Get ahead with a $300 test prep scholarship
| Enter to win by Tuesday 9/24
muscular system review
Terms in this set (79)
what are the 3 types of muscle tissue?
what type of muscle tissue is the muscular system comprised of?
ONLY skeletal muscle tissue
what is another name for cardiac muscle cells?
5 cardiac muscle cell characteristics
2. mono or multi-nucleate
3. branched/woven in appearance
4. joined by intercalated discs
what are contained in intercalated discs?
gap junctions and desmosomes
what does it mean to be autorhythmic?
able to generate muscles impulses without stimulation from the nervous system
what is another term for autorhythmic?
if cardiac muscles are able to generate their own impulses, what regulates the rate of their contractions?
autonomic nervous system stimulation
where are smooth muscle fibers found?
walls of blood vessels, digestive tract organs, and ducts
smooth muscle fiber characteristics
1. cells are short and fusiform with one nucleus
2. no striations (sarcomeres)
3. dense bodies present within the cells
4. autonomic nervous system control
what is the purpose of the dense bodies found within smooth muscle fibers?
points of attachment for thick and thin protein filaments
what are the 4 properties of muscle tissue
ability to response to outside stimuli which initiate action potentials and lead to muscle contractions
stimulations leads to contraction of a muscle fiber
the ability of a muscle fiber to return to its original length after contraction
ability of a non-contracted muscle to be stretched past it relaxed length
what is type of tissue is found within each skeletal muscle?
epithelial, connective, muscular, and nervous (ALL TISSUE TYPES)
what are the functions of skeletal muscle tissue?
1. body movement
2. maintenance of posture
3. temperature regulation
4. storage and movement of materials
5. provide support for abdominal organs
skeletal muscle structural hierarchy
actin and myosin --> myofilaments --> myofibrils --> muscle fiber --> fascicles --> muscle
what does working out change in the skeletal muscle hierarchy?
can ONLY change the number of myofibrils NOT the number of muscle fibers!
term for cell membrane of a muscle
term for cytoplasm of a muscle
term for smooth ER of a muscle
what are the 3 main myofilaments (proteins)
what is found within the sarcoplasm of a muscle fiber?
what is the function of myofibrils
to shorten, which contracts the entire muscle cell
what are myofibrils composed of?
what are the repeating groups found in myofilaments called?
actin and associated proteins (troponin and tropomyosin)
two main types of myofilaments
actin and myosin
what is the functional contractile unit of a skeletal muscle fiber?
what causes skeletal muscle to appear striated?
the organization of thick and thin filaments (sarcomeres)
what is an A band?
the dark band (contains thick filaments and a portion of thin filaments)
what is an I band
the light band (contains thin filaments only)
what are the 4 layers of connective tissue?
4. deep and superficial fascia
where is endomysium found
innermost layer that insulates each muscle fiber
where is perimysium found
where is epimysium found
surrounds the entire muscle
where is the deep and superficial fascia found?
surround and separate muscles
what do tendons do?
connect muscle to bone
what is an enthesis?
point where a tendon connects to a bone
what is an aponeurosis?
a wide flat tendon
what moves when a muscle contracts?
what are the 3 classes of levers in the human body?
1. first class
2. second class
3. third class
a _____ is an elongate, rigid object that moves at a point called a _______
first class lever
fulcrum in the middle between resistance and effort
where is a first class lever in the human body?
the head sitting on the neck
second class lever
load in the middle between fulcrum and effort
where is a second class lever in the human body
third class lever
effort in the middle between resistance and fulcrum
where is a third class lever in the human body?
elbow, knee, and jaw
steps of muscle contraction
a motor neuron impulse (action potential) stimulating a muscle fiber and releasing a neurotransmitter onto its surface
what is a neuromuscular junction?
location where a motor neuron and muscle fiber come close together
what are the 4 components of a neuromuscular junction?
1. synaptic knob
2. synaptic vesicles
3. motor end plate
4. synaptic cleft
expanded end of an axon terminal
tiny sacs filled with a nuerotransmitter
motor end plate
part of the sarcolemma which meets the synaptic knob
the space between the synaptic knob and motor end plate
what is a motor unit
one motor neuron and the collection of muscle cells it controls
increase in the muscle fiber size from exercise (increase in myofibrils and myofilaments)
reduction in muscle mass due to lack of exercise
what are the 3 types of skeletal muscle fibers?
slow muscle fiber characteristics
intermediate muscle fiber characteristics
fast muscle fiber characteristics
what type of muscle fibers are found in majority of skeletal muscles?
trick question! majority of skeletal muscles contain all 3 types of muscle fibers
what type of muscle fibers are controlled by a single motor unit
only fibers of the same type
where can slow muscle fibers be found?
postural muscles of the back and the calf
where can fast muscle fibers be found?
eyes and hand muscles
what are the 4 fascicle patterns of muscles?
what are the subtypes of pennate muscle pattern
circular muscle pattern examples
sphincters and obicularis oris
parallel muscle pattern examples
rectus femoris, rhomboid major, and rectus abdominus
convergent muscle pattern examples
latissimus dorsi ad pectoralis major
unipennate muscle pattern example
bipennate muscle pattern example
multipennate muscle pattern example
deltoid, soleius, gastrocnemius
what are the 6 things muscles are named upon?
6. unusual features