The document discusses the four main types of tissues in the human body: epithelial, connective, muscle, and nervous tissue, detailing their structures and functions. Epithelial tissue serves protective and absorptive roles, connective tissue supports and binds other tissues, muscle tissue facilitates movement, and nervous tissue transmits signals throughout the body. Each tissue type is further categorized into subtypes based on specific characteristics and functions.

1. Tissue level of organization
Tissues

2. Tissue
The tissues of the body consist of large numbers of cells
and they are classified according to the size, shape and
functions of these cells.

3. Classification of Tissues
There are four main types of tissue, each of which has
sub divisions. They are:
1.Epithelial tissue or epithelium
2.Connective tissue
3.Muscle tissue
4.Nervous tissue.

4. Epithelial tissue provides a covering
(skin, the linings of the various passages inside the body).
Connective tissue supports other tissues and binds them
together (bone, blood, and lymph tissues).

5. Muscle tissue includes striated (also called voluntary)
muscles that move the skeleton, and smooth muscle,
such as the muscles that surround the stomach.
Nerve tissue is made up of nerve cells (neurons) and is
used to carry "messages" to and from various parts of
the body.

6. 1. Epithelial Tissue
Epithelial tissue, commonly referred to as epithelium
is made up of one or more layers of cells that covers or
lines the external and internal surfaces of various body
parts.
It consists of variously shaped cells closely arranged
in one or more layers.

7. Epithelial tissue
This group of tissues is found covering the body and
lining cavities and tubes.
It is also present in glands.
Functions of Epithelium tissues
• Protection of underlying structures from, dehydration,
chemical and mechanical damage
• Secretion
• Absorption

8. The cells are very closely packed and the intercellular
substance, called the matrix.
The cells usually lie on a basement membrane.
Epithelial tissue may be:
• simple: a single layer of cells
• stratified: several layers of cells.

9. Simple Epithelium
 Simple epithelium consists of a single layer of identical
cells and is divided into four types.
 It is usually found on absorptive or secretory
surfaces, the single layer enhances these processes.
 The types are named according to the shape of the cells,
which differs according to their functions.
 The more active the tissue, the taller are the cells.

10. Classification of epithelium tissues
Epithelium tissues are classified in to Two types
1.Simple Epithelium
 Squamous
 Cuboidal
 Columnar
 Ciliated
 Pseudostratified
 Glandular
2.Compound epithelium

11. 1.Squamous (pavement) epithelium
This is composed of a single layer of flattened cells.
The cells fit closely together like flat stones, forming a thin
and very smooth membrane.

12. Squamous (pavement) epithelium
This epithelium occurs in the walls of blood
vessels, air sacs of the lungs where oxygen
and carbon dioxide are exchanged,lymph
vessels, wall of Bowman’s capsule, loops of the
nephrons of Kidneys.

13. Functions of squamous epithelium
Exchange of gases.
Filtration in Bowman’s Capsule.
Exchange of materials in blood capillaries and
tissue fluid

14. Diffusion takes place freely through this thin,
smooth, inactive lining of the following
structures:
Heart
Blood vessels
Lymph vessels where it is also known as
Endothelium
alveoli of the lungs

15. 2.Cuboidal (cubical) epithelium
Cuboidal cells epithelium are single-layered cells that are
shaped like a cuboid.

16. Cuboidal (cubical) epithelium
These are found in small collecting ducts of
kidneys, pancreas, and salivary glands
Cuboidal epithelium is actively involved in
secretion,absorption and excretion

17. Functions of cuboidal epithelium
The main function of the cuboidal cell
epithelium is to help in absorption, excretion,
and secretion.

18. 3.Columnar Epithelium
This is formed by a single layer of cells,
rectangular in shape, on a basement membrane.

19. It is found lining the organs of the alimentary tract
and consists of a mixture of cells.
Some absorb the products of digestion and others
secrete mucus.
Mucus is a thick sticky substance secreted by
modified columnar cells called goblet cells.

20. 4.Ciliated epithelium
This is formed by columnar cells each of which
has many fine, hair-like processes, called cilia.
The cilia consist of microtubules inside the
plasma membrane that extends from the free
border (luminal border) of the columnar
cells.
.

21. Ciliated epithelium
The wave-like movement of many cilia propels
the contents of the tubes, which they line in one
direction only

22. Ciliated epithelium is found lining the uterine
tubes and most of the respiratory passages.
In the uterine tubes the cilia propel ova towards
the uterus and in the respiratory passages they
propel mucus towards the throat.

23. Functions ofCiliated Epithelium
It is responsiblefor passingof ovumthroughfallopian
tube.
In respiratory tract, it helpsin expellingthe mucus and
particles trappedin it, towardsthe pharynx.

24. Stratified Epithelia
Stratified epithelia consist of several layers of cells of
various shapes.
The superficial layers grow up from below.
Basement membranes are usually absent.
The main function of stratified epithelium is to protect
underlying structures from mechanical wear and ear.
There are two main types: stratified squamous and
transitional

25. Stratified squamous epithelium
This is composed of a number of layers of cells
of different shapes representing newly formed
and mature cells.
In the deepest layers the cells are mainly
columnar.as they grow towards the surface, they
become flattened and are then shed.

