The Muscular System Flashcards
What are muscles?
Muscles are composed of many bundles of stringy fibres bound together in bunches
Three types of muscle tissue?
Skeletal
Smooth
Cardiac
Origin
Fixed end of a muscle
Insertion
Moving end of the muscle
Action
The job or function of the muscle
Tone
Contraction and relaxing of muscles.
There will always be a few muscle fibres contraction even while sleeping.
Muscle is always in a state of partial contraction even when resting
Attachment
At their origin and insertion muscles attach to bone via tendons to produce movement of joints.
Belly
Thickest part or main body of muscle: usually the middle part away from insertion and origin
Fascia
Fascia is a thin casing of connective tissue that surrounds and holds every organ, blood vessel, bone, nerve fibre and muscle in place.
Tendons
White fibrous cords
Connects muscle to bone
Tension
Over stimulating of muscle fibres. More fibres contract than is needed to maintain postural tone
Fatigue
If muscles overwork without sufficient rest periods there is a shortage of glucose and oxygen, thus muscles cannot produce enough energy to contract which produces lactic acid
Composition of muscle
Muscle is 75% water, 20% proteins, 5% fats, mineral salts and glycogen
How a muscle works
A muscle’s function is to contract and by doing so starts a movement in the surrounding structures ( the tendons, ligaments and eventually bones).
The muscle contracts in reaction to a nerve stimulus sent by the brain through a motor nerve.
The muscle then shortens becoming fatter at the centre
Functions of muscles
- Contracts and thereby produces movement i.e. to move a joint
2.Stabilises joints
3.Maintains postural tone
4.Aid in temperature control i.e. shivering and dilation of capillaries
The function of skeletal muscle
These are the muscles which we consciously control i.e. our arms and legs . If we want to walk we do so.
Smooth Muscle is also known as….
non striated and involuntary
Function of Cardiac muscle
To power the pump action of the heart
What is the smallest skeletal muscle?
Stapedius in the ear
What is largest muscle in the body?
Latissimus dorsi, the flat back muscle which covers the central and lower back
What is strongest muscle in the body?
Gluteus maximus which forms the main bulk of the buttocks
Does the agonist contract or relax the muscle?
Contract!
Does the antagonist contract or relax?
Relax!
How does a muscle contract?
Motor nerves enter the muscles and break into many nerve endings , each one stimulation a single muscle fibre
Muscular dystrophy
genetic progressive weakness & degeneration of the skeletal muscle
Myositis
inflammation of a muscle
Repetitive strain injury
overuse of ligaments or muscles
Atrophy
reduction size, wasting muscle bulk
Cramp
localised painful contraction of a muscle
Fibromyalgia
rheumatic, effects tendons & ligaments
Spasticity
spinal reflexes causes sustained contraction
Sprain
Injury to a ligament, stretch or tearing
Strain
Injury to a muscle or tendon, stretching or tearing
Spasm
sudden muscular contraction
Rupture
Tearing or ripping of muscle fascia
What is the action of the peroneus longus?
The peroneus longus platarflexes and everts the foot
Muscle that flexes the knee
The Sartorius
The main muscle of mastication?
The masseter
The muscle that medially rotates the humerus
The subscapularis
Action of the orbicularis oculi?
Closes the eye
Action of Pronator teres
Pronates the forearm
The rhomboids adduct ……
The scapula
The muscle that dorsiflexes and inverts the foot
The tibialis anterior
The adductor magnus extends….
The hip
What muscles lift the ribcage during inhalation?
The external intercostals
The levator labii superioris lifts …..
The upper lip
Does the origin of a muscle move?
The origin of a muscle is the part that does not move
