chapter 11 - the muscular system

the muscular system...

transform chemical energy into mechanical work, 600 skeletal muscles in the body, responsible for movement, posture, joint stabilization, and heat generation

the fixed (stabilized) end of the muscle (muscle attachment & action)

origin

the moveable end attached to the bone being pulled (muscle attachment & action)

insertion

muscles PULL, not PUSH; draws insertion towards origin (muscle attachment & action)

action

principle muscle producing movement; provide example of one

agonist; quadriceps in a knee extension

assists agonist in producing movement

synergist

muscles with opposite action of the agonist; maintains body or limb position, control rapid movement; include example

antagonists; ex/ hamstrings in a knee extension

what are skeletal muscle fibers grouped into

fascicles

what do fascicle arrangments impact

force generation and range of motion

greater movement, less force (fascicle arrangement)

parallel

controls passage size (fascicle arrangement)

circular

versatile in movement direction (fascicle arrangement)

convergent

greater force, less movement (fascicle arrangement)

peeennaate

bones act as _, and joints as _

levers, fulcrums

muscles provide _, and body parts/objects provide _

effort, load

effort arm longer than load arm; move heavy loads with less effort

power levers

load arm longer than effort arm; move lighter loads faster and farther

speed levers

roots help identify...

location and function of muscle

ab- means what?

away from

duct- means what?

to move

digitus- means what?

digit

ad- means what?

to, toward

minimus- means what?

mini, tiny

support and move the head, neck, vertebral column, and thoracic cage

axial muscles

move the upper and lower limbs and stabilize the pectoral and pelvic girdles

appendicular muscles

limbs are organized into compartments by...

deep fasccciiaa

what are the axial muscles of the head, neck, and back responsible for?

chewing/swallowing, facial expression, eye movement, head movement, posture, respiration

orbicularis oris

closes the lips, purses the lips (kiss) (muscles of facial expression)

orbicularis oculi

closes the eye (muscles of facial expression)

zygomaticus major

elevates the corners of the mouth (smile) (muscles of facial expression)

frontalis

raises the eyebrows (muscles of facial expression)

temporalis

closes the mandible

masseter

closes the mandible

sternocleidomastoid

lateral flexion of neck, flexes and extends neck

what are the axial muscles of the chest, back, and abdomen responsible for?

breathing, trunk movement, posture, increasing intra-abdominal pressure (coughing, defecation)

pectoralis major (chest)

adducts the arm

rectus abdominus (abdomen)

flexes the trunk

fibrous line running vertically from the sternum to the pubic bone, separates left and right side of abdominal muscles (abdomen)

llinneaa allbbaa

trapezius (back)

elevates the shoulder (shoulder shrug), retracts the shoulder

erector spinae group (back)

extends (erects) the spine

latissimus dorsi (back)

extends the shoulder/arm, adducts the shoulder/arm

erector spinae group (name the 3)

spinalis, longissimus, iliocostalis muscles

what are the appendicular muscles including the shoulder and upper limb responsible for?

positioning and stabilizing the pectoral girdle, moving the upper limb

what is included in the appendicular muscles of the shoulder and upper limb?

muscles for pectoral girdle, shoulder joint movers, muscles of the arm, forearm, and hand

biceps brachii (anterior arm)

flexes shoulder and elbow

brachioradialis (anterior arm)

flexes elbow

triceps brachii (posterior arm)

extends shoulder and arm

deltoid (lateral arm)

abducts arm/shoulder

supraspinatus (rotator cuff muscles)

abducts the shoulder

infraspinatus (rotator cuff muscles)

externally rotates the shoulder

teres minor (rotator cuff muscles)

externally rotates the shoulder

subscapularis (rotator cuff muscles)

internally rotates the shoulder

flexor digitorum superficialis

flexes the digits of the hand

extensor digitorum

extends the digits of the hand

what are the appendicular muscles of the pelvic girdle and lower limbs responsible for?

stabilizing and moving the pelvic girdle, thigh, leg, ankle, and foot; generally larger/stronger than upper limb due to weight-bearing and locomotion roles

adductor magnus

adducts the thigh/hip

gluteus maximus

extends the thigh/hip

gluteus medius

abducts the thigh/hip

hamstrings

extend the thigh/hip and flex the knee

hamstrings include:

biceps femoris, semitendinosus, semimembranosus

all of these flex the thigh/hip and extend the knee; includes what?

quadriceps group; rectus femoris, vastus medialis, vastus intermedius, vastus lateralis

a large connective tissue fascia band along the lateral thigh that helps stabilize the leg and knee during movement

IT band (iliotibial band/iliotibial tract)

tensor fascia latae

connects the IT band, action is abduction of thigh/hip

tibialis anterior

dorsiflexion of ankle/foot (anterior lower leg)

extensor digitorum longus

extension of digits of the foot, also helps with dorsiflexion (anterior lower leg)

gastrocnemius

plantarflexion of ankle/foot (posterior lower leg)

flexor digitorum longus

flexion of digits of the foot, also helps with plantarflexion (posterior lower leg)

name what part of the body the pectoralis major is located

chest

name what part of the body rectus abdominus and linea alba are located in

abdomen

name what part of the body the trapezius, erector spinae group, and latissimus dorsi are located in

back

what part of the body are the biceps brachii and brachioradialis located in

anterior arm

what part of the body are the triceps brachii located in

posterior arm

what part of the body are the deltoid located in

lateral arm

what is supraspinatus, infraspinatus, teres minor, and subscapularis considered

rotator cuff muscles

what part of the body are flexor digitorum superficialis located

anterior forearm

what part of the body are extensor digitorum located

posterior forearm

what part of the body are adductor magnus located in

medial thigh/hip

what part of the body are gluteus maximus, gluteus medius, hamstrings, biceps femoris, semitendinosus, semimembranosus

posterior thigh/hip

what part of the body are quadriceps, rectus femoris, vastus medialis, vastus intermedius, and vastus lateralis located in

anterior thigh/hip

what part of the body are the IT and tensor fasssiicca latae located in?

lateral thigh/hip

what part of the body are the tibialis anterior and extensor digitorum longus located in

anterior lower leg

what part of the body are gastrocnemius and flexor digitorum longus located

posterior lower leg