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HUMAN TISSUES by: pr ,Dr, Sanaa El-Sherbiny
Cells are :The unit of structure of
living creatures
In 1665 Robert Hooke, observed thin
sections of cork with a simple
microscope of his own
making. He described his
findings as having
the appearance
of cells in a jail.
Cells and Tissues
• Cytology or cell biology : the study of cells
• Histology : the micro-study of living tissues
and organs of all living creatures .
• Levels of Organization of human:
cell---tissue --organ---systems--body
• Types of organisms:
• Unicellular Organism:
-consists of one cell (bacteria , amiba)
• Multicellular Organism:
-consists of more than one cell ( plants and animals)
Human cell formed of 3 Main Parts
1) Nucleus – a spherical body often located near the center of the cell which contains the chromosomes that carry the genetic code of the cell and serves as the cell’s master control center.
2) Cytoplasm – the fluid medium for the many molecules and organelles the cell contains
3) Cell organelles: Membranous and
non-membranous cell organelles .
Tissue : definition
•Types of tissues
A group of connected, interdependent cells
that cooperate to perform
a specific function
1. Epithelial Tissue
2. Connective Tissue
3. Muscle Tissue
4. Nervous Tissue
Epithelial Tissues • General Features
1- Formed of one or more Cellular Layer
on a Basement Membrane.
2- Not Penetrated By Blood Vessels ,
get Blood supply from underlying connective tissue.
3- but nerve fibers ramify between cells.
4- Rapid Rate of Cell Regeneration.
5- Embriologically derived from
ectoderm, mesoderm or endoderm.
** Structural Classification According to number of layers and
Cell Shapes: 2 types :
simple and stratified.
**Functional Classification: 1-covering-epith.
2-glandular-epith.
3-neuro-epith.
Classifications of Epithelia
• Simple • stratified
Simple epithelium • One layer of cells on a
basement membrane
SIMPLE Squamous . epithelium
**structure: one layer of flat cells
on a basement membrane
**Sites : – THE Lung ALVEOLI
– ENDOTHELIUM
LINING blood and
LYMPHATIC
VESSELS
WHICH 1
IS
YOURS…
1 or 2…?
1
2
simple cuboidal
epithelium
** formed of one layer of cubical cells on a basement membrane
– Sites: lining the secretory
follicles in salivary and
– Thyroid glands.
– Lining medium sized ducts of glands
– Lining kidney tubules .
Simple Columnar Epithelium one layer of columnar cells on a basemen
membrane
Figure 4.3c
simple columnar epithelium (types)
1-Non modified :lining ducts of glands
• 2-Modified:- absorptive Epithelium, lining
the , small intestine
- secretory Epithelium, lining the stomach.
- ciliated, Epithelium, lining the
uterus and fallopian tube
Microvilli
Pseudo-stratified Columnar
Epithelium
• One layer of overcrowded cells with
many levels of nuclei , so is one type
• Of simple epithelium
Pseudostratified Ciliated Columnar Epithelium lining trachea and bronchi
Figure 4.3d
20
بسم هللا الرحمن الرحيم
)رأمنمممار مممما خرر أممما خ ران ممم أولمممير ر ممذااروخمخر رممممنرخطفم يخخ
رل مممارممم م ررمخبمم نخخر وضمموأمممخر ممماخر ممممارممممنرخ مممخرر
رر العظامرووخررم يخخر مخمنة رر شأوآرأونرم خ هارالنذىرأ
رع يخر ر ق )ووخخربكخر
عظيم له ال
(79: 77 سورة يس) صدق ال
Stratified Epithelium
Stratified Squamous Keratinized
Epithelium ( st,sq,ker,epith)
Function: Protection
Locations:
epidermis
of
the skin
Stratified Squamous
Epithelium
• Many layers
• Basal one columnar
• Intermediate layers
• Polygonal in shape
• Upper layers are
• Squamous flat cells with
central oval nuclei
Stratified Squamous non-keratinized Epithelium
:found in* mouth cavity
*conjunctiva of the eye
Figure 4.3e
Transitional Epithelium
Figure 4.3h
TRANSITIONAL EPITH.
