1. Chapter 8-Muscular System

2. Case Study # 1 Signs and Symptoms: -Respiratory Acidosis -Accelerated oxygen consumption -Extreme heat production Case Study # 2 Signs and Symptoms: -Muscle weakness -Easily fatigued -Muscles eventually cease to function Case Study # 3 Signs and Symptoms: -Uncoordinated movements -Jerky to-and-fro motion of trunk and limbs

3. Three Types of Muscle Tissue 1)Skeletal Muscle -Striated -Voluntary 2) Cardiac Muscle -Striated -Involuntary 3) Smooth Muscle -Non-striated -Involuntary

4. Functions of Muscular Tissue 1)Produce body movements 2)Stabilize body positions 3)Store and move substances within the body 4)Produce heat

6. Skeletal Muscle Tissue -Each muscle is a separate organ -Composed of thousands of cells → muscle fibers - Fibers packed in fascicles

7. Connective Tissue -Between Skin and Muscle → Hypodermis -Areolar connective tissue -Adipose tissue -Individual muscles surrounded by Fascia -Dense irregular connective tissue -Supports muscles -Helps form tendons

8. Connective Tissue -Epimysium: surrounds whole muscle -Perimysium: surrounds fascicle -Endomysium: surrounds muscle fibers All 3 extend beyond muscle to form a tendon

9. Nerve and Blood Supply -Need A LOT of nutrients and oxygen -Need to get rid of waste -Each muscle fiber is in close contact with capillaries and neurons

10. Skeletal Muscle Histology

11. -Sarcolemma: plasma membrane -Sarcoplasm: inner material of fibers (like cytoplasm) -Contains A LOT of mitochondria - Sarcoplsmic reticulum: fluid-filled tubules that store calcium (like SER) -Myofibrils: made of protein filaments that extend along length of fiber The Muscle Fiber (Cell)

12. Skeletal Muscle Histology

13. Myofibrils -Two types of Myofilaments (proteins): 1)Actin → Thin filaments 2)Myosin → Thick filaments -Overlap to form light and dark bands

14. Sarcomere -The basic functional unit of contraction -Thin filaments (actin) anchored to Z disc -Thick filaments (myosin) bind to thin filaments at myosin- binding site Z disc Sarcomere Z disc Sarcomere (b) Myofibril Thin filament Thick filament Thin filamentThick filament

15. Actin and Myosin Myosin tail Myosin Myosin heads Myosin-binding site (covered by tropomyosin) Actin Troponin Tropomyosin

16. Fasicles Fibers Myofibrils ActinMyosin