Exam - Chapter 9 Flashcards
an increase in muscle mass and cross-sectional area; increase in dimension is due to an increase in the size (not length) of individual muscle fibers
muscle hypertrophy
Factors involved in muscle hypertrophy
satellite cells, immune system, growth factors, growth hormone, testosterone, muscle fiber types
fuse to the existing muscle fiber, donating their nuclei to the fiber, which helps to regenerate the muscle fiber
satellite cells
a peptide hormone that stimulates IGF (insulin-like growth factor) in skeletal muscle, promoting satellite cell activation, proliferation, and differentiation
growth hormone
produced in significantly greater amounts in males, has an anabolic (muscle building) effect; increases protein synthesis, which induces hypertrophy
testosterone
structures containing the contractile proteins actin and myosin
thick and thin filaments
overlapping parallel groups of thick and thin filaments in a repeating pattern; the underlying basis for the striation pattern
myofibril
a single muscle cell, multinucleate and may be many centimeters long
muscle fiber
a bundle of muscle fibers within a muscle; covers each skeletal muscle; alters of dense connective tissue
fascicle
a bundle of fascicles
muscle
the connective tissue associated with a muscle that forms these broad fibrous sheets; may be attached to bone or the coverings of adjacent muscles
aponeuroses
the layer of connective tissue that closely surrounds a skeletal muscle
epimysium
another layer of connective tissue that extends inward from the epimysium and separates the muscle tissue into small sections called fascicles
perimysium
a thin covering that surrounds the muscle fiber within a fascicle
endomysium
muscle cell membrane
sarcolemma
muscle cytoplasm; contains mitochondria, sarcoplasmic reticulum, myofibrils, and actin and myosin
sarcoplasm
thick filaments composed of protein
myosin
thin filaments composed of primarily this protein
actin
the functional unit of a muscle; the relating units of striations (myosin and actin)
sarcomere
rod-shaped protein; occupies the longitudinal grooves of actin helix, held in place by troponin
tropomyosin
a set of membranous channels that extend from the cell membrane into the cytoplasm; has two cisternae on each side
transverse (T) tubules
an electrical impulse that is sent down axons of neurons
action potential!
the functional connection between a neuron and another cell; the neuromuscular juntion
synapse
chemical is released after neurons communicate with the cells they control
neurotransmitters
neurons that control effectors; stimulate muscle fibers to contract
motor neurons
the muscle fiber membrane forms this!; where nuclei and mitochondria are abundant and a sarcolemma is extensively folded
motor end plate
order of muscle dimension: largest to smallest
muscle, fascicles, muscle fibers (cells), myofibrils, thick and thin filaments
a small gap that separates the membrane of the neuron and the membrane of the muscle finer; where electricity comes down an axon and neurotransmitters are transferred
synaptic cleft
the neurotransmitter that motor neurons use to control skeletal muscle conrtraction
acetylcholine
synthesized in the cytoplasm of the motor neuron and is stored in the synaptic vesicles at the distal end of its axon; released into the synaptic cleft when action potential occurs
acetylcholine again!
Sodium ion concentration is higher ____ the cell and potassium ____ the cell
outside/inside
happens in response to stimulation of the sarcoplasmic reticulum and releases calcium ions; binds to troponin and causes tropomyosin to shift and expose active sites on the actin for myosin binding
excitation-concentration coupling
when the overlapping thick and thin myofilaments slide past one another, the sarcomere shortens and the muscle contracts
sliding filament theory
a myosin head can attach to an actin binding site to form a cross bridge which pulls on the actin filament
crossbridge cycling
occurs when a muscle contracts (equal force, change in length)
isotonic contraction
rapidly decomposes acetylcholine remaining in the synapse, which prevents continuous stimulation of a muscle fiber
acetylcholinesterase
The energy sources of muscle contraction
ATP, phosphocreatine, anaerobic (glycolysis), aerobic (oxidative phosphorylation)
synthesized in muscle cells; temporarily stores some oxygen
myoglobin
contraction where muscle shortens; force is greater than resistance and shortens
concentric contraction
muscle lengthens; contracts with face less than resistance
eccentric contraction
muscle contracts but does not change length (holding body upright)
isometric contraction
stored glucose
glycogen
C6H10O5
glycogen
C6H12O6
Glucose
consists of one motor neuron and the muscle fibers associated with it
motor unit
Will many motor units be needed for finer muscle movements?
