1. MUSCLE TISSUE
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2. Objectives Students should be able to:
Specify and interpret light microscopic sections of stained muscle (eg. Muscle type, structure, fibre type, metabolic profile).
Identify structural features, similarities and differences between various types of muscle fibres.

3. SLIDE 101 Striated skeletal muscle (mouse)
Examining this section under low magnification.
Distinguish between the muscle groups and the limb bone in the centre of the section.
H&E stain.
0.5 mm

4. SLIDE 101 Striated skeletal muscle (mouse)
Examining this section under low magnification.
Distinguish between the muscle groups and the limb bone in the centre of the section.
H&E stain.
M : muscles
limb bones
X : areas of damage on section M X M X M M X
0.5 mm

5. SLIDE 101 Striated skeletal muscle (mouse)
Indicate : bundles of muscle fibres.
epimysium.
perimysium.
endomysium. G T Q F I S
Dog Hindlimb (caudolateral view)
Forceps indicate transverse
section of M. biceps femoris
S – Semitendinous m.
Q – Quadriceps femoris m.
G – Gluteus medius m.
F – Fascia lata
T – Greater trochanter of femur
I – Ischiadic n.
250 µm

6. SLIDE 101 Striated skeletal muscle (mouse)
Indicate : bundles of muscle fibres.
epimysium Connective tissue surrounding whole muscle.
perimysium. Connective tissue surrounding bundles of muscle cells.
endomysium. Connective tissue surrounding individual muscle cells.
250 µm

7. SLIDE 101 Striated skeletal muscle (mouse)
Indicate : bundles of muscle fibres.
epimysium.
perimysium.
endomysium.
bundles of muscle fibres
bone
epimysium
endomysium
perimysium
250 µm

8. SLIDE 101 Striated skeletal muscle (mouse)
Indicate : bundles of muscle fibres.
epimysium.
perimysium.
endomysium.
50 µm

9. SLIDE 101 Striated skeletal muscle (mouse)
Indicate : bundles of muscle fibres.
epimysium Not visible on this section.
perimysium.
endomysium.
perimysium Bv
endomysium
surrounds individual
muscle fibres Bv
Bv :blood vessels Bv
muscle fibres
50 µm

10. SLIDE 102 Striated skeletal muscle (mouse)
This section is viewed at low magnification.
Distinguish between the muscle groups and the limb bone in the centre of the section.
H&E stain.
1.0 mm

11. SLIDE 102 Striated skeletal muscle (mouse)
This section is viewed at low magnification.
Distinguish between the muscle groups and the limb bone in the centre of the section.
H&E stain.
bone
bone marrow
muscle
epimysium
1.0 mm

12. SLIDE 102 Striated skeletal muscle (mouse)
Examining this section under high magnification.
Find muscle fibres seen in a) transverse section.
Dog Hindlimb (lateral view)
S – Sartorius m.
T – Tensor fasciae latea m.
B – Biceps femoris m.
St – Semitendinous m.
250 µm

13. SLIDE 102 Striated skeletal muscle (mouse)
This section is viewed under high magnification.
Find muscle fibres seen in a) transverse section.
bone
perimysium
muscle fibres cut in
transverse section
250 µm

14. SLIDE 102 Striated skeletal muscle (mouse)
Transverse fibres in the outer regions of the muscle.
Note peripherally located nuclei and areas of epimysium perimysium and endomysium.
100 µm

15. SLIDE 102 Striated skeletal muscle (mouse)
Transverse fibres in the outer regions of the muscle.
Note peripherally located nuclei and areas of epimysium perimysium and endomysium.
P : peripheral nuclei
epimysium P
perimysium P
endomysium
100 µm

16. SLIDE 102 Striated skeletal muscle (mouse)
Again identify the multinucleated muscle cells with peripherally located nuclei.
Some endothelial cell nuclei of capillaries can be seen between the fibres.
50 µm

17. SLIDE 102 Striated skeletal muscle (mouse)
Again identify the multinucleated muscle cells with peripherally located nuclei.
Some endothelial cell nuclei of capillaries can be seen between the fibres.
P : peripheral nuclei
C : capillaries
endomysium P
perimysium C
50 µm

