Question Answer
contractility ability of skeletal muscle to shorten with force
excitability capacity of skeletal muscle to respond to a stimulus
extensibility ability to be stretched
elasticity ability to recoil to their original resting length after they have been stretched
epimysium connective tissue sheath that surrounds each skeletal muscle
fascia connective tissue that surrounds and separates muscles
perimysium loose connective tissue that surrounds muscle fasciculi
muscle fasciculi (fascicle) numerous visible bundles that compose a muscle
fibers single muscle cells that compose fasciculi
endomysium connective tissue sheath that surrounds each fiber
myofibrils threadlike structure that extends from one end of the fiber to the other
2 major kinds of protein fibers actin myofilaments and myosin myofilaments
actin myofilaments thin myofilaments that resemble 2 minute strands of pearls twisted together
myosin myofilaments thick myofilaments that resemble bundles of minute golf clubs
sarcomeres basic structural and functional unit of the muscle.
I band light area that consists of actin on each side of the Z line
A band darker central region that extend the length of the myosin
H zone light area that consists only of myosin in the center of each sarcomeres
M line dark staining band where myosin filaments are anchored
resting membrane potential charge difference across the membrane
action potential brief reversal back of the charge
motor neurons nerve cells that carry action potentials to skeletal muscle fibers
synapse branches that connect to the muscle forms
motor unit single motor neuron and all the skeletal muscle fibers it innervates
presynaptic terminal enlarged nerve terminal
synaptic cleft space between the presynaptic terminal and the muscle cell
postsynaptic terminal muscle fiber
synaptic vesicles vesicles contained in each presynaptic terminal
acetylcholine neurotransmitter
acetylcholinesterase enzymes that break down the acetylcholine
sliding filament mechanism sliding of actin myofilaments past myosin myofilaments during contraction
muscle twitch contraction of an entire muscle in response to a stimulus that causes the action potential in one or more muscle fibers
lag phase time between application of a stimulus to a motor neuron and the beginning of a contraction
contraction phase time of contraction
relaxation phase time during which the muscle relaxes
tetany where the muscle remains contracted without relaxing
recruitment increase in number of motor units being activated
ATP adenosine triphosphate
ADP adenosine diphosphate
creatine phosphate high-energy molecule
anaerobic respiration without oxygen
aerobic respiration with oxygen
oxygen debt amount of oxygen
muscle fatigue result when ATP is used during muscle contraction faster than it can be produced in the muscle cells
2 types of muscle contractions isometric and isotonic
isometric contraction equal distance
isotonic equal tension
muscle tone constant tension produced by muscles of the body for long periods of time
fast-twitch fibers fibers that contract quickly and fatigue quickly
slow-twitch fibers fibers that contract more slowly and are more resistant to fatigue
origin most stationary end of the muscle
insertion end of the muscle undergoing the greatest movement
belly portion of the muscle between the origin and the insertion
synergists muscles that work together to accomplish specific movements
antagonists muscles that work in opposition to one another
Occipitofrontalis raises the eyebrows
Orbicularis oculi close the eyelids
Orbicularis oris puckers the lips
Buccinator flattens the cheeks
zygomaticus smiling muscle
levator labii superioris sneering
depressor anguli oris frowning
mastication chewing
4 pairs of mastication muscles 2 pair of pterygoids, temporalis, and masseter
intrinsic tongue muscles change the shape of the tongue
extrinsic tongue muscles move the tongue
neck muscle sternocleidomastoid
erector spinae group of muscles on each side of the back
external intercostals elevate the ribs during inspiration
internal intercostals contract during forced expiration
diaphragm accomplishes quiet breathing
dome-shaped muscle aids in breathing
linea alba tendinous areaof the abdominal wall
tendinous inscriptions cross the rectus abdominis at three or more locations
trapezius rotates scapula
serratus anterior pulls scapula anteriorly
pectoralis major adducts and flexes the arm
latissimus dorsi medially rotates, adducts, and powerfully extends the arm
deltoid attaches the humerus to the scapula and clavicle
triceps brachii extends the forearm
biceps brachii flexes the forarm
brachialis flexes forearm
brachioradialis flexes and supinates the forearm
flexor carpi flexes the wrist
extensor carpi extends the wrist
flexor digitorium flexes the fingers
extensor digitorium extends the fingers
intrinsic hand muscles 19 hand muscles
interossi muscles responsible for abduction and adduction of the fingers
gluteus maximus buttocks
gluteus medius hip muscle and common injection site
quadriceps femoris extends the leg
sartorius flexes the thigh
hamstring muscles flexes the legs and extends the thigh
Gastrocnemius and soleus form the calf muscle
peroneus muscles lateral muscles of the leg
intrinsic foot muscles flex, extend, abduct, and adduct the toes
Chapter 6 Muscles

Leave a Reply

Your email address will not be published. Required fields are marked *