Sketch

Simple        Thin single cell   Artery, veins
Squamous      layer where the    and
              width is greater   for exchange
              than the cell’s    Bowman’s
                                 Capsule barrier
Simple        Thin single cell   Kidney
Cuboidal      Layer where the    absorption and
              width, depth,      secretion
              and height of      absorption and
              the cell are       conduit
              the same
Classification     Description          Location            Drawing
                                        /Function           /Sketch

Simple             Thin single cell     Gall Bladder
Columnar           Layer where the      absorption
                   height of the cell   Small Intestine
                   is much greater      Absorption And
                   than the width       secretion
Pseudostratified   Stratified but       Trachea
                   Some cells do        secretion/conduit
                   not reach the        Epididymis
                   free surface but     absorption/
                   All cells reach      conduit
                   The basement
Classification   Description              Location        Drawing
                                          /Function       /Sketch

Stratified       Multiple layers of       Keratinized-
squamous         cells but the top        Skin and
                 layer is squamous        Non-
                 Keratinized – layer      Keratinized-
                 of dead apical cells     Esophagus
                 Non-keratinized –        Act as
                 layer of living apical   barrier/
                 cells                    protection
Stratified       Multiple layers of       Sweat
cuboidal         cells but the top        glands, large
                 layer is cuboidal        ducts in
Classification   Description        Location           Drawing
                                    /Function          /Sketch

Stratified       Multiple layers    Largest ducts of
Columnar         of cells but the   exocrine glands,
                 top layer          anorectal
                 is columnar        junction

Transitional     Stratified         Urinary
(Urothelium)     Epithelium has     bladder
                 the ability to     barrier,
                 change form        Distensible
                 Quickly to         property
                 increase surface
Connective tissues are also called as supporting
 tissue, these type of tissues support and
 connect the other body tissues.
Connective tissues of the cells, which are
 scanty, embedded into ground substance, the
 Matrix (ground Substance and fibers),
 containing cells and fibers
     Components of Connective Tissue

The connective tissue consists of:-
1. Cells
2. Fibers
3. Ground Substance
Matrix is the combination of fibers and
   ground Substance
Many cells are found in different varieties of connective tissues. Cells
   are found in connective tissue proper are:
1. Fibroblast
2. Fat Cells
3. Histiocytes
4. Plasma Cells
5. Mast Cells
6. Some white blood cells
The cells which are present in the connective tissue all the time are
   called as fixed connective tissue cell, these are Fibroblast and Fat
   cells remaining cells are appear on demand they are called as
   Wandering Cells. Only loose areolar connective tissue contains all
   varieties of cells, other connective tissue varieties contain one or
   more tissue cells types.
Most abundant variety of
  connective tissue cells.
  Fibroblasts appear as
  large, flattened, roughly
  ovoid cells with
 Produce various
  connective tissue fibers
 Secret the Ground
         HISTIOCYTES (Macrophages)
Abundantly found in loose
  areolar connective tissue,
  being most numerous as
  fibroblast. They are derived
  from Monocytes. In inactive
  phase histiocytes do not
  easily differ from fibroblast.
  In resting condition,
  histiocytes appear as
  irregular cells with short
  blunt process. Activated
  histiocytes become clearly
  distinguishable from
       HISTIOCYTES (Macrophages)
Entire cell becomes larger with
  bigger, cytoplasm filled with
  granules and vacuoles
  containing ingested
Related to defense
  mechanism, act as
  scavenger cells, because of
  their mobility and engulf
  dead cells, extravasated red
  blood cells, bacteria and
  foreign bodies
                     Plasma cells
These cells are rare in
  connective tissue but
  mostly present at the sites
  where subject to
  penetration to bacteria and
  foreign proteins occur, like
  intestinal mucosa. They are
  frequently found in the
  lymphoid organs.
Plasma cells are large and
  ovoid cells. The nucleus is
  spherical and eccentric in
                  Plasma cells
Within the nucleus,
  chromatin occurs as
  coarse granules arranged
  in a regular manner near
  the nuclear membrane,
  called as cart-wheel
Production of antibodies
                  MAST CELLS
Mast cell is large, round
 or ovoid cell with
 centrally placed
 nucleus. The
 cytoplasm is full of
 coarse granules,
 presence of these
 nucleus gives these
 cells their name mast
 means well fed.
                    MAST CELLS
Mast cells are widely
  distributed in connective
  tissue but are more
  abundant in the loose
  connective tissue around
  the blood vessels.
Functions: Secret
Heparin, a powerful
Histamine, potent
Fat cells are large, have an
  ovoid or spherical
  shape. The cytoplasm is
  displaced to the
  peripheral region of cell
  by a single large fat
  droplet. The nucleus,
  flattened and
  surrounded by a small
  amount of cytoplasm, is
  usually found pressed
  against the cell
In ordinary histological
   preparation, the fat is
   dissolved out of the cell
   and is represented by a
   large vacuole. Thus after
   staining the peripheral
   rim of cytoplasm and
   eccentric, flattened and
   nucleus collectively give a
   characteristic appearance
   “Signet Ring
Wandering cells are not
 normally present in
 the connective tissue
 but they are
 temporary shifted the
 blood and lymph.
 These include
 eosinophils and
Connective tissue fibers are long, slender
  protein polymers .
Connective Tissue fibers are three Major
   Collagen Fibers
   Reticular Fibers
   Elastic Fibers
These three types are found in different
  proportions in various types of connective.
The predominate fiber type is responsible for the
  specific properties of connective tissue and specific
For e.g. a connective tissue contains more
  collagenous fibers than this type is called as dense
  connective tissue, if a connective tissue contains
  abundant of Reticular fibers than this is called as
  loose connective tissue, if a connective tissue
  contains abundant of elastic fibers than it is called
  as Elastic connective tissue.
Collagenous (white)
  fibers: are secreted by
  fibroblast. There are        Bundles of Collagen Fibers