Nope! fewer=finer
a type of muscle fiber; always oxidative and resistant to fatigue; red fibers (contain myoglobin); rely on oxygen to function
slow twitch (type 1)
type of muscle fiber; primarily fatigue resistant; less common
fast twitch - oxidative (type IIa)
a type of muscle fiber, white fibers because they have less myoglobin and poorer oxygen supply); reduced ability to carry on the aerobic reactions of cellular respiration and and to fatigue quickly; fewer mitochondria, capillaries, and myoglobin
fast twitch - glycolytic (type IIb)
piriformis action
abduction an lateral rotation of thigh
sartorius action
flexion of thigh and knee, abduction of leg, lateral rotation of thigh
What are the three muscles of the hamstring?
Biceps femoris, semitendinosus, semimembranosus
Action of biceps femoris
flexion of knee, lateral rotation of leg, extension of hip
semitendinosus
flexion of knee, medial rotation of leg, extension of hip
semimembranosus
flexion of knee, medial rotation of leg, extension of hip
What are the four quadriceps femoris muscles?
Rectus femoris, vastus lateralis, vastus intermedialis, vastus medialis
Rectus femoris
Extension of knee and flexion of hip
vastus lateralis, intermedialis, medialis
extension of knee
tibialis anterior
dorsiflexion and inversion of foot
fibularis tertius
dorsiflexion and eversion of foot
extensor digitorum longus (of foot)
dorsiflexion and extension of toes
gastrocnemius
plantar flexion of foot, flexion of knee
soleus
plantar flexion of foot
plantaris
plantar flexion of foot and flexion of knee
flexor digitorum longus (leg)
plantar flexion and inversion of foot, flexion of lateral toes
tibialis posterior
plantar flexion and inversion of foot
fibulas longus
plantar flexion and eversion of foot
masseter
elevation and protraction of mandible
temporalis
elevation and retraction of mandible
sternocleidmastoid
lateral flexion of neck, rotation of head, flexion of neck
splenius capitis
rotation of head, lateral flexion and extension of neck
semispinalis capitis
extension of neck and rotation of head
scalenes
flexion of neck
quadrates lumborum
extension of lumbar
erector spinae
extension of neck and rotation of head
trapezius
rotation and retraction of scapula
rhomboid major
retraction, elevation, and rotation of scapula
rhomboid minor
retraction and rotation of scapula
levator scapulae
elevation of scapula
serrates anterior
protraction and rotation of scapula
pectoralis minor
depression and protraction of scapula
coracobrachialis
flexion of shoulder and adduction of arm
pectoralis major
flexion of shoulder, adduction of arm, medial rotation of arm
teres major
extension of shoulder, adduction and medial rotation of arm
latissimus dorsi
extension at shoulder, adduction and medial rotation of arm, depression and retraction of shoulder
supraspinatus
abduction of arm
infraspinatus
lateral rotation of arm
teres minor
lateral rotation of arm
biceps brachii
flexion of elbow, aspiration of forearm and hand
triceps brachii
extension at elbow
brachialis
flexion at elbow
brachioradialis
flexion at elbow
supinator
lateral rotation of forearm and supination of forearm and hand
pronator teres
medial rotation of arm, pronation of forearm at elbow
pronator quadratus
medial rotation of forearm at wrist; pronation of forearm and hand
flexor carpi radialis
flexion of wrist and abduction of hand
flexor carpi ulnaris
flexion of wrist and adduction of hand
palmaris longus
flexion of wrist
flexor digitorum superficialis
flexion of hand at wrist and flexion of joints in fingers
extensor carpi radialis longus
extension of hand and abduction of hand
extensor capri radialis brevis
extension of hand and abduction of hand
extensor carpi ulnaris
extension of hand and adduction of hand
extensor digitorum (hand)
extension of wrist and joints in fingers
external oblique
compression of abdomen and flexion/rotation of vertebral column
internal oblique
flexion and rotation of vertebral column
transverse abdominis
flexion and rotation of vertebral column
rectus abdominis
flexion and rotation of vertebral column
psoas major
flexion of hip
iliacus
flexion of hip
tensor fasciae latae
abduction and flexion of thigh, medial rotation of thigh
pectineus
flexion and adduction of thigh
adductor longus
adduction of thigh and flexion of hip
adductor brevis
adduction of thigh and flexion of hip
adductor magnus
adduction and flexion of thigh, posteriorly - extension of hip
gracilis
adduction of thigh and flexion of knee
gluteus maximus
extension of hip
gluteus medius
abduction and medial rotation of thigh
gluteus minimus
abduction and medial rotation of thigh