Muscular System Flashcards
Functions of the muscular system (not in anaphy lab)
Respiration
Constrictions of organs and vessels
Contraction of the heart
Which muscle is autorhythmic
Cardiac
Smooth (in some smooth muscle)
What is the function of the skeletal muscle
Body movements
What is the function of the smooth muscle
Moving food through the digestive tract
Empty urine bladder
Regulate blood vessels diameter
Contract gland ducts
What is the function of the cardiac muscle
Pump blood
What are the 2 main aspects to muscle contractions
Electrical component and mechanical component
What are the electrical component structures
Sarcolemma
Transverse tubles
Sarcoplasmic reticulum
What are the 3 protein filament of myofibrils in muscle cells
Actin, myosin, titin
What are the 2 contractile proteins
Actin & myosin
Name the elastic protein in the myofilament
Titin
What are the 3 protein of thin myofilament
Actin, tropomyosin, troponin
The parallel arrangement of myofilaments in a sacromere allows them to
Interact which cause muscle contractions
When muscle relaxes, sacromere…
Lengthens
What are the functions of the head at the myosin molecule
- Bind to active site on the actin molecule = cross bridges to contract muscle
- Attached to rod portion by a hinge region that bends & straighten during contraction
- Breaks down ATP ( adenosine triphosphate)
What is electrically excitable
Muscle fibers
Action potential travels from the
Brain or spinal cord
Electrically excitable cells are
Polarized
What are the 2 ion channels that ions can more across the cell membrane
Leak and gated ion channels.
What inhibits the movement of charged particles
The hydrophobic environment in the phospholipid interior
What occurs when the excitable cells are stimulated
Action potential
The positively charged Na + makes the inside of the cell membrane…
Depolarized (more positive)
What is triggered when the depolarization causes the membrane potential to reach threshold
Action potential
Action potential produced in thesarcolemma of a skeletal muscle fiber can lead to…
Contraction of the muscle fiber
Where is the Ca 2+ stored?
In the sarcoplasmic reticulum
Where is acetylcholine released at
Released from the vesicles and into the synaptic cleft.
(At the presynaptic terminal, acetylcholine storage occurs within the presynaptic vesicles)
Release of acetylcholine at the neuromuscular junction (synaptic connection between the terminal end of a motor nerve and a muscle) will produce an…
Action potential in the sarcolemma
What occurs when acetylcholine is no longer released at the neuromuscular function
Muscle relaxation
The lack of… along the sarcolemma stops… release from the sarcoplasmic reticulum
Action potential
Ca 2+
keeps acetylcholine from accumulating within the synaptic cleft where it would act as a constant stimulus at the motor end-plate, producing continuous contraction in the muscle fiber.
Acetylcholinesterase
the mechanical component of muscle contraction
Cross-Bridge Movement
Cross-BridgeMovement cause the sarcomeres to
shorten and the muscle will contract
Response of a muscle fiber to a single action potential along its motor neuron
Muscle Twitch
the gap between the time of stimulus application to the motor neuron and the beginning of contraction
Lag phase/latent phase
It commences once the Ca2+ released from the sarcoplasmic reticulum initiates cross-bridge formation and cross-bridge cycling.
