OSCe.pdf in Babylon university College o

It is a PDF about our histo class in hamurabi medical college in Iraq

2. •40% of body weight
•Fibers = multinucleate cells (embryonic cells fuse)
•Striated
•Voluntary contraction
SKELETAL MUSCLES

3. SKELETAL MUSCLES
ATTACHMENTS
•One bone to another
•Muscles usually span one or more joints
–Biarticular / multi-joint muscles
–Cause movements at two joints

4. SKELETAL MUSCLES
COVERINGS
Epimysium: surrounds
whole muscle
Perimysium is
around fascicle
Endomysium is around each
muscle fiber

5. SKELETAL MUSCLES
•Sarcomere
–Basic unit of contraction
–Myofibrils are long rows of
repeating sarcomeres
–Boundaries: Z discs (or lines)

6. MYOFIBRILS
•Made of three types of
filaments (or
myofilaments):
–Thick (myosin)
–Thin (actin)
–Elastic (titin)
______actin
_____________myosin
titin_____

7. SLIDING FILAMENT MODEL
__relaxed sarcomere__ _partly contracted_
fully contracted
“A” band constant
because it is caused
by myosin, which
doesn’t change
length
Sarcomere shortens
because actin pulled
towards its middle by
myosin cross bridges
Titin resists overstretching

9. EM (ELECTRON
MICROSCOPE):
PARTS OF 2
MYOFIBRILS
Labeled and unlabeled

10. Smooth muscle
•Muscles are spindle-shaped cells
•One central nucleus
•Grouped into sheets: often running
perpendicular to each other
•Peristalsis
•No striations (no sarcomeres)
•Contractions are slow, sustained and resistant to
fatigue
•Does not always require a nervous signal: can be
stimulated by stretching or hormones
6 major locations:
1.inside the eye 2. walls of vessels 3. respiratory tubes
4. digestive tubes 5. urinary organs 6. reproductive organs

11. •Cells are striated
•Contractions are involuntary (not voluntary)
CARDIAC MUSCLES

12. TYPES OF MUSCLE TISSUE
Skeletal
•Attach to and move skeleton
•40% of body weight
•Fibers = multinucleate cells (embryonic cells fuse)
•Cells with obvious striations
•Contractions are voluntary

Cardiac: only in the wall of the
heart
•Cells are striated
•Contractions are involuntary
(not voluntary)
Smooth: walls of hollow organs
•Lack striations
•Contractions are involuntary (not voluntary)

13. Myofibrils
Made of three types of filaments (or myofilaments):
Thick (myosin)
Thin (actin)
Elastic (titin) actin
myosin
titin

14. Cells are very long, cylindrical no branched and striated
Multinucleated, found towards periphery

Skeletal Muscle:

15. I Band = actin filaments

17. cardiac muscle can be identified by Central Nuclei, striations, branching, and
intercalated discs
cardiac muscle

19. young chondrocytes
mature chondrocytes
matrix

20. hyaline cartilage
(Most common type of cartilage. found in trachea) contains
collagen fibers and Chondrocytes are found in large lacuna.

21. Elastic fibers
chondrocytes

22. Fibrocartilage
Fibrocartilage is a tissue with characteristics intermediate between
dense connective tissue and hyaline cartilage
chondrocytes
Matrix

24. 2-Cartilage in the air passages
Cartilage in the air passages; allows them to remain open during
respiration

25. 4- Cartilaginous component of the ear & lower part of the nose; helps
to retain shape & allows bending

27. Most common forms temporary skeleton in the embryo persists in the
adult at specific sites can calcify or ossify in old age & disease
Hyaline Cartilage

28. Hyaline Cartilage
Chondrocytes & Matrix
Matrix
Chondrocyte
Chondrocyte Lacuna

29. Elastic Cartilage
Chondrocytes & Matrix

30. Fibrocartilage
Irregular dense fibrous tissue with few Chondrocytes.
No perichondrium.
Found in intervertebral.
dissociated with some discs and other discs joints(e.g. knee, pubic
symphysis) where resistance to compression, durability & strength are
needed.

33. EM of relatively quiescent osteocyte (left) with cytoplasmic processes extend
within canaliculi. And formative osteocyte (right) showing Golgi body (G), rER,
and collagen fibers (arrows).

34. Histology of compact and spongy done

35. osteoblast
osteocyte
Osteoprogenitor cell

36. Histologically, there are two kinds of mature bone:
Compact bone and spongy bone








-Compact bone is also called cortical bone.
-Spongy bone is also called cancellous bone, trabecular bone and
medullary bone.

37. Between the lamellae of an osteon are present lacunae containing
bone cells called osteocytes. Canaliculi connect the lacunae with one
another and with the Haversian canal.

39. periosteum

40. Endosteum

41. external circumferential lamellae are located immediately
beneath the periosteum.