26. Stratified epithelium

27. Non-keratinised stratified epithelium.
This is found on wet surfaces that may be
subjected to wear and tear but are protected
from drying.
e.g. the conjunctiva of the eyes, the lining of the
mouth, the pharynx, the esophagus and vagina.

28. Keratinized stratified epithelium
This is found on dry surfaces that are subjected
to wear and tear, i.e. skin, hair and nails. The
surface layer consists of dead epithelial cells to
which the protein keratin has been added.

29. This forms a tough, relatively waterproof
protective layer that prevents drying of the
underlying live cells.
The surface layer of skin is rubbed off and is
replaced from below

30. Transitional epithelium
This is composed of several layers of pear-
shaped cells and is found lining the urinary
bladder.
It allows for stretching as the bladder fills.
Urinary bladder.

31. Connective tissue
Connective tissue is the most abundant tissue in the
body.
The cells forming the connective tissues are more
widely separated from each other than those
forming the epithelium, and intercellular substance
(matrix) is present in considerably larger amounts.

32. There may or may not be fibres present in the
matrix, which may be of a semisolid jelly-like
consistency or dense and rigid, depending upon
the position and function of the tissue.

34. 2. MuscularTissue
Muscle: an organ composed of one of
three types of muscle tissue (skeletal,
cardiac or smooth) , specialized for
contraction to produce voluntary or
involuntary movement

35. Muscular Tissue

36. Muscular Tissue
A group of cells (fibers) specialized to
produce motion in response to muscle
action potentials by its qualities of
contractility, extensibility, elasticity and
excitability

37. Properties of Muscular Tissue
1. Excitability: an ability of muscle to
generate impulse.

38. 2. Contractility: it is either shortening or
development of tension or both.
A. Isotonic Contraction-contraction in which
tension remains same whereas changes
occurs in the length of muscle fiber. E.g.
flexion of arm
B. Isometric Contraction-contraction in
which length of muscle fibers remain
same and tension is increased. E.g.
holding book by hand, pulling any heavy
object

39. 3. Muscle Tone- the muscle fibers always
maintain a state of slight contraction with
certain degree of vigor and tension. This
is a state of partial contraction of
muscles. It is achieved by the contraction
of a few muscle fibres at a time.
4. Extensibility- an ability of muscle fibers
to stretch without being damaged
5. Elasticity- an ability of muscle fibers to
return to its original length and shape
after contraction or extension

40. Functions of Muscular tissue:
Through sustained contraction or alternating
contraction & relaxation, muscular tissue
has four functions:
1. Producing Body Movements-
movements of the whole body such as
walking and running, and localized
movements such as holding pen,
nodding head, rely on integrated
functioning of bones, joints and skeletal
muscles

41. 2. Stabilizing Body Positions- Skeletal
muscle contractions stabilize joints and
help maintain body positions such as
sitting & standing
3. Storing and moving substances
within body- sustained contractions of
sphincters temporarily stores food in
stomach and urine in urinary bladder.
Cardiac muscle contractions pump blood
through blood vessels of the body.
-cont.

42. Smooth muscles contractions move food
and substances such as bile, enzymes
through g.i.t., push gametes through
passageway of reproductive system,
propel urine through urinary system.
Skeletal muscle contractions promote the
flow of lymph and helps the return of blood
to heart.
4.Generating heat- As muscular tissue
contracts, it produces heat, by
thermogenesis. Heat generated by muscle
is used to maintain normal body temp.

43. Types of Muscular Tissue
Muscle Striations Control Nerve
Supply
Skeletal Present Voluntary Somatic
Cardiac Present Involuntary Autonomic
Smooth Absent Involuntary Autonomic

44. Cells of connective tissue
Connective tissue, excluding blood (Ch. 4), is
found in all organs supporting the specialized
tissue.
The different types of cell involved include:
 fibroblasts
 fat cells
 macrophages
 leukocytes

45. COMPOSITION OF
CONNECTIVE TISSUE
• Collagen Fibers: Large fibers made of the
protein collagen and are typically the most
abundant fibers. Promote tissue flexibility.
• Elastic Fibers: Intermediate fibers made of the
protein elastin. Branching fibers that allow for
stretch and recoil
• Reticular Fibers: Small delicate, branched fibers
that have same chemical composition of
collagen. Forms structural framework for organs
such as spleen and lymph nodes.

