TISSUE GLANDS

1. DR NILESH KATE
MBBS,MD
PROFESSOR
DEPT. OF PHYSIOLOGY
TISSUE &
GLANDS

2. What is a Tissue?
 A Tissue is a group of
similar cells that
usually has a common
embryonic origin and
functions together to
carry out specialized
activities.

3.  A Tissue may he defined as
an aggregate of same type of cells combined
subserving the same general function
independently and united by varying amounts
of intercellular substance (e.g., blood, bones,
cartilage, muscle, nervous tissues, etc.).
 An Organ is a group of two or more tissues,
which basically function independently in some
instances, in particular patterns to form larger
functional units (e.g., blood vessels, kidney, skin,
glands, ‘etc.).

4. ELEMENTARY TISSUES OF THE HUMAN
BODY
The human body is composed of the following
elementary tissues:
1. Epithelial tissue.
2. Connective (Mesenchymal) tissue.
3. Muscular tissue.
4. Nervous tissue.

5. EPITHELIAL TISSUE
It Forms a limiting and a lining membrane .
The cells remain close together with a minimum
amount of intercellular cement substance.
There is generally a basement membrane upon
which the epithelial cells are set.
The cementing substance, here, is a Mucoprotein
containing Hyaluronic acid and Calcium salts.
Functions :
1.Protection 2. Absorption 3. Secretion 4. Excretion

6. EPITHELIAL TISSUE
CLASSIFICATION

7. EPITHELIAL TISSUE
 An epithelial tissue
consist of cells arranged
in continuous sheets, in
either single or multiple
layers.
 Epithelial tissue is a
avascular.
 The various surface of
epithelial cells often
differ in structure and
have specialized
functions.

8. Types of epithelium
 Covering and lining epithelium
 Glandular epithelium
Types of Covering and lining epithelium
1. Simple epithelium
a. Simple squamous epithelium
b. Simple cuboidal epithelium
c. Simple columnar epithelium (non ciliated & ciliated)
2. Stratified epithelium
a. Stratified squamous epithelium (keratinized & non
keratinized).
b. Stratified cuboidal epithelium
c. Stratified columnar epithelium
d. Transitional epithelium
3. Psuedostratified columnar epithelium (non ciliated &
ciliated)

9. Covering and lining epithelium
A. Simple squamous epithelium
Description:
single layer of
flat cells, centrally located
nucleus.
Location:
lines heart, blood vessels,
lymphatic vessels, air sacs
of lungs, glomerular
capsule of kidneys, and
inner surface of the
tympanic membrane,
Function:

10. B. Simple cuboidal epithelium
Description: single layer
of cube-shaped cells,
centrally located
nucleus.
Location: covers the
surface of ovary, lines
the anterior surface of
the lens of eye, lines
kidney tubules and
smaller ducts of many
glands, and secreting
ducts of some glands

11. C. Non ciliated simple
columnar epithelium
Description: single
layer of nonciliated
rectangular cells with
nuclei near base of
cells, contains goblet
cells and cells with
microvilli in some
locations.
Location lines the
gastrointestinal tract
from the stomach to

12. D. Ciliated simple columnar
epithelium.
Description: single
layer of ciliated
rectangular cells with
nuclei near base of cells,
contains goblet cells in
some locations.
Location: lines a few
portions of upper
respiratory tract,
uterine tubes (fallopian
tubes), uterus, some
paranasal sinuses, and
central canal of spinal

13. E. STRATIFIED SQUAMOUS
EPITHELIUM.
Description: several layers of
cells, cuboidal columnar
shape in deep layers,
squamous cells form the
apical layer and several
layers deep to it, cells from
the basal layer replace
surface cells as they are lost.
Location: keratinized variety
forms superficial layer of
skin, non keratinized variety
lines wet surfaces, such as
lining of mouth, oesophagus

14. PAPANICOLAOU TEST
A Papanicolaou test, Pap test , or pap smear involves
collecting and microscopically examination of epithelial cells that
have sloughed off the apical layer of a tissue.
A very common type of pap test involves examination the
cells from the nonkeratinized stratified squamous epithelium of
the cervix and vagina.
This type of Pap test is performed mainly to detect early
changes in the cells of the female reproductive system that may
indicate cancer or a precancerous condition.