  different varieties of
  collagenous fibers, but
  most commonest
  Varieties are Type I & III
  (which is also called as
  Reticular Fibers)

Reticular (thin) Fibers:
  are thin collagenous
  fibers of type III variety,
  they also secreted by
  the fibroblast. Both
  varieties usually take
  part in formation of
  Basement Membrane.

Elastic (Yellow)
  Fibers: These fibers
  have elasticity, they          Elastic
  can be stretched
  like rubber than
  come back to its
  original position.
                   ELASTIC FIBERS
Found in the connective tissues
  through out the body but they
  are particular abundant in the
  organs those are subject of
  constant pressure or pulling
  force and than return to their     Elastic Fibers

  original size and shape for e.g.
  Lungs and large Arteries.
  Certain Ligaments are rich in
  elastic fibers and called as
  Yellow Elastic Ligament.

                                          Wall of Aorta
              GROUND SUBSTANCE
The cells and fibers of
  connective issue are
  embedded in highly
  hydrated gel which is called
  as ground substance. The
  water contents in ground
  substance serves as the
  medium through which
  metabolites and gases are
  exchange between cells
  and blood vessels.
 Ground substance is an
amorphous material
contains Proteoglycans
(rich in carbohydrates and
less in Proteins) and
Glycoproteins (less in
Carbohydrates & rich in

                    Mucopolysaccharide Ground Substance
                 Ground substance
Ground substance is found in all cavities and clefts between
  the fibers and cells of connective tissues. Water, salts and
  other low molecular substances are contained within the
  ground substance, but its main structural constituent are
  Ground substance is soluble in most of the solvents used
  to prepare histological sections and therefore not visible
  in ordinary sections.
Proteoglycans are responsible for the highly viscous
  character of the ground substance. Proteoglycans consist
  of proteins (~5%) and polysaccharide chains (~95%),
  which are covalently linked to each other. The
  polysaccharide chains belong to one of the five types of
  glycosaminoglycans, which form the bulk of the
  polysaccharides in the ground substance.
   Different types of Proteoglycans are

Glycosaminoglycan Hyaluronic acid
s Non-sulfated

Glycosaminoglycan chondroitin-4-sulfate, chondroitin-6-
Sulfated          sulfate, dermatan sulfate, heparan
                  sulfate, heparin

