1. The Muscular System
Lab 7

2. REVIEW What are the four tissue types? Epithelial Connective Muscular
Nervous

3. Objective 1 Types of Muscle Tissue

4. SKELETAL MUSCLE

5. Structure of SKELETAL MUSCLE
Muscle  Fascicles  Muscle Fibers (cells)  Myofibrils
A muscle cell (fiber)
is a bundle of myofibrils

6. Myofibrils of a Muscle Fiber (Cell)

7. Human Body Explorer link
SKELETAL MUSCLE
Human Body Explorer link

8. 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

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

10. Striations in skeletal muscle due to sarcomeres

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

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

13. A-bands, I-bands, & Sarcomere

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

15. 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

16. CARDIAC MUSCLE

17. 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

18. CARDIAC MUSCLE – Lab notes

19. 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

20. Branching cells
Heart muscle is made of different cell types that ‘talk’ to each other so the tissue can respond to changing conditions and efficiently pump blood round the body. This image by Patrizia Camelliti and Peter Kohl shows the microscopic architecture of heart muscle, showing the muscle in red closely associated with fibroblast cells in green.

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

22. Cardiac Muscle
Central nuclei
Intercalated disk

23. Cardiac Muscle
Intercalated discs

24. SMOOTH MUSCLE

25. 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

26. 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

27. Cells are arranged closely to form sheets.
Smooth Muscle
Cells are arranged closely to form sheets.

28. Note cell and nucleus shapes
Smooth Muscle
Note cell and nucleus shapes

29. REVIEW
Skeletal muscle
Cardiac muscle
Smooth muscle

30. Objective 2 Connective Tissue Coverings of Skeletal Muscle

31. Note that the endomysium surrounds the sarcolemma

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

33. Objective 3 Neuromuscular Junction

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

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

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

37. Neuron Axon
Skeletal muscle fiber
Axon Terminal

38. Muscles Origin, Insertion, Action, Innervation

39. 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

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

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

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

43. We have to learn the names and locations of a lot of muscles
Now the hard part
We have to learn the names and locations of a lot of muscles

44. Objective 4 Human Muscles

45. Frontalis
Orbicularis oculi
Orbicularis oris
Occipitalis
Sternocleidomastoid
Mentalis
Buccinator
Masseter
Trapezius

46. Splenius capitis
Trapezius
Levator scapulae
Supraspinatus
Teres minor
Infraspinatus
Teres major
Teres major
Rhomboid minor
Infraspinatus
Infraspinatus
Rhomboid major
Latissumus dorsi

47. External intercostals
Longissimus
External intercostals
(longest)
Iliocostalis
(most lateral)
Semispinalis
Spinalis
(most medial) (along spine)

48. Pectoralis minor
Deltoid
Subscapularis
Biceps brachii
Biceps brachii
Serratus anterior
Serratus anterior
Pectoralis major
Brachialis
Internal intercostals
External intercostals
Brachioradialis

49. Pronator teres
Brachioradialis
Flexor carpi radialis
Palmaris longus
Brachioradialis
Flexor carpi ulnaris
Supinator
Extensor carpi radialis longus
Extensor digitorum
Extensor carpi radialis brevis
Extensor carpi ulnaris
Pronator teres

50. Transverse abdominus
Rectus abdominus
External oblique
Internal oblique
External oblique

51. Directions of the fibers
Rectus abdominus
Directions of the fibers

52. Adductors Hamstrings Quadriceps Anterior Anterior deep Posterior
Iliopsoas
Psoas major
Iliacus
Gluteus minimus
Adductors
Adductor brevis
Adductor longus
Tensor facsiae latae
Pectineus
Adductor longus
Adductor magnus
Hamstrings
Vastus lateralis
Gracilis
Rectus femoris
Gracilis
Semimembranosis
Quadriceps
Biceps femoris
Semitendinosis
Sartorius
Vastus medialis
(Medial)
(Lateral)

53. Extensor digitorum longus
Tibialis anterior
Extensor digitorum longus
Gastrocnemius
Tibialis posterior
Fibularis longus
Fibularis longus
Soleus
Fibularis brevis
Extensor halicus longus
Flexor digitorum longus
Fibularis brevis

54. How many of these muscles can you name?

55.
Muscular System
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