15. F. STRATIFIED CUBOIDAL
EPITHELIUM.
Description: two or
more layers of cells in
which the cells in the
apical layer are cube-
shaped.
Location: Ducts of adult
sweat glands and
esophageal glands and
part of male urethra.
Functions: Protection
and limited secretion

16. G. STRATIFIED
COLUMNAR EPITHELIUM
Description: several
layers of irregularly
shaped cells, columnar
cells are only in the apical
layer.
Location: Lines part of
urethra, large excretory
ducts of some glands, such
as esophageal glands,
small areas in anal
mucous membrane, and
part of the conjunctiva of
the eye.

17. H. TRANSITIONAL EPITHELIUM.
Description: appearance is
variable, shape of cells in
apical layer ranges from
squamous (when stretched)
to cuboidal (when relaxed).
Location: Lines urinary
bladder and portions of
ureters and urethra.
Function: permits distention.

18. I. PSEUDOSTRATIFIED
COLUMNAR EPITHELIUM.
Description: Not a true stratified
tissue, nuclei of cells are at
different levels, all cells are
attached to basement membrane,
but not all reach the surface.
Location: pseudostratified ciliated
columnar epithelium lines the
airways of most of upper
respiratory tract, pseusostratified
nonciliated columnar epithelium
lines larger ducts of any glands,
epididymis, and part of male
urethra.
Function: secretion and movement
of mucus by ciliary action.

19. GLANDULAR EPITHELIUM
J. ENDOCRINE GLANDS.
Description: secretory
products (hormones)
diffuse into blood after
passing through
interstitial fluid.
Location: Include pituitary
gland at the base of brain,
pineal gland in brain,
thyroid and parathyroid
glands near larynx,
adrenal glands superior to
kidneys, pancreas near
stomach, ovaries in pelvic

20. GLANDULAR
 The holocrine type-Here
the secretion collects inside
the whole of the cell.
 The cell ultimately dies and
disintegrates and thus the
secretion is discharged.
 The adjoining younger cells
multiply and replace the
lost one,
 e.g., sebaceous glands..

21. GLANDULAR
(2’) The apocrine type— Here the
secretion collects in the outer
portion of the cell only, which
gradually swells up and bursts.
The rest of the cell remains intact
and alive, and repeats the
process again,
e.g.. mammary glands and
possibly the goblet. cells

22. GLANDULAR
 3) The MEROCRINE (or
epicrine) type—Here no
gross histological change is
visible in the cell.
 The secretion is quietly
liberated through the cell
membrane. e.g., digestive-
glands, endocrine glands,
etc.

23. K. EXOCRINE GLANDS
Description: Secretory products
released into ducts.
Location: Sweat, oil, and earwax
glands of the skin, digestive
glands such as salivary glands,
which secrete into mouth
cavity, and pancreas, which
secretes into the small
intestine.
Function: Produce mucus, sweat,
oil, earwax, saliva, or digestive
enzymes.

24. MULTICELLULAR EXOCRINE
GLANDS

25. CONNECTIVE (MESENCHYMAL)
TISSUE
General character.
1. They are all developed from the Mesoderm.
2. The intercellular substance is prominent
and may be considerable in amount. This is
a great contrast with the epithelial tissues.
3. The intercellular ground substance may
contain different types of fibrous elements.

26. CONNECTIVE TISSUE
Most abundant and most widely distributed.
Binds,supports & strengthens other body
tissues.
Protects & insulates internal organs.
Compartmentalizes structure like skeletal
muscle.
Eg – Blood, Adipose tissue

27. CONNECTIVE TISSUE CELLS
Mesodermal embryonic cells called mesenchymal
cells give rise to these cells.
Each major type of connective tissue contain an
immature class of cells (-blast)
Immature cells in
connective tissue - fibroblast
cartilage - chondroblasts
bone - osteoblast
Blast cells retain the capacity for cell division &
secrete the matrix.
Mature cells have reduced capacity for
cell division & matrix formation.

