Module 4 Flashcards
(122 cards)
4 properties of muscles
- excitability
- contractility
- extensibility
- elasticity
Fn of muscle tissue
- motion
- movement of substances
- posture, support of organs
- heat production
hierarchy of muscle (small>big)
Myofibril>myofilaments>muscle fiber>fascicle>Muscle
Muscle connective tissue (layers out to in)
- Epimysium
- Perimysium
- Endomysium
Skeletal muscle
striated, multinucleate, attached to skeleton
Cardiac muscle is
branched, single nucleus, striated, dintercalated discs, involuntary
Smooth
spindle shape, lines the hollow part around organs, ie the stomach
Blood supply needed in muscles because
blood carries oxygen, glucose, and CO2, -> cellular respiration to produce ATP, which is needed to power the action potential, the interaction between the actin and myosin
Aponeuroses is
a flattened tendon
Muscle fiber structure (out>in)
- sarcolemma
- mitochondrion,
- Terminal cisternae
- sarcoplasmic reticulum
- transverse tubules (t-tubules)
- Myofibril
- Triad
T-tubules are
extensions of the sarcolemma
Triad includes
2 terminal cisternae and 1 t-tubule
Thick myofibril is made up of
myosin (darker)
thin myofibril is made up of
actin (lighter)
Sarcromere
functional unit that can contract(from z-line to z-line)
- I-band
- A-band
- Z-line
- H-zone
- M-line
Neuromuscular junction parts
- Synaptic terminal of motor neuron
- Synaptic vesicle
- Neurotransmitters
- synaptic cleft
- Motor end plate of muscle fiber (folded sarcolemma)
The motor unit
is the neuron plus all the muscle fibers that it controls,
bigger muscle= bigger motor unit
muscle size changes
- muscle hyperthrophy: building up due to use
- Muscle atrophy: loss of mass due to lack of use
Skeletal muscle fiber types
- Slow twitch: slow to contract, don’t tire as fast, high myoglobin content (darker)
- Fast twitch: fast to contract, tire rapidly, low myoglobin content (lighter)
Muscle fiber orientation types
- Parallel
- Convergent: fibers converge from single point
- Pennate: pen-like
- Circular
Origin
does not move during contraction
Insertion
moves during contraction
Synergists
helper muscles to the agonists
Facial and muscles
- frontalis
- platysma
- orbicularis oculi
- orbicuclaris oris
- depressor labii inferioris
- zygomaticus major
- risorius
- buccinator
- masseter
- temporalis
- medial pterygoid
- lateral pterygoid