Muscle Physiology

Question 1

What are the universal characteristics of a muscle and what does each one mean?

Answer 1

-Excitability: to chemical signals, stretch and electrical changes across plasma membrane
-Conductivity: Electrical excitation initiations wave of excitation that travels across the muscle fibre
-Contractability: shortens when stimulated
-Extensibility: capable of being stretched between contractions
-Elasticity: returns to original rest length after being stretched

Question 2

What are some properties of skeletal muscles?

Answer 2

• They attach bone by tendons
• They are voluntary straiated muscle that are attached to one or more bones
• They exhibit alternating light and dark tranverse bands called striations
• They are subject to conscious control
• They are quite large, and therefore the cells are usually called muscle fibres or Myofibres

Question 3

What are muscles comprised of and what are they supplied with

Answer 3

• Comprised of Fasciles
• Supplied with nerves and blood vessels and enclosed in a fibrous epimysium that separates it from neighbouring muscles

Question 4

What are Fasciles comprised of and what are they supplied with

Answer 4

• Bundles of tighly packes long parrelel cells
• Supplied by nerves & blood vessels & enclosed in fibrous perimysium that separates it from neighboring fascicles.

Question 5

What is a Scarcolemma

Answer 5

Slender, elongated, enclosed in specialized plasma membrane

Question 6

What is a Myofibril

Answer 6

Contains densely packed bundles of contractile protein filaments, multiple nuclei immediately beneath the sarcolemma & an extensive network of specialized smooth endoplasmic reticulum