28. Classification
I . Embryonic connective tissue.
a) Mesenchyme.
b) Mucous connective tissue.
II. Mature connective tissue.
a) Loose connective tissue.
1. Areolar connective tissue.
2. Adipose tissue.
3. Reticular connective tissue.
b) Dense connective tissue
1. Dense regular connective tissue
2. Dense irregular connective tissue
3. Elastic connective tissue.

29. C. Cartilage.
1. Hyaline cartilage.
2. Fibrocartilage.
3. Elastic cartilage.
D. Bone tissue.
E. Blood tissue.
F. Lymph.

30. Representative cells and fibers in connective tissue

31. TYPES OF CELLS
FIBROBLAST
Large,flat cells with
branching.
Present in several
connective tissue.
They migrate through the
con.tissue, secreting the
fibres &ground substance
of the matrix.

32. 2.MACROPHAGE
 Develop from Monocyte.
 Have irregular shape with short
branches.
 Capable of engulfing bacteria &
Cellular debris by Phagocytosis.
 Some are fixed Macrophages.
Eg., Alveolar Macrophage – Lungs.
Spleen Macrophage – Spleen.

33. PLASMA CELLS
Small cells that develop from a type of WBC
called B Lymphocyte.
Secrete antibodies, proteins that attack or
neutralize foreign substance.
Important for bodies immune system.
Reside mostly in connective tissue in GIT and
Respiratory tract.
Also seen in salivary gland, Lymph node &
Bonemarrow

34. Mast cells
 Are abundant along
the side of the
blood vessels.
 They produce
histamine, which
dilates small blood
vessels as a part of
the inflammatory
response.

35. ADIPOCYTE
 Also called fat cell
are adipose cell
 They store
triglycerides.
 They are found
below the skin and
around organs such
as heart and kidneys.

36. White Blood Cell
 Are not found in normal connective tissue.
 But in response to certain condition they
migrate from blood to connective tissue.
Eg., Neutrophils and Eosinophils.

37. Connective Tissue Matrix
GROUND SUBSTANCE:
 Is a component between cells & fibres
 Supports cells, binds & provides a medium for
exchange between the blood and cells.
 Contains water and large molecules (complex
combinations of polysaccharid and protein)
 Polysaccharid include hyaluronic acid, chondrotin
sulfate, dermatan sulfate and keratan sulfate –
referred to as glycosaminoglycans or GAGs.
 Most important property of GAGs is that they trap
water making ground substance more jellylike.

38. Fibres
Three types of fibres are
embedded in the
matrix between the
cells.
 Collagen fibres
 Elastic fibres
 Reticular fibres

39. COLLAGEN FIBRES
 Are very strong & resist pulling forces and
promotes tissue flexibility
 Different types of collagen fibres in various tissues
have slightly different properties
Eg., Collagen in cartilage and collagen in bone
 They occur in bundles parallel to one another
 Collagen fibres consist of protein; collagen
 Are found in bone, cartilage tendon and ligaments.

40. ELASTIC FIBRES
 Are smaller in diameter then collagen fibres.
 Branch and join together to form a network within a
tissue.
 Consist of molecule of the protein, elastin surrounded by a
glycoprotein fibrillin which strengthens and stabilzes.
 Because of their unique molecular structure elastic fibres
are strong but can be stretched up to 150% of their
relaxed length (elasticity).
 Present in skin, blood vessels walls and lung tissues.

41. RETICULAR FIBRES
 Consists of collagen arranged in fine bundles and
a coating of glycoprotein.
Eg., Areolar tissue, Adipose tissue and smooth
muscle tissue.
 They are produced by fibroblasts.
 Are much thinner than collagen fibres and form
branching networks
 Provide strength and support
 Are plenty in reticular connective tissue which
form the stroma of soft organs like spleen and
lymph nodes.

