Muscular System Study Guide

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

muscle acts to flex the finger joints and wrist

flexor digitorum

Motor end plate

folded area where muscle and neuron communicate

Synapse

gap between the neuron and motor end plate (synaptic cleft)

Which muscle has an action of hip extension

gluteus maximus

Myofibrils

individual parallel muscle fibers, within sarcoplasm

Sarcoplasm

inner material surrounding fibers (like cytoplasm)

Sarcolemma

muscle fiber membrane

Muscle Fatigue

muscle loses ability to contract after prolonged exercise or strain

Atrophy

muscles become small and weak due to disuse

Hypertrophy

muscles enlarge (working out or certain disorders)

Muscles whose names contain the root cervi- would be found in the

neck

Specific name for the plasma membrane of the myofiber.

sarcolemma

Perimysium

separates and surrounds fascicles

how do muscles help maintain homeostasis?

skeletal muscle contractions help maintain body temperature.

orbicularis oculi Insertion

skin around eyelids

An olympic long distance marathon winner most likely has an increase number of _______ muscle fibers.

slow

The following describes ___________ fibers. - Contains increased amount of capillary networks, providing oxygen - Contain a red pigment called myoaglobin - Contain oxygen reserves - Contain a relatively larger number of mitochondria than do fast muscle fibers

slow

A person whose genetic makeup makes him or her a better marathon runner than a sprinter probably has more __________ in his or her leg muscles.

slow fibers

Nonstriated, involuntary muscle is _________.

smooth

The muscle that inserts with the gastrocnemius to the calcaneus, via the calcaneal tendon, is the

soleus

What muscle types guard the enterance and exits of the body ?

sphincters

Which of the following acts to flex the neck?

sternocleidomastoid

Skeletal Muscle

striated and voluntary

Cardiac Muscle

striated, heart

Origin

the attachment of the muscle on the more stable bone

Action Potential

the change in electrical potential, passage of an impulse along the membrane (sarcolemma) of the muscle cell

At rest, active sites of the actin are covered by

tropomyosin

_________ moves away from the active sites.

tropomyosin

Neuromuscular junction

where a nerve and muscle fiber come together

Synaptic vesicles

where neurotransmitters are stored (these are released into the cleft and tell the muscle to contract)

Muscles dominated by fast fibers appear _________.

white

Masseter Origin

zygomatic arch

All-or-None Response

Fibers do not contract partially, they either do or don't

The orgin of the soleus is ________ and the insertion is __________

Fibula/tibia; calcaneus

________ allows for electrical stimuli sent from the brain, to reach deep into each fiber

T- tubules

threshold stimulus

The minimal strength required to cause a contraction (Motor neuron releases enough acetylcholine to reach threshold)

ATP-PC (Phosphagen System)

The most immediate system available Delivers instant energy at a high rate Dominant system in repeated, brief, maximal, high-intensity bursts Ex. weightlifting, short sprints, or throwing a ball Maxes out after around 10 seconds of all-out exertion

Motor Unit

The muscle fiber + the motor neuron

What is an effect of aging on the muscular system?

Tolerance for exercise decreases.

Which muscle inserts on the clavicle and scapula?

Trapezius

Type 2 Fibers

White in appearance Fast contraction speed "Fast twitch fibers" Used for anaerobic activity Used for short durations Fatigue easily High force production Low mitochondrial density Low oxidative capacity High Glycolytic capacity Major fuel storage: Creatine Phosphate, Glycogen

Fascia

a band or sheet of fibrous connective tissue that covers, supports, and separates muscle

Antagonist

a muscle whose action counteracts that of another specified muscle

Agonist

a muscle whose contraction moves a part of the body directly

Muscle Cramp

a sustained involuntary contraction

The deltoid acts to

abduct arm

Myofibrils are made primarily of __________.

actin and myosin

Myofilaments

actin and myosin

The striated appearance of skeletal muscle results from

actin and myosin arrangement on the sarcomere

Which of the following terms is a descriptive word for a muscle's action ?

adductor

is developed by performing frequent, brief, intense workouts

anaerobic endurance

A skeletal muscle that is not regularly stimulated by a motor neuron will become smaller and weaker; such as in those individuals that are paralyzed by spinal injuries. The term used when this occurs to the muscles is _______________.

atrophy

Insertion

attachment of the muscle to the more moveable bone.

