Muscle Tissue

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columnar tissues and the trachea S- column shaped ciliated cell with hair like structures called cillia covering the exposed cell surface. F-une the trachea in the respiratory system in order to protect the lungs from infection - So what? they do this by sweeping any pathogens away. from the lungs. cullia produce rapid wave like motions to move mucus and trapped foreign bodies such as pathogens up and out of the respiratory system. goblet columnar tissues and the trachea S- column shaped goblet cells that contain many.. secretory vesicles F- secrete cproduce) mucus into the trachea So what? the mucus traps particles that are in the air that breathe in you protecting your lungs by preventing unwanted particles reaching the alveoli ENDOTHELIUM endothelial tissue unes surfaces that do not normally come into contact with the outside external environment vascular system. Endothelial tissues, arteries, velns and capillaries squamous endothelial s-layer of flattened cells, one layer thick F-found lining the heart, blood vessels. reduces friction and allows for smooth flow of blood So what? provide a short diffusion pathway for the movement of various substances such as: 1-products of digestion into blood capillaries blood plasma and tissue fluid in and out of blood capillaries risk factors that damage endothelial lining. tissues - smoking, diet and high blood pressure damaged endothelial cells release substances. that cause blood vessels to constrict effect of white blood cells (roam cells) plaque in artery ways reduction of lumen diameter. rupture of protective membrane over plaque formation of blood clot (thrombus) Atherosclerosis - how it develops 1. the endothelial cells of the artery are damaged by smoking 2. white blood cells called foam ceus. 3. form a fatty deposit called a plaque in the artery walls Cunder the endothelial ceus] 4. the diameter of the lumen is reduced (narrowed) 5. the blood pressure can go up and as the heart needs to work harder 6. the protective membrane over the plaque can rupture 7. this can cause the blood to clot - thrombus muscular tissue 3 types of muscle tissue: - skeletal bones. smooth = digestive crood) - cardiac = heart. muscle function = contract for movement & relax Skeletal muscle tissue muscle tissue is made up of muscle ceus. a muscle fibre is a single muscle cell each fibre contains many my afibrils Key words. sarcolemma = specialised muscle cell membrane sarcoplasma = muscle cell cytoplasm. mult, nucleated= many nuclel. Nuclel are just beneath the sarcolemma T-tubules = cell membrane extends into the muscle cell to carry nerve impulses into the cell to tell it to contract Sarcopiasmic reticulum = specialised SEB releases ca ²5 lons, - controls ATPase activity so control muscle muscle contraction has a striated cstripers appearance. - many mitochondria to provide energy for contraction myofibrils - in more detail (round inside muscle fibres) Sarcomere = name of an individual unit. made of 2 proteins: Actin' = thin (light bands) Myosin = 1= thick coark bands) contracts during muscle contraction. L> shortens. zune 5 I band mune A band ↳ movement causing. Aband sarcomere A band = dark thick myosin I band = thin, actin isn't across myosin I band At the sarcomere: I band shortens. H zone disappears i gets smaller z Lines get closer together. Sarcomere shorters and muscle contracts. z une During contraction, the A band is constant and the I band shortens. P Slow twitch muscle fibres the soleus muscle in the leg, by contrast has a high proportion of slow-twitch fibres and requires about 100 mis to reach max tension Fatigue resistant aerobic respiration contain more mitochondria and myoglobin less glycogen - adapted to lower intensity. and long duration activity Less sarcoplasmic reticulum - faciating a slower release of calcium high number of oxidative enzymes high myoglobin content hence named red fibres darker appearance myoglobin oxygenated blood - use oxygen to produce energy slow ability to generate aerobic energy + don't fatigue as quickly slow less for contraction. long distance running / swimming / cycling / marathon good blood supply + more umited Power for longer durations CHARACTERISTICS Rate of contraction more low Rate of fatigue Type of respiration high high dark Mitochondria Glycogen Myoglobin Sarcoplasmic reticulum Appearance fast Blood supply quick Respiratory enzymes Why? Less So? high more low 39 Suitable for activity ught Fast twitch muscle fibres highest rate of contraction crapid Firing) of all the muscle fibre types easily fatigued anaerobic respiration Lower concentrations of mitochondria higher concentrations of glycogen and creatine phosphate more sarcoplasmic reticulum and greater density of calcium pumps anaerobic respiration calycosis alone) to produce two molecules of ATP per molecule of glucose. Low myoglobin content hence called white fibres ughter appearance don't use oxygen to make energy so don't need rich blood supply sprinting / jumping jacks/ box jumping / weightlifting / strength training contract quickly help you perform fast, high intensity activities 1 The figure below shows a single muscle libre. a) What two proteins are responsible for the typical banding pattern seen in skeletal muscle? A Myosin B Elastin C Titin D Actin [2] Muscle contraction is thought to occur as a result of the sliding filament theory. d Give an outline of the sliding filament theory, stating how it brings about muscle contraction. [2] b) What name is given to the mesh that wraps around a muscle fibre? What is its function? endomysium - separates single muscle fibres from one another. [6] the sliding filament theory describes the mechanism that allows muscle to contract. According to this theory, myosin binds to actin. the myosin then alters it's configuration, resulting in a 'stroke' that pulls on the actin filament and causes it to slide across the myosin -fllament. Two types of muscle fibres exist; fast- and slow-twitch. d) Explain why fast-twitch muscles are paler than slow-twitch muscles. as they do not generally require oxygenation, they contain fewer blood vessels and mitochondria than slow- twitch fibres. and less myoglobin resulting in a pale colour. e) Tick which two of these sports are likely to benefit most from fast-twitch muscle fibres. A Archery B Sprinting C Weightlifting D Marathon running [2] [2] MUSCLE CELL "Sarcolemma specialised cecc membrane -Sarcoplasm = musce cell cytoplasm -multi nucleated many nuclec. Nuclec are- Just beneath the sarcolemma -T-tubules = cell membrane extends into the muscle cell to carry nerve impulses into the cell to tell it to contract -Sarcoplasmic reticulum specialised SER releases Ca²+ ions, controls ATPase activity so control muscle contraction - has a striated (stripey) appearance - many mitochondria - energy for contraction SARCOMERE -name of an individual unit made of 2 proteins: -actin = thin (light bands) -myosin = thick (dark bands) -myofibrets found inside muscle fibres Line Line I band Line 7 A band I band MUS TIS SCLE SUE 12) sarcomeres shorten but my csin Jactin filaments themselves don't alter their lengths. SLIDING FILAMENT THEORY 1) myosin heads binds to actin fuaments, obscured by troponin canother protein molecule) 2) in resting, ATP bound to myosin head and is hydrolysed by myosin an enzyme, head acting as myasın head ready to bind to actin binding site 3) nerve impuise at neuromuscular Junction sets up action potential in sarcolemma. 4) causes release of calcium ions from sarcoplasmic reticulum in muscle fibres 5) Calcium cons bind to in troponin, so it moves, exposes myosin binding sites 6) myosin heads bind to actin binding sites 7) ADP and p released, releases energy allowing flexible neck region to rotate pulling actin Filament towards centre of sarco 8) a new ATP attaches to myosin head mere 4) myosin head detaches from actin filam 10) ATP hydrolysed to ADP and P, chemical energy released is converted to potential energy and stored in myosin. ent 1) myosin head can now attach further along actin ficament and cycle is repeated. Actin threads are sud towards centre of sarcomere.