Function of the muscular system: There are three types of ways that the muscles move. The first one is an agonist. Agonist muscles cause a movement to occur through their own contraction. For example, the triceps brachii contracts during the up phase of a push-up (elbow extension). During the down phase of a push-up, the same triceps brachii actively controls elbow flexion while relaxing. It is still the agonist, because while resisting gravity during relaxing, the triceps brachii continues to be the prime mover, or controller, of the joint action. Agonists are also interchangeably referred to as "prime movers," since they are the muscles considered primarily responsible for generating a specific movement. This term typically describes skeletal …show more content…
muscles. The second type of movement in the muscles an antagonist. Antagonist muscles oppose a specific movement. This controls a motion, slows it down, and returns a limb to its initial position. Antagonism is not an intrinsic property; it is a role that a muscle plays depending on the motion. If a motion is reversed, agonist and antagonist muscles switch roles. Because a flexor muscle is always a flexor, in flexion it is the agonist, and in extension it is the antagonist. Conversely, an extensor muscle is the agonist in extension and the antagonist in flexion. Using the example above of the triceps brachii during a push-up, the elbow flexor muscles are the antagonists during both the up phase and down phase of the movement. Citation needed. The last type of movement is a fixator.
The fixator is a movement in the muscle(s) that stabilises the origin of the agonist and the joint that the origin spans (moves over) in order to help the agonist function most effectively. In the bicep curl this would be the rotator cuff muscles, the ‘guardians of the shoulder joint’. The majority of fixator muscles are found working around the hip and shoulder joints. Types of contraction: The first type of muscle contraction is an isometric contraction. An isometric muscle contraction, or static exercise, is one in which the muscle fires but there is no movement at a joint. In this type of muscle contraction, there is no change in length of the muscle, and no movement at the joints but muscle fibres fire. An example of isometric exercise includes pushing against a wall. The second type of muscle contraction is a concentric contraction. A concentric muscle contraction is a type of muscle activation that increases tension on a muscle as it shortens. Concentric contractions are the most common types of muscle activation athletes perform in a gym when lifting …show more content…
weights. The last type of muscle contraction is an eccentric contraction.
An eccentric muscle contraction is a type of muscle activation that increases tension on a muscle as it lengthens. Eccentric contractions typically occur when a muscle opposes a stronger force, which causes the muscle to lengthen as it contracts. Fibre types: The first fibre type is a slow oxidative. Slow oxidative muscle, as the name suggests contract slowly, and they depend on aerobic metabolism for energy. These fibres take three times as long as fast fibres to reach peak contraction, hence the term 'slow twitch.' Slow fibres are specialized to maintain prolonged contraction, as we need for standing or sitting. Human postural muscles, along with the chicken leg, contain a lot of slow fibres. These slow fibres have relatively low force, or contraction strength, and high endurance. The second fibre type is a fast oxidative-glycolytic. Fast oxidative-glycolytic fibres, are fast twitch muscle fibres which have been converted via endurance training. These fibres are slightly larger in diameter, have more mitochondria as well as a greater blood supply and more endurance than typical fast twitch
fibres. Intermediate fibres, also known as fast glycolytic fibres, are fast twitch muscle fibres which have been converted via endurance training. These fibres are slightly larger in diameter, have more mitochondria as well as a greater blood supply and more endurance than typical fast twitch fibres.
In the beginning phases of muscle contraction, a “cocked” motor neuron in the spinal cord is activated to form a neuromuscular junction with each muscle fiber when it begins branching out to each cell. An action potential is passed down the nerve, releasing calcium, which simultaneously stimulates the release of acetylcholine onto the sarcolemma. As long as calcium and ATP are present, the contraction will continue. Acetylcholine then initiates the resting potential’s change under the motor end plate, stimulates the action potential, and passes along both directions on the surface of the muscle fiber. Sodium ions rush into the cell through the open channels to depolarize the sarcolemma. The depolarization spreads. The potassium channels open while the sodium channels close off, which repolarizes the entire cell. The action potential is dispersed throughout the cell through the transverse tubule, causing the sarcoplasmic reticulum to release
One of the most important muscles in both a mink and a human are those of the arms and shoulders because of their involvement with movement. One of the primal movers of arm abduction along the frontal plane is the deltoid muscle found in both minks and humans. In both species, deltoid muscles allow for the abduction of the humerus. The next two muscles are the biceps brachii and its opposing muscle the triceps brachii. The biceps brachii consists of two heads, which arise from the scapula and join to form a single muscle that ends upon the upper forearm. The most important functions of the biceps brachii are the supination of the forearm and the flexing of the elbow. The triceps brachii on the other hand extends the forearm in both minks and humans and has three heads as opposed to two in its antagonist biceps brachii (Scott). The origin of the triceps brachii is also from the scapula like the biceps brachii. In a mink, the extensor digitorium originates on the lateral epicondyle of the humerus yet in humans it is present in the posterior forearm and is responsible for extending the phalanges, wrist, and elbow in both species. Anothier muscle with similar functions to the extensor digitorium is the flexor carpi ulnaris but instead it is soley responsible for flexin...