The following describes _______ type of skeletal muscle fibers. - Produce powerful contractions - Fatigue rapidly - Few mitocondria

fast

A muscle _________ contains a sarcolemma, sacroplasm and myofibrils

fiber

Aponeruosis

A broad sheet of collagen fibers that connects muscles to each other. Similar to bones, but do not connect to a bone.

Acetylcholine

A neurotransmitter that enables learning and memory and also triggers muscle contraction

Which filiament is a thin twisted protein that contains specific active sites?

Actin

Glycolytic System

Anaerobic lactic energy system Can produce ATP Rapidly Used during activities which require bigger bursts of energy Max out in 10-90 seconds Uses carbohydrates in the form of blood glucose and stored glycogen to produce ATP Ex. 800 meter run, basketball, volleyball

Orbicularis oris Insertion

Blends into fibers of orbicularis oris

How do skeletal muscles produce movement?

By pulling on tendons that then moves bones

Tendon

Connective tissue that attach muscle to a bone

Tendon

Connects muscle to bone

After death, rigor mortis lasts until

Decomposition begins

Smooth Muscle

Involuntary muscle

Diaphragm

Muscle used for inhalation for breath

Type 1 Fibers

Red in appearance Slow contraction speed "Slow twitch fibers" Used for aerobic activity Used for long durations Very fatigue resistant Low force production High mitochondrial density High oxidative capacity Low Glycolytic capacity Major fuel storage: Triglycerides

Oxidative/Aerobic System

Requires oxygen to produce ATP, because carbohydrates and fats are only burned in the presence of oxygen Preferred one for long-duration, relatively low intensity cardiovascular activities. Used for exercise durations of 3 min + Ex. Jogging, Rowing, Cycling

What 3 muscles that make up the hamstring group ?

Semimembranosus Biceps femoris Semitendinosus

Endomysium

Surrounds each individual muscle fibers

Muscle tone

Sustained contraction of individual fibers, even when muscle is at rest

The muscle that flexes the knee

biceps femoris

Buccinator Insertion

blends into fibers of orbicularis oris

Fasicle

bundle of muscle fibers

orbicularis oculi Action

closes eye

Orbicularis oris Action

compresses and protrudes the lips

Buccinator Action

compresses cheek

The supraspinatus assists the ______________ muscle.

deltoid

Action

describes what happens when the more moveable bone is brought toward the more stable bone during muscular contraction.

describe the action of the trapezius

elevates, adducts, depresses, or rotates the scapula

A layer of collagen fibers that surrounds an entire muscle is called ________.

epimysium

Muscle Fibers

long, slender cells that make up muscles

Which of the following is a muscle that originates from the zygomatic arch and functions in elevating the mandible?

masseter

Buccinator Origin

maxillary bone and mandible

Orbicularis oris Origin

maxillary bone and mandible

orbicularis oculi Origin

medial margin of orbit

Recruitment

more and more fibers contract as the intensity of the stimulus increases

The less-movable end of a skeletal muscle is the

origin

Epimysium

outermost layer, surrounds entire muscle

Oxygen Debt

oxygen is used to create ATP, - not have enough oxygen causes Lactic Acid to accumulate in the muscles → Soreness

A sheath of connective tissue surrounding a bundle of striated muscle fibers is called __________.

perimysium

cellular respiration

process that releases energy from food in the presence of oxygen

Origin

the immovable end of the muscle

Insertion

the movable end of the muscle

Muscle origins and insertions describe the places where

the muscle attaches to the bone

sliding filament theory

theory that actin filaments slide toward each other during muscle contraction, while the myosin filaments are still

Myosin

thick filament

Actin

thin filaments

sarcoplasmic reticulum

transport