chapter 10-11

includes all of the muscles and there actions

primary tissue types

epithelial, nervous, connective, muscle

excitability

ability to respond to electrical stimulation / action potentials

contractility

ability to shorten and generate force

extensibility

ability to stretch

elasticity

ability to return to its original length after being stretched

what are the 3 types of muscle?

skeletal, cardiac, smooth

is skeletal muscle voluntary or involuntary?

voluntary

what does skeletal muscle do?

moves the skeleton, stabilizes joints, protects organs, and produces heat

is cardiac muscle voluntary of involuntary

involuntary

where is cardiac muscle found?

only in the heart

what does the cardiac muscle do?

pumps blood

is smooth muscle voluntary or involuntary?

involuntary

where is smooth muscle found

organs, blood vessels, airways, eyes, and skin

is smooth muscle striated

no

what is the order of skeletal muscle organization

muscle, fascicle, muscle fiber, myofbril, sarcomere

what is a fascicle

a group of muscle fibers

what is a muscle fiber

a muscle cell

what is a myofibril

a contractile structure inside a muscle fiber

what is a sarcomere

the basic unit of muscle contraction

what does the epimysium surround

the entire muscle

what does the perimysium surround

a fascicle

what does the endomysium surround

an individual muscle fiber

what is the sarcolemma

the muscle cells plasma membrane

what are myofibrils made of

sarcomeres

what are the 2 main filaments in a sarcomere

actin and myosin

actin=?

thin filament

myosin=?

thick filament

what does the sarcoplasmic reticulum (SR) do

stores and releases calcium

what do T-tubules do

carry electrical signals deep into the muscle cell

what does the A band contain

actin + myosin

what does the I band contain

actin only

what does the H zone contain

myosin only

what is the M line

the middle of the H zone anchors myosin

what is the Z disc

the boundary of a sarcomere anchors actin

what happens during muscle contraction

myosin pulls actin toward the M line shortening the sarcomere

what causes muscle contraction to being

an action potential

what does the SR release

calcium

what is needed for muscle contraction

calcium and atp

what is excitation contraction coupling

the process that connects an electrical signal to muscle contraction

what is the NMJ

The space where a motor neuron communicates with a muscle cell

what a neurotransmitter is released at the NMJ

Acetylcholine (ACh)

what does ACh do

triggers an action potential in the muscle

what happens after the muscle action potential

The SR release calcium

what is an isotonic contraction

Muscle changes length

what is a concentric contraction

muscle shortens

what is an eccentric contraction

muscle lengthens

what is an isometric contraction

muscle creates tension without changing length

what is muscle tone

the constant slightly contracted state of muscles

why is muscle tone important

keeps muscles firm and ready to respond

what do muscles do

transform chemical energy into mechanical work

what are the main functions of skeletal muscles

movement, posture, joint stabilization, and heat generation

about how many skeletal muscles are in the body

over 600

what is the origin of a muscle

the fixed stabilized end of the muscle

what is the insertion of a muscle

the movable end attached to the bone being pulled

do muscles push or pull

pull muscle activation draws the insertion toward the origin

what is an agonist (prime mover)

the main muscle producing a movement

what is a synergist

a muscle that assists the agonist

what is an antagonist

a muscle that performs the opposite action of the agonist

example of agonist vs antagonist during knee extention

quadriceps - agonists hamstrings - antagonists

what are fascicles

groups-bundles of skeletal muscle fibers

what does fascicle arrangement affect

force generation and range of motion

what does parallel arrangement provide

greater movement, less force

what does pennate arrangement provide

greater force less movement

what does circular arrangement do

controls the size of an opening / passage

what does convergent arrangement allow

versatile movement directions

what acts as the lever in the body

bone

what acts as the fulcrum

joints

what provides the effort

muscles

what is a power lever

the effort arm is longer than the load arm > moves heavy loads with less effort

what is a speed lever

the load arm is longer than the effort arm > moves lighter loads faster and farther

what can muscle names tell you

shapes, size, location, fiber direction, number of origins, or action

what does deltoid tell you

its shape is triangular

what does biceps tell you

it has two origins

what does flexor tell you

its action decreases a joint angle

what do axial muscles do

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

what do appendicular muscles do

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

what does orbicularis Oris do

closes and purses the lip

what does orbicularis oculi do

closes the eye

what does zygomaticus major do

raises the corners of the mouth > smiling

what does frontalis do

raises the eyebrows

what do temporalis and masseter do

closes the mandible/ jaw

what does the sternocleidomastoid do

moves/flexes the neck and causes later flexion

what does pectoralis major do

adducts the arm

what does rectus abdominis do

flexes the trunk

what is the linea alba

a fibrous vertical line from the sternum to the public bone that separates the left and right abdominal muscles

what does trapezius do

elevates and retracts the shoulder

what does erector spinae do

extends/erects the spines

what does latissimus Dorsi do

extends and adducts the shoulder/arm

what does biceps bracii do

flexes the shoulder and elbow

what does triceps brachii do

extends the shoulder and arm

what does deltoid do

abducts the arm/shoulder

what are the 4 rotator cuff muscles

supraspinatus, infraspinatus, teres minor, subscapularis

what does supraspinatus do

abducts the shoulder

what does infraspinatus do

externally rotates the shoulder

what does teres minor

externally rotates the shoulder

what does subscapularis do

internally rotates the shoulder

what does flexor digitorum superficialis do

flexes the fingers/digits

what does extensor disitorum do

extends the fingers/digits

what does adductor magnus do

adducts the thigh/hip

what does gluteus maximus do

extends the thigh/hip