Glycoproteins         fibronectin, laminin,
    Non Sulphated Glycosaminoglycans
Properties                           Distributions

Hyaluronic acid is the dominant      Synovial fluid,
glycosaminoglycan in connective      umbilical cord, viterous
tissues. Hyaluronic acid serves as   humor, loose connective
a "backbone" for the assembly of     tissues
other glycosaminoglycans in
connective and skeletal tissue.
 Sulfated Glycosaminoglycan
Chondroitin             Cornea
Chondroitin 4-sulfate   Aorta, bone, cartilage, cornea
Chondroitin Sulfate A
Chondroitin 6-sulfate   Cartilage, nucleus Pulposus,
Chondroitin Sulfate C   Sclera, tendon, umbilical cord
Dermatan Sulfate        Aorta, heart valve,
Chondroitin Sulfate B   ligamentum nuchae, sclera,
                        skin, tendon
Keratan sulfate         Bone, cartilage, Cornea,
                        nucleus pulposus, kidney
Sulfated Glycosaminoglycan
Heparin           Mast Cells

Heparan Sulfate   Lung, Arterial wall, cell surface
proteins      Fibronectin: mediates adhesion between cells
              and extracellular matrix components
              Fibrillin: main component of microfibrils
              Elastin: hydrophobic protein which is the main
              component of elastic fibres
              Collagen: More than 19 different collagens
              have been identified
Structural    •Laminin: major component of basement
glycoproteins membranes
              •Entactin: binds laminin to type iv collagen
             Basement Membrane
The most important function of
  connective tissue is to
  support and nourish other
  tissue of body (Epithelia,
  Nervous and muscle tissues).
  The Basement Membrane is a
  thin layer of extracelluar
  material. The basement
  membrane is formed by the
  collagen fibers and
  proteoglycane. It supports
  the epithelia, muscles fibers
  and nerve fibers.
                                  Basement Membrane
The connective tissues are classified into various types
    depending on the following Four Factors.
1. Relative proportion of the various fibers present
2. Compactness and arrangement of fibers
3. Nature of ground substance (matrix)
4. Types of cells
On these ground the connective tissues are divided into
    basic Groups
A. Embryonal Connective Tissue
B. Adult Connective Tissues
                              Connective Tissue

   Embryonal                                                 Adult

                              Proper             Cartilage                   Bone

Mesenchyme                             Hyaline       Fibro             Elastic

                                                             Regularly Arranged



Areolar           Reticular              Adipose
      Embryonal Connective Tissue
 developmentally, the
 connective tissue are
 derived from mesoderm
 which one of the three
 Primary embryonic Layers
 (others two are ectoderm
 and Endoderm). Immature
 connective tissue of
 embryo derived from the
 mesoderm is called as
      Embryonal Connective Tissue
Mucous Tissue: At the later
 stages of development of
 foetus the mesnechmye
 acquired abundant of
 fibers, the increased
 number of fibers in
 mesenchyme now called
 as Mucous, which widely
 distributed through out
 the body of embryo.

                              Mucous Tissue
Loose Areolar connective
This type is widely
  distributed through out
  the body. All three basic
  components of
  connective tissue (cells,
  fibers and ground
  substance) are best
  represented in the loose     Green Lines - Collagen Fiber
                               Blue Circle - Mast Cells
  aerolar connective tissue.   Yellow arrows - Elastic Fiber
         1- Loose Areolar connective Tissue:
The two most common cell
  types, fibroblast and
  histiocytes are present but
  other varieties of cells also
  present. Collagenous fibers
  are more abundant but
  elastic fibers are also present.
Reticular fiber are few in
 Subcutaneous Tissue
  (Superficial & deep fascias)
 Mesentery                        Green Lines - Collagen Fiber
 Omentum                          Blue Circle - Mast Cells
                                        Yellow arrows - Elastic Fiber

This variety of loose
  connective tissue consists
  of reticular cells and
  reticular fibers. Reticular
  cells have a stellate shape
  and possess long
  processes which pass
  indifferent directions to
  make contact with
  neighboring cells.            Reticular Tissue