According to Neumann, a force can be considered a push or pull that can produce, arrest or modify movement and can be measured as F=ma (Neumann, 2010). Force can also be considered the load. In regards to muscle contraction force relative to the joint, the force can be the internal force produced by the muscle itself, the force of gravity or the force of the particular load/weight. Torque is a cross product between force and the distance of the force from the fulcrum and is the ability of a force to cause rotation on a lever. Torque is a measure of how much a force acting on an
...st the sacrolemma will depolarized, thus activation potentials along the T-tubules. This signal will transmit from along the T-tubules to sarcroplasmic reticulum's terminal sacs. Next, sarcoplasmic reticulum will release the calcium into the sarcroplasm leading to the next second event called contraction. The released calcium ions will now bind to troponin. This will cause the inhibition of actin and mysoin interaction to be released. The crossbridge of myosin filaments that are attached to the actin filaments, thus causing tension to be exerted and the muscles will shorten by sliding filament mechanism. The last event is called Relaxation. After the sliding of the filament mechanism, the calcium will be slowly pumped back into the scaroplasmic reticulum. The crossbridges will detach from the filaments. The inhibition of the actin and myosin will go back to normal.
A rotator cuff is simply a group of four tendons and muscles that are located right on the shoulder and on top of the humerus bone. (Source 1) The rotator cuff is what controls the shoulder and allows it to move and be mobile. The four main muscles that consist of the tendons are the supraspinatus, infraspinatus, teres minor, and subscapularis muscles. (Source 2). Too much wear and tear on these muscles (such as too many thrown fastballs) is precisely what causes the rotator cuff to begin to tear, as well as swelling in the tendons.
As we have learned through our reading, most all bodies skeletal muscles are made up of primarily three types of skeletal muscle fibers, but their proportion differs depending on what action the muscles is doing. For example, type I fibers such as muscles of the neck, back, and leg have a higher proportion. According to Quinn (2014), type I muscles are slower and more effective, they tend fire a lot slower than fast twitch fibers and they fatigue at a much slower rate. Hence, slower twitch fibers are pronounced at helping athletes run marathons and bicycle for hours. Shoulder and arm muscles are not always active but are intermittent in their use; these muscles tend to have a larger amount of tension for uses in throwing and lifting. These muscles have a combination of both type I and type II B fibers. These fast twitch fibers use anaerobic metabolism to create energy and are the "classic" fast twitch muscle fibers that excel at producing quick, powerful bursts of speed. These muscles are used in events such as 100m sprint, basketball, soccer and football. Since this muscle fiber fires at such a high rate of contraction it will fatigue much faster and will not last long before needing to rest.
The surfaces of the joint are organised to allow only back and forth motion such as bending and straightening. This type of joint can be found between your upper arm and your lower arm, in the elbow. This type of joint is incredibly important as it allows an up and down movement, without this type of joint, we wouldn’t be able to move our arm up and down. Muscles are attached to this type of joint by tendons to allow it to contract and relax and be able to move the bone within this joint. Ligaments attach the bones in a hinge joint together, for example, the humerus and the tibia are joined by ligaments but they also have antagonist muscle pairs attached to them by tendons which allow the bone to move by contraction and relaxation of the muscles.
Muscle endurance is the ability to perform a lot of repetitions against a given resistance for a long period of time. The combination of strength and endurance results in muscle endurance. Muscle endurance is used in may sports such as rowing, swimming, cycling, distance running, field hockey and American football. Normally, an endurance muscle program involves lifting about 12-25 repetitions of moderate loads. In some cases, this is inadequate for many sports such as boxing, canoeing and x-cross skiing.
