chapter 11 muscles

joint in the middle sea saw force and load are balanced

first class lever

the joint between the occipital bone of the skull and the first cervical vertebra is part of which class lever system

first class.

general age related effects on skeletal muscles include

decreased skeletal muscle fiber diameters, diminished muscle elasticity, decreased tolerance for exercise, and decreased ability to recover from muscular injuries.

depressor anguli oris

depresses corners of the mouth

depressor labbi inferioris

depresses lower lip

digastric

depresses mandible or elevates larynx

buccinator

moves food around cheeks

the three functional groups tat make up the muscles of the lower limbs

muscles that move the thigh, muscles that move the leg and muscles that move the foot and toes

constricts the mouth opening

ocularis oris

laterial pterygoids

opens jaws, protrudes mandible,or performs lateral excursion

antagonist

opposes prime mover

what muscle surrounds the mouth

orbicularis oris

muscles have one fixed point of attachment called the muscles have one moving point of attachment called the

origin insertion

fibers parallel to long axis of muscle

parallel fibers

examples of convergent muscles

pectoralis muscles, trapezius muscles

correct names of muscles include the names muscle except:

platysma diaphragm

axial muscles

position head and spinal column move rib cage 60% of skeletal muscles

muscles that rotate the radius without prodcuting either flexion or extension of the elbow are the

pronator teres and supinator

origin is usually what to insertion

proximal

corrugator supercilia

pulls the eyebrows down to make a sad expression

frontalis

raises eyebrows wrinkles forehead

a pulled hemstring is what

refers to a strain affecting one or more of the three muscles that collectively flex the knee: the biceps femoris, seimembranosus, and semitendinosus.

splenius capitus

together two sides extend neck, alone each flexes and laterally flexes that neck to the side

proximal

towards an attached base

what muscles move the pectoral girdle

trapezius rhomboidius levator scapulae serratus anterior pectoralis minor

major extensor of the elbow

triceps brachhii

how would a torn calcaneal tendon affect movement of the foot

would make plantar flexion difficult because this tendon attaches the soleus and gastrocnemius muscles to the calcaneus.

what 3 functions are accomplished by the muscles of the pelvic floor

1. suppport the organs of the pelvic cavity flex joints of the sacrum and coccyx and control movment of materials through urethra and anus.

TEMPORALIS

ELEVATES MANDIBLE

prime mover

agonist

second class lever

ankle extension plantar flexion.

the linea alba is a

aponeurosis.

distal

away from an attached base

nuchal

back of neck

example of parallel muscle

biceps brachi

third class lever

biceps brachii

hallucis

big toe

damage to intercostal musces would interfere with

breathing.

fascicles

bundles of muscle cells or fibers

effects of exercise

cardiovascular system: increasing heart rate and dilating blood vessels rate and depth of respiration increases sweat gland secretion increases.

orbicularis oculi

closes eye

compartment syndrome results from

compartments swelling with blood due to an injury involving blood vessels. torn ligaments in a given compartment. pulled tendons in the muscles of a given compartment. f

nasalis

compresses bridge depresses tip of nose elevates corners of nostrils

buccinator

compresses cheeks

orbicularis oris

compresses, purses lips

muscular system

consists only of skeletal muscles

shrugging your shoulders uses which muscles

contracting your levator scapulae muscles.

broad area converges on attachment site muscle fibers pull on different directions

convergent muscles

risorious

draws corners of mouth to the side

mentalis

elevates and protrudes lower lip

mylohoid

elevates floor of hyoid bone or depresses mandible

masseter

elevates mandible and closes the jaw.

scalenes

elevates ribs or flexes neck

medial pterygoid

elevates the mandible and closes the jaw or moves jaw side to side (lateral excursion)

levator labii superioris

elevates upper lip

examples of pennate muscles

extensor digitorum rectus femorus deltoid

pennate muscles

form an angle with the tendon contain more myofibrils and make more tension than parallel muscles

epicranial muscles

frontalis +occipitalis

what major function does the muscular system perofrm for the body as a whole

generates heat that maintains normal body temperature.

inguinal

groin

synergist

help in the movement

a blank develops when an organ protrudes through an abnormal opening

hernia

the powerful flexors of the hip are the

iliopsoas

ilio

ilium

injury of the flexor carpi ulnaris muscle would

impair the ability to perform flexion and adduction at the wrist.

which leg movement would be impaired by injry to the obturator msucle

impair your ability to perform lateral rotation of the hip.

mechanically bones are a what and joints are a what

lever and joints are a fulcrum.

lumboraum

lumbar region

strongest masticatory muscle is the

masseter

the force is in the middle

most common levers in the body greater force moves smaller load maximizes speed in the human body most common muscle used

zygomaticus major

retracts and elevates corner of the mouth

zygomaticus minor

retracts and elevates upper lip

load in middle wheelbarrow is an example small force moves a large weight load between applied force and fulcrum

second class lever standing on tip toes

appendicular muscles

support pectoral and pelvic girdles support limbs 40 % skeletal muscles

muscles involved in a roator cuff injurty are the

supraspinatus, infraspinatus, teres minor, subscapularis

why can swallowing help alleviate the pressure sensations at the eardrum when you are in an airplane that is changing altitude

swallowing invovles contractions of the palatal muscles. elevation of the superior portion of the pharynx enlarges the opening to the auditory tube permitting airflow to the middle ear and the inside of the eardrum.

elongated bursae that reduce friction and surround the tendons that cross the dorsal and ventral surfaces of the wrist form

synovial tendon sheaths

occipital belly

tenses and retracts scalp

platysma

tenses skin of neck depresses mandible

what is fibrosis

the development of increasing amounts of fibrous connective tissue. fibrosis causes muscles to be less flexible and the collagen fibers can restrict movement and circulation.

if you've been lifting things which muscle is most likely sore

the erector spinae muscles especially the longissimus and iliocostalis muscles of the lumbar region.

muscle that rotates the eye medially

the medial rectus

which bones do the four rotator cuff muscles originate and insirt

the supraspinatus infraspinatus and teres minor originate on the posterior body of the scapula, and the subscapularis originate on the anterior body of the scapula. all 4 muscles insert on the humerus.

skeletal muscles are classified by

the way fascicles are organized by relationships of fascicles to tendons

knee extensors known as the quadripcs consist of the

three vastus muscles and the rectus femoris muscle

sternocleidomastoid

together they flex the neck alone one side bends head toward shoulder and turns face to opposite side