Människans effektorsystem (fys) 22:12 (Michael Dimitriou) PDF

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Michael Dimitriou...

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Människans effektorsystem (fys) 22/12 (Michael Dimitriou) The word effector describes either a muscle or a gland.

Muscles Three types of muscles 1. Heart (cardiac muscle)- not voluntary controlled 2. Smooth muscle (glatt muscular)- not voluntary controlled 3. Skeletal muscle- voluntary controlled. Normally attached to bones. Effect on our environment, moving, manipulating object and so on. ’To move things is all a mankind can do’ Glands (kurtlar 1. Exocrine, release their substances in body or outside, like sweat 2. Endocrine, release their substances in bloodstream The brain express its all thorough muscles. Biomimetic- artificial muscles for applications in actuators, robotics, prosthetics

Skeletal muscle Made up of many different fibers, of cells. These cells are specialized to convert chemical Membran covering the fibers is called sarcolemma Each fiber has Myfibril, Sarcoplasmic reticulum, Thin filament, actin Thick filament, 200 myosin molecule. Each myosin is a stem. . extends from the middle of the sarcomere.

Motor unit Motor neuron, is the smallest motor unit that can be controlled by the motor system. The nervous system cannot control indenpendatly the …(?). but it controls 2 types of motor neurons in the spine, 1. Alfa motor neuron, these a re large neurons that has there their cellbodys inside the core. Can receieve information from many different sources. 2. Gamma motor neuron Each individual muscle fibre is innervated by one motor unit. Etc fiber belngs to one motor unit. The muscle axon extends from the core. The motor units can vary in size. Small, less then 10 fiber muscle Large more than 1000 muscle fibers Intermediate size, Complex muscle, like the eyes or finger have more neuron, more delicate in control. Muscle used for more powerful movements, like legs, has smaller number of larger motor units. So the muscle fibers that a re active aided in single motor units are morally distributed dividely. All muscle fibers are innervated in the same motor unit. (?)

Classification of motor unit 3 skeletal muscle main types: 1. Slow with type 1, motor units in the slow. The muscle fiber take relative long time to produce maximal force. Small force, but fatigue, they can. Keep produce for a long time 2. Fast fatigue-resistant 3. Fast fattigable, high threshold, many fibers fats to produce, but fatigue very early. The 3 types, differ in colcou. Slow red, ffr pink, ff white.

With fibers produce energy by breakdown of glucose. Small use oxygen, the redness is from myoglobin (protein) Most muscles hads more of one fiber type. The neuromuscular junction The axon of the motor union. Axon has branches, The cross bridge contraction mechanism Active process that require (?) Lack of ATP causes rigor mortis ADP release, ATP detach, ATP converts to ADP.

Ca2+ and excitation-contraction (EC) coupling Calcium bindes to tryponin ATP controll, power the Electrical excitation causes DHP allows opening of the Ryanodine receptor. Muscle contaraction force Depend on the simulation of the stimulation. Electrical stimuli on a low frequency can give twitches. Release of calcium gives twitch, in falling of twitches The higher the friequnece of action potential the higher force. Lenght- tension force relationship The amount of force depends of the length of the fibers. If we really stretch the muscle a lot, the sarcomere….. Active force depends on myolfilament overlap

Passive force at longer lengths

Mucles can pull, but they cannot push Z disk to come closer together. Velocity- startong from a isometric point of no movement, the faster the muscle shorter the faster the muscle decreases its length during concentric contraction. Because when the muscle is dynamically shortening, it takes longer detaching. The mysion head spending more time being connected. The total pulling force is the sum of the active and passive force. The active is dependent of the length and the (?). muscles are often modeled as viscoelastic spring. (’’Hill-type’’ muscle models) CE- contractile element PE- passive element SE- series element

Human body has over 600 skeletal muscle, each muscle has mechanical action of one joint, or more. Flexors or extenders. Flexor will bring the bone closer to the joint, bicep for example Extensor will extend push the bone away from the joint, tricep example Antagonist, decelerates the movement, acts like a brake. Point to point action, from point a to point b normally involves a third phase, the agonist first, the antagonist brake, and the agonist again a little bit. Depends on where it’s connected in relation ot the joint. The action of a muscle can be described as a torque. The muscle force that I required to contract th emuscle is defined as the product of the. Functional changes in skeletal muscular The different types of motor units develop after birth. But motor units. Muscle growth we can hypertrophy, mostly represents an increase in the number of mayoribrils.

When we overuse our muscle they get tires, and fatigue. Less force, slower to contract and relax. The brain may not. Mostly a metabolic issue, biochemical proåerdies, energy or getting rid of chemical waste. Metabolic fatigue can happen because of shortage, not having enough to produce energy, or accumulation of metabolism, end product. A waste. Muscle fatigue, normally both shortage of energy and accunaltion of waste product., can disrupt moucls contraction in different ways. The protein less sensitive to calcium. ’ Lactic acid (mjölksyra)- higher acidity- negative effects. Mjölksyra has other roles, such in energy production. So we don’t know.

Smooth muscle One main difference can not be controlled voluntary, and the contraction protein are positioned both parallel and (?) Not striated like skeletal muscles. Slow contractions• Multiunit, finely-graded contractions • visceral type (single-unit), nearby cells, large cells to interact wave like contraction, spontaneous activity in th absence of nerve stimulation. Smooth muscle does not have tryponin (which triggers cross bridge contraction in skeletal muscle). Mysion light chain kinase.

Cardiac muscle (heart) Cardiac muscle cells are shorter than skeletal ones, The heart can keep beating on its own, but normally the brain modulates the rates and strength of the heart. In contrast to neural action potential, cardiac muscle cells generates much longer action potentials. Cardiac muscle cells have a slow mysion type which causes a slow contraction. Comparisons between the different muscle types Difference between cardiac muscle and the other, the number of cells can not vary, all of them requires Avery time. The amount off calcium can

Glands are also effectors Salivary glands, glands som producerar spott. En liter saliv per dag. Saliva helps lubricate food, which makes it easier to swallow. Three types of saliva glands....