Muscular System ALLLL

Muscular system comprises nearly

½ our weight

Muscular system has over

650 muscles

Each muscle is made of hundreds of thousands of

muscle fibers

myofibrils

Bundles of threadlike structures

myofibrils are composed of

myosin, and actin

myofibrils form an overlapping pattern called

sacromere

TYPES OF MUSCLES

skeletal, smooth, cardiac, sphincter

sphincter muscles are

circular muscles

Skeletal muscles are attached to

bone

Skeletal muscle have what appearance

striated, striped appearance

are skeletal muscles voluntary or involuntary?

voluntary

smooth muscles aka

visceral muscles

are smooth muscles voluntary or involuntary?

involuntary

smooth muscles are located in

walls of digestive system, uterus & blood vessels

Cardiac muscle is found only in the

heart

cardiac muscle appearance

striated, branched

are cardiac muscles voluntary or involuntary?

involuntary

in cardiac muscle the cells are

fused, when one contracts, they all contract, creating the heartbeat

Sphincter muscles aka

dilator muscles

Sphincter muscles def

Special, circular muscles

sphincter muscles are located in the

digestive system, urinary system

Tendons

connect muscle to bone to strengthen and stabilize

fascia tissues

 attach, stabilize,  strengthen, separate muscles, and enclose different organs.

Fascia is made up of

Fibrous connective tissue sheets that wrap around muscle bundles

types of connective tissue

Endomysium, Perimysium, Epimysium 

How do skeletal muscles get their names?

Location, Size, Direction, Number of origins, Location of origin and insertion

PROPERTIES OF MUSCLE 

Contractibility, Excitability, Extensibility, Elasticity 

Muscle tone

partial contraction of muscles 

CONTRACTIBILITY def

The ability of the muscle to pull or shorten

Example of contractibility

“flexing bicep”doing a  push up or a handstand

Myoneural stimulation + Contraction of muscle proteins =

movement

EXCITABILITY def

The ability to respond to a stimulus, which may be delivered from a motor neuron or a hormone

EXTENSIBILITY

The ability of a muscle to be stretched..like before or after running

EXTENSIBILITY example

when you run, the hamstring in the back of your thigh contracts while your quadriceps are extended

ELASTICITY def

The ability to return to it’s original state; to recoil or bounce back to the muscle's original length after being stretched

MUSCLE TONE def

The firmness of your muscle in a relaxed state that is slightly contracted and ready to pull, prepares you for action, maintains your balance and posture, generates heat that keeps your muscles healthy, allows for a quick, unconscious reaction to any sudden internal/ external stimuli

Atrophy

shrinking/loss of mass…can occur when you don’t use your muscle for long periods of time such as after being in a cast, being bedridden, or with the genetic condition muscular dystrophy 

Hypertrophy

increased development . Think working out, building muscle 

What is muscle fatigue?

From overuse with lactic acid build up and lack of rest 

In aerobic, or “with oxygen” exercise, your body uses

oxygen as the form of energy to maintain endurance

Aerobic exercise example

jogging, biking, swimming

Anaerobic “without oxygen” exercise, your body breaks down

glucose as the form of energy to build muscle mass. This exercise prolonged can cause lactic acid build up if no proper rest

Anaerobic exercise examples

lifting weights, yoga, pilates

Rheumatologist

musculoskeletal disorder specialist

Electromyography or nerve conduction tests

which use electrodes to test muscle and/or nerve function

Muscle Biopsy

the removal and exam of a small sample of muscle tissue

FIBROMYALGIA def

Widespread, chronic muscle pain and weakness/fatigue

cause for FIBROMYALGIA

No known cause 

cure for FIBROMYALGIA

No known cure.

Treatment for FIBROMYALGIA

Treatment focuses on symptom reduction. 

Symptoms of FIBROMYALGIA

Depression/Mood Swings/Forgetfulness, Sleeping Difficulties

FIBROMYALGIA is more common in

women

HERNIA

bulging tissue through an opening in the abdominal wall 

HERNIA is most common in the

abdominal region

Cause of hernia

Can be caused by weakened muscles

MUSCLE SPASMS aka

cramps

MUSCLE SPASMS def

Involuntary contractions of a muscle, typically harmless and temporary, but can be painful.

cause of cramps

Fatigue, Overuse/build up of lactic acid, Dehydration, Electrolyte Imbalances, Stress

treatment for MUSCLE SPASMS

Treat underlying causative agent--rest, drink water or Gatorade

Muscle Fatigue

Decrease in function of muscle over a period of time

causes of muscle fatigue

Exhaustion and build up of lactic acid

Treatment for muscle fatigue

Treat underlying causative agent

MUSCULAR DYSTROPHY def

A group of genetic diseases that cause progressive weakness and loss of muscle mass.

MUSCULAR DYSTROPHY can cause problems in

walking, chewing, swallowing, breathing and cardiac issues

MUSCULAR DYSTROPHY cure

no cure

Treatment for MUSCULAR DYSTROPHY

treatment focused on keeping muscles mobile (ie Physical Therapy/Respiratory Therapy)

MYASTHENIA GRAVIS def

A weakness and rapid fatigue of skeletal muscles

MYASTHENIA GRAVIS can cause problems

breathing, walking, swallowing, talking, etc----usually dx d/t weakness of the eyes

MYASTHENIA GRAVIS caused by

by an autoimmune disorder

MYASTHENIA GRAVIS treatment

Treatment targeted at immune system suppression. Plasma exchange and IVIG have shown some relief of symptoms by exchanging/creation of antibodies

MUSCLE STRAIN

Involves tearing of muscle fibers and bleeding within the muscle belly. An overstretched or torn muscle or tendon

MUSCLE STRAIN caused by

 over-use, improper use, fatigue

MUSCLE STRAIN treatment

 involves rest and pain relief 

TENDONITIS 

Inflammation of the tendons

TENDONITIS caused by

overuse

TENDONITIS treatments

anti-inflammatory medications, ice, brace, rest, cortisone injection,  surgery ( at times)

TETANUS

A serious bacterial infection that causes painful muscle spasms and can lead to death.

TETANUS aka

lock-jaw

TETANUS cause by

a skin wound/puncture that is exposed to bacteria from dirt/soil

TETANUS prevention

tetanus shot every 8-10 years, plus a booster if suspected exposure

TETANUS cure

Impossible to cure once infected