MUSCULAR Flashcards
Give functions of Muscular System
Over all body movement Maintenance of posture Respiration Body heat production Communication ◦ (speaking, writing, gestures, facial expressions) Constriction of organs and vessels Contraction of the heart
The correct way of how the organs are placed
Position
Ability of organism to express his/her ideas
Communication
What are the properties of muscle tissue
Contractility, Excitability, Extensibility, Elasticity, Adaptability
Shorten forcefully
Contractility ◦
Respond to stimuli through nerves
Excitability ◦
Stretching beyond normal resting length
Extensibility
Recoil to original resting length.
Elasticity ◦
To adjust in his/her environment (hypertrophy/atrophy)
Adaptibility
Increase in size due to high endurance muscle
Hypertrophy
Reduction in a mass when it is not being used
Atrophy
Striated 40% of body weight Attached to the skeletal system With connective nervous & adipose tissue Multinucleated Peripheral location
Skeletal muscle
T or F
Myofibrils are not made up of myofilament
F
T or F
Actin and myosin are example of contractil
T
It covers myofibril
Sacromere
Composed of alternating actin myosin
myofibril
Responsible for many cell movements Actin Troponin – binding sites for Ca++ tropomyosin
ACTIN AND MYOSIN FILAMENTS
This is exclusively found in the heart muscle
Troponin
◦ Charge difference across the cell membrane
Resting membrane potential (RMP)
All cells have a negatively charged inside compared to their outside
Resting membrane potential
the change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell.
ACTION POTENTIAL ◦
Na+ outside ; K+ inside Channels closed
Resting potential
Some Na+ opens ; Na+ enters If threshold is passed they all open
Stimulus/threshold
Na+ channels open; Na+ enters ; cell becomes positive Chain reaction of Na+ channels opening the axon
Depolarization
Na+ gates close ; K+ gates open K+ moves out & the cell becomes negative.
Repolarization
How many milliseconds does it take for muscles to react?
2 milliseconds
chemical synapse formed by the contact between a motor neuron and a muscle fiber. It is at the neuromuscular junction that a motor neuron is able to transmit a signal to the muscle fiber, causing muscle contraction.
Neuromuscular Junction
Neuromuscular Junction is also known as
myoneural junction
the neurotransmitter used at the neuromuscular junction to activate muscles contraction drugs that influence this neurotransmitter can cause various degrees of movement disruption or even paralysis carries signals from motor neurons to the body’s skeletal muscles drugs that affect cholinergic systems can have very dangerous effects ranging from paralysis to convulsions.
ACETYLCHOLINE
Why does stroke and numbness happen?
Because acetylcholine ethanolamine neurotransmitter is blocks
Sedatives that block electrical impulses
Anesthesia, alcohol, tranquilizer, sleeping pills
Outer covering of muscle fiber/myofibril
Sacrolema
Spaces/area contains actin myosin
Sacromere
These allow muscle to contract
Actin/ myosin
Single muscular contraction in response to stimulus.
◦ Lots of people get twitches in the eyelid, thumb & calf muscle.
◦ go away after a few
◦ stress or anxiety related
Muscle twitch
3 phases of muscle twitch
◦ Latent phase – application of stimulus/beginning of contraction
◦ Contraction phase
◦ Relaxation Phase
Muscle twitch are due to?
◦ stress, too much caffeine, a poor diet, exercise, or as a side effect of some medicines.
is prolonged contraction without relaxation and results from repeating stimulation before the muscle has a chance to relax at all.
Tetanus
is the addition of a second twitch, resulting in greater tension, and it results from stimulating the muscle before it has a chance to relax completely.
summation or treppe
Aerobic production of ATP during exercise and normal condition Anaerobic ATP production during intensive short term work. Conversion of CREATINE PHOSPHATE to ATP Conversion of 2 ADP to one ATP and one AMP during heavy exercise.
Energy requirement/ muscle contraction
What is the difference bet. aerobic production of ATP and anaerobic ATP production
Aerobic production has the presence of oxygen while anaerobic ATP production has less oxygen but more CO2
Temporary state of reduced work capacity
Muscle Fatigue
we experience muscle fatigue because?
◦ Build up of lactic acid ◦ Drop in PH (acidosis) ◦ Depletion of ATP (increase consumption) ◦ Oxidative stress (build up of ROS – free radicals) ◦ Localized inflammatory reactions.
- reduced amount of ATP to bind to myosin filament. Incapable of contracting/relaxing. Psychological Fatigue
- involves the CNS (“perceives contraction is NOT possible.
Physiological Contracture
Symptoms of muscle fatigue
◦ soreness. ◦ localized pain. ◦ shortness of breath. ◦ muscle twitching. ◦ trembling. ◦ a weak grip. ◦ muscle cramps.
Aid for muscle fatigue
RICE (rest,ice, compression, elevation)
growth and increase of the size of muscle cells. The most common type of muscular hypertrophy occurs as a result of physical exercise such as weightlifting, and the term is often associated with weight training
Muscle hypertrophy
is when muscles waste away due to lack of physical activity. This can happen when a disease or injury makes it difficult or impossible to move an arm or leg
Muscle atrophy
is a strong, painful contraction or tightening of a muscle that comes on suddenly and lasts from a few seconds to several minutes. It often occurs in the legs.
Muscle cramp
These are under isotonic contraction
Concentric and Eccentric
=during the upward phase of exercise
=biceps brachii produces tension and shortens
= pulls the forearm upwards to cause flexion of the elbow
Concentric
=downward phase of exercise
=biceps brachii produces tension and lengthens
=it slows the lowering of the forearm and controls extension of the elbow
Eccentric
=Holding the weight still
=briceps brachii develops tension and stays the same length
=it stops flexion and extension of the elbow
Isometric contraction
Muscles are attached to the bones by
TENDONS
How many muscles are there in human body (adult)
640
this deals with MUSCLES:
Location Size Shape Orientation of fascicles Origin & insertion Number of Heads Function
Muscular nomenclature
▪ orbicularis oculi, ▪ nasalis, ▪ levator labii superioris alaeque nasi, ▪ depressor labii inferioris, ▪ procerus, ▪ auriculars, ▪ zygomaticus major, ▪ zygomaticus minor, ▪ buccinator, ▪ occipitofrontalis, ▪ corrugator supercilii, risorius, ▪ depressor anguli oris, orbicularis oris, ▪ mentalis.
Facial and mastication muscles
These muscles act to change the volume of the thoracic cavity during respiration.
Thoracic muscles
What are the effects of aging on skeletal muscle
=slow progressive loss of skeletal muscle mass begins as a direct result of increasing inactivity
=size and power of all muscles tissues also decrease
=lost muscle mass is replaced by either adipose or fibrous connective tissue
=muscle strength and endurance are impaired
=decreased cardiovascular performance
=increased circulatory supply to active muscles occurs much more slowly
=tolerance for exercise decreases
=tendency toward rapid fatigue
=muscle tissue has a reduced capacity to recover from disease or injury
=elasticity of skeletal muscle also decreases
Examples of diseases /disorder of muscular system
muscular dystrophy (muscle weakening diseases),
Muscular atrophy
Muscular Hypertrophy
tendonitis (degenerative tendon disease),
fibromyalgia (chronic pain),
mitochondrial myopathy (mitochondria ATP disorder),
myasthenia gravis (immune system problem),
tetanus (paralyzing bacterial infection).