43. The arrow labeled o points to
an osteocyte in its lacuna.
Canaliculi (not visible here)
connect the lacunae of
osteocytes to each other and
to the marrow spaces
between the trabeculae.

44. Cells: Osteocytes , osteoblasts line all trabeculae and large Osteoclasts
occupy Howship's lacunae

45. Spongy bone (Cancellous bone)
Cavities
Trabeculae

47. Most human cells are 10 – 20 µm
in diameter (about 5 times smaller
than the smallest visible particle).

48. OOCYTE
100µm, 0.1mm

50. Non-staining areas may indicate that the cell contains mucous
secretory vacuoles or fat droplets.

51. Nucleus
A cell that is actively synthesizing large quantities of protein usually has a large, pale
staining nucleus (due to active transcription of chromatin) with prominent nucleoli (sites
of active ribosomal RNA synthesis).

52. An inactive cell has a compact deep-staining nucleus (little chromatin
being transcribed) which lacks visible nucleoli (minimal ribosome
production).

53. Pink-staining granular cytoplasm often contains accumulations of
organelles (mitochondria or secretory granules) that take up acidic dye.

56. The phospholipid bilayer (membrane) forms a relatively impermeable barrier to most water-
soluble molecules. The protein molecules, “dissolved” in the lipid bilayer mediate most of the
other functions of the membrane.

57. Membrane proteins can be associated with the
lipid bilayer in different ways.

58. Nucleus (TEM)
Control center of cell
separates nucleus from
rest of cell
Double membrane has
pores

Contains
Chromosomes
Nucleolus

60. Perinuclear space Nuclear pore
complex Inner and outer
Nuclear membrane
Chromatin
Rough ER

61. Scanning EM of the inner nuclear membrane (nucleoplasmic face) showing portions of the
nuclear lamina (NL) meshwork with many embedded nuclear pore complexes (NPC). The
preparation is from an actively growing amphibian oocyte. Nuclei of these very large cells
can be isolated manually, facilitating ultrastructural studies of the nucleaenvelope.X100,000
NL
NL
NPC

63. The Golgi apparatus

65. Primary lysosome
Secondary lysosome

66. Three peroxisomes in a rat liver cell.
Peroxisomes in liver and kidney cells detoxify
(oxidise) a number of molecules including
alcohol, phenols, formic acid and
formaldehyde.
RH2 + O2 R + H2O2

R’H2 + H2O2 R’ + 2H2O

68. In steroidogenic cells the mitochondrial cristae
are typically tubular (or finger- like)

69. Dividing of mitochondria

70. Actin filaments (microfilaments) – 5-9nm diameter, mainly cortical in
distribution.

72. ENDOPLASMIC RETICULUM (ER)
Network of interconnected membranes.
Two types of endoplasmic reticulum.
1-Rough endoplasmic reticulum .
2-Smooth endoplasmic reticulum .

73. Golgi apparatus
Consists of saucer shaped stacks of cisternae (pancake-like)
proteins migrate from the convex to the concave end of the stack.
Functions primarily to sort, concentrate, package, and modify proteins
synthesised by the rer.

74. Golgi body
Structure: divided in to three fundamental components:
The nuclear face ( cis-face), the medial face (cisternae) trans-face

75. Functions of the Golgi apparatus
Functions of the Golgi apparatus
Functions primarily to sort, concentrate, package, and modify proteins
synthesised by the rer.

76. LENS FOUND BENEATH
THE STAGE THAT
CONCENTRATES LIGHT
BEFORE IT PASSES
THROUGH THE SPECIMEN
TO BE VIEWED .

condenser

77. DIAPHRAGM AND LIGHT SOURCE
Diaphragm
Open holes on a disk under the
stage that regulates the amount
of light passing through the
specimen

Light Source
Located beneath the Stage
and Diaphragm. Sends light
towards the hole in the stage.

78. A) Stratified squamous non keratinized epithelium :-

79. Note how cells at the surface are very flattened as opposed to the
nearly columnar basal cells. Surface cells are continuously lost and
replaced by cell division in deeper layers

basal cells

80. Keratin

81. Keratin
Stratified Squamous Keratinised Epithelia

83. Stratified cuboidal epithelium

87. Thin epoxy section of the trachea showing cilia (C) on a
pseudostratified columnar epithelium (arrows).
Note how the goblet cells (G) between the epithelial cells lack cilia.
G
C

88. Microvilli (MV) are finger-like
projections from the apical surface
of (usually columnar) epithelial
cells.
They increase the surface area of
the cell surface and are found in
areas involved with absorption
such as the small intestine and
proximal convoluted tubule of the
kidney.
In these two areas they are often
referred to as a “brush border”
brush border
Microvilli

89. brush border
goblet cell

90. Stereocilia are very long, modified microvilli and concerned with
absorptive functions. They are chiefly found in parts of the male
reproductive tract.
Stereocilia