Forms the supporting
  network of the liver,
  spleen, bone marrow and
  lymphoid organs.
 Precursor for Fibroblast
 Producing Reticular fibers
 Phagocytic Properties
             3- ADIPOSE TISSUE
This variety of loose
  connective consists of
  entirely of fat cells,
  organized into lobules
  which are separated
  from each other by
  fibrous septa. Within a
  lobule, the individual fat
  cells are supported by a
  mesh work of delicate
  reticular fibers.
                  3- ADIPOSE TISSUE
 Food reserve for the body
 Chief site for energy storage
 Mechanical functions for
  shock absorbing pad for e.g.
  sole of foot.
 Temperature Regulation
      By production heat as a result
     of metabolism of fat.
       By acting as the insulator
     under the skin & preventing the
     heat loss.
This variety of connective
  tissue proper is
  characterized by close
  packing of fibers. It
  contains fewer cells and
  lesser amount of
  amorphous ground
  substance but the
  number of fibers are
According to the
   arrangement of its
   component fibers, the
   dense connective tissue
   is subclassify into two
1. Regularly Arranged
   connective Tissue
2. Irregularly Arranged
   connective Tissue
They are three types:-
a- Tendons: composed of
   almost entirely of closely
   packed collagen fibers. A
   few fibroblasts are present
b- Aponeuroses: have same
   structure as the tendon,
   but they are broad and
c- Ligaments: same as
   tendons but more sronger.
This type of dense connective
   tissue occurs in the form of
   sheets. It mainly consists of
   collagenous fibers, but elastic
   and reticular fibers are also
Dermis of skin
Capsules of some organs (liver,
   spleen, lymph nodes
Fibrous Sheaths of cartilage
Fibrous Sheaths of bone
              Composition of Blood
Blood (about 5.5 L in a man)
  consists of the cells and
  fluid. Blood is made up of
  two parts: formed
  elements, or blood cells,
  and plasma, the liquid in
  which the formed elements
  are suspended. The formed
  elements are erythrocytes
  (red blood cells), platelets,
  and leukocytes (white
  blood cells).
             Composition of Plasma
A typical sample of plasma
  is composed of 90%
  water, 8% protein, 1%
  inorganic salts, 0.5%
  lipids and 0.1% sugar, the
  rest being made of lesser
  components. The three
  main groups of protein in
  plasma are albumin,
  globulins & fibrinogen.
Erythrocytes contain large
  amounts of oxygen-
  carrying haemoglobin, are
  primarily involved in the
  transport of oxygen and
  carbon dioxide, and
  function exclusively within
  the vascular system. The
  whole mass of red blood
  cells and their precursors
  in the bone marrow is
  called the erythron.
The leucocytes constitute an
  important part of the
  defence and immune
  systems of the body and,
  as such, act mainly outside
  blood vessels in the
  tissues; thus the leucocytes
  found in circulating blood
  are merely in transit
  between their various sites
  of activity.
                 Types of Leucocytes
Five types of leucocyte are
   normally present in the
   circulation. These are
   traditionally divided into two
   main groups based on their
   nuclear shape and cytoplasmic
Mononuclear leucocytes
Platelets play a vital role
  in the control of
  bleeding (haemostasis)
  by plugging defects in
  Figure blood vessel walls
  and contributing to the
  activation of the blood-
  clotting cascade.

