Muscular System Flashcards
What are the 3 types of muscles?
Skeletal muscle
Cardiac muscle
Smooth muscle
What is the skeletal muscles?
- it is voluntary
- connected to skeletal system via tendons
- responsible for movement, contracting and pulling bones
- help provide strength and power, posture and also helps generate heat
- can become fatigued during exercise
What is the cardiac muscle?
- only found in the wall of your heart
- works continuously
- involuntary
- does not fatigue
- helps circulate blood through and out of the heart
- contractions help to force blood through your blood vessels
What is smooth muscle?
- involuntary under the control of the nervous system
- located in walls of digestive system
- regulates digestion and blood flow
- control body functions such as movement of food
What’s the agonist?
The muscle that contracts - responsible for movement
What is the antagonist?
The muscle that relaxes
What are the antagonistic muscles for the trunk?
Abdominals and erector spina
What antagonistic muscle pair moves the shoulder?
Deltoid and latissimus dorsi
E.g. golf swing, breaststroke
What is a synergist?
It assists the agonist
What is a fixator?
Stabilises the origin
What is the role of the pectorals?
Helps with addiction of the shoulder and the horizontal flexion of the shoulder
What is a sporting example of isometric contraction?
Plank
Crucifix in gymnastics on the rings
What is a sporting example for concentric contraction?
Bicep curl
In the preparation phase, when rugby players prepare to kick the ball, hamstrings contract and shorten to flex the knee
What is a sporting example for eccentric contraction?
Lowering a dumbbell in a bicep curl
What is an isometric contraction?
Length of the muscle does not change, the joint angle does not alter
Muscle holds a static position
What is a concentric contraction?
Muscle will shorted and a movement occurs
What is an eccentric contraction?
When a muscle returns to its normal length after shortening against resistance
What is an isotonic contraction?
Where the muscle changes length as it contracts and causes movement of a body part.
What are the three muscle fibre types?
Type 1 (slow twitch)
Type 2 (IIa) (fast twitch)
Type 2x (IIX) (fast twitch fibres)
What is type 1?
- slow twitch
- contract slowly
- contract with less force
- most resistant to fatigue
- longer durations, aerobic activities
- rich blood supply
- contain many mitochondria
- high capacity for aerobic respiration
Type 2 (IIa)
- fast twitch
- produce a great force when contracting
- resistant to fatigue
- fatigue faster than type 1
- use oxygen
- suited to speed, power and strength activities
Type 2x (IIx)
- fast twitch fibres
- produce the greatest force when contracting
- contract rapidly
- anaerobic activities
- depend upon anaerobic respiration
- high intensity/ short duration activities
What is the all or none law?
In order for a muscle to contract, it must receive a nerve impulse.
This impulse must be sufficient to activate the motor unit.
Once activated, all the muscles fibres within the motor unit contract. If the impulse is not strong or sufficient to activate the motor unit, then none of the muscles contract.
This is the all or none law of muscle contractions.
What are the 2 responses of the muscular system?
Acute
Chronic
What is an acute response ?
Immediate responses
What is a chronic response?
Responses that take place over a long period of time
Acute response- Increased blood supply
➢When we exercise, there is a greater demand for oxygen/glucose. Therefore, the muscles are met with greater blood supply.
➢Blood vessels will expand to allow more blood to enter the muscle.
➢This is called Vasodilation.
➢It ensures the working muscles are both;
➢Supplied with oxygen
➢Waste products are removed such as carbon dioxide.
Acute response - increased muscle temperature
Muscles require energy from fuels like carbohydrates and fats.
When fuels are broken down, heat is released as the by- product.
The more you exercise, the more energy is needed.
As a result, the more heat your muscles will produce.
This is the principle of a warmup.
Chronic response - increased muscle pliability
➢Through increasing temperature, we can increase pliability.
➢This also enables us to become more flexible.
➢Pliable muscles are less likely to suffer strains.
➢Pliable muscles will increase ranges of movement at joints
Acute response - lactate
➢During high intensity lactate will build up in the working muscles as there is a lack of oxygen.
➢This is a waste product during anaerobic exercise.
➢This build up, results in rapid fatigue.
➢It also impedes (prevents) muscle contractions.
Acute response - micro tears
➢During resistance training (weights) you place stress
on muscles.
➢This stress results in micro tears in the muscle fibre.
➢Micro tears cause swelling in the muscle. This puts pressure on the nerve endings, resulting in pain.
➢Training improvements are made when we rest; allowing repair.
➢After micro tears repair, the muscles become a little stronger. Protein will support the repair.
What does DOMS stand for?
Delayed onset of muscle soreness
Chronic response - doms
➢DOMs is the pain felt in the muscle 24-48 hours after exercise.
➢DOMs is caused by micro-tears.
➢They occur if you’re not accustomed to high intensity
exercise.