46. CLASSIFICATION OF CONNECTIVE
TISSUE
1) Loose connective tissue :
a) Areolar connective tissue
b) Adipose connective tissue
c) Reticular connective tissue
2) Dense connective tissue:
a) Dense regular connective tissue
b) Dense irregular connective tissue
c) Elastic connective tissue

47. CLASSIFICATION OF
CONNECTIVE TISSUE
3) Cartilage:
a) Hyaline cartilage
b) Fibro cartilage
c) Elastic cartilage
4) Bone tissue
Liquid connective tissue
a) Blood tissue
b) Lymph

48. Loose connective tissue
Areolar Connective tissue:
1)They forms a loose network in intracellular
material .
2)It consists of collagen, elastic fibers, reticular
fibers and several kinds of cells.
Location: Below the skin, fill space between
muscles, supports blood vessels and nerves in
alimentary canal.
Functions: It gives strength, elasticity and
support to tissue.

49. Areolar Connective tissue:

50. ADIPOSE CONNECTIVE TISSUE
• It consists of adipocytes which stores fat.
Location: It is present in subcutaneous layer deep in
the skin, around the heart and kidneys
Functions :
• Prevents heat loose from body.
• Act as reservoir of energy.
• It give shape to the limbs and body.
• It protects underlying organ from injury.

51. ADIPOSE CONNECTIVE TISSUE

52. RETICULAR CONNECTIVE
TISSUE
• It contains reticular fibers and reticular cells.
• Location: It is present in the supporting
framework of liver, spleen, lymph nodes, red
bone marrow and it is also found around blood
vessels and muscles.
• Functions: It binds together smooth muscle
tissue cells, filters and removes microbes in the
lymph node.

53. RETICULAR CONNECTIVE
TISSUE

54. DENSE CONNECTIVE TISSUE
• In this tissue, fibers are densely packed.
• The fiber content is higher.
• Cell content is lower as compared to loose
connective tissue.

55. DENSE REGULAR CONNECTIVE
TISSUE
• Bundles of collagen fibers are arranged in
parallel patterns to provide strength to tissue.
• Fibroblast are appear in rows between the
fibers.
• It is tough in nature.
Location: It forms tendons (attach muscle bone)
and ligaments(attach bone to bone).
Functions: It provides strong attachment to
structure.

56. DENSE REGULAR CONNECTIVE
TISSUE

57. DENSE IRREGULAR
CONNECTIVE TISSUE
• It contains collagen fibers which are irregular
arranged and a few fibroblasts are appear in
rows between the fibers.
Location: It present in dermis layer of skin,
membrane capsules around kidneys, liver,
testes and lymph node, heart valves.
Functions: It provides strength to different
organs.

58. DENSE IRREGULAR
CONNECTIVE TISSUE

59. ELASTIC CONNECTIVE TISSUE
• It consists of freely branching elastic fibers.
• Fibroblast are present in space between fibers.
• It is yellowish in colour.
Location: It is present in tissues , walls of elastic
arteries, trachea, bronchial tubes and vocal
cords.
Functions: It allows stretching of various
organs.

60. ELASTIC CONNECTIVE TISSUE

61. CARTILAGE
• It consist of network of closely packed
collagen fibers and elastic fibers.
• The cells of mature cartilage called as
chondrocytes.

62. HYALINE CARTILAGE
• It is bluish white in color.
• It consists of fine collagen fibers and many
chondrocytes.
Location: It is present at the end of long bones,
anterior ends of ribs, nose and parts of larynx,
trachea, bronchi, bronchial tubes.
Function: It provides small surface for
movement at joints, flexibility and support.

63. HYALINE CARTILAGE

64. FIBRO CARTILAGE
• It is strongest form of cartilage.
• The chondrocytes are scattered among the
bundle collagen fibers within the extracellular
matrix.
Location: It is present in inter-verteblar disc.
Functions: It covers and protects bony structures
of body.

65. FIBRO CARTILAGE

66. ELASTIC CARTILAGE
• The chondrocytes are located within a
threadlike network of elastic fibers within
extracellular matrix.
Location: It is present in pinna of ear and top of
larynx.
Functions: It provides strength and elasticity
and maintain the shape of certain organs such
as the external ear.

67. ELASTIC CARTILAGE

68. 4. Nervous Tissue
The human body is composed of approximately
200 distinctly different types of cells. These cells
are organized into four basic tissues that in turn,
are assembled to form organs.

69. Nervous tissue consists of two kinds of
nerve cells:
Neurons are the basic structural unit of the
nervous system.
Each cell consists of the following parts; the cell
body contains the nucleus and other cellular
organelles.

70. The dendrites are typically short,
slender extensions of the cell body that
receive stimuli.
The axon is typically a long, slender
extension of the cell body that sends
stimuli.

71. The axon branches are, typically, smaller
extensions of the axon.
Neuroglia, or glial cells, provides support
functions for the neurons, such as insulation or
anchoring neurons to blood vessels.

72. Neuron

73. References:
1. Presentation on Introduction To Human Anatomy
& Physiology, By Mr. Abhay Shripad Joshi.
2. Human Anatomy and Physiology-I,
By Dr. Mahesh Prasad, Dr. Antesh Kumar
Jha, Mr. Ritesh Kumar Srivastav, Nirali
Prakashan, As per PCI Syllabus.
Page No. 1.23 to 1.28.
3. www.google.com.

74. THANK YOU