18. SLIDE 102 Striated skeletal muscle (mouse)
High magnification of an area cut in longitudinal section. ( H & E stain)
Peripheral nucleus visible, also cross striations.
10 µm

19. SLIDE 102 Striated skeletal muscle (mouse)
High magnification, (using oil immersion lens) of an area cut in longitudinal section.
(H & E stain).
Peripheral nucleus visible, also cross striations.
Cross striations
A bands
I band
Z lines N
N : muscle cell nuclei
10 µm

20. SLIDE 103 Striated skeletal muscle (rat)
Examining this section under low magnification.
1.0 mm

21. SLIDE 103 Striated skeletal muscle (rat)
Examining this section under low magnification.
Locate a suitable area.
1.0 mm

22. SLIDE 103 Striated skeletal muscle (rat)
This section has been stained with Heidenhain’s Haematoxylin.
The selected area contains longitudinally cut muscle fibres.
250 µm

23. SLIDE 103 Striated skeletal muscle (rat)
This section has been stained with Heidenhain’s Haematoxylin.
The selected area contains longitudinally cut muscle fibres.
perimysium
between bundles
endomysium
between fibres
muscle fibres
250 µm

24. SLIDE 103 Striated skeletal muscle (rat)
Examining this area under high magnification Identify : myofibrils.
cross-striations.
muscle fibre nuclei.
endomysium.
10 µm

25. SLIDE 103 Striated skeletal muscle (rat)
Examining this area under high magnification Identify : myofibrils.
cross-striations.
muscle fibre nuclei.
endomysium.
cross striations
endomysium
muscle cell
(myocyte, muscle fibre or myofibre)
each cell contains numerous
longitudinal myofibrils
muscle cell nucleus
endomysium
10 µm

26. SLIDE 103 Striated skeletal muscle (rat)
Identify : A-bands.
I- bands.
Z-lines
capillary in
the endomysium
10 µm

27. SLIDE 103 Striated skeletal muscle (rat)
Identify : A-bands.
I- bands.
Z-lines
capillary in
the endomysium
10 µm

28. SLIDE 103 Striated skeletal muscle (rat)
Identify : A-bands.
I- bands.
Z-lines
capillary in
the endomysium
10 µm

29. SLIDE 103 Striated skeletal muscle (rat)
Identify : A-bands.
I- bands.
Z-lines
sarcomere
capillary in
the endomysium
10 µm

30. SLIDE 103 Striated skeletal muscle (rat)
What is the major protein found in the A- band?
What is the major protein found in the I –band?
What is the major protein found in the Z – line?
10 µm

31. SLIDE 103 Striated skeletal muscle (rat)
What is the major protein found in the A- band? myosin.
What is the major protein found in the I –band?
What is the major protein found in the Z – line?
10 µm

32. SLIDE 103 Striated skeletal muscle (rat)
What is the major protein found in the A- band? myosin.
What is the major protein found in the I –band? actin.
What is the major protein found in the Z – line?
10 µm

33. SLIDE 103 Striated skeletal muscle (rat)
What is the major protein found in the A- band? myosin.
What is the major protein found in the I –band? actin.
What is the major protein found in the Z – line? α–actinin.
10 µm

34. SLIDE 104 Striated skeletal muscle (dog) Myotendon junction (diaphragm)
Section as seen under low magnification.
Note the tapering muscle and the continuity of the
connective tissue sheath with the tendon.
tendon
Canine Thorax
Left view, left lung removed
Myotendinous junction of
diaphragm circled
muscle
250 µm

35. What is the major protein found in the tendon matrix?
SLIDE 104 Striated skeletal muscle (dog) Myotendon junction (diaphragm)
What is the major protein found in the tendon matrix?
50 µm

36. SLIDE 104 Striated skeletal muscle (dog) Myotendon junction (diaphragm)
What is the major protein found in the tendon matrix?
Collagen Fibres : Collagen type I.
What cells produce this matrix?
tendon
tapering muscle
connective tissue
50 µm

