Please enable JavaScript.
Coggle requires JavaScript to display documents.
Nikkhi Garcia Period 1 Muscular System - Coggle Diagram
Nikkhi Garcia Period 1
Muscular System
Major Functions
Produce
movement
Maintain
posture
& body posture
Stabilize
joints
Generate
heat
Sarcomere
sarcomere
- smallest contractile unit of muscle fiber, has A band (dark region) and half of I band (light region)
A band
- dark region
H zone
- lighter region in middle of A band
M line
- myomesin that bisects H zone vertically
I band
- light region
-
Z disc/line
- coin shaped sheet of proteins on midline of I band
Sliding Filament Theory of Muscle Contraction
Nerve sends signal,
Ca
releases
Ca
reveals
actin
binding sites
3.
Myosin head
attach to actin =
cross bridges
Myosin pulls actin toward center of sarcomere
(power stroke)
ATP gives energy so myosin detaches & repeat process
Filaments slide past each other shortening muscle
Nervous system stimulates muscle fiber, myosin heads bind to actin
(cross bridge)
, = cause sliding process to begin
States that during contraction thin filaments slide past thick filaments causing actin & myosin to overlap more
Contraction
: activation of cross bridges to make force
Muscle Coverings
All
skeletal
muscles covered in connective tissue to support cells & make muscles stronger
Epimysium
- dense irregular conn. tissue that covers the whole muscle
Perimysium
- fibrous conn. tissue that covers fasicles
Endomysium
- fine areolar conn. tissue that covers muscle fibers
Muscle - bundles of fascicles
Fascicles - bundles of muscle fibers
Muscle fibers - bundles of myofibrils
Myofibrils - bundles of sarcomeres
Disorders associated with Muscular System
Myasthenia Gravis
: neuromuscular disorder that blocks neurotransmitter
Causes: autoimmune, age, common in women
Symptoms: muscle weakness, facial paralysis, shortness of breath
Treatment: no known cure, medications, thymectomy
Myositis
: inflammtion of the muscle
Causes: autoimmune, infection, muscle trauma
Symptoms: muscle weakness, tenderness, fatigue
-Treatments: medication, antibiotics, reduce inflammatio
Fibromyalgia
: muscle pain
Causes: exact cause unkown, physical trauma, infection
Symptoms: muscle pain, tender points, fatigue
Treatment: physical therapy, massage, medication
Cerebral Palsy
: spastic paralysis causing muscle weakness
Causes: brain injury, premature birth, brain infections
Symptoms: muscle tightness, paralysis, delayed development
Treatments: no cure, medication for symptoms, surgical intervation
Muscular Dystrophy
: muscle weakness & atrophy
Causes: genetic, becker, myotonic
Symptoms: mental retardnation, muscle weakness, eyelid dropping
Treatment: no known cure, physical therapy, surgery
Names of Skeletal Muscles
Anterior
Torso
Sternocleidomastoid
- sides of neck
Trapezius
- upper shoulder by neck
Sternohyoid
- middle of neck
Pectoralis major
- upper chest
Serratus anterior
- upper sides of ribs
External oblique
- sides of torso
Rectus abdominis
- abs/belly
Limbs
Arms
Tricep brachii
- sides and behind upper arm
Brachialis
- upper inner elbow
Bicep brachii
- bicep/upper arm
Pronator teres
- front of forearm
Deltoid
- shoulders
Brachioradialis
- lateral side near thumb forearm
Flexor carpi radials
- front of forearm toward thumb side
Palmaris longus
- middle front of forearm
Flexor carpi ulnaris
- front forearm toward pinky
Legs
Adductor longus
- inner thigh near groin
Gracilis
- long runs down inner thigh
Pectineus
- upper inner thigh
Iliopsoas
- deep front of hip
Tensor fasciae latae
- outer front hip near top of thigh
Rectus femoris
- front middle thigh
Sartorius
- long muscle run diagonal across thigh
Vastus lateralis
- outer side of thigh
Vastus medialis
- inner front thigh
Fibularis longus
- outer lower leg
Extensor digitorum longus
- front outer lower leg
Gastrocnemius
- calf
Soleus
- deep in back of calf
Tibialis anterior
- near shin
Head
Orbicularis oculi
- around eyes
Zygomaticus
- cheekbone area
Temporalis
- sides of head
Masseter
- cheek
Frontalis
(epicranium frontal belly) - forehead
Orbicularis oris
- around mouth
Posterier
Torso
Teres major
- below infraspinatus
Rhomboid major
- upper middle back btwn shoulder blade & spine
Infraspinatus
- back of shoulder blade
Latissimus dorsi
- middle& lower back
Trapezius
- upper back from neck to upper shoulders
Sternocleidomastoid
- sides of neck
Head
Occipitalis
- back of head
Limbs
Arms
Brachioradialis
- outer forearm near thumb side
Extensor carpi radialis
- back of forearm thumb side
Tricep brachii
- back of upper arm
Extensor carpi ulnaris
- back forearm pinky side
Deltoid
- shoulder
Flexor carpi ulnaris
- inner front forearm near pinky side
Legs
Gracilis
- long inner thigh
Biceps femoris
- outer back thigh
Adductor magnus
- inner thigh
Semitendinosus
- inner back thigh
Gluteus maximus
- main muscle buttocks
Semimembranosus
- inner back thigh under semitendinosus
Gluteus medius
- upper outer butt near hip
Gastrocnemius
- calf
Soleus
- deep under gastrocnemius wraps around
Fibularis longus
- outer lower leg
Calcaneal tendon
- back of ankle
Neuromuscular Junction
Axon terminals (end of axon) meet muscle fiber forms NMJ / Motor end plate
1.) AP arrives at axon terminal
2.) Voltage-gated Ca channels open, Ca enters motor neuron
3.) Ca entry causes ACh (neurotransmitter) release into synaptic cleft
4.) ACh diffuses across ACh receptors on sarcolemma
5.) ACh binding to receptors, allows Na entry = end plate potential
6.) Acetylcholinesterase breaks down ACh
Action Potential in Muscle Fiber
AP caused by changes in electrical charges
Happens in 3 steps:
1.
Generation of end plate potential
2.
Depolarization
3.
Repolarization
1.)
EPP
ACh released from motor neuron binding to ACh receptors on sarcolemma
Causes chemically gated ion channels on sarcolemma to open
Na enters into muscle fiber, causes inside to be less negative
Results in local depolarization called end plate potential
2.)
Depolarization
If EPP reaches threshold, voltage gated Na channels open
More
Na enters
muscle fiber
AP spreads across sarcolemma causing area to depolarize
3.)
Repolarization
Na channels close & K channels open
K leaves cell, restoring membrane resting electrical state
3 Muscle Types & Functions
Skeletal
- elongated & called muscle fibers/cells, moves bones/body
Smooth
- // as above, moves substances through organs
Cardiac
- pumps blood
Skeletal
muscle details
organ made of 3 diff tissues w 3 fts:
nerve & blood supply, connective tissue sheaths, attachments
Characteristics of all
Contractility
- shorten when stimulated
Extensibility
- stretch
Excitability
- receive & responsiveness
Elasticity
- recoil to og length