42. MARFAN SYNDROME
 Inherited disorder caused by a defective
fibrillin gene.
 Tissues rich in fibrillin is malformed or
weakened.
 Most affected are the covering layer of the
bone,the ligament that suspends the lens,walls
of large arteries.

43. B. ADIPOSE TISSUE
Description:
consists of adipocytes, cells specialized to
store triglycerides (fats) as a large
centrally located droplet, nucleus and
cytoplasm are peripherally located.
Location:
Subcutaneous layer deep to skin, around
heart and kidneys, padding around joints.
Function:
Reduces heat loss through skin, serves as
energy reserve, supports and protects. In
newborns it generates considerable heat
to maintain proper body temperature.

44. C. RETICULAR CONNECTIVE
TISSUE
Description:
Consists of a network of interlacing
reticular fibers and reticular cells.
Location:
Stroma(supporting framework) of liver,
spleen, lymph nodes, red bone marrow
and around blood vessels and muscles.
Function:
Forms stroma of organs, binds together
smooth muscle tissue cells, filters and
removes worn out blood cells and
microbes in lymph nodes and spleen.

45. Dense Connective Tissue
D. Dense regular connective tissue.
Description:
Matrix looks shiny white,
consists mainly of collagen
fibers arranged in bundles,
fibroblasts present in rows
between bundles.
Location:
Forms tendons (attach muscle
to bones), most ligaments
(attach bone to bone) and
aponeuroses (sheet like
tendons that attach muscle to
muscle or muscle to bone).
Function:
Provides strong attachment
between various structures.

46. F. ELASTIC CONNECTIVE TISSUE.
Description:
Consists of predominantly freely
branching elastic fibers,
fibroblasts present in spaces
between fibers.
Location:
Lung tissue, walls of elastic
arteries, trachea, bronchial
tubes, true vocal cords,
suspensory ligament of
penis, and ligaments between
vertebrae.
Function:
Allows stretching of various organs.

47. G. Hyaline Cartilage.
Description:
Consists of a bluish-white, shiny
ground substance with fine collagen
fibers and many chondrocytes, most
abundant type of cartilage.
Location:
Ends of long bones, anterior ends of
ribs, nose, parts of larynx, trachea,
bronchi, bronchial tubes, and
embryonic and fetal skeleton.
Function:
Provides smooth surfaces for
movement at joints, as well as
flexibility and support.

48. BONE TISSUE J. COMPACT BONE
Description:
Compact bone tissue consists of
osteons (Haversian systems)
that contain lamellae, lacunae,
osteocytes, canaliculi and
central (Haversian) canals. By
contrast, spongy bone tissue
consists of thin columns called
trabeculae, spaces between
trabeculae are filled with red
bone marrow.
Location:
Both compact and spongy bone
tissue make up the various parts
of bones of body.
Function:
Support, protection, storage,
housses blood forming tissue,
serves as levers that act together

49. Blood tissue K. Blood
Description:
Consists of blood plasma and
formed elements; red blood
cells (erythrocytes), white
blood cells (leukocytes), and
platelets (thrombocytes).
Location:
Within blood vessels (arteries,
arterioles, capillaries,
venules, and veins) and
within the chambers of the
heart.
Function:
RBCs transport oxygen and
carbon dioxide: WBCs carry on

50. MUSCULAR TISSUES
The characteristics property of muscular tissue is its ability to
contract when exited . there are different types of muscular
tissues. These can be classified according to
(a) the presence of cross-striation
(i) striated and
(ii) non striated (plain or smooth);
(b) nature of control
(i) voluntary; (controlled by volition),
(ii) involuntary ay (not controlled by volition); and lastly

52. (c) distribution
(i) skeletal,
(ii) cardiac,
(iii) visceral.
These different types of classifications can be
summarised in the following way:
1. Skeletal—striated voluntary (Fin. 59).
2. Cardiac—striated involuntary (Fin. 60).
3. Visceral—non-striated (plain or smooth)
involuntary