➢DOMs is often associated with exercises where eccentric muscle contraction has occurred.
What are the 7 adaptations of the muscular system?
- Hypertrophy
- Increased tendon strength
- Increase in the number and size of mitochondria
- Increase in myoglobin stores
- Increase in storage of glycogen
- Increase in storage of fat
- Increased tolerance to lactate
What is hypertrophy?
Regular resistance training where the muscles are overloaded will increase muscle size and strength.
The increase in muscle size is a result of the muscle fibres becoming larger due to the increases in protein in the muscles cells; this is known as hypertrophy.
The muscle fibres increase in size over time so that they can contract with greater force.
Adaptation - increased tendon strength
Tendons are tough bands of fibrous connective tissue designed to withstand tension. Like muscles, tendons adapt to the overloading of regular exercise.
Ligaments and tendons, the connective tissue structures around joints, will increase in flexibility and strength with regular exercise. Cartilage also becomes thicker
Adaptation - increased size of mitochondria
When muscles are overloaded as part of resistance training, the muscle fibres will become bigger hypertrophy). Within these muscle fibres are tiny structures called mitochondria. Mitochondria is responsible for energy production. Due to the increase in fibre size, there is room for more and larger mitochondria, which results in the
muscles being able to produce more aerobic energy which will improve aerobic performance.
Adaptation - increase in myoglobin stores
Myoglobin is a type of haemoglobin (the red protein in blood used to transport oxygen) that is found exclusively in muscles and is
responsible for binding and storing oxygen in the blood within the skeletal muscles.
Regular exercise can increase the amount of myoglobin stored in the muscles.
This is important as myoglobin will transport oxygen to the mitochondria which in turn will release energy.
The more myoglobin you have, the more energy will be
available for the muscle.
Adaptation - Increase in storage of glycogen
When we eat carbohydrates, our body changes it into a form of sugar called glucose that can be used for energy. The glucose, in turn, is changed to Glycogen, a form of sugar that can be easily stored by our muscles and liver. It is the predominant storage form of glucose and carbohydrates in animals and humans.
Your body needs a constant and steady supply of glycogen in order to produce energy. As your body adapts to long term exercise, your muscles are able to store more glycogen.
This means that you will be able to train at higher intensities for longer, as muscle glycogen does not require oxygen to produce energy.
Adaptation - Increase in storage of fat
You are able to use your fat stores to produce energy through a process called aerobic glycolysis. Well-trained athletes are able to use these fats more efficiently, breaking them down into fatty acids and into energy using oxygen. This enables them to use fats as an energy source when
carbohydrate becomes scarce.
Adaptation - increase tolerance to lactate
Anaerobic training stimulates the muscles to tolerate higher levels of lactic acid and clear it away more efficiently. With endurance training the capillary network
extends, allowing greater volumes of blood to supply the muscles with oxygen and nutrients. The muscles are able to use more fats as a fuel source, and become more efficient at using oxygen, increasing the body’s ability to work harder for longer without fatiguing. Resulting in an increases in the body’s maximal oxygen consumption.
What type of contraction occurs when cramp occurs?
Tetanic
Why does cramp happen to the muscles?
Lack of minerals, dehydration, lack of electrolytes
How can we prevent cramp?
Good warm up, good fitness, keep hydrated
Describe cramp
Cramp occurs due to an involuntary contraction of your muscle which is also called a tetanic contraction. This is happening to the muscles due a lack of minerals and lack of electrolytes because of the nerve impulse not being able to help
generate movement through the fibres.
Cramp is not always avoidable but how we can try to prevent is through regular hydration, electrolyte drinks, adequate nutrition, a good warm up and good fitness levels.
Describe how age can affect the muscles
Our muscles mass decreases as we get older, this begins around the age of 50. Production of testosterone which ultimately reduces the muscles size and power resulting in a decrease in muscle strength and power. We can’t really avoid it but we can prevent it by doing lifelong exercise and use the right adequate form of weight bearing exercises.
Deltoids
Abduction of shoulder
Bicep
Flexion of elbow
Tricep
Extension of elbow
Pectoral
Horizontal adduction of shoulder
Wrist flexors
Flexes the hand at wrist
Wrist supinators
Pronate the forearm
Abdominals
Flexion and extension of the lumbar vertebrae
Obliques
Lateral flexion of the waist
Quadriceps
Extension at the knee
Hamstings
Flexion at the knee
Hip flexors
Flexion at the hip
Gluteals
Extension/ hyper extension at the hip
Tibialus anterior
Dorsiflexion at the ankle
Gastrocnemius
Plantar flexion at the ankle
Erector spinae
Extension of the spine
Soleus
Plantar flexion at the ankle
Trapezius
Elevated and depresses the scapula
Latissimus dorsi
Adduction at the shoulder
Soleus
Plantar flexion at the ankle