37. SLIDE 104 Striated skeletal muscle (dog) Myotendon junction (diaphragm)
What is the major protein found in the tendon matrix?
Collagen Fibres : Collagen type I.
What cells produce this matrix?
Fibroblasts.
tendon
tapering muscle
connective tissue
50 µm

38. Longitudinally cut muscle fibres close to the myotendon junction.
SLIDE 104 Striated skeletal muscle (dog) Myotendon junction (diaphragm)
Longitudinally cut muscle fibres close to the myotendon junction.
25 µm

39. Longitudinally cut muscle fibres close to the myotendon junction.
SLIDE 104 Striated skeletal muscle (dog) Myotendon junction (diaphragm)
Longitudinally cut muscle fibres close to the myotendon junction.
muscle cell nuclei
capillaries in the
endomysium
25 µm

40. SLIDE 104 Striated skeletal muscle (dog) Myotendon junction (diaphragm)
muscle nucleus
endomysium
10 µm

41. SLIDE 105 Striated skeletal muscle (dog) Myotendon junction (diaphragm)
This section has been stained blue-black to emphasise the cross-striations of the muscle fibres and the wavy bundles of collagen fibres within the tendon.
1.0 mm

42. The stain used is Heidenhain’s haematoxylin.
SLIDE 105 Striated skeletal muscle (dog) Myotendon junction (diaphragm)
The stain used is Heidenhain’s haematoxylin.
tapering muscle fibres
wavy collagen of tendon
50 µm

43. SLIDE 105 Striated skeletal muscle (dog) Myotendon junction (diaphragm)

44. SLIDE 105 Striated skeletal muscle (dog) Myotendon junction (diaphragm)
Cross striations arrowed, N : muscle cell nucleus. N
endomysium
25 µm

45. SLIDE 1 Lip (cat) (H&E stain)
Identify striated muscle fibres in this section.
1.0 mm

46. SLIDE 1 Lip (cat) (H&E stain)
Identify striated muscle fibres in this section.
inner oral surface
muscle
labial margin
sinus hair follicles
outer surface : hairy skin
1.0 mm

47. What feature(s) is/are most helpful in aiding your identification?
SLIDE 1 Lip (cat)
What feature(s) is/are most helpful in aiding your identification?
100 µm

48. SLIDE 1 Lip (cat)
What feature(s) is/are most helpful in aiding your identification?
Peripheral nuclei.
Cross striations (when visible in good high magnification longitudinal sections).
blood vessel
nerve fibre
TS muscle
LS muscle
100 µm

49. Identify striated muscle fibres in this section.
SLIDE 1 Lip (cat)
Identify striated muscle fibres in this section.
50 µm

50. Identify striated muscle fibres in this section.
SLIDE 1 Lip (cat)
Identify striated muscle fibres in this section.
transverse muscle fibres
longitudinal muscle
fibres
muscle nuclei
50 µm

51. Transverse section from striated muscle of lip showing myofibrils.
SLIDE 1 Lip (cat)
Transverse section from striated muscle of lip showing myofibrils.
myofibrils visible in
TS section of fibre
25 µm

52. SLIDE 3 Tongue (cat) H&E stain
Transverse section whole of slide shown.
2.0 mm

53. SLIDE 3 Tongue (cat) Identify striated muscle fibres in this section.
How would you describe the orientation of the various fibre bundles?
250 µm

54. SLIDE 3 Tongue (cat) Identify striated muscle fibres in this section.
How would you describe the orientation of the various fibre bundles?
Fibre bundles running in many directions, often orthogonal (right angles) to each other.
striated muscle fibres
unilocular adipocytes
250 µm

55. SLIDE 3 Tongue (cat)
Cross striations and peripheral nuclei visible in this higher magnification view of the tongue.
25 µm

56. SLIDE 28 Oesophagus (dog)
Identify striated muscle fibres in this section.
Canine Thorax
Left view, left lung removed
O - Oesophagus
1.0 mm
250 µm

57. SLIDE 28 Oesophagus (dog)
Does this muscle layer extend throughout the length of this organ in the dog?
muscle layers
1.0 mm
250 µm

