Muscles

Origin

end of muscle attached to a fixed (stabilized bone)

Insertion

moveable end of muscle that attaches to bone/structure being pulled

Agonist (prime mover)

principle muscle involved in movement

Antagonist

muscle with opposite action of the prime mover, maintain body or limb position such as holding arm out or standing, controls rapid movement (ability to check motion of a limb)

Example of forearm flexion occurs via three interacting

agonist: biceps brachii, synergist: brachioradialis (in forearm), synergist: brachialis (deep to biceps, upper arm)

Synergist

muscle that assists the agonist

Knee extension

agonist: quadricep femoris, antagonist: hamstrings

Knee flexion

agonist: hamstrings, antagonist: quadriceps femoris

how does fascicles affect movement

fascicle arrangement affects muscle force generation and range of motion

Parallel

fascicles arranged in same direction as long axis muscles, (majority of skeletal muscles, may be a flat sheet or rotund)

circular

fascicles arranged concentrically (sphincter, orbicularis oris encircles mouth)

circular: relaxation

larger opening

circular: opening

contraction=smaller opening/closure

convergent

widespread expansion over sizeable area but then narrows to a common attachment (pectoralis major converges on greater tubercle of humerus via tendon)

Pennate

blend into tendon that runs through central region of muscle (like a feather) muscle fibers only pull at angle therefore not moving tendon far, produces a lot of tension for tension for relative size due to sheer numbers of fiber present

unipennate

fascicles are located on one side of tendon: example, extensor digitorum

bipennate

fascicles are located on both sides of tendon

multipennate

muscle fibers wrap around tendon sometime forming individual fascicles: example, deltoid

can the pennate muscle be stimulated

yes, due to the arrangement of fascicles, it can be stimulated to change direction, example: whole deltoid contraction vs anterior fascicle contraction

How many muscles are in the body

680 in the typical human, around 320 bilateral pairs

what can muscles grouped into?

muscle of head, neck, and back, muscles of torso/trunk, muscles of upper limbs, muscles of lower limbs

orbicularis oris

moves the lips

occipitofrontalis

raises scalp and eyebrows, composed of two muscles (frontalis, occipitalis) connected by broad tendon known as epicranial aponeurosis

Buccinators

comprises cheek, allow whistling, blowing, sucking, and chewing

corrugator supercilia

prime mover of eyebrows, fingers on eyebrows at bridge of nose, raise eyebrows in surprise, lower in frown

what is eyeball movement controlled by

extrinsic eye muscles, originate outside the eye and insert onto outer surface of sclera

rectus muscles

originate at common tendinous ring, superior, inferior, lateral, and medial, responsible for up/down/side movement of eyeball

oblique muscles

superior and inferior, responsible for rotational movement of eyeball

levator palpabrae

opens eyes

orbicularis oculis

closes eye

masseter

primary muscle in chewing, elevates mandible to close mouth

temporalis

retracts mandible, fingers on temples as you chew

pterygoid muscles

lateral and medial, moves jaw side to side

Tongue muscles

can have extrinsic and intrinsic muscles

extrinsic muscles

move the whole tongue, there are four muscles

Genioglossus

(originates on mandible) moves tongue forward and downward

styloglossus

(originates on styloid bone) upward and backward motion

palatoglossus

(originates on soft palate) elevates back of tongue

hypoglossus

(originates on hyoid) move tongue down and flatten it

intrinsic

change changes shape of tongue, longitudinal muscles (superior and inferior), vertical muscle, transverse muscle

Muscles of anterior neck

aisst in swallowing, speech (by controlling lrynx and hyoid bone), categorized according to their position relative to hyoid bone

suprahyoid muscles

raise hyoid bone, floor of the mouth and larynx during swallowing, located superior to the hyoid, digastric, stylohoid, mylohoid, geniohyoid

Infrahyoid Muscles

generally depress hyoid and control position of larynx located inferiorly to hyoid, omohyoid, sternohyoid, thyrohyoid, sternohyoid

when muscles of neck act unilaterally

head rotates

when muscles contract bilaterally

flexes or extends, also responsible for moving cervical vertebrae and scapulae

sternocleidomastoid

primary muscle responsible for lateral flexion and rotation of head, fingers on either side of neck, turn head left to right

capitis group

semispinalis, splenius, longissimus

muscles of posterior neck and back

posterior neck muscles largely involved with head movements such as extension, back muscles stabilize and move vertebral column, they are grouped according to lengths and directions of fasicles

splenius muscles (posterior neck and back)

originate at midline and run laterally and superiorly to their insertions, responsible for extending, laterally flexing and rotating head, splenius capitis, splenius cervicis

erector spinae group

forms majority of muscle mass of back, primary extensor of vertebral column

erector spinae group (iliocostalis group)

laterally placed, iliocostalis cervicis, iliocostalis thoracis, iliocostalis lumborum

erector spinae group (longissimus group)

intermediately placed, longissimus capitis, longissimus cervicis, longissimus thoracis

erector spinae group (spinalis group)

medially placed, spinalis capitis, spinalis cervicis

erector spinae group

spinalis thoracis

transversospinalis group

run from transverse process to spinous processes of vertebrae

transversospinalis group (semispinalis group)

semispinalis capitis,semispinalis cervicis,semispinalis thoracis

multifidus muscle

located in lumbar region, helps extend and laterally flex vertebral column

segmental muscle group

important in stabilization of vertebral column

segmental muscle group

interspinales

segmental muscle group (intertransversarii)

bring together spinous and transverse process of each consecutive vertebrae

scalene muscles

flex, laterally flex and rotate head, contribute to deep inhalation, anterior scalene, middle scalene (longest), and posterior scalene