• many cell layers -
stretch
• cube-shaped and
elongated cells
• line urinary
bladder, ureters,
and part of urethra
Transitional Epithelium
• 6-8 layers in empty
bladder
• 2-3 layers in full one
• Basal layer columnar
on ill defined b.m
• Intermediate layers
polygonal
• Upper layer large
may be bi-nucleated
• Second layer flask
shaped
GLANDULAR EPITHELIUM
• THE CELLS ARE SPECIALISED FOR SECRETION.
• ACCORDING TO NUMBER OF SECRETORY CELLS WE HAVE:
• UNICELLULAR GLANDS AS GOBLET CELLS.
• MULTICELLULAR GLANDS AS SALIVARYGLANDS.
• Uni-cellular glands as
GOBLET CELLS.
• Multi-cellular
gland
1-ACCORDING TO
SECRETORY PASSAGES
• A-EXOCRIN GLANDS:
• Have duct system
• SUCH AS :salivary glands.
• -ENDOCRINE GLANDS:
• No ducts ,secrete directly into the blood
• SUCH AS:THE PITUITARY GLAND.
Types
Major ♥ Submandibular
♥ Sublingual
♥ Parotid
Minor ♥ Buccal
♥ Labial
♥ Palatine
♥ Lingual
Second Year Section 4 2009/2010
Function Secretion of
saliva
Second Year Section 4 2009/2010
Structure
Second Year Section 4 2009/2010
• Connective tissue element Stroma
• Epithelial element Parenchyma
stroma
1- Capsule
2- Trabeculae
3- Reticular network
Parenchyma 1.Secretory part (salivary acini)
2.Transport system (branching
ducts)
Model of the gland: a bunch of grapes: berry= acinus
stalk of berry: intercalated duct
Classification
According to the nature of
secretion
There are 3 types:
Mucous
Serous
Mucoserous
Second Year Section 4 2009/2010
Second Year Section 4 2009/2010
4-ACCORDING TO SHAPE OF
SECRETORY PART
• ALVEOLAR GLANDS:
• AS MAMMARY GLANDS.
• Tubular GLANDS
• AS GASTRIC GLANDS
• TUBULO-ALVEOLAR
GLANDS AS
SALIVARY GLANDS
NEURO EPITHELIUM • THE EPITHELIAL CELLS ARE SPECIALIZED FOR
RECEPTION OF
• EXTERNAL STIMULI SUCH AS:
• RETINA OF THE EYE, OLFACTORY MUCOSA,
TASE BUDS and ORGAN OF CORTI .
• Neuroepithelium is formed of :
• Sensory cells &
• Supporting cells
• And stem basal
• cells
Taste buds
Olfactory epithelium and all neuro-
epithelium are formed of3 types of cells :
1-sensory cells 2-supporting cells
and 3-basal stem cells
Name this type of epithelium-------
Mention two sites for simple Squamous
Epithelium 1----------
2-------------
Figure 4.3a
This is --- ---- epithelium
Name this type of epithelium-------
Stratified
epithelium
This is ----- ----- ------
epithelium
it is found in -----------------------
This epithelium is --- ----- --------
-------- ------- with ------------ cells.
This is ------ ----- ----------------
its site is -----------------------
The arrow indicates ----- -------
This is ------ ----- -------------epithelium
its site is -----------------------------------
• Identify a tissue type
• 1. mucous gland
• 2. stratified columnar epithelium
• 3. stratified squamous epithelium
• 4. unicellular exocrine gland (goblet cell)
• Identify a tissue type
• 1. alveolar gland
• 2. mucous gland
• 3. simple columnar
epithelium
• 4. simple cuboidal
epithelium
• Identify a tissue type
• 1. mucous gland
• 2. serous gland
• 3. stratified columnar epithelium
• 4. pseudostratified
• 5. transitional epithelium
• Identify a tissue type
• 1. stratified cuboidal epithelium
• 2. stratified columnar epithelium
• 3. simple columnar epithelium
• 4. mucous acinus
• 5- simple columnar epithelium with goblet cells(absorptive )
• This is a histological section of:
• 1- Stratified squamous epithelium.
• 2- simple squamous epithelium.
• 3- simple cuboidal epithelium.
• 4- simple columnar epithelium.
• 5- stratified columnar epithelium.