58. SLIDE 28 Oesophagus (dog)
Does this muscle layer extend throughout the length of this organ in the dog?
Yes : In dogs and ruminants it extends for the entire length.
How about in the cat?
muscle layers
1.0 mm
250 µm

59. SLIDE 28 Oesophagus (dog)
Does this muscle layer extend throughout the length of this organ in the dog?
Yes : In dogs and ruminants it extends for the entire length.
How about in the cat?
No : In the cat striated muscle is found in the cranial four fifths.
( In horses and pigs it extends for the cranial two thirds).
( In humans it extends for the cranial one third).
muscle layers
1.0 mm
250 µm

60. SLIDE 28 Oesophagus (dog)
The striated muscle in the oesophagus is found in the tunica muscularis.
It forms an outer longitudinal layer : Picture A.
and an inner circular layer : Picture B. A B
25 µm

61. SLIDE 106 Striated cardiac muscle (cat)
In longitudinal section identify key features characteristic of cardiac muscle.
Intercalated discs.
Central nuclei.
Peri-nuclear cytoplasm free of striations. R L
Canine Thorax
Left view, left lung removed
L – Left ventricle
R – Right ventricle
25 µm

62. SLIDE 106 Striated cardiac muscle (cat)
In longitudinal section identify key features characteristic of cardiac muscle.
Intercalated discs.
Central nuclei.
Peri-nuclear cytoplasm free of striations.
intercalated discs
arrowed R L
C : central nucleus C
P : perinuclear space P
capillary
25 µm

63. SLIDE 106 Striated cardiac muscle (cat)
In longitudinal section identify key features characteristic of cardiac muscle.
Intercalated discs.
Branching fibres.
25 µm

64. SLIDE 106 Striated cardiac muscle (cat)
In longitudinal section identify key features characteristic of cardiac muscle.
Intercalated discs.
Branching fibres.
intercalated discs arrowed
branching fibres
25 µm

65. SLIDE 106 Striated cardiac muscle (cat)
Locate muscle fibres cut transversely.
Identify their nuclei.
Identify cut ends of myofibrils.
Cardiac muscle fibres are unicellular - True or False?
25 µm

66. SLIDE 106 Striated cardiac muscle (cat)
Locate muscle fibres cut transversely.
Identify their nuclei.
Identify cut ends of myofibrils.
Cardiac muscle fibres are unicellular - True or False?
False : rows of cells joined by intercalated discs, fibres branch.
central nuclei
cut ends of myofibrils
25 µm

67. SLIDE 45 Smooth muscle duodenum (cat)
Longitudinal section through the duodenal wall.
Identify smooth muscle cells,seen in transverse and longitudinal section, from the outer wall of the duodenum.
Canine Abdomen
D – diaphragm
da – ascending duodenum
dd – descending duodenum
j – jejunum
p – pancreas
100 µm
1.0 mm

68. SLIDE 45 Smooth muscle duodenum (cat)
Longitudinal section through the duodenal wall.
Identify smooth muscle cells,seen in transverse and longitudinal section, from the outer wall of the duodenum.
outer longitudinal muscle layer
inner circular muscle layer
seen in transverse section
100 µm
1.0 mm

69. SLIDE 45 Smooth muscle duodenum (cat)
With respect to this organ, can you define the two smooth muscle layers?
50 µm

70. SLIDE 45 Smooth muscle duodenum (cat)
With respect to this organ, can you define the two smooth muscle layers?
Inner circular and outer longitudinal layers of the tunica muscularis.
What is the functional significance of the arrangement of the muscle cells in these structures?
outer longitudinal layer
inner circular layer
50 µm

71. SLIDE 45 Smooth muscle duodenum (cat)
With respect to this organ, can you define the two smooth muscle layers?
Inner circular and outer longitudinal layers of the tunica muscularis.
What is the functional significance of the arrangement of the muscle cells in these structures?
The two layers enable propulsive movements (peristalsis) to occur in the digestive tract.
outer longitudinal layer
inner circular layer
50 µm

72. SLIDE 42 Smooth muscle duodenum (mouse)
This section shows the duodenum cut in transverse section.
Note : The previous slide 45 was duodenum, but cut in longitudinal section.
Think of how this will affect the microscopic appearance of the muscle layers in these sections.
1.0 mm
100 µm