(feet and toes) Intrinsic muscles

provide support for foot and arch, contribute to movement of toes

(feet and toes) plantar aponeurosis

principal support for longitudinal arch of foot, deep fascia, plantar fasciitis

(feet and toes)dorsal group muscle

extensor hallucis longus, extensor digitorum longus, brevis (extends toes 2-5)

(feet and toes)What do plantar muscles consist of

layers to counterbalance weight of body (abductors, flexors, adductors)

(feet and toes)Posterior compartment of leg

superficial and deep compartments, superficial muscles all insert onto calcaneal tendon (achilles tendon), large and strong, maintain upright position

(feet and toes)superficial posterior

gastrocnemius, soleus, plantaris, tibialis posterior

deep posterior

popliteus, flexor digitorum longus, flexor halluces longus

(feet and toes) anterior compartment of leg

contribute to raising the front of the foot, tibialis anterior, extensor halluces longus, extensor digitorum longus

lateral compartment of leg includes two muscles

responsible for plantar flexion and eversion, fibularis longus, fibularis brevis

how many compartments is the lower leg divided into

divided into three compartments by fascia

thigh muscles that move the femur, tibia, femur (posterior compartment)

includes muscles that flex leg and extend thigh

thigh muscles that move the femur, tibia, femur (hamstring group)

tendon of these muscles form popliteal fossa, diamond shape space at back of knee, biceps femoris, semitendinosus, semimembranosus

thigh muscles that move the femur, tibia, femur (anterior compartment)

responsible for flexing thigh and extending leg

thigh muscles that move the femur, tibia, femur (quadriceps femoris)

share common tendon, quadriceps tendon inserts into patella and continues below it as patellar ligament which attaches to tibial tuberosity (vastus lateralis, vastus medialis, vastus intermedius)

thigh muscles that move the femur, tibia, femur (sartorius)

band like muscle extends from anterior superior iliac spine to medial side of proximal tibia, flexes leg laterally at the knee as well as flexes, adducts, and laterally rotates leg at hip (cross-legged)

thigh muscles that move the femur, tibia, femur (medial compartment)

responsible for adducting femur at hip

thigh muscles that move the femur, tibia, femur

adductor longus, adductor brevis, adductor magnus, pectineus, gracilis

what separates the thigh into different compartments

deep fasicia

Gluteal muscles that move the femur

Muscles that laterally rotate femur at hip Obturator internus, obturator externus, inferior gemellus, quadratics femoris

Gluteal muscles that move the femur (most muscle that insert on femur and move it originate on where

The pelvic girdle, iliopsoas group , gluteal group, tensor fasciae latae (acts as synergist to iliopsoas and gluts in flexing and abducting thigh), and piriformis

Appendicular muscles of pelvic girdle and lower leg movement and purpose

Much less movement is possible in pelvic girdle due to connection to sacrum at base of skeleton, designed for stability and support

Muscles of thigh

Center gravity must remain fixed (standing and walking would be hard otherwise) legs make up for range of motion and versatility with size and power

Muscles that move the hands, wrist, and fingers: intrinsic muscles

Originate and insert within hand, allows fingers to make precise movements

Muscles that move the hands, wrists, and fingers: thenar muscles

Radial aspect of palm, act on the thumb

Muscles that move the hands wrists and fingers: hypothenar muscles

Medial aspect of palm, act of the little finger

Muscles that move the hands wrist and fingers:intermediate

Midpalmar, act on all the patients

Muscles that move the hands wrist and fingers: deep anterior compartment

Produces flexion and bends fingers to make a wrist, flexor pollicis longus, flexor digitorum profundus

Deep posterior compartment

Muscles originate on the radius and ulna, extensor pollicis brevis, extensor pollicis longus, extensor incidis, abductor pollicis longus

Tendons of forearm attach to wrist and extend into hand

Fibrous band sheaths tendons at wrist retincula, extensor retinaculum (extends over dorsal surface of hand)flexor retinaculum (extends over planar surface of hand)

Muscles that move hands, wrists, and fingers: extrinsic muscles anterior compartment of forearm

Muscles originate on humerus and insert into different parts of the hand, make up bulk of forearm

Muscles that move the wrist, forearm, and hand superficial compartment

Flexor capri radialis, palmaris longis, flexor capri ulnaris, flexor digitorum superficialis( flexes hand and digits at knuckles)

What are the two parts upper limbs are grouped into

Forearm, origin of extrinsic muscles of hand and palm, origin of intrinsic muscles of hand

Muscles that move the forearm: flexors

Biceps brachii (two headed muscle, crosses shoulder and elbow joint) brachialis (deep to the bicep, provides additional power) Brachioradialis (quick flex and slow lift), these three make up anterior compartment

Muscles that move the forearm: extensors

Triceps brachii, anconeus

Muscles that move the arm: pronators

Pronator teres, pronator quadratus

Muscles that move the forearm: supinator

Supinator

How many types of motion does the forearm have at the hinge elbow

Flexion, extension, pronation, supination, many muscles are named for the action they produced

Muscles that move the humerus: scapular

Atomical and ligamental structure allows arms to carry out diverse motion

Muscles that move the humerus:deltoid

Thick muscle that creates the rounded lines of shoulder, major abductor of arm