Chapter 9 Skeletal Muscle, Tissue and Muscle Organization.

Define the following terms. Label them on Figures 9.5, i. Actin

Thin Protein Filaments

6. Define tendons and aponeuroses.

Epimysium, periumysium, and endomysium converge to form tendons. Tendons connect a muscle to a bone. Aponeuroses- Connect a muscle to a muscle.

5. List and briefly describe 3 layers of connective tissue found in muscles. Label these layers on Fig 9.1

Epimysium: Dense tissue surround the entire muscle. Perimysium: Dense tissue that divides the muscle into parallel compartments of fascicles Endomysium: Dense tissue that surrounds individual muscle fibers.

2. List and briefly describe 4 basic muscle properties.

Excitability: Ability to respond to stimuli. Contractility: The ability to shorten and exert a pull or tension. Extensibility: The ability to continue to contract over a range of resting lengths. Elasticity: The Ability to rebound toward its original length.

4. List the general components of muscular tissue that are studied at the Gross Anatomy and Microscopic Anatomy levels.

Gross Anatomy Level: Overall organizations of muscles, Connective tissue associated with muscles, Nerves associated with muscles, blood vessels associated with muscles. Microscopic Anatomy Level: Myofibrils, Myofilaments, Sarcomeres.

8. Define motor unit and its relationship to muscle tension.

motor neurons controlling muscle fibers. Muscle tension depends on the frequency of stimulation and the number of motor units involved.

Define the following terms. Label them on Figures 9.5, g. Myofilament

Make up sarcomeres. Made with actin and myosin.

Define the following terms. Label them on Figures 9.5 ii. Myosin

Thick Protein Filaments

7. Define the following terms. Label them on Figures 9.5, 9.6 a. Sarcolemma

Membrane that surrounds the muscle cell.

7. Define the following terms. Label them on Figures 9.5, 9.6 c. Muscle fiber/muscle cell

Multinucleate 30-40cm long

9. How are motor units related to precise and less precise control?

Precise Control: A motor neruon controlling two or three muscle fibers. The eye is an example. Less Precise Control: A motor neuron controlling perhaps 2000 muscle fibers. Leg muscles would be an example.

3. List and briefly describe 5 functions of skeletal muscle.

Produce movement: Pull tendons to move bones. Maintain posture: Stabilize the Joints Support soft Tissue: Support Visceral Organs Regulate Entering and exiting of Material: Voluntary control over swallowing and urination. Maintain Body Temperature: Energy for contraction is converted to heat.

7. Define the following terms. Label them on Figures 9.5, 9.6 e. Sarcomere

Repeating units of Myosin and Actin that create striations. Main functioning unit of muscle fibers.

7. Define the following terms. Label them on Figures 9.5, 9.6d. Myofibril

Responsible for the contraction of muscles.

7. Define the following terms. Label them on Figures 9.5, 9.6 b. Sarcoplasm

The cytosol of the muscle cell.

1. List and briefly describe 3 types of muscle tissue.

Skeletal Muscle: Striations, Pulls on skeletal Bones, Voluntary Contraction. Cardiac Muscle: Striations, Pushes blood through arteries and veins. rhythmic contractions. Smooth Muscle: No Striations, Pushes fluids and solids along the digestive tract. Involuntary contraction.

7. Define the following terms. Label them on Figures 9.5, 9.6 f. Sarcoplasmic Reticulum

Surround each myofibril.