73. SLIDE 42 Smooth muscle duodenum (mouse)
This section shows the duodenum cut in transverse section.
Identify smooth muscle cells seen in transverse and longitudinal section.
50 µm

74. SLIDE 42 Smooth muscle duodenum (mouse)
This section shows the duodenum cut in transverse section.
Identify smooth muscle cells seen in transverse and longitudinal section.
transversely sectioned
smooth muscle cells of
the outer longitudinal
layer.
longitudinally sectioned
smooth muscle cells of
the inner circular layer.
50 µm

75. SLIDE 42 Smooth muscle duodenum (mouse)
Smooth muscle fibres are unicellular- True or False?
25 µm

76. SLIDE 42 Smooth muscle duodenum (mouse)
Smooth muscle fibres are unicellular- True or False?
True.
outer longitudinal layer
seen here in TS section.
inner circular layer
seen here in LS section.
25 µm

77. Identify smooth muscle cell nuclei in the wall of this artery.
SLIDE 57 Arteries (dog)
Canine Thorax
Left view, left lung removed
A – Aorta
S – Left subclavian Artery
P – Pulmonary Artery A A
Identify smooth muscle cell nuclei in the
wall of this artery. S S P P
500 mm
100 µm

78. Identify smooth muscle cell nuclei in the wall of this artery.
SLIDE 57 Arteries (dog) A
Identify smooth muscle cell nuclei in the wall of this artery. S P
elongated nuclei of smooth muscle cells
500 mm
lumen of artery
100 µm

79. SLIDE 57 Arteries (dog)
What is the functional significance of the arrangement of muscle cells in this structure?
50 µm

80. SLIDE 57 Arteries (dog)
What is the functional significance of the arrangement of muscle cells in this structure?
The smooth muscle is in a near-circular tight helical arrangement.
Muscular arteries control blood flow to various organs.
smooth muscle cell nuclei
in the tunica media
50 µm

81. SLIDE 92 Ureter TS section
Identify smooth muscle nuclei in the wall
of this organ.
50 µm
1.0 mm

82. SLIDE 92 Ureter TS section
Identify smooth muscle nuclei in the wall
of this organ. K
longitudinal smooth muscle
transverse smooth
muscle K B
Canine Abdomen
GIT removed.
String ligates descending colon.
Desiccated appearance of left kidney is artefact
B – Bladder
K – Kidney
Ureter - arrowed
lumen
50 µm
1.0 mm

83. SLIDE 92 Ureter
What is the functional significance of the arrangement of muscle cells in this structure?
50 µm

84. SLIDE 92 Ureter
What is the functional significance of the arrangement of muscle cells in this structure?
Inner longitudinal and outer circular layers ensure that the star shaped lumen is maintained and cannot be completely closed, thereby ensuring voluntary urination.
inner longitudinal layer
(seen in TS section).
outer circular layer
seen in LS section
50 µm

85. Identify smooth muscle nuclei in the wall of this organ.
SLIDE 180 Uterus (cat)
Identify smooth muscle nuclei in the wall of this organ.
1.00 mm
100 µm

86. Identify smooth muscle nuclei in the wall of this organ.
SLIDE 180 Uterus (cat)
Identify smooth muscle nuclei in the wall of this organ.
smooth muscle nuclei
lumen
1.00 mm
100 µm

87. SLIDE 180 Uterus (cat)
What is the functional significance of the arrangement of muscle cells in this structure?
50 µm

88. SLIDE 180 Uterus (cat)
What is the functional significance of the arrangement of muscle cells in this structure?
The two smooth muscle layers of the uterus define the myometrium. A circular inner layer and a longitudinal outer layer are present, although these are often somewhat ill-defined. The muscle layers increase in size during pregnancy.
muscle cells
50 µm

89. Lectures Dr P.Chantler.
First Year Histology Muscle tissue J.Bredl
Gross Anatomy Correlates Dr S.Frean
Histology Slides and Stains Tanya Hopcroft
This version compressed ppt to 200 dpi 2006, 2007.