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Ricardo Munoz p.1: Muscular - Coggle Diagram
Ricardo Munoz p.1: Muscular
Major functions of the muscular system
Maintain body posture
Stabalize joints
Produce Movment: allows locomotion and minipulation
Contract/generate heat when contracting
3 types of muscles & their functions
Cardiac: Involentarraly pumps blood and citculate oxygenand nutrients throughout the body
Smooth: Involentary directing movment of material inside hollow organs
Skeletal: Provide volentary movment of limbs and joints by attaching to bone
Sliding filament theory of muscle contraction
Contraction:
activation of bridges to generate force
shortening:
when tension of cross bridges' thin filaments exceeds force opposing shortening
Once the action potential reaches the axon terminal, voltage-gated calcium channels open, allowing calcium ions to enter the neuron.
neuromuscular junction begins when an action potential travels along a motor neuron toward a skeletal muscle fiber, eventually reaching the axon terminal.
The calcium triggers synaptic vesicles to release the neurotransmitter acetylcholine into the synaptic cleft, where it travels toward the muscle fiber.
Acetylcholine binds to acetylcholine receptors on the motor endplate, a specialized region of the muscle fiber's sarcolemma, opening sodium/potassium channels.
Sodium ions enter the muscle fiber while potassium ions exit, generating an end-plate potential that triggers a muscle action potential and initiates contraction.
acetylcholinesterase breaks down acetylcholine in the synaptic cleft, ending the signal and allowing the neuromuscular junction to reset.
Action potential in a muscle fiber:
Depolarization: generation and propagation of action potential
: sodium influx causes membrane voltage to surpass threshold, causing voltage gated sodium membrane channels to open and lead to unstopable fiber contraction.
Repolarization:
Sodium voltage gated channels close and voltage gated Calcium channels open leading to a setteling to a resting membrane voltage and refractory period where muscle fibers can't be stimulated
End plate potential:
Local depolarazatin due to chemically gated ion channel opening their sodium to the greater muscle fiber when ACH is released and binds on sarcolema
Disorders associated with the Muscular system
Duchenne muscular dystrophy (DMD):
Most common and serious muscular diseas, affecting upward extrematies and cuases easily tearing muscle and reduced regenerating capacity
Myasthenia Gravis:
drooping upper eyelid, difficulty swallowing and talking, and generalised muscle weakness
Fibromyalgia
: Muscle pain
Cerebral Palsy:
spastic paralysis causing muscle weeakness
Myositis
: inflimmation of muscle
Sarcomere: The smallest muscle contractile unit, made of repeating myofilaments
Thin (actin) filament
Thick (myosin) filament
Z disc
: boarder of a single sarcomere in muscle tissue
Thin elastic (titin) filaments
H Zone
: Thick filaments only
A band
area of entire myosin and ends of actin when myosin heads attach to actin when contracting
I band
: light band only including thin actin fiber
M Line:
dark band only including myosin fiber
Muscle coverings
CT sheaths:
covers every skeletal muscle and muscle fiber. Epimysium=Dense irregular CT, perimysium=Fibrous CT surround fascicles, Endomysium=areolar CT
Neuromuscular junction:
Ca entry causes release of ACH neurotransmitter to synaptic cleft
ACH diffuses across to ACHreceptors on sarcolemma
Voltage-gated calcium channels open,
ACH binds to receptors, opens gates, letting NA+ enter resulting in end plate potential
AP arrives at axon terminal
Acetylcholinoesterase degrades ACh
Names of all the skeletal muscles
Anterior
Torso
:
trapezulus
serratus anterior
pectoralis major
internal oblique
rectus abdominus
Arms:
Deltoid
tricepts
bicepts brachi
brachialis
pronactor teres
brachioradialis
flexor carpi radialis
palmaris longus
flexor carpi ulnaris
Head and neck:
Epicranius (frontal belly)
Orbicularis oculi
zygomaticus
orblcularis oris
masseter
temporals
sternohyloid
sternocleidomastiod
legs:
sartorius
gracilis
vastus medialis
Tibialis anterior
vastus lateralis
Fibularis brevis
Quadricep femorals
adductor longus
gastrocnemius
fibulares longus
soleus
Prosterior
Torso
teres minor
teres major
trapezius
rhomboid major
infraspinatus
latissimus dorsi
Arms:
Deltoid
brachialis
flexor carpi radialis longus
extensor digitorum
extensor carpi ulnaris
flexor carpi ulnaris
Head and neck:
Epicranius occipital belly
sternoleidomastiod
Legs:
gracils
semmimembranosus
semitendinosos
gstocneminus
adductor
soleus
gluteus medius
fibularis longus
gluteus maximus
calcaneal