                   Electron micrograph of human platelets.
Blood is also a sub-variety of connective tissue. Blood
  consist of:
• Formed Elements:
  Erythrocytes 3-5 million cells / cubic millimeter
  Leucocytes 4000 -1100 cells / cubic millimeter
  Platelets 150,000-400,000 cells / cubic millimeter
• Plasma: the plasma is the liquid intercellular
  material that impart the fluid properties to the
  blood. The relative volume of the formed element
  and plasma is 45% and 55% respectively.
Although blood is a fluid but it may be taken as a
  connective tissue which consists of a ground
  substance, blood plasma, and cell elements, blood
  corpuscles. The only difference with the other
  connective tissues is that it does not contain fibers
  elements . The blood is slightly alkaline in nature
  (pH 7.4).
Plasma is a yellowish, straw-coloured liquid which
  consists mainly of water (>90%). The other 10% of
  the blood plasma consists of dissolved substances
  of which the following are the most important:
  Organic constituents (2%) which include nutrients
  such as glucose, fats, amino acids and vitamins.
Inorganic salts and ions which include ions such as
  bicarbonates, phosphates, sulphates, chlorides,
  calcium potassium, sodium and magnesium.
  Secretions such as enzymes and hormones.
Dissolved gases such as oxygen and carbon oxide, i.e.
  gases involved with respiration. Antibodies which
  are protective protein compounds. Plasma proteins
  (7%), the most important of which are fibrinogen,
  albumen and globulin.
In humans there are about 5 million
   erythrocytes per cubic millimetre
   of blood (3 to 5 million / cu mm) .
   Erythrocytes are small, round, bi-
   concave discs which float in the
   blood plasma. Each adult red
   blood cell represents a cell
   without a nucleus, which is
   surrounded by a thin, elastic
   membrane. They are soft, flexible
   and elastic and therefore move
   easily through the narrow blood
   capillaries. In living state each
   erythrocytes measures about 8
   mm in diameter and 2 mm in
   maximum thickness.
Approximately 90% of the
  content of each erythrocyte
  is haemoglobin which
  supplies the characteristic
  colour of the red corpuscles.
  Red blood cells are formed
  in the red marrow of long
  and flat bones, especially in
  the spongy regions in the
  heads of the long bones. The
  life span of an erythrocyte is
  approximately 4 months.
Leucocytes are far less numerous than red blood corpuscles.
  Leucocytes are larger than red blood corpuscles and have a
  definite nucleus. They are irregular in shape, slightly
  translucent and nearly colourless. They are able to change
  their shape because of the fact that they move by means of
  pseudopodia (false feet). Many are phagocytic, i.e. they are
  able to engulf micro-organisms and foreign intruders into
  their cytoplasm by flowing around them. There are five
  types of leucocytes which can be divided into two groups,
  namely granular white blood cells where the cytoplasm is
  granular, and non-granular white cells where the cytoplasm
  does not contain granules.
• Granular white blood cells
  Neutrophils 40-75%
  Eosinophils 1-6%
  Basophils 0.5-1%
• Non-granular white cells
  Lymphocytes 20-40%
  Monocytes 2-10%
Neutrophils, are the most abundant
  type of white blood cells and form
  an integral part of the immune
  system. Their name arrives from
  staining characteristics on
  Hematoxylin and Eosin (H&E)
  histological preparations, cells
  stained as salmon pink (a shade of
  pink tinged with yellow ). These
  phagocytes are normally found in
  the blood stream. However, during
  the acute phase of inflammation,
  particularly as a result of bacterial
  infection, neutrophils leave the
  blood vessels and migrate toward
  the site of inflammation in a
  process called chemotaxis.
Neutrophils has polymorph
  nucleus that means nucleus
  has characteristic
  multilobulated shape.
  Neutrophils are the most
  abundant white blood cells;
  they account for 70% of all
  white blood cells.
Function: Neutrophils are active
  phagocyte, capable of
  ingesting microorganisms or
Eosinophil: A type of
  leukocyte with coarse
  round granules of uniform
  size within its cytoplasm
  and typically a bilobate
  (two-lobed) nucleus.
  Eosinophils are so named
  because their cytoplasmic
  granules stain red with the
  dye eosin. Eosinophils
  normally constitute 1 to
  3% of the peripheral blood
 Responsible for combating
  infection by parasites in the
 Play role in allergy and
Gastrointestinal track,
Lymph nodes.
Basophils are the least common of
  the granulocytes, representing
  about 0.0% to 0.3% of
  circulating leukocytes (white
  blood cells). They contain large
  cytoplasmic granules. The
  nucleus is visible and it usually
  has 2 lobes. The mast cell, a cell
  in tissues, has many similar
  characteristics. Like all
  circulating granulocytes,
  basophils can be recruited out
  of the blood into a tissue when
Basophils play a role in acute
  allergic reactions. Their
  granules contain histamine
  and heparin, that are released
  in response to the presence of
  allergens. These substances
  cause increased vascular
  permeability, smooth muscle
  spasm, vasodilatation.
• Lymphocytes are present in blood
  and also in the lymphoid tissues
  and organs too, as well as the
  lymph circulating in the lymphatic
  vessel. The lymphoid organs
  include thymus, bone marrow,
  spleen, lymphoid nodules,
  palatine tonsils, Peyer's patches
  and lymphoid tissue of respiratory
  and gastrointestinal tracts.
• Most lymphocytes circulating in
  the blood is in a resting state.
  They look like little cells with a
  compact round nucleus which
  occupies nearly all the cellular
  volume. As a consequence, the
  cytoplasm is very reduced. In the
  blood, lymphocytes are 20-40 %
  of all leukocytes.
The two major classes of lymphocytes
   are: B cells and T cells, which are
   processed in the thymus. Both B cells
   and T cells recognize specific antigen
B cells work chiefly by secreting soluble
   substances called antibodies into the
   body's fluids. (This is known as
   humoral immunity.) Antibodies
   typically interact with circulating
   antigens such as bacteria and toxic
   molecules. T cells, in contrast,
   interact directly with their targets,
   attacking body cells that have been
   commandeered by viruses or warped
   malignancy. (This is cellular
Monocytes are the largest cells
 found in normal blood. The
 nucleus is centrally or
 peripherally located, indented,
 and ovoid or horseshoe-
 shaped; the nuclear
 chromatin is not as dense as
 that of lymphocytes. They
 consist of between 3 to 8
 percent of the leukocytes in
 the blood. In the tissues
 monocytes mature into
 different types of
 macrophages at different
 anatomical locations.
A monocyte is a leukocyte,
  part of the human body's
  immune system that
  protects against blood-
  borne pathogens and
  moves quickly (aprox. 8-12
  hours) to sites of infection
  in the tissues. Monocytes
  are usually identified in
  stained smears by their
  large bilobed nucleus.
These are small, colourless,
  plate-like discs. No nucleus
  is visible. They are not true
  cells but are cytoplasmic
  fragments of large cells
  (megakaryocytis) found in
  red bone marrow. When
  tissue is damaged and the
  platelets leave the blood
  vessels, they release a
  substance which
  transforms soluble
  fibrinogen in the plasma to
  a network of fibrin threads.
              MUSCULAR TISSUE
Consists of the muscular Tissue cells and intercellular
  substance. The cells of muscle tissue are very much
  elongated and therefore they are called as fibers.
  The muscle cells are specialized cells as they have
  got the property for contraction, as they are
  shorten and thickened actively. This property is due
  to presence of specialized contractile element, the
  myofibril, in the cytoplasm of muscle cells.
Muscle tissue may be classified as
Morphological classification (based on structure)

