1. The Muscular System
6 minute video clip on image

2. - more than 50% of body weight is muscle !
Did you know that ?
- more than 50% of body weight is muscle !
Video link on image (10:30 min).

3. Three types of muscle Skeletal Cardiac Smooth
Where would we find smooth muscles in the body?
Skeletal
Cardiac
Smooth

4. Classification of muscle
Voluntary
Involuntary
Skeletal
Cardiac
Smooth
Limbs
Heart
Viscera
What are striations? Tissue that is marked by transverse dark and light bands (appearance)
Viscera? Hollow organs (ex: Intestines)
Striated
Non-striated

5. Skeletal muscle Large muscles Maintain posture Facilitate locomotion
Move jointed bones
Found in antagonistic pairs
Joined to bones by tendons
Antagonistic means? As one muscle contracts, the other relaxes- work as a pair
EX; biceps and triceps: To contract the triceps relaxes while the biceps contracts the arm.

6. Structure of skeletal muscle
Each cell fibre is long and cylindrical
Muscle fibres are multi-nucleated
The contractile elements of skeletal muscle cells are called myofibrils
How do muscles contract?
Form and have multiple nuclease
Myofibril is a basic rod-like unit of a muscles cell. Muscles are composed of tubular cells called myocytes, these contain many chains of myofibrils.
VIDEO CLIP

7. Skeletal muscle - Summary
Voluntary movement of skeletal parts
Spans joints and attached to skeleton
Multi-nucleated, striated, cylindrical fibres

8. Cardiac muscle Main muscle of heart Pumping mass of heart
Heart muscle cells
behave as one unit
Heart always contracts to it’s full extent

9. Structure of cardiac muscle
Cardiac muscle cells are short, branched and interconnected
Cells are striated & multi-nucleated
Adjacent cardiac cells joined via electrical synapses (gap junctions)
These gap junctions appear as dark lines when viewed under a microscope and are called intercalated discs
What other body system did we see this same principal take place?

10. Cardiac muscle - Summary
Found in the heart
Involuntary rhythmic contraction
Branched, striated fibres with intercalated discs
Intercalated discs are microscopic identifying features of cardiac muscles. Cardiac muscles consist of individual heart mucles cells (cardiomyocytes) connected by intercalated discs to work as a single functional organ.

11. Smooth muscle Lines walls of viscera
Found in longitudinal or circular arrangement
Alternate contraction of circular & longitudinal muscle in the intestine leads to peristalsis
Also found in blood vessels to help with vasoconstriction

12. Structure of smooth muscle
Spindle shaped uni-nucleated cells
Striations not observed
Actin and myosin filaments are present
Myosin filaments are attached to dense bodies at the end of each cell
Muscles are composed of Proteins (thick) myosin and (thin) actin. Muscle contractions occur when these filaments slide over one another in a series of repetitive events.

13. Smooth muscle - Summary
Found in walls of hollow internal organs
Involuntary movement of internal organs
Elongated, spindle shaped fibres with single nucleus

14. Muscle Control Stop Day One Notes  Type of muscle Nervous control
Type of control
Example
Skeletal
Controlled by CNS
Voluntary
Lifting a glass
Skeletal
Cardiac
Regulated by ANS
Involuntary
Heart beating
Peristalsis?
CNS= brain and spinal cord
ANS= Autonomic Nervous System also controls exocrine glands (sweat, salivary, sebaceous glands) outside
Smooth
Controlled by ANS
Involuntary
Peristalsis
Stop Day One Notes 

15. Muscular System Vocabulary
Flexion – Movement that decreases angle between 2 bones.

16. Muscular System
Extension – movement that increases angle between 2 bones

17. Muscular System
Abduction – movement away from the midline of the body

18. Muscular System
Adduction – movement towards the midline of the body

19. Muscular System
Rotation – movement around a longitudinal axis

20. Muscular System
Supination – Hand turned upward

21. Muscular System
Pronation – occurs when palms rotate downward or posteriorly

22. Muscular System Dorsiflexion – elevation of the top of the foot
Plantar flexion – bottom of foot is directed downward