lecture exam 4 Flashcards
(93 cards)
muscular system: explain the internal structure of skeletal muscle
- epimysium: the outer most layer/membrane covering the whole muscle structure
- perimysium: membrane of the fascicle ( bundles of muscle fibers )
- endomysium: the membrane of individual muscle fibers
- sarcolemma: membrane of the individual muscle cell
- myofibril: smaller units within muscle fiber
- actin and myosin: thick and thin myofilaments
- sarcomere: actin and myosin ( the functional unit )
muscular system: What are actin and myosin?
- Actin: thin filament
- Myosin: thick filament
muscular system: what starts the muscle contraction process starting with the axon? ( step 1 muscle contraction process)
- axon terminal shoots out acetylcholine into the sarcolemma and binds to sarcolemma receptors
muscular system: what happens after the axon releases acetylcholine that binds to sarcolemma receptors? ( step 2 muscle contraction process)
- action potential travels along sarcolemma and down into the transverse tubules
muscular system:what happens after the action potential traveled down the sarcolemma and into the transverse tubules? ( step 3 muscle contraction process)
- once at the sarcoplasmic reticulum, calcium is released
muscular system: what happens after the action potential triggering the release of calcium? ( step 4 muscle contraction process)
- Calcium will bind with troponin, Troponin will interact with tropomyosin and that exposes the active site and the myosin head will form the cross bridge
muscular system: what happens after Ca+ binding with troponin and myosin head creating cross bridge? ( step 5 muscle contraction process)
- Myosin head will swivel and contraction (shortening) will occur
muscular system: what happens after swimming myosin head contracts? ( step 6 muscle contraction)
- ATP will allow the myosin head to release and re-grab the actin
muscular system: what happens after ATP attaches to myosin head for release/re-grab actin?
- Once action potential stops (no Ach), then Ca is reabsorbed the troponin moves the tropomyosin and will block the active site on the actin (muscle relaxed)
muscular system: how does the nervous system interact with skeletal muscle?
- action potentials sent by neurons sending chemical messages to the myofilaments of the muscle
- ” End of the neuron releases a chemical (acetylcholine) that will bind to receptors on the sarcolemma “
muscular system: what role does an action potential have to the process of muscle contraction?
- action potential releases acetylcholine, sending chemical signal for contraction, one action potential stops and calcium ions is reabsorbed by troponin and moves tropomyosin causing muscle is relaxed
muscular system: what role does ATP have in the process of muscle contraction?
- ATP will allow the myosin head to
release and re-grab the actin - made by anaerobic and aerobic respiration
msucular system: What are the different ways ATP can be made?
- aerobic respiration
-requires oxygen
-requires mitochondria
-requires time
-most efficient way to generate ATP long term
-Glycogen –stored glucose (75% of all glycogen in the body is stores in muscle) - anaerobic respiration
- muscles can shift to anaerobic
glycolysis.
-during prolonged or heavy exercise
when the supply of oxygen to the
mitochondria is just not enough - no oxygen needed BUT not as efficient
-lactic acid is made (this will need to be processed)
-undergo oxygen debt
- muscles can shift to anaerobic
respiratory system: what is the function of respiration?
- get oxygen (O2) from the environment
- release carbon dioxide (CO2) from the
body
respiratory systems: what is diffusion?
- diffusion of gases across a membrane
-differences in concentration are important
respiratory systems: how is surface area connected to diffusion?
- surface area correlates to amount/quality of diffusion
-larger surface for better exchange
respiratory systems: what other ways can rate of diffusion be increased?
- reducing the thickness of the barrier of diffusion
-simple versus stratified epithelial tissue - Pressure differences between the different sides of the membrane (pumping mechanisms - ventilation)
-becomes increasingly important in water environments with low O2 partial pressure
respiratory systems: what is cellular respiration?
- energy from food
-oxygen is the final electron acceptor in this process - internal and external respiration
respiratory systems: What is external respiration?
- external respiration: exchange of oxygen and carbon dioxide between an organism and it’s environment across a respiratory surface
- at skin surface
- gills
- lungs
respiratory systems: what is internal respiration?
- internal respiration: gases exchanged with tissues throughout the body
- with the help of the circulatory system
respiratory systems: in what ways does an aquatic environment or an air environment impact gas exchange?
-air contains more oxygen and the amount usually doesn’t vary much
* water –less in amount and greater variation
-gas molecules diffuse more rapidly in air than water
* aquatic animals must have pretty efficient ways of removing oxygen from water
-respiratory surfaces must be thin and moist
* benefit to aquatic animals
* air breathers –internal structures and development of pumping mechanisms
respiratory systems: what is the difference between evagination and invagination?
- aquatic respiration: evagination of structures
-external gills are evaginated from the body and project directly into the environmental medium
internal gills are evaginated from the body and project into a superficial body cavity, through which the environmental medium is pumped - air respiration: invagination of structures
- lungs are invaginated from the body and contain an environmental medium
respiratory systems: what is gas exchange by direct diffusion?
- cutaneous respiration
-relies on surface area
-can supplement other forms of breathing
-larger animals must have other structures- gills
- trachea
- lungs
respiratory system: what is beneficial about gills compared to that of diffusion through your body surface?
- gills: branchia
- increased surface area and exposure to water
- less systems to go through and superficial surface area is best for diffusion