Contraction phase
much longer than the contraction phase, because the concentration of Ca2+ in the sarcoplasm decreases slowly due to active transport into the sarcoplasmic reticulum
Relaxation phase
are isotonic contractions in which tension in the muscle is great enough
to overcome the opposing resistance, and the muscle shortens
Concentric contraction
are isotonic contractions in which tension is maintained in a muscle but the opposing resistance is great enough to cause the muscle to increase in length
Eccentric contraction
Two major types of skeletal muscle fibers
Slow-Twitch Muscle Fibers (Type I)
Fast-Twitch Muscle Fibers (Type II)
contract more slowly, have a better-developed blood supply, have more mitochondria, and are more fatigue-resistant than fast- twitch muscle fibers
Slow-Twitch Muscle Fibers
have a less-well-developed blood supply, have very little myoglobin, fewer and smaller mitochondria, contract rapidly for a shorter time and fatigue relatively quickly
Fast-Twitch Muscle Fibers (type II)
What are the 2 types of Fast-Twitch Muscle Fibers (type II)
Fast - Twitch oxidative glycolytic (type ii a)
Fast-twitch glyolytic (type iib)
Which characteristic of skeletal muscle fiber that have a high myoglobin
SO
FOG
Which characteristic of skeletal muscle fiber that have low myoglobin content
FG
Which characteristic of skeletal muscle fiber that have many mitochondria
SO
FOG
Which characteristic of skeletal muscle fiber that have few mitochondria
FG
Which characteristic of skeletal muscle fiber that have many capillaries
SO
FOG
Which characteristic of skeletal muscle fiber that have few capillaries
FG
Which characteristic of skeletal muscle fiber that have high aerobic metabolism
SO
Which characteristic of skeletal muscle fiber that have intermediate metabolism
FOG
Which characteristic of skeletal muscle fiber that have low metabolism
FG
Temporary state of reduced work capacity
Muscle fatigue
Acidosis and ATP depletion due to either an
increased ATP consumption or a decreased ATP production
characterized by the buildup of excess reactive oxygen species
Oxidative stress
It is a local inflammatory reactions
Muscle fatigue
Highly repetitive eccentric muscle contractions produce pain more readily than concentric contractions
Muscle soreness
In people with exercise-induced muscle soreness, enzymes that are normally found inside muscle fibers can be detected in the
extracellular fluid
They contain less actin and myosin than skeletal muscle cells
Smooth muscle
Muscle is connected to the bone by a
Tendon
the most stationary, or fixed, end of the muscle
Origin
end of the muscle attached to the bone undergoing the greatest movement
Insertion
Members of a group of muscles working together to produce a
movement
Synergist
plays the major role in accomplishing the desired movement
Prime mover
are muscles that hold one bone in place relative to the body while
a usually more distal bone is moved
Fixators
Identify the fascicles arrangement:
Fascicles arranged in a circle around an opening, act as a sphincters to close the opening
Circular
Identify the fascicles arrangement:
Broadly distributed fascicles convergent at a single tendon
Convergent
Identify the fascicles arrangement:
Fascicles lie parallel to one another and to the long axis of the muscles
Parallel
What are the effects of Aging
Reduction in muscle mass
lower response time for muscle contraction
Reduction in stamina
Increased recovery time
Loss of muscle fibers begins as early as 25 years of age, and by age 80 the muscle mass has been reduced by approximately 50%
The DMD gene is responsible for producing a protein called
dystrophin
Identify the pathophysiology:
Painful, spastic contractions of a muscle
Usually due to build up of lactic acid
Cramps
Identify the pathophysiology:
Widespread pain in muscles with no cure
Aka chronic muscle pain syndrome
Fibromyalgia
Identify the pathophysiology:
Decrease in muscle size due to a decrease no. Of myofilament
Atrophy
Identify the pathophysiology:
Enlargement of a muscle due to an increased no. Of myofibrils as occur with increased muscle use
Hypertrophy
Identify the pathophysiology:
Group of genetic disorder in which all types of muscle degenerate and atrophy
Muscular dystrophy
Identify the pathophysiology:
Muscles are weak and fail to relax following forceful contractions
Affects the hand most severely
Mythic muscular dystrophy
Identify the pathophysiology:
Inflammation of a tendon or its attachment point, due to overuse of the muscle
Tendinitis
Identify the pathophysiology:
Results from an abnormal gene on the X chromosome and is therefore a sex - linked condition
Duchenne muscular dystrophy
Loss of muscle fibers begins as early as
25
By the age at 80, the muscle mass has been reduced by approximately…
50%