There are two types of muscle based on the morphological
  classification system

1. Striated
    Skeletal muscle
    Cardiac muscle
2. Non striated or smooth
    Smooth muscle
                Functional classification
There are two types of muscle based on a functional
  classification system

1. Voluntary
   Skeletal muscle
2. Involuntary
   Cardiac muscle
   Smooth muscle
            Properties of Skeletal Muscle
 Skeletal muscle consists of
  very long tubular cells (also
  called muscle fibers).
 Skeletal muscle fibers
  contain many peripherally
  placed nuclei.
 Skeletal muscle fibers show
  in many preparations
  characteristic cross-
  striations. It is therefore
  also called striated muscle.
      Properties of Skeletal Muscle
Skeletal muscle is
 innervated by the
 somatic nervous
Skeletal muscle makes
 up the voluntary
• The striated skeletal muscle cell is an
  elongated multinucleate cell, which is
  commonly called a "muscle fiber".
  The cytoplasm (also called
  sarcoplasm) of the fiber is packed
  with longitudinal myofibrils, and also
  contains numerous mitochondria, a
  smooth-surfaced endoplasmic
  reticulum (called the sarcoplasmic
  reticulum), a small Golgi complex. The
  term sarcolemma refers to the
  plasma membrane of the muscle cell.
whole muscle if made up of
 many smaller bundles
 known as fascicles. Each
 fascicle is made up of many
 muscle cells (myofibers).
 Myofibers contain
 cylindrical bundles of
 myofibrils which in turn
 contain many smaller
 bundles of myofilaments
 (Actin & Myosin).

