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Leidy Esquivel Per:2 Muscular System - Coggle Diagram
Leidy Esquivel Per:2 Muscular System
Action potential in a muscle fiber
Generation of end plate potential
generated by a conductance increase in the end-plate membrane.
brings the membrane potential toward the reversal potential
Diminishes the driving force for inward current flow.
Depolarization
Generation and propagation of an action potential (AP)
Causes the rapid change in membrane potential from negative to positive state
the membrane depolarizes above the threshold voltage
Repolarization
𝑁𝑎+ voltage-gated channels close
voltage-gated 𝐾+ channels open
Restoration of resting conditions
𝐾+ efflux out of cell rapidly brings cell back to initial resting membrane voltage
Major Functions of the Muscular Systsem
Produce Movements-responsible for all locomotion and manipulation
Walking, digesting, pumping blood
Maintain posture and body position
Stabilize Joints
Generate heat as they contract
Skeletal Muscles
Arm
Biceps brachii - The ventral portion of the upper arm
Brachialis - The anteroinferior area of the arm
Triceps brachii - The dorsal part of the upper arm
Thorax
Pectoralis minor/major - on each side of the sternum (chest)
Serratus anterior - The lateral wall of the thorax
Forearm
Brachioradialis - the radial side of the forearm
Flexor carpi radialis - The anterior part of the forearm
Palmaris longus - Anterior forearm flexor group in the human upper extremity
Extensor carpi radialis longus - The posterior compartment of the forearm
Flexor carpi ulnaris - The anterior compartment of the forearm
Extensor carpi ulnaris - The posterior compartment of the forearm
Extensor digitorum - The posterior compartment of the forearm
Shoulder
Trapezius - Upper back
Deltoid - shoulder
Teres major - Thick muscle of the shoulder joint
Leg
Extensor digitorum longus - The anterior compartment of the lower leg
Tibialis anterior - Distal one-third of the tibia
Fibularis longus - Uperficially in the lateral compartment of the leg
Gastrocnemius - Under skin at the back of the lower leg
Soleus - calf muscle
Abdomen
External oblique - The outer surface of the sides of the abdomen
Internal oblique - The lateral side of the abdomen
Rectus abdominis - Down the middle of abdomen from ribs to the front of pelvis
Transversus abdominis - The abdomen immediately inside of the internal oblique muscle
Pelvis/thigh
Pectineus - Medial thigh
Sartorius - The anterior compartment of the thigh
iliopsoas - Hip
Adductor longus - The medial aspect of the thigh
Gracilis - The medial compartment of the thigh
Rectus femoris - The anterior compartment of the thigh
Vastus lateralis - The lateral side of the thigh
Vastus medialis - The anteromedial part of the thigh and part of the quadriceps femoris
Neck
Sternohyoid - Along the entire length of the front of the neck
Sternocleidomastoid -the manubrium of the sternum and the clavicle
Platysma- Neck
Hip
Gluteus medius - Upper buttock
Gluteus maximus - Hip joint
Head/Facial
Epicranius- The forehead that lift the eyebrows.
Orbicularis Oculi - Underneath the skin of the eyelid
Massester - cheek bone to jaw
Zygomaticus - cheekbone
Temporalis - Side of head
Orbicularis oris - Upper lip and lower lip
Sliding filament theory of muscle contraction
Thin filaments slide past thick filaments
Cross Bridge
Calcium-dependent interaction of actin and myosin during muscle contraction.
attachments form and break several times
Pulls thins filaments a little closer toward center of sarcome in a ratcheting action
Z discs are pulled toward M line
I bands shorten
Z discs become closer
H zones disappear
A bands move closer to each other
Actin and myosin to overlap more
Types of Muscle and their functions
Cardiac
Muscle in walls of heart responsible for the contractility of the heart and, therefore, the pumping action.
Skeletal
Muscle attached to bones and allows movements
Smooth
Muscle in stomach that helps with digestion and nutrient collection
Sarcomere
structural unit of a myofibril in striated muscle
Thick Filament
composed of myosin with the globular heads
Thin Filament
The main site of Ca+2 regulation
Z line
the lateral boundaries of a single sarcomere
H zone
center of the A band where there is no overlap between the thick and the thin filaments
I band
The region of a striated muscle sarcomere that contains thin filaments.
M line
The attachment site for the thick filaments.
Titin
Filamentous protein
Actin
Attached at their plus ends to the Z disc
Neuromuscular junction
Events
AP arrives at axon terminal
Voltage-gated calcium channels open, calcium enters motor neuron
Calcium entry causes release of ACh neurotransmitter into synpatic cleft
ACh ACh diffuses across to ACh receptors on sarcolemma
ACh ACh binding to receptors, opens gates, allowing 𝑁𝑎+ to enter
Acetylcholinesterase degrades ACh
Axon of motor neuron
Travel from central nervous system to skeletal muscle
Synaptic vesicle with ACh
Contain neurotransmitter acetylcholine
Axon terminal of motor neuron
Makes a synapse with a motor endplate on a skeletal muscle cell
Synaptic cleft
Space that separates two neurons.
Junctional folds
Infoldings of sarcolemma
Muscle coverings
Perimysium
Fibrous connective tissue surrounding fascicles
Provide structural support to muscles.
Endomysium
Fine areolar connective tissue surrounding each muscle fiber
Separates single muscle fibres from one another
Epimysium
Dense irregular connective tissue surrounding entire muscle
Protects muscles from friction against other muscles and bones
Disorders associated with the Muscular system
Myasthenia Gravis
Cause & Risk Factors
Autoimmune
Age
More common in women
Symptoms
Shortness of breath
Drooping eyelids
Double vision
Autoimmune disease that causes muscle weakness
Treatments
Medication
Thymectomy
Eye patch for double vision
Cerebral Palsy
Causes & Risk Factors
Brain Injury
Premature birth
Bleeding in brain
Symptoms
Muscle tightness
Abnormal gait
Seizures
Injury in brain that results in a disconnected between brain and muscle movement
Treatments
Medication for symptoms
Physical Therapy
Surgical intervention
Fibromyalgia
Cause & Risk Factors
Infection
Physical Trauma
Sleep disturbances
Symptoms
Tender joints
Muscle pain
Depression
Muscle Pain and tenderness
Treatments
Physical Therapy
Massage
medication
Myositis
Cause & Risk Factors
Infection
Autoimmune
Muscle trauma
Symptoms
Swelling
Muscle weakness
Rash
Treatments
Medication
Antibiotics
Reduce inflammation
Inflammation of muscles
Muscular Dystrophy
Causes & Risk Factors
Genetic
Becker
Myotonic
Symptoms
Muscle weakness
Lack of coordination
Loss of strength
Genetic disease that damages the muscle fibers
Treatments
Medication
Surgery to improve function
Physical Therapy