1. The Muscular System
Labs 7 & 8

2. In Lab today:
Draw the muscle types & indicated structures from prepared slides
Identify the portions of skeletal muscle from diagrams, slides and models
Identify the connective tissue coverings associated with skeletal muscle
Draw the neuromuscular junction from a prepared slide & identify the indicated structures
Identify the human muscles from models and diagrams
Study models and diagrams in preparation for the muscle quiz in 2 weeks

3. Objective 1 Types of Muscle Tissue

4. Location Structure Function
Skeletal Muscle
Location Structure Function
Attached to the Long, thin cells (fibers) are: posture, movement, skeleton - striated stabilizes joints - multinucleated nuclei are in the periphery of the cell
The plasma membrane of the muscle fiber

5. Striations of the myofibrils are seen through the muscle fiber

6. Striations: A bands & I bands
(dark bands) (light bands)

7. A-bands, I-bands, Sarcomeres, & Sarcolemma

8. Skeletal Muscle
Note multi-nucleation
Whole mount, oil immersion

9. Skeletal Muscle Nuclei A-band I-band Sarcomere Sarcolemma
Note nuclei on the periphery of the cells (fibers)
Nuclei
A-band
I-band
Sarcomere
Sarcolemma
Longitudinal section, oil immersion

10. CARDIAC MUSCLE

11. The heart muscle (myocardium) forms the bulk of the heart.
It is arranged in a spiral or circular bundles.
Cardiac
muscle
bundles
“Helical heart” model

12. CARDIAC MUSCLE

13. Intercalated Disc Nucleus Cardiac Muscle Location Structure Function
Wall of the heart Cells (myocytes) are: provide pressure - faintly striated for the circulation - branching of blood with one (or two)
centrally placed nuclei
Cells are connected by intercalated discs
(gap junctions/desmosomes)
Intercalated Disc
Nucleus

14. Cardiac Muscle Branching cells are in 3-D;
may not be particularly visible in 2-D
Central nuclei
Intercalated disk

15. Cardiac Muscle
Central nuclei
Intercalated disk

16. Cardiac Muscle
Intercalated discs

17. SMOOTH MUSCLE

18. Smooth muscle is found in the walls of hollow visceral organs.
Contractions force fluids and other substances along.
Cells are arranged closely to form sheets.
Epithelial Tissue
C.T.
C.T.
Connective Tissue
E.T.
E.T.
C. T.
Epithelial Tissue

19. Location Structure Function
Smooth Muscle
Location Structure Function
Walls of hollow Cells are: move fluids
organs - spindle shaped and other contents
- have a single nucleus
- not striated
nucleus

20. How you might see it under High Power
Smooth Muscle
How you might see it under High Power

21. How you might see it under Oil Immersion
Smooth Muscle
How you might see it under Oil Immersion

22. REVIEW
Skeletal muscle
Cardiac muscle
Smooth muscle

23. Objective 2 Connective Tissue Coverings of Skeletal Muscle

24. Note that the endomysium surrounds the sarcolemma

25. Cross section through a skeletal muscle
Epimysium
Perimysium
Endomysium / muscle fiber

26. Skeletal Muscle, cs & ls A muscle fiber is filled with myofibrils
Nuclei

27. Cross section through a skeletal muscle
endomysium
Magnified image

28. Epimysium
Perimysium / Fascicle
Endomysium / muscle fiber

29. Objective 3 Neuromuscular Junction

30. Reflex Arc
N-M junction
(Myoneural junction)

31. Neuromuscular Junction
Axon terminal
Motor Neuron Axon
Skeletal muscle fiber

32. Neuromuscular Junction
as you will see it under the microscope
Skeletal muscle fiber
Skeletal muscle fiber
Motor Neuron Axon Axon Terminal

33. Neuron Axon
Skeletal muscle fiber
Axon Terminal

34. Muscles Origin, Insertion, Action, Innervation

35. The immovable (or less moveable) bone to which the muscle is attached
Origin
The immovable (or less moveable) bone
to which the muscle is attached
Scapula
Biceps brachii

36. Insertion The movable bone to which the muscle is attached
(The bone that the muscle moves)
Radius
Biceps brachii

37. Joint movement(s) caused by contraction of the muscle
Flexes and supinates forearm

38. The nerve that acts on the muscle
Innervation
The nerve that acts on the muscle
Musculocutaneous

39.
Muscular System
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