A muscle cell or fiber is of consists
    a several myofibrils. Myofibrils
    are composed of individual
    contractile proteins called
    myofillaments. These
    myofilaments are generally
    divided into thick and thin
The thin myofilaments are
    composed mainly of a protein
    known as actin.
The thick myofilaments are
    composed mainly of the protein
It is the orderly overlapping of the
    actin and myosin filaments that
    give cardiac and skeletal muscle
    their striated appearance (light
    and dark bands).
         Properties of Cardiac Muscle
 Cardiac muscle consists of
  muscle cells with one centrally
  placed nucleus.
  Nuclei are oval, and located
  centrally in the muscle cell.
 Cardiac muscle is innervated
  by the autonomic nervous
 Cardiac muscle exhibits cross-
 Cardiac muscle is also called
  involuntary striated muscle.
Although equal in ultra
  structure to skeletal muscle,
  the cross-striations in cardiac
  muscle are less distinct. In
  contrast to skeletal muscle
  cells, cardiac muscle cells
  often branch at acute angles
  and are connected to each
  other by specializations of the
  cell membrane in the region
  of the intercalated discs.
  Intercalated discs invariably
  occur at the ends of cardiac
  muscle cells
This is a longitudinal section of
   cardiac muscle. The yellow
   arrows are indicating the
   Cardiac muscle fiber. It is
   different from muscle fibers in a
   couple ways. It is made up of
   more than one cell, it is not
   very symetrical and has
   intercelated discs. The blue
   arrows are pointing to the
   structure that gives away that
   this is a section of cardiac
   muscle which is the centrally
   located nuclei.
yellow arrow - Cardiac Muscle
Blue arrow - Centrally located
                    CARDIAC MUSCLE
Cardiac muscle closely resembles
  skeletal muscle, but has certain
  special features. Cardiac muscle is
  composed of separate cells and
  that intercalated discs are the sites
  of their end-to-end attachment.
  Cardiac muscle is striated but,
  unlike skeletal striated muscle, it is
  made up of a continuous,
  morphologically distinct network
  of branching and anastomosing
  cells. Cardiac muscle, like striated
  muscle, has actin and myosin
  microfilaments. Cardiac cells has
  centrally placed nucleus
             Properties of Smooth Muscle
 Smooth muscle consists of
  spindle shaped cells of variable
  The largest smooth muscle cells
  occur in the uterus during
  pregnancy. The smallest are
  found around small arterioles.
 Smooth muscle cells contain
  one centrally placed nucleus.
 The innervation of smooth
  muscle is provided by the
  autonomic nervous system.
                                     Centrally Located
 Smooth muscle makes up the         Nucleus
  visceral or involuntary muscle.
Smooth muscle cell are described
  as spindle shaped. That is they
  are wide in the middle and
  narrow to almost a point at
  both ends. Smooth muscle cells
  have a single centrally located
  nucleus. Smooth muscle cells
  do not have visible striations
  although they do contain the
  same contractile proteins as
  skeletal and cardiac muscle,
  these proteins are just laid out
  in a different pattern.
                  SMOOTH MUSCLE
Smooth muscle is found in
  the walls of many hollow
  organs, Like the small
  intestine, the urinary
  bladder, uterus, arteries
  and veins. The cytoplasm
  of the tapered smooth
  muscle cell contains
  longitudinally arranged
            Smooth Muscle fibers
• The green arrow is showing
  the Width of the smooth
  muscle tissue. While the
  yellow arrows are pointing
  to the nuclei of the smooth
  muscle cells.
• Yellow Arrow - Nuclei of
  Smooth Muscle Cell
• Green Arrow - Width of
  Smooth Muscle Tissue
                Nervous System
The Nervous System consists of two types of cells the
  “Excitable Cells” the Neurons and “Supporting Cells”
  Glial Cells.
Neurons are the structural and functional units of nervous
  system. About 100 million neurons present in nervous
Neurons connected to each other like electric circuit, they
  can generate the impulse and propagate to other nerve
Glial Cells, the supporting cells the they are present
  between neuron act like the insulator and perform a
  number of functions in nervous system
 Anatomical Division of Nervous system