Kinesiology can be defined as the study of mechanics of body movements, so I think that is very important to know the meaning of movement when studying kinesiology. Everything in kinesiology has to do with the movement. Every action the body takes is a movement which is what kinesiology is. You cannot be successful in the field of kinesiology no matter what you are doing if you do not understand what movement is. It is the study of human movement, performance, and function by applying the sciences of biomechanics, anatomy, physiology, and neuroscience. It looks at movement and which muscles are involved to create movement relating to strength exercising and sports technique. Movement is an act of changing physical location or position or of
Cardiac muscle is a type of involuntary muscle found only in the walls of the heart, specifically the myocardium. Cardiac muscles contract automatically to tighten the walls of the heart in a rhythmic fashion. The heart beats nonstop about 100,000 times each day. Smooth muscle is a type of involuntary muscle found within the walls of blood vessels such as in small arteries and veins. Smooth muscle is also found in the urinary bladder, uterus, male and female reproductive tracts, gastrointestinal tract, and the respiratory tract. Skeletal muscles are voluntarily controlled and are attached to bones by tendons. Skeletal muscles also vary considerably in size and shape. They range from extremely tiny strands such as in the muscle of the middle ear as large like in the muscles of the thigh. The three individual muscle types also serve five main functions. The five basic functions are movement, organ protection, pumping blood, aiding digestion, and ensuring blood flow.
...gth of contraction: The muscle can be fine or coarse depending on the amount of motor units connected to muscle fibers. For example, the fine muscles contract faster because of higher number of motor units. The length of muscle in terms of its sarcomeres has an effect on the contraction length. The actions potentials have to get farther along and reach more sarcomeres to have them contract (Q3) [1], [2].
The soleus, gastrocnemius and tibialis anterior contract isometrically to keep the ankle stable at 90 degrees (Teachpe.com n.d.) (The previous reference was used to identify key joint types and muscles throughout my analysis). The knee joint is extended when in the standing position, to stabilize this joint the biceps femoris, semi-mebranosus, semi-tendonosus (hamstrings) and the rectus femoris, vastus lateralis, vastus transcriptis and vastus medialis (quadriceps) co-contract isometrically. The vertebral column of the body remains stable due to the isometric co-contraction of the erector spinae, rectus abdominus and the external and internal obliques.... ...
When observing both cell types under a microscope several differences are obvious. Firstly, skeletal muscles are larger than smooth muscle cells (one muscle cell can be up to 100µm in length). They are also multinucleated whilst smooth muscle cells are uninucleate (Alberts et al, 2002: 961). Additionally, skeletal muscle cells appear to be striated, whereas smooth muscle cells do not show this banding pattern; but are instead smooth and tapered. The absence of this patterning in smooth muscle cells suggests that they consist of a less organised collection of contractile fibres (Silverthorn, 2007: 397). This banding pattern in skeletal muscles is known as the sarcomere.
Cardiac muscle is a type of involuntary muscle found only in the walls of the heart, specifically the myocardium. Cardiac muscles contract automatically to tighten the walls of the heart in a rhythmic fashion (pp.212-216). The heart beats nonstop about 100,000 times each day (p.18). Smooth muscle is a type of involuntary muscle found within the walls of blood vessels such as in small arteries and veins. Smooth muscle is also found in the urinary bladder, uterus, male and female reproductive tracts, gastrointestinal tract, and the respiratory tract. Skeletal muscles are voluntarily controlled and are attached to bones by tendons. Skeletal muscles also vary considerably in size and shape. They range from extremely tiny strands such as in the muscle of the middle ear as large like in the muscles of the thigh (Martini, 2000). The three individual muscle types also serve five main functions. The five basic functions are movement, organ protection, pumping blood, aiding digestion, and ensuring blood flow.
There are three different types of muscles in the body, and the first to be talked about are skeletal muscles. The body consists of about 640 skeletal muscles and they just so happen to be the only voluntary or (controlled) muscles. Their main function is to contract and expand so that your bones are able to move. Most skeletal muscles are attached to bones or joints so that the muscle can either expand or contract to create motion. They consist of band like fibers attached and bundled together that run along the bone. These fibers are held together by connective tissue called epimysium, which also protects the muscle. Skeletal muscle is what makes the body able to walk and move, without these skeletal muscles the body could not function properly because it would have nothing to rely on for stabilization and strength. They contain what is called striated cells, which is cells that are shaped like bands and are individual, they stretch out the length of the muscle so that they are able to contract with it and these cells are also what give the muscle energy through respiration of proteins fats and glucose which is the energy supplement for all muscles. For example refer to figure 1-1 1-4 and1-5 for the cell