Muscle Test

Excitability

The ability of muscles to be stimulated and recieve and respond to stimuli.

Contractility

The ability of muscles tissue to actively contract

Extensibility

The ability of muscles tissue to be stretched or extended

Elasticity

The ability of muscles tissue to return to its original shape after contraction or extension.

• All muscles pull never push

Function: Motion

• Involuntary: (ex: heart beating)

• Voluntary: choosing to make movement (ex: moving arm)

Function: Maintenance of posture

Skeletal muscles hold body in stationary positions

Function: Heat production

Produce most of the heat generated in the body.

• most heat comes from muscle contractions

type of muscle: skeletal

• striated

• Attachment: bones, skin, other muscles

• Striated: muscles overlap

• voluntary

Type of muscle: cardiac

• around wall of heart

• Striated microscopically

• Involuntary

Type of muscle: Smooth

• Maintains the internal environment

• Ex: vessels, stomach, intestines etc.

• Non-striated

• Involuntary

Fascia

• Protects muscles

• Holds fluids in place

• A sheet of fibrous tissue beneath skin, around muscles, and organs.

• Stores water and fat

• itis: inflammation

Tendones

Cord of dense connective tissue that attaches a muscle to the membrane of a bone.

• ligaments attach bone to bone

• Tendons attach bone to muscle

Nerve and blood supply

• For muscles to contract, it must be stimulated by nerve impulses from a nerve cell.

• Contraction requires energy

• Micro tears makes muscles stronger.

• Lactic acid is muscle waste.

Contraction

• Nerve impulses reach the muscle.

• Acetylcholine is released, starting muscle contraction.

• Filaments slide across each other when Ca2+ is released and transferred.

• calcium also released

Recruitment of fibers

Asking more fibers to do a job

Two attachments to bone for each skeletal muscle

• Origin: The attachment of the proximal muscle tendon (muscle to bone, skeletal muscle).

• Insertion: The attachment of the distal muscle tendon

• Belly: the large area between the tendons

Direction of muscle

• Rectus: parallel to midline (vertical)

• Transverse: perpendicular to midline (horizontal)

• Oblique: Diagonal to midline

• In different directions because you want to have a large range of motion.

• All 3 are in abdominal region.

Location

• Coincide with names of regions and bones

• Brachial: region in arm

Size

• Maximus = large

• Medius = medium

• Minimus = small

• Longus = longer

• Brevis = shorter

Number of Origins

• Biceps = 2

• Triceps (calf muscle) = 3

• Quadriceps = 4

• origins: when muscles meet bone

• Surae: latin for leg muscle

Shape

• Deltoid: Triangular (in shoulder)

• Trapezius: trapezoid-like (back of shoulder)

• sterocleiomastoid: sternum connected to jaw

Action

• Flexor: Decrease angle at joint (flexing)

• Extensor: increase angle at joint (extend)

• Abductor: away from midline (moves away from)

• Adductor: toward midline (inside)

• Levator: upward (levitate)

• Depressor: downward

• Supinator: turn up

• Pronator: turn down

• Sphincter: decreases an opening

• Tensor: more rigid (makes you tense)

• Rotator: rotates around axis of bone

Atrophy

• Deterioration of tissue due to lack of use.

• troph: growth

  • Consumption for growth

  • Fbers no longer able to produce force (ex: coma)

Strain

• inflammation or partial tear of muscle or tendon.

Illiotibial Tract Friction Syndrome

• Friction between muscle and bone, causing inflammation and pain (burning sensation)

Medial Tibial Stress Syndrome (middle Shin)

Tendonitis of toe flexors or stress fractures of the tibia.

Achilles Tendonities

Inflammation of the tendon in the calcaneal tendon area.

Plantar Fascitis

• Inflammatory response to chronic irritation of plantar fascia at the origin on the calcaneus.

• Happens to people line dancers or athletes

• Damaged tendon takes weeks to heal.

Tetanus

• Infection causing the muscles to lock up

  • Caused by a puncture from anything dirty.

Venom

• Myotoxins that interfere with the use of muscles and cause the breakdown of tissue.

  • Venom: actively put into you (snake)

  • Poison: ingested or through touch

• Examples:

  • Myotoxin: Muscle

  • Neurotoxin: Nerves

  • Hemotoxin: Blood

  • Necrotoxin: Flesh

Sterile environment

No bacteria exposure or presence

Muscular Dystrophy

• Disorder that causes muscles to develop improperly or incompletely.

• Genetic

  • CRISPR: technology used to edit DNA