Central Nervous System
• Brain
• Spinal Cord
Peripheral Nervous System
• Peripheral Nerves
• Ganglia
Nerve cells or neurons, are responsible for the reception,
  transmission, and processing of stimuli; triggering of
  certain cell activities; release of neurotransmitters and
  gathering the informations.
Different Parts of a Neuron:
• Dendrites, have the multiple processes, specialized to
  stimuli from environment, sensory epithelial cells, or other
• Cell Body or Perikaryon, the trophic center for the whole
  cells and receives the stimuli.
• Axon, a single Process specialized in generating or
  conducting nerve impulses to other cells, like Nerve,
  muscle and gland cells.
Axons may receive the informations from other Neuron, this
  informations only modified the transmission of action
  potential to other neurons.
The distal part of axon is usually branched and constitutes
  Terminal Aborization. Each branch of this aborization
  terminates on the next cell in dilatation called End Bulbs or
  Boutons, which interact with other neurons or non-nerve
  cells, forming physiological communication, the Synapses.
  Synapses transmit information to next cell in the circuit.
              Structure of Neuron
Neuron and their processes are variable in size and
 shape. The cell bodies can be spherical, ovoid or
 angular. Some of neuron are very large, measuring
 up to 150 mm in diameter. Other nerve cells are
 smallest nerve cells in the body, measuring 4-5 mm.
     Calcification of Neuron on the Basis of
              Number of Processes
• Unipolar Neurons: Have only one Process. e.g. Mesencephalic
   Nucleus of V Nerve, Amacrine cells
• Pseudo- unipolar neurons; Have got single processes which divided
   into a Peripheral and a Central Processes.
e.g. Dorsal Root ganglia and Sensory ganglion of Trigeminal Nerve
• Bipolar Neurons: have two Processes one each pole of cell body.
e.g. Bipolar Neurons of Special Senses
• Multi-polar Neurons: have got many Processes out of which one long,
   the axon and remaining the dendrites.
e.g. most of the neurons of the body, Anterior Horn cells, Purkinje cells,
   Pyramidal cells.
  Calcification of Neuron on the Basis of
• Motor (efferent) Neurons: control the organs such
  as muscles fibers, and exocrine and endocrine
• Sensory (afferent) Neurons: are involved in the
  reception o sensory Stimuli from the environment
  and from within body.
• Interneurons: Establish relationship among other
  neurons, forming complex network.
  Calcification of Neuron on the Basis of
              Length of Axons
• Golgi Type I Neurons: have got many Dendrites and
  very long Axon, take part in formation of Peripheral
  nerve. e.g. are pyramidal cells of cerebral cortex
  and anterior horn cells of the Spinal Cord.
• Golgi Type II Neuron: have got many branched
  dendrites and short neuron. These neurons are
  numerous in cerebral and cerebellar cortices. Most
  of the Inter-neurons are Golgi type II variety.
Cell body is the part of neuron that contains the Nucleus and
  surrounding the cytoplasm without cell processes. The cell
  body is the trophic center maintaining integrating of all
  parts of Neuron. The Perikaryon of most of neuron receives
  a great number of nerve endings that convey excitatory or
  inhibitory stimuli generated in other nerve cells.
Most of nerve cells have a spherical, larger, pale staining
  nucleus with prominent nucleolus. Binuclear nerve cells are
  seen in sympathetic and sensory ganglia. The chromatin is
  finely dispersed, reflecting the intense synthetic activity of
  these cells.
The cell body contains highly developed Rough Endoplasmic
  Reticulum organized into aggregates of parallel Cisternae.
  In the cytoplasm between cisternae are numerous
  polyribosomes, suggesting that the cells synthesize and
  both structural proteins and proteins for transport. When
  appropriate stains are used, Rough Endoplasmic reticulum
  and free Ribosomes appear under the light microscope as
  basophilic Granular areas called as NISSL BODIES. The
  number of Nissl bodies varies according to type of neuron
  and functional state. They are abundant in large nerve cell
  such as Motor neurons.