HSA MA Ch. Muscular

how many muscles in human body

600

functions:

• Movement

• Heat 

• Protection of internal organs, nerves, and blood vessels 

• Help w structure 

• Helping blood flow return to the heart 

Passive range of motion: movement of joint by external force like by a therapist for ex

Muscle fuel

glycogen—→ carbohydrates in muscles

glycogen—→ glucose

heat is released as hthis fuel is used

stores glucogen is important bc tis used in fight/flight

Skeletal muscle tissue

• Attaches to bone to permit movement

• Voluntary movement

• Skeletal muscle cells

• Long and strong

• Arranged in bundles

• Enclosed in tough connective tissue sheaths 

smooth muscle tissue

• Small delicate muscle cells 

• Found throughout the internal organs of the body

• Involuntary

• Occurs constantly in functions

• Ex: breathing, peristalsis, blood vessel contraction, and pupil dilation

myocardial muscle tissue

• Muscle tissue found in the heart

• Continuous network without sheath separation

• When one cell receives the signals to contract

- all neighboring cells are stimulated and they contract together 

Skeletal muscle action

• When muscles contract they become shorter and thicker

• Flexors- bend joint

• Extensors- straighten out joint

• Flexor muscle paired with extensor muscle

• Ex. biceps and triceps of upper arm are ex of a muscle team

• Another ex. Is flexor is hamstring and extensor is quadriceps 

Muscle tone

• Skeletal muscles are partially contracted at all times

• Muscle tone: constant state of contraction

• Loss of muscle tone; muscles arent used, atrophy

tendons

muscle to bone, Strong fibrous connective tissue sheaths that do not bend/stretch, cord-like

ligaments

bone t bone; Flexible fibrous tissue that supports organs

apnoneurosis aka fascia

• Designates either a fascia or a flat tendon type of muscle attachment

• Extremely delicate, thin sheath-like structure 

largest tendon in body

achilles

origin vs insertion

the end nearest center of the body; usually immobile

insertion: end distant; usally mobile

for ex bicept connects shoulder to forearm, forarm 9insertion) usualyl moves

tetanus

repeated stimulation, muscle maintained in a state of contraciton,

usually: At all times, motor units are alternately either contracted or relaxe but in tetnaus its always ocntracted

torticollis

congenital/acquired neck deformity

bends head toward affected side and rotates chin to opposite side

cause: shortening/spasm of sternocleidomastoid muscle

during infancy

muscles have little conective tissue so the msucles js conects to bone wihtout tendons

With maturity the connective tissue increases as do the elastic fibers→ tendons

muscles grow in relation to structures to which they are attached so,,

as bone lengthens and grows, so does muscle attached to it

diapghram

when we breathe in (inhalation)—→ diaphgram contracts/moves down

when we exhale——> diaphgram moves back up to normal state as dome shape

hiccups

caused by involuntary spasms of dipahgram