Microscopy

MUSCLE
The purpose of this practical session is to demonstrate muscular tissue. Study each muscle type
according to the following scheme:
(i)
(vii) Number and position of the blood vessels and connective tissue Smooth muscle
This is a cross section through the umbilical cord. The three large blood vessels are used as examples of smooth muscle. Identify:
The orientation of the blood vessels in the umbilical cord. Microscopic (i) Longitudinally sectioned smooth muscle fibres. Draw and annotate:
A few longitudinal and cross sectioned smooth muscle fibres. Note the shape and different
diameters of the smooth muscle fibres.
Questions:
What is characteristic of the cellular and nuclear shapes? ……………………………………………………………………………………………………… How does the nucleus appear in a contracted smooth muscle fibre? ……………………………………………………………………………………………………… How does the nucleus appear in a contracted smooth muscle fibre? ……………………………………………………………………………………………………… What is found between the muscle fibres? ……………………………………………………………………………………………………… Skeletal muscle (Striated)
Slide 18 contains a longitudinal and cross section of skeletal muscle. Slide 33 is a section through the tip of the tongue in which the skeletal muscle is sectioned longitudinallly, obliquely and crosswise. To view the striations of skeletal muscle in an H/E specimen, the condenser of the microscope must be turned down to obtain as much contrast as possible. (Remember to turn the condenser back to its original position after you have finished). Identify:
Nuclei of the skeletal muscle fibres and connective tissue Skeletal muscle fibres arranged in bundles Size, shape and diameter of the muscle bundles Draw and annotate:
A longitudinal section of skeletal muscle: Questions:
What is characteristic of skeletal muscle? ……………………………………………………………………………………………………… What is characteristic of the nuclei of skeletal muscle and how do they differ from those of smooth muscle? ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… How does skeletal muscle differ in longitudinal and cross section from smooth muscle? …………………………………………………………………………………………… ……………………………………………………………………………………………………… What are skeletal muscle fibre bundles called? ……………………………………………………………………………………………………… Can all the subdivisions of muscle connective tissue be seen on this specimen? What is the connective tissue is called? ……………………………………………………………………………………………………… …………………………………………………………………………………………… Skeletal muscle (striated)
This is a section through the tip of the tongue stained to show the cross striations. Identify:
The different bands in the longitudinal section that form the cross striations Nuclei of the skeletal muscle and connective tissue Draw and annotate:
A skeletal muscle fibre. Indicate al the different components in detail. Questions:
How many of the cross striation of skeletal muscle are visible under the light microscope? ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… Heart muscle
This is a longitudinal section through heart muscle. To view the cross striations the condenser of the microscope must be turn downward to produce contrast. Identify:
Nuclei of the heart muscle fibres and connective tissue (iii) Intercalary discs and cross striations (iv) Draw and annotate:
A heart muscle fibre. Indicate the characteristic components in detail. Questions:
What is characteristic of heart muscle fibres? ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… How do heart muscle fibres differ from skeletal and smooth muscle? ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… What is the connective tissue found between the heart muscle fibres called? ……………………………………………………………………………………………………… Heart muscle
This is a specimen of a cross section of heart muscle. Identify:
Draw and annotate:
A few cross sectioned heart muscle fibres. Questions:
What is characteristic of heart muscle in cross section? ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… How does heart and skeletal muscle differ in cross section? ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… Which connective tissue/s found in skeletal muscle is/are also found in heart muscle? ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… Heart muscle
This is a longitudinal section through heart muscle, stained to show the cross striations clearly. Identify:
Draw and annotate:
A few heart muscle fibres. Indicate the different components in detail. Questions:
Which bands are visible with the light microscope? ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… What are the regions at the poles of the nucleus called and how are they formed? ……………………………………………………………………………………………………… ………………………………………………………………………………………………………

Source: http://histoweb.co.za/afd08/08muscle.pdf