53. MUSCLE TISSUE (THREE TYPES)
 Skeletal muscle
 Smooth muscle
 Cardiac muscle
FUNCTIONS OF MUSCLE TISSUE:
 Muscle functions alternate by phases of contraction
and relextation
 When fibres contract they become thicker and shorter.
 Skeletal muscle fibres are stimulated by motor nerve
impulses originating from brain and spinal cord.
 Smooth and cardiac muscle have the intrinsic ability to
initiate contraction.
 In addition
1. ANS
2. Hormones
3. Local metabolites also stimulate

54. MUSCLE TONE
 This is the partial contraction of muscle. Skeletal
muscle tone is essential for maintenance of posture
– sitting and standing
MUSCLE FATIGUE
 If a muscle is stimulated to contract at a very
frequent intervals its response gradually
becomes depressed and will in time cease.

55. ENERGY SOURCE FOR MUSCLE
CONTRACTION :
 The chemical energy (ATP) which muscle require
is derived from the breakdown of carbohydrate &
fat (catabolism).
 Protein molecules inside the fibres are used to
provide energy when carbohydrate and fat are
deficient. For them oxygen is required.
 When the breakdown process and the release of
energy is complete, the waste products are co2
and water.

56. ISOTONIC CONTRACTION:-
Tension remains same. Changes
occur in the length.
Eg., Flexion of arm.
ISOMETRIC CONTRACTION:
Length same . Tension increased
Eg., Pulling any heavy object.
TISSUE REGENERATION
 By mitosis tissue regeneration occur.

57. MEMBRANES : are sheets of epithelial tissue and
their supporting connective tissue that cover
or line internal structures (or) cavities.
 Eg.,mucous, serous, synovial
MUCOUS :
GIT, respiratory system, urinary
tracts.
SEROUS:
secrete serous watery fluid. They consists
of double layer of loose areolar connective
tissue (parietal and visceral layer) eg., Pleura,
pericardium.

58. SYNOVIAL MEMBRANE: membrane lining the
joint cavities and surrounding tendons.
Synovial membrane secrets clear, sticky, oily
synovial fluid, act as lubricants to the joints.
GLANDS:
Glands are group of epithelial cells which
produce specialized secretions
 Exocrine glands & endocrine glands

59. NERVOUS TISSUE
This is a highly specialised tissue for
reception, discharge of stimuli. and
transmission. It is made up of nerve cells and
their processes, called the nerve fibres.

60. APPLIED ASPECT
1. When the motor nerve to a skeletal muscle is cut it
causes:
i) ‘atrophy’ of the muscle i.e., shrinkage of muscle
fibers, which finally gets replaced by fibrous tissue
(fibrous muscle)
ii) Complete paralysis of the muscle called flaccid
paralysis
iii) appearance of fine, irregular contractions of
individual fibers called fibrillations.
iv) abnormal excitability of the muscle and increases
its sensitivity in circulating A-ch (Denervation
hypersensitivity)

61. RELATION OF THYMUS TO
Myasthenia gravis
Myasthenia gravis is
a disorder of neuromuscular transmission
characterized by attacks of severe muscular
weakness, fatigability specially affecting
eyelids, deglutition, speech and is relieved by
anticholinesterase, (eg.,neostigmine)

62. MUSCULAR DYSTROPHY
It is a syndrome characterized by progressive muscle
weakness due to mutation in dysrophin gene, which results
in congenital defect in dystrophin-glycoprotein complex.
MYOTONIA
A condition characterized by difficulty and slowness in
relaxing muscle after voluntary effort.
When muscle fibers are completely depleted of ATP and
phosphocreatine, they develop a state of extreme rigidity
called rigor. When this occurs after death, the condition is
called rigor mortis. In rigor, almost all of the myosin heads
attach to actin but in an abnormal, fixed and resistant way.

63. Thank
You