1. Muscles
And their close connection to the nervous, skeletal, and respiratory/cardiac systems

2. Skeletons
Hydrostatic Skeletons: Fluid is held underpressure and muscles control movement. Ex. Circular and longitudinal muscles in worms.
Hard Skeletons: Hard supporting elements such as bones, plates that are moved by muscles.
Ex. Endoskeletons & Exoskeletons

3. Exoskeletons vs. Endoskeletons
Compare and contrast
Material
Position
Mechanism for movement

4. 3 Roles for the Human Skeletal System
Protection
Movement
Blood cell formation
Can you think of a bone that is an example of each?

5. Skeletal and Musclar Systems Interact
Be able to distinguish
Muscles
Bones
Tendons
Ligaments
Joints
Cartilage

6. Muscles contract for movement
Antagonistic pairs.
One contracts (Flexor)
One relaxes (Extensor)

7. Skeletal Muscle at the microscopic level
Note that each muscle cell contains actin and myosin arranged in a specific manner.

8. Describe a Muscle Contraction
Sarcomere:
A band:
Z lines:
H band:
I band:
M line:

9. Sliding Filament Theory

14. Structure Meets Function: How do the heads bind?
Role of Ca2+
Role of Tropomyosin
Role of Troponin

15. Control: How nerves control muscles

16. Similar to threshold Tetanus
Action potentials combine together and a series at high frequency leads to a contraction.

17. Which would have more mitochondria?
Fast fibers
Quick rapid contractions
Need lots of calcium storage
“White Meat”
Slow Fibers
Long sustained contractions require steady energy.
Less smooth ER (sarcoplasmic reticulum)
“Dark meat” rich blood supply

18. Goals Review muscles with Campbell’s activities 49C and 49D
Observe a frog’s muscles.
Use the web and microscopes to observe the structural differences and determine the functions of skeletal, cardiac, and smooth muscle.

19. Comparison of Muscle Tissue