91. Stereocilia

92. Stereocilia
pseudostratified columnar
epithelium

93. Keratinised stratified epithelium from the skin. Note how the basal layers are folded
forming papillae. These serve to attach the epithelium to the underlying tissues. In
inset note the mitotic figures; cells lost at the surface of both forms of stratified
squamous epithelium are replaced by division of cells in the basal layers.
Keratin
mitotic figures

94. Zonula Occludens
Zonula adherens
Desmosome

98. 16
Simple Squamous & Cuboidal Epithelia
Squamous (single arrow)

•Formed by flattened cells whose
nuclei often appear to bulge
outwards.
•Found in places where there is
movement of materials and even
cells across the epithelium.
Example here is from the loop of
Henle in the kidney, also found
lining all blood vessels, forming
Bowman’s capsule in the renal
cortex.

Cuboidal (double arrows)

•In section cell profiles appear as
squares with central nuclei.
•Found lining tubules in kidney,
walls of thyroid follicles Often
involved in secretory functions

99. 17
Nucleus of simple
squamous cell
Nucleus of simple
cuboidal cell

106. Cartilage Tracheal gland
Respiratory epithelia

107. Respiratory epithelium is the classic example of pseudostratified ciliated columnar epithelium. (a)
Details of its structure vary in different regions of the respiratory tract, but it usually rests on a very
thick basement membrane (BM) and has several cell types, some columnar, some basal, and all
contacting the basement membrane. Ciliated columnar cells are most abundant, with hundreds of
long robust cilia (C) on each of their bulging apical ends that provide a lush cover of cilia on the
luminal surface. Most of the small rounded cells at the basement membrane are stem cells and their
differentiating progeny, which together make up about 30% of the epithelium. Mucus secreting
goblet cells (G) and intraepithelial lymphocytes and dendritic cells are also present in respiratory
epithelium. The lamina propria is well-vascularized (V). Mallory trichrome. (b) Scanning electron
microscopy (SEM) shows the luminal surface of goblet cells (G) among the numerous ciliated cells.
a b

108. ALVEOLI
1.Alveoli are saclike evaginations (about 200 m in
diameter) of the respiratory bronchioles, alveolar
ducts, and alveolar sacs.
2.Structurally, alveoli resemble small pockets that are
open on one side, similar to the honeycombs of a
beehive. Within these cuplike structures, O
2 and CO
2
are exchanged between the air and the blood. The
structure of alveolar walls is specialized to enhance
diffusion between the external and internal
environments.
3.Interalveolar septum is wall lies between two
neighboring alveoli. These septa is vascularized with
the richest capillary network in the body.

109. BLOOD-AIR BARRIER
1.Surface lining and cytoplasm of the alveolar cells,
2.Fused basal laminae of the closely apposed alveolar cells and capillary
endothelial cells,
3.Cytoplasm of the endothelial cells

Nucleus of capillary
endothelial cell
Nucleus
of alveolar
type I cell
Alveolar
connective
tissue
Erythrocyte Capillary
alveolar cells

110. The cardia and the pylorus .
The mucosa of these two
stomach regions contains
tubular glands, In both regions
the glands secrete abundant
mucus, as well as lysozyme,
an enzyme that attacks
bacterial walls.

111. In the fundus and body, the mucosa's
lamina propria is filled with
branched, tubular gastric glands.
consists of
1.Stem cells, give rise to all epithelial
cells of the glands
2.Mucous cells produce mucus
3.Parietal cells produce HCl
4.Chief (zymogenic) cells. secrete
pepsinogen,
5.Various enteroendocrine
cellssecrete a variety of hormones

114. The urothelium is composed of the following three layers:
1.a single layer of small basal cells resting on a very thin basement membrane,
2.an intermediate region containing from one to several layers of more columnar cells,
3.a superficial layer of very large, polyhedral or bulbous cells called umbrella cells
which are occasionally bi- or multinucleated and are highly differentiated to protect
underlying cells against the cytotoxic effects of hypertonic urine

115. 2-Lining epithelium (trachea)
They are sheets of continuous cells that cover surfaces, line
cavities of the body and are the major tissues of glands.
Epithelial Tissues = Epithelium
1-Covering epithelium (skin)
3- Glandular epithelium (salivary gland)

116. Epithelial Tissue 12/4/2015
[email protected]
10
Renal cortex

117. (H&E) 40x (H&E) 10x
Simple cuboidal epithelium
(follicular cell)
Parathyroid
Follicles
thyroid
Thyroid Gland
The thyroid gland locates in the
cervical region anterior to the
larynx, consists of two lobes
united by an isthmus .

121. The ultrastructural components of the basement membrane are revealed by TEM. The dense
basal lamina (BL) may appear with thin clear zones on each side and is anchored to a thicker,
more diffuse reticular lamina (RL) containing collagen III reticular fibers. Hemidesmosomes (H)
bind the basal surface of the epithelial cell (C) to the basal lamina
BL
RL
H