Please enable JavaScript.
Coggle requires JavaScript to display documents.
Jocelyn Gomez Anatomy period 1 muscular - Coggle Diagram
Jocelyn Gomez Anatomy period 1 muscular
SARCOMERE
main contractile unit of the muscle fiber in the skeletal muscle, composed of myofilaments, myosin, actin and myofibrils
sarcomeres are describing with dark and light bands, thick and thin myofilaments
Link Title
A bands
dark bands that contain whole thick myosin (thick) filaments
I bands
light bands that contain only actin (thin) filaments, located between two z discs
Z discs
sarcomere can be described as the structure between the two z discs
M line
marks the middle of the sarcomere and contains the protein called myosin
H zone
area between the M line and Z discs, contains myosin
THIN / THICK FILAMENTS
THIN FILAMENTS
composed of fibrous protein (thin)
THICK FILAMENTS
composed of protein (myosin), contains six polypeptide chains: two heavy and four light chains
3 TYPE OF MUSCLES
SMOOTH MUSCLE
in walls of hollow visceral organs
single, spindle shaped,
no striations
SKELETAL MUSCLE
attached to bones or the skin
single, long cylindrical shape l,
striations
, multinucleate
CARDIAC MUSCLE
walls of the heart, muscle located only in the heart
branching chains,
striations
, uni/binucleate
MUSCLE COVERINGS (CONNECTIVE TISSURE COVERING)
Epimysium
layer of dense connective tissue which cover the entire muscle; can blend with fascia
Endomysium
wispy layer of areolar connective tissue that covers each muscle fiber or muscle cell
perimysium
layer of connective tissue which groups muscle fibers into bundles or fascicles
MUSCULAR JUNTION
NEUROMUSCULAR JUNCTION
chemical synapse between a motor neuron and a muscle fiber, allows neuron to transmit a signal to the muscle fiber, causing muscle contraction
simplest type of synapse, neuro signals from the brain or spinal cord interact with skeletal muscle fibers causing them to contact
AP arrives at axon terminal
ACh binding to receptors, opens gates, allowing 𝑁𝑎+ to enter resulting in end plate potential
SLIDING FILAMENT THEORY
1) myosin heads split ATP and became reoriented and energized
2) myosin heads bind to acting, forming cross bridges
3) myosin heads rotate toward center of the sarcomere (power stroke)
4) as myosin heads bind ATP, the crossbridge detach from actin
sliding filament theory describes the mechanism of muscle contraction
CONTRACTIONS
isotonic contraction
any contraction in which a muscle shortens to overcome resistance
muscle change in length and moves load
isometric contraction
muscle tension increases but does not exceed load, no shortening
does not cause shortening, or lengthening
FUNCTIONS OF THE MUSCULAR SYSTEM
joint support
maintains posture and structure for the human body
produce movement, circulation and digestive properties important for the human body
generates heat provided for the body
MUSCLE TISSUE
excitability
ability to receive and respond to stimuli
elasticity
ability to recoil to resting length
extensibility
ability to be stretched
elasticity
ability to recoil to resting length
DISORDER ASSOSIACTED WITH MUSCULAR SYSTEM
cerebral palsy
brain injury, brain abnormalities, premature birth, brain infection
mild to severe, seizures, muscle tightness
Spasic paralysis causing muscle weakness
myositis
inflammation of the skeletal muscle caused by an infection
autoimmune, infection, muscle trauma
fatigue, muscle weakness, difficulty breathing
muscular dystrophy
muscle weakness and atrophy; more common in woman
physical trauma, infection, sleep disturbance,
muscle pain, joint pain, stiffness, deppression/insomnia
fibromyalgia
neuromuscular disorder that blocks transmitters; more common in woman
muscle pain, tender joints, fatigue
physical trauma, infection, sleep disturbance
myasthenia gravis
muscle weakness, double vision, facial paralysis
neuromuscular disorder that blocks neurotransmitters
autoimmune, possible tumor of the thymus, aged woman
rigor mortis
3/4 hours after death, muscle begin stiffening
muscles stay contracted until muscle proteins break down, causing myosin to release
intracellular calcium levels increase because ATP is no longer being synthesized, calcium can no longer be pumped back into SR
SKELETAL MUSCLES
posterior
adductors magus
fibulas longus
soleus
extensor capri radialis longus
gluteus Medius
glutes maximus
rhomboid major
teres major
infraspinatus
brachioradialis
trapezius
triceps brachial
deltoid
levator scapulae
occipitals
extensor dithorium
flexor capri ulnar is
semimembranosus
gracillis
gastrocnemius
anterior
vastus medialsis
vastus laeralis
soleus
extensor digitorium longus
adductor longus
brachioradialis
pectineus
biceps brachial
iliopsoas
rectus abdominis
rectus formis
deltoid
serratus anterior muscle
sartorius
pectorals major
frontalis
orbicularis oculi
temporalis
masseter
zygomatics (cheek bone)
orbicularis Oris
external oblique
internal oblique
GENERATION OF AN ACTION POTENTIAL ACROSS THE SARCOLEMMA
generation of the end plate potential
what is the end plate potential?
end plate potentials are the voltages which cause depolarization of skeletal muscle fibers caused by neurotransmitters binding to the postsynaptic membrane in the neuromuscular junction
causes chemically gated ion channels on sarcolemma to open
results in local depolarization called end plate potential
depolarization
what is depolarization in the sarcolemma?
neurotransmitters release occurs when an action potential travels down the motor neurons axon, resulting in altered permeability of the synaptic terminal membrane
as ACH binds at the motor end plate, this depolarization is called an
end plate potential
generation/propagation of an action potential (AP)
AP spreads across sarcolemma from one voltage-gated channel to the next
repolarization
what is repolarization?
action potentials result from the depolarization of the cell membrane (sarcolemma), which opens voltage sensitive channels become inactive and the membrane is repolarized through the outward current of potassium ions
refectory period is when muscle fibers cannot be stimulated for a specific amount of time until repolarization is complete
restoration of resting conditions
SLIDING FILAMENT THEORY OF MUSCLE CONTRACTION
what is the sliding filament theory?
the sliding filament theory describes how much muscles are supposed to contract at the cellular level
5 steps pf sliding filament theory
the sarcolemma reticulum stimulated to release calcium ions
calcium ions bind to troponin
cross bridges (on myosin) pull on actin (power stroke)
cross bridge detached from building sites on actin
muscle fibers lengths and relaxes
calcium ions actively pumped back into sarcoplasmic reticulum