P1 PHYSIOLOGY Flashcards
Skeletal muscle contraction
functions of the skeletal muscles
- production of heat
- Stabilising body’s posture
- movements
the process of activation of the skeletal muscles cross bridge cycle is known as
excitation- contraction coupling
Calcium channel receptor formed by scaropalsmic reticulum protein
ryanodine
type of muscle contraction
- isometric
- isotonic
Type of Muscle Contraction in which the muscle does not change in length
isometric
Importance of isometric contraction
- Maintaining posture
- Supporting objects in a fixed place
Type of Muscle Contraction in which the muscle does change in length
Isotonic
Importance of isotonic contraction
Body movements
Moving external objects
2 subtypes of isotonic contraction
Concentric & eccentric
which sub type if isotonic is used for balance of body
Eccentric
subtype of isotonic in which the muscle lengthens as the resistance becomes greater
Eccentric
subtype of isotonic in which the muscle shortens
concentric
give example of a concentric muscle
biceps brachii
Importance of muscle tone
- stability of joint
- maintain posture
name the phase during which excitation and contraction are being coupled but contraction has yet to occur.
latent phase
name this contraction / twitch & its importance
Soleus muscle: slow contraction for continual, long-term support of the body against gravity
An α motor neuron and the extrafusal muscle fibers it innervates is known as
motor unit
small muscle neurons are seen in
extraocular muscles
fingers
large MNs are seen in
thighs & back muscles
mention 2 factors that enables the muscle to accomplish gradation
1-The frequency of action potentials (nerve impulses)
2- the number of motor neurons transmitting the action potentials
very rapid sequence of stimuli: no relaxation is known as
Tetanus
tension required to extend a resting muscle is known as
passive tension
in the load- velocity relationship ,
as the load increases it will result in
1- longer latent period
2- shorter duration of twitch
3- shorter distance of shortening
4- slower velocity of shortening
Direct phosphorylation pathway is for what activities
short bursts of high intensity activities
in Direct phosphorylation pathway
the phosphate donor is
creatine phosphate
Direct phosphorylation produces how many ATPs
1 ATP / CP
Anaerobic pathway is for what activities
high intensity short-duration exercises
energy source in Anaerobic pathway
Glucose
Products of Anaerobic pathway
2 ATPs / glucose & lactic acid
Disadvantages of Anaerobic pathway
less ATP & leads to lactic acidosis
which pathway is a very slow one but produces the highest amounts of ATP
aerobic pathway
how many ATPs are produced in aerobic pathway
32 ATPs
the 2 main differences between the types of muscle fibres
1- speed of contraction
2- ATP synthesising ability
mention the 3 types of muscle fibres
- slow oxidative
- fast oxidative
- fast glycolytic
Oxidative fibers Uses which pathways
Aerobic pathway
- fast glycolytic uses which pathway
Anaerobic pathway
name the principle that explains MU recruitment
Henneman’s size principle
what type of muscle fibers are first stimulated
slow oxidative
what type of muscle fibers are stimulated after slow oxidative fibers in case of additional tension
fast oxidative fibers
what type of muscle fibers are finally stimulated
fast glycolytic fibers
Changes in muscle fiber diameter is seen in
Weight lifting exercises
Anaerobic short duration high intensity exercises
Changes in ATP-synthesizing capacity is seen in
aerobic exercises
in weightlifting as an example ,
the 2 muscle changes are
1- increase in muscle size . Hypertrophy
2- increase in number of muscle fibers / hyperplasia
a decline in the ability of the muscle to sustain the strength of contraction is known as
Muscle fatigue
mention at least 3 causes of muscle fatigue
1- rapid build-up of lactic acid
2- Decrease in oxygen supply
3- Decrease in energy supply
4-Conduction failure
5-Buildup of ADP and Pi
6- Decreased neurotransmitter at the synapse
7- Psychological factors
