Exercise Psy week 9 part 1

winniesmith2's version from 2018-01-09 13:04

Section 1

Question Answer
Muscle biopsy; type 1 fibres stain darker
muscle biopsy; type 11B doesn't take up stains
Muscle biopsy; type 11Astains lighter
Classification of muscle fibres; type 1- slow twitch - slow glyolytic. Oxidative capacity; high. Glycolytic capacity; low. Mitochondrial density; high. Capillary density; high. Myoglobin (Mb) content - high.
Classification of muscle fibres - type 11A-fast twitch A -fast oxidative glycolytic. Oxidative capacity; medium. Glycolytic capacity; high. Mitochondrial density; medium. Capillary density; medium. Myoglobin content; medium
Classification of muscle fibres; type 11B (11x)-fast twitch -fast glycolytic. oxidative capacity; low. Glycolytic capacity; highest. mitochondrial density; low. Capillary density; low. myoglobin content; low.
Are all muscle fibre types unique?no - hybrid fibres also exist ef. 11A/11x

Section 2

Question Answer
What does myoglobin do -shutters 02 from cell membrane to one mitochonrida. Mb has increased affinity for 02 than hb. -even at low partial pressures of O2. Allows mb to store 02.
Fibre type distribution -% type 1 and type 11(2) fibres not the same throughout the body. -typically similar between arms ans legs. - some exceptions (soleus muscle composed of high % if type 1 fibres in everyone.
What is a motor unit -term used to describe a motor neuron and all the muscles cells that it innervates.
skeletal muscle fibres; fast glycolytic fibres fatigue very quickly. more innervation is going to more fibres.
skeletal muscle fibres; fast oxidative glycolytic fibres more force but gets fatigue
skeletal muscle fibres; slow oxidative fibres low force production but low fatigue so can maintain it. less innervation and smaller cell bodies.
Msucle fibre characteristics ; type 1Contraction time; 80-100ms
Type of myosin ATPase; slow
Nerve conduction velocity; slow
Rate of fatigue; low
Fibres per motor neurone; 10-180
Motor unit force ; low
Muscle fibre characteristics;
type 2a
Contraction time; 50ms
Type of myosin ATPase; fast
Nerve conduction velocity; fast
Rate of fatigue; intermediate
Fibres per motor neurone; 300-800
Motor unit force; high
Muscle fibre characteristics;type 2x/bContraction time; 50ms
Type of myosin ATPase; fast
Nerve conduction velocity; fast
Rate of fatigue; high
Fibres per motor neurone; 300-800
Motor unit force; high
All or nothing?when a motor neuron fires all the fibres that it innervates contract, but the number of neurone firing will differ depending on desired force production
order of recruitment?progressive recruitment of type 1 followed by 11a then 11x motor units as the insanity of the activity increases.
Size principal type 1 (smallest) -- fatigue -> type 11a --fatigue--> type 11x. As type 1 become fatigued, type 11a are activated (larger)

Section 3