Lesson 16 - Muscular Physiology

Question 1

Muscle

Answer 1

40% of total body mass
-Most of body work and where we stores ATP

Contains skeletal, smooth and cardiac muscle

Types:

Skeletal muscle -strained and voluntary
Smooth muscle - not strained and involuntary
Cardiac muscle: strained and involuntary

Skeletal = fastest, instant
Cardiac = intermediate, 1 sec
Smooth = 5 seconds or longer, slowest

Question 2

Connective tissue and organization

Answer 2

Epimysium=outside layer, muscle group

Perimysium, muscle fascicles

and then Endomysium, muscle fibers

Muscle group to muscle fascicles (bundles) to muscle fibres to myofibrils and then myofilaments (actin and myosin)

muscle consist of fascicles which contain fibers

Question 3

Types of fascicles pattern to tendon

Answer 3

parallel
fusiform
Circular
Triangular
Pennate
convergent

Question 4

Lever sytem (III)

Answer 4

Fulcrums= joints acts us fulcrums for support

Levers = bones

Effort = muscle contraction, applies force where muscle attaches to bone

Load= bone, total resistance. anything lifted

Lever 3: common and effort is always between fulcrum and the load. always at a mechanical disadvantage.

Just have to know we use third class levers all the time (bicep curl)

Question 5

Structure of skeletal muscle

Answer 5

Myofibrils are surrounded by sarcoplasmic reticulum, like wrapped around and stores calcium

M line: anchors in
Z disc = end, tether thin filament, tension
H zone =only thick filament (myosin)
A band = dark region (myosin+ actin)
I band= just actin region

Question 6

Actin and myosin

Answer 6

Myosin:
-always activated
- binding site for actin and ATP

Actin:
-double helix that overlaps
-binding sites for myosin (black circle on ball)
-covered by tropomyosin

Question 7

Sliding filament mechanism

Answer 7

-overlapping zones get bigger
- Myosin binds and pivots
-Z discs get closer