quiz chapter 6

3 types of muscle tissue

cardiac, skeletal, smooth

muscle functions

provide movement, maintain posture, stabilize joints, generate heat

skeletal muscle

attaches to bones, largest muscle fibers, striations and multi nucleotide

muscle fibers

muscle cells

fascicle

bundle of muscle fibers

endomysium

connective tissue surrounding each muscle fiber

perimysium

connective tissue encasing each fascicle

epimysium

connective tissue covering entire muscle, blends into tendon

sarcolemma

cell membrane of muscle fiber

myofibrils

ribbon like organelles, gives striped appearance

sarcomeres

tiny chains of contractile myofibrils

myofilaments

thread like protein strands within sacomers, slide over each other contractions

thick filaments

made of myosin, enzymes split atp for energy

thin filaments

made of actin

responsiveness

ability to respond and receive to stimulus

contractility

ability to shorten when stimulated

extensibility

ability to be stretched

elasticity

ability to recoil & resume resting length

motor unit

one neuron & all the muscle cells it stimulates

synaptic cleft

space left between neuron & muscle

acetylcholine

neurotransmitter specifically stimulates skeletal muscle, influences Na+ K+

action potential

electrical current generated by “upset” of Na+ K+ impulse travels

muscle reaction process

1. nerve impulse reaches end of neuron

2. calcium channels open, calcium enters

3. entry of calcium causes release of ACh

4. ACh diffuses across synaptic cleft binds to receptors in sarcolemma

5. ACh binds to sodium/potassium channels in cell membrane Na+ K+ out

6. upset leads to action potential

7. enzyme breaks down ACh ending it

grades response

different degrees of contraction

isotonic

tension, myofilaments slide, muscle shortens movement occurs

isometric

tension, myofilaments try to slide, muscle pitted against less moveable object

muscle twitches

single, brief, jerky, contractions

regeneration of ATP

1. phosphorylation of ADP by creating phosphate, cp broken down, ATP made,15sec

2. Aerobic respiration, non intense muscle activity, oxygen,30sec

3. anaerobic glycolysis and fermentation, intense muscle activity, lack of oxygen,30-60sec

muscle fatigue

muscle is unable to contract even tho it’s stimulated

endurance exercise

stronger more flexible muscle, muscle don’t increase in size, resistant to fatigue

resistance exercise

muscles pitted against object, muscle contracts with force, lifting

orgin

part of muscle attached to immovable bone

insertion

part of muscle attached to the movable bone

flexión

decreases the angle of the joint brings bones together

extension

opposite of flexión increases angle or distance between bones

rotation

movement of a bone around its longitudinal axis

abduction

moving limb away from midline

addiction

opposite of abduction moves limb to midline

circumduction

flexión extensión and abduction

plantar flexión

pointing toes

inversion

foot turns medially

eversión

sole of foot turns laterally

supination

forearm rotates laterally palm goes anterior

pronation

forearm rotates medically so palm posterior

opposition

unique action where thumb has ability to touch every finger

prime mover

major responsibility of muscle movement

antagonist

opposite or reverse movement

synergists

helps prime movers complete movement

fixators

hold bone still so tension can move insertion

frontalis

covers frontal bone raises eyebrows

orbicularis oculi

squinting winking blinking close eyes drain tears

orbicularis oculi

closes mouth perturbe lips

buccinator

runs across cheek helps chew

masseter

covers lower jaw closes mandible

temporalis

acts with masseter acts with temporal bone

platysma

sheet like muscle covers neck orginate chest pulls mouth

sternocleidomastoid

paired muscles on side of neck neck fixation

pectoralis major

covers upper part of chest orgin sternum shoulder girdle first 6 ribs insertion proximal humerus

intercostal muscles

deep muscles found between ribs helps breathing

rectus abdominis

paired muscle flexes vertebrae column compresses abdomen most superficial

external oblique

paired muscle make up lateral walls of abdomen rotate trunk flex vertebrae bend trunk

internal oblique

paired muscle deep to external oblique

transverse abdominis

deepest muscle compresses abdomen

trapezius

most superficial muscle of neck orgin occipital bone to end of vertebral column or thoracic cavity insertion scapula clavicle

latissmus

large flat muscles cover back orgin lower spine illium insertion proximal end of humerus

erector spine

group of muscles paired span length of vertebral column

deltoid

forma rounded shape of shoulder orgin scapula and clavicle insertion humerus

bicep brachii

large muscle of upper arm buldges when flexed orgin shoulder girdle insertion radius

triceps brachii

flashes out exterior humerus elbow extend antagonist to biceps orgin shoulder girdle and humerus insertion ulna

brachialis

deep to bicep important in flexión orgin humerus insertion ulna

flexor carpi ulnaris

forearm muscle orgin humerus and posterior ulna insertion carpals and 5th metacarpals

flexor carpi radialis

forearm muscle flex wrist abducts hand orgin distal humerus insertion 2 3 metacarpals

flexor digitorum

forearm muscle orgin distal humerus ulna and radius insertion middle phalanges

extensor carpi radialis

forearm muscle wrist extender and abducts hand orgin base of metacarpals insertion humerus

extensor digitorum

forearm extends fingers and wrist muscle orgin distal humerus insertion distal phalanges

gluteus maximus

most superficial muscle of hip and buttocks brings thigh under pelvis orgin sacrum insertion femur

gluteus medius

muscle of posterior hip stabilize pelvis

iliopsoas

two fused muscles hip flexor prevent falling orgin lower vertebrae and pelvis insertion femur

adductor muscles

group of muscles on medial side of thigh adduct thighs orgin pelvis insertion femur

hamstring group

three muscles of posterior thigh thigh extension and knee flexión orgin bottom do pelvis insertion tibia

quadriceps group

four muscles of anterior thigh extend knee hip flexor prevent falling orgin genus and pelvis insertion tibia

sartorius

most superficial thigh muscle weak thigh flexor flexes thigh

tibialis anterior superficial muscle on anterior leg dorsiflex and invert foot orgin tibia insertion distal toes

fibularius muscles

three muscles lateral part of leg flexes and everts foot orgin fibula insertion metatarsals of foot

gastrocnemius

forms curvature of calf flexión of foot and knee orgin distal femur insertion calcaneous

soleus

fleshy muscle deep to gastrocnemius flexes feet orgin proximal tibia and fibula insertion calcaneous