Functions and more for muscular system Flashcards
Functions of the muscular system and what they do (1)
Movement
- pull on bones
- levers that muscles move
Functions of the muscular system and what they do (2)
Posture and position
- works for long periods of time
- keeps everything in line with- where they are supposed to be
Functions of the muscular system and what they do (3)
Construction of organs and vessels
- moves blood/food around
Functions of the muscular system and what they do (4)
Guards entrances and exits
- so that things stay in when they need to
Functions of the muscular system and what they do (5)
Body temperature
- moving muscles provides heat
Functions of the muscular system and what they do (7)
Respiration
- makes intercostals move to breath
- gets us to get air
Functions of the muscular system and what they do (6)
communication
- verbal - muscles changing tension in vocal chord
- facial expression
contractility
ability to get shorter with force
excitability
- capacity of muscle to respond to a stimulus
- muscle can be turned on and off
extensibility
-muscles can be stretched
- go beyond normal degree of flexibility
elasticity
- ability to recoil
- stretch and recoil
- way stronger
Gross anatomy
The whole thing
Connective tissue: fascia
connects everything - covers all of muscle
epimysium
- covers whole muscle
- deeper than fascia
tendon
- comes out of epimysium
- epimysium gathered at one end
perimysium
- around sections of muscle tissue
- nearest to blood vesselz
fascicule
section of muscle
endomysium
- around individual fiber
- smallest part
nerves and blood vessels
- run through perimysium - changeable
- more use - stronger/more
Microanatomy - fiber
cell
sarcolemma
cell membrane
sarcoplasm
cytoplasm - fluid inside cell
transverse tubules (t. tubules)
(across tubes)
- into muscle fiber
- makes way across
Sarcoplasmic reticulum (S.R.)
- tubes
- run parallel
- stores calcium
Myofibrils
bundles of protein inside muscle fiber
sarcomere
smallest section of muscle that contracts
functional unit
actin
thin - heads wrapped around each other
myosin
thick - clubs stacked away from each other
Cross bridges
- connection between actin and myosin
- myosin head attaches to active sites on actin - atp is used to make it let go
troponin and tropomyosin
2 proteins - part of sarcomere
troponin - bead-like protein attached to both actin and tropomyosin
tropomyosin - ribbon-like protein that lies along actin
- at rest - covers up active sites
calcium will bind to troponin and change its shape - when troponin changes shape, it pulls tropomyosin off of active sites
calcium is the trigger
Inside a muscle fiber, outside a myofibral
transverse tubule (t. tubule)
- action potentials travel down t. tubule and stimulate a voltage sensitive protein and changes its shape so that the foot like projection moves
sarcoplasmic reticulum
- the foot-like projection of the VSP is attached to a protein gate inside the SR
- calcium is stored in SR
- when calcium gate opens - calcium floods out of SR
- calcium pumps - being run by ATP
motor end plate
- where neuron communicates - don’t actually touch
- action potential starts
sarcolemma
electrical current travels all over it
muscle stimulation
comes from neurons
motor neuron
commands coming from brain
neuromuscular junction
(where the neuron meets the muscle)
synaptic cleft between them
acetylcholine
name of neurotransmitter that tells it to contract
motor units
- your brain calls on how many/which motor units to fire
- one neuron and all the muscles fibers it controls
- motor recruitment - how many motor units are asked to use
- motor learning - your brain figuring out which motor units to use
ATP
- every single cell in your body uses ATP
- ATP is always being used/made
- at any given moment your muscle cells with have 2 to 3 seconds ATP is floating around
CP or PC
- creatine phosphate
- takes its energy and puts it into ATP really fast
- 4 to 10 seconds of activity on CP
- takes between 5 and 8 minutes to put CP back together
anaerobic respiration
(without oxygen)
getting energy out of food (metabolism - glycolysis)
- 10-45 seconds of activity on anaerobic respiration
- happens in the sarcoplasm
- a lot of energy very quickly - doesn’t last long
- glucose <——————> glycogen (stored)
-
- +2 ATP
-
pyruvate <——————> lactic acid
- with training, you can store more glycogen
- can increase tolerance for lactic acid
- cool down keeps capillaries open in the working muscle so you can get rid of the junk
Aerobic respiration
- uses oxygen
- always happening until you die
- happening in mitochondria
- glucose —> pyruvate —> mitochondria —>
(kreb’s cycle) —> +2 ATP +6 NADH + 2FADH2
(oxidative phosphorylation)—>NADH and FADH2 and ATP
I I
+36 ATP
-operates slower, but produces more energy
- O2 enters and waste produced by the mitochondria is CO2 and H2O
oxygen debt
- when you breathe really heavy after an exercise even though you’re muscles aren’t being used anymore
- happens when you use too much anaerobic respiration
why keep breathing heavy?
- need to replace ATP
- need to replace CP
- get rid of lactate and turn it into pyruvate or burn it in heart
- repair cells (requires ATP)
Muscle fatigue
High intensity
- run out of ATP
– Change PH of cells
Low intensity
– Mental game creates muscle fatigue
– Intro muscle – run out of fuel in muscle glycogen depletion – more sugar in muscles, the easier it is
– Extra muscle – run out of fuel in body exercise longer than two hours – starts with a sugar, turns to fat – slows you down
– Decreased oxygen delivery to working skeletal muscle – more red blood cells – more oxygen – if temperature is high – send less blood to muscle
muscle fiber types – type one
Slow twitch
– Smaller motor units, 1 to 6
– Endurance
– Lots of blood vessel
– Stay skinny
– Legs
– Myoglobin – mostly water – some iron makes it red
– Lots of mitochondria
– Fatigue resistant
– Low in anaerobic ability – not as much glycolysis
– Low in glycogen storage
– Slow ATPase
muscle fiber types – two a
Fast twitch
– Medium motor units 7 to 10
– Fast
– Medium amount of blood vessels
– Get bigger
– Legs
– Not much myoglobin
– Medium amount of mitochondria
– Fast fatigue resistant
– Highest anaerobic
– Highest glycogen storage
– Fast ATPase
muscle fiber types – two b
Fast twitch
– Large motor units – 10
– Power
– Few blood vessels
– Gets biggest
– Arms
– Little or none of myoglobin
– few mitochondria
– Fast fatigable
– High anaerobic
– High in glycogen storage
– Fast ATPase
isotonic
Same tension
isometric
same length
isokinetic
same speed
Prime mover
Main muscles to the action
synergist
Stabilize and help
Antagonist
do opposite action
If working out – many body parts/muscles first, single/specific muscles – also do both side sides – push and pull
concentric
Muscle gets shorter while working
Eccentric
Muscle gets longer while working
Origin
more stable side to muscle
insertion
More movable side to muscle
twitch
– One command to contract
– Super quick
– Sustained contraction in tetanus
Recruitment
– Your brain firing neurons to decide which ones to use
– Knowing which ones to use - coordinated
all or nothing
– If muscle fiber is told to contract, it will contract to its best ability
– If lifting something light, just less fibers
how is smooth muscle different
– Involuntary – unlike voluntary skeletal system
– Smooth – consistent
– With the contract if stretched
– Hormones might tell it to contract
How is cardiac muscle different?
– Involuntary – unlike voluntary skeletal system
– Striated – not smooth under microscope – lines
– Tell themselves to contract
– Have a huge amount of mitochondria
– Always aerobic
– pyruvate is never waiting so it doesn’t cramp
