muscle structure and function

Question 1

what do muscles do?

Answer 1

*Produce movement
* Maintain postures and positions
* Other functions – protection, heat production (themogenesis)
and driving circulatory system (vascular pump)

Question 2

what are the 3 types of muscles we have?

Answer 2

1. smooth muscle
   2.cardiac muscle
   3.skeletal muscle

Question 3

how do muscles contract?
*balloonist theory
*swammerdam

Answer 3

• balloonist theory-contracting muscles seem to swell(volume of muscle increases)
  -swammerdam- volume does not increase ,instead it decreases by small amount(water level should go up if vol increases but it doesn’t)

Question 4

what happens in muscle fibre contraction?

Answer 4

Each contractile fibre generates tension, which applies force to both ends

Question 5

what does a tendon do?

Answer 5

-it attaches muscle to bone

Question 6

parallel vs muscles

Answer 6

Pennate muscles are stronger because more fibres are packed
aponeurosis
fibres

Question 7

parallel vs pennate muscle:PCSA

Answer 7

Pennate muscles are stronger because more fibres are packed
Pennate muscles have greater PCSA
Physiological Cross-Sectional Area (PCSA)

Question 8

parallel vs pennate :speed

Answer 8

Pennate muscles are slower because fibres have to shorten over a
greater distance to shorten the muscle over the same distance

Question 9

what are the 3 types of muscles contraction?
*what’s does contracting not always mean?

Answer 9

• contraction doesn’t=shortening
  1.isometric:external force=muscle force so muscle length stays constant
  2.concentric:external force<muscle force the muscle shortens in contraction
  3.eccentric:external force>muscles force so muscles can be lengthened

Question 10

brief explanation of sliding filament model:

Answer 10

-the myosin head binds to acting binding sites forming cross bridges.then theres a power stroke causing the contraction (‘nod’s myosin head )