Module One, Lecture Eight

Question 1

What are the types of Muscle in the Human Body? ( 3 )

Answer 1

1. Smooth
2. Cardiac
3. Skeletal

Question 2

Describe the structure and function of Smooth Muscle… ( 5 )

Answer 2

1. Spindle-shaped with a central elongated nucleus
2. Involuntary movements in the body
3. Controlling organ size, wall movement and stiffness
4. Regulating blood vessel diameter, allowing food to move through the digestive system
5. Enables bladder control

Question 3

Describe the structure and function of Cardiac Muscle… ( 3 )

Answer 3

1. Branched shape, intercalated discs which form a network that facilitates rapid coordinated contraction ( heartbeat )
2. To contract rhythmically and involuntary
3. Generates the force needed to pump blood through the entire body

Question 4

Describe the structure and function of Skeletal Muscle…

Answer 4

1. Complex structures composed of various layers of connective tissue, muscle fibres, and cellular components
2. Production of voluntary movements
3. Maintaining Posture
4. Stabilizing Joints

Question 5

Detailed Structure of Skeletal Muscles… ( 4 )

Answer 5

1. Individual muscle cells are called muscle fibres that are gathered into bundles called fascicles
2. Fibres, fascicles, and muscles are sheathed in connective tissue
3. Connective tissue is gathered to form tendons, which connect muscles to bones

Question 6

What is a Muscle Fibre comprised of?

Answer 6

Myofibrils which are made of repeating units called sacromeres

Question 7

What are Sacromeres made of? ( 2 )

Answer 7

1. Actin ( thin filaments )
2. Myosin ( thick filaments

Question 8

What is the Cell Membrane that lines the Muscle Fibre?

Answer 8

The Sarcolemma

Question 9

What are Transverse Tubules?

Answer 9

Tube-like extensions of the sarcolemma

Question 10

What is the function of T-Tubules? ( 3 )

Answer 10

1. Excitation-Concentration Coupling
2. Signal Transmission
3. Calcium Release

Question 11

Define Excitation-Contraction Coupling…

Answer 11

The process by which an electrical signal ( action potential ) triggers a muscle fibre to contract

Question 12

Define Signal Transmission…

Answer 12

The facilitation of the AP into the cell’s interior, ensuring that the entire muscle fibre is activated simultaneously

Question 13

Define Calcium Releasing…

Answer 13

The arrival of the AP at the T-Tubules triggers the release of calcium from the sarcoplasmic reticulum ( SR )

Question 14

What is the function of the Sarcoplasmic Reticulum?

Answer 14

Take up and store calcium while the muscle is relaxed, then to release calcium into the cytoplasm when the muscle contracts