Module 2 Flashcards
when did muscles first appear
- They appeared in single celled ukaryotes
- then in sponges with contractile cells but not muscles
- Cnidaria aros first true myocytes
What are the different filaments in the cytoskeleton
Microtubules
* hollow tubes
* maintain cell shape
* resist griders
* maintain cell motility in Cillia or flagella
* chromosome movements in cell division
Mircofilaments
* 2 intertwined strands of actin
* maintain cell shape
Intermediate filaments
* fibrous cablle proteins
* tension bearing elembts
* anchorage of neucleus and other organelles of nuclear lamina
What are the motors
- myosins move on actin tracks
- myosins are in every cell but porteins use myosin II
- myosin is arranged in bundles where the heads stick out and are stacked like golf clubs
What is the tropomyosin-troponin complex
- around the actin molecules
- tropomyocines are like cables and tropinin are the physical blockers for the myosin acting sites
What are the different kinds of muscles
Smooth muscle - thick and thin filaments but scattered around the cell in all directions
Straiated muscle - repeating units of sarcomeres
Sarcomeres are arranged in end to end into long myofibrils
What is the variation in muscle structure and function
- all muscles are built on thick and thin filaments
- Innervation pattersn determin whether a muscle contracts once- twitch or has a sustained contraction - tonic
- muscle recruitment determines the contractil force of the arrangements. May be soecific for force or shrotening veolicyt
- Nerve and muscle components determine frequency
Whata re muscles to locomotor system
- Stretched into skeletal systems attached by tendons and arranged around levers
- They are typically arranged in antagonistic groups where one will be contracted and will be relaxes think bicep and tricep
- SOmetimes they are not however like in fleas when they jumo or kangaroos
What are the different phsiology models
- Krogh model - Suggests that studying a system or biological process where it can be observed easily or conviently monmitored is good. If you want to know how mammals regulate body temperature look at mice becasue they are so small and simple and easy to observe
- Evolutionary models - can be mathematical or genetic. Hardy weinbird is this or wright fischer. used to see changes in environment mutations or migration
- applied model is either of these
What are reoccuring themes in biology
- Integrative biology from molecules to organisms - connectioms between genes macromolecules cells, tissues and systems, reductionism and emergent properties
- Form and function variation, both witin and between ani,als, DIstinction between proximate and ultimate causation origgins of variation, regulation, remodelling and evolution of interactons
- Alternative appracohes to homeostasis - Humans are but one species and many animals use fundamentally different solutions to deal with challenges in homeostais
Whata re the proximate and ultimate causes of gifraffe
- Asking how did a triat arise comes from prixmate cause of ultimate cause.
Why does giraffe have long neck
* how does it use it to its advanatage
* how did it evolve from its ancestors
* what genetic differences explain it
* How does it arise in development
* what physiological challenges exist and how do they cope with it
how is evolution and development interdependent
- Small set of transcription factors determine how long a structure like the vertebrae continues to grow
- a single gene will determine length of the neck
What are unexpected consequences of the girfaffe
- Huge heart and high BP
- thick walled blood vessels in limbs
- Strengthened musculoskeletal system to support weight
What are the reoccuring terms in animal physiology
Integration - giraffe ness depends non similar proteins usedi n different ways to build higher order structures
Emergent properties - How do you go from gene variants to a complex phenotype
Reductionism - mutating a single gene can give insight to complex processes
proximate vs ultimate causation - why does giraffe have a long neck
Regulation - How does homeostasis differ in giraffe because of its neck, is it evolution and development - how dpes giraffe differ from short necked relative
Models - What does giraffe tell us about humans, can you use a mode lto understand giraffe
What are the princiuples of animal form and function
Animal form and function are correlated at all levels of organization - Physiology is an integrative duscupline. SIze and shape, interaction with the ebvironment, body plans
Feedback control maintains the internal environment in many animals - regulating conforming homeostais and allostaiss, feedback and control
Energy requirements are rleated to size activity and engironment - energy allocation and metabolic rate
Homeostatic processes for thermoregulation form and function and behaviour, - tyhermal statgies and balances
How do we determine form and function
- to see conections
- undertsanding of how genes are controlled is needed
- How cells interact to make tissues and organs
- How does this relationsho change over time and differ amongst individuals
What deternines cell form and function
- How does anumals genome result in specific type of cell
- How does cell change itself in repsonse to condictions - plastiocity
- How do differences between individuals arise - evolution
- These are all answered by genes
What are cell to cell connections and cellular polarity
- Most epithelial cells transport something to the other side
- to do this they need - strong connections to each other
- strctural platform - basla lamina
- polarity - differences/specializations of the cell membrane
- aplical membrane may differ form the basolateral
How are cells origanized into layers
- Cuboidal epithelium
- SImple saquanamous epithelium
- simple columal epithelim
- Stratified squanamous epiethli,
Apical layer - closest to the outside
basal layer - closest to the inside
Understanding differencesi n form and function
- Regulation - changes existing hardware in a few mechamisms
- Remodelling or plasticity changes hardware and may be irreverisable
- developmental plasticity is irreverusble
- reversible ie acclimatization, or acclimation
- Differences between indviiduals seen over generations within a speices, artifical and natural selection between species fast slow animals
- Many interactions between regulations, plasticity and evolution
What are the different plasticities
- Developmental means happens during development and is not going to change likely
- accilimitzation and acclimation is if it grows in an nevinomrnt with predators, Theres a transcutionm that will activate enzymes to develop this
What is acclimatization
- Reversible changes in physiology in response to environment
- Changes from one season to another is an example
- Dogs change how much fur they shed, temperature triggers is the days they can ciunt hours if daylight nad track it being shorter and begin shedding
How can a bird change
- within a species many differences arise as a result of developmental and varation between individuals at the same developmental stage
- Birds go from smaller to bigger
- In comparision it is not a mutation because they are stuck with their genome
- Looking at variation of indivudals overtime
- WHat causes closely related species to be related to each other
- What evolutionary events caused lineages to diverge a shared ancestor unrelated lineages
What is allometric scaling
- Metabolic rate of a mouse will be significant faster for the same mass of elephant
- explanation is body temlerature because high body temperature of mouse allows them to shed weight much faster
- Small animals have a greater mass specific metabolic rate
Whata re side effects of temperature change
- Changes in metabolic rate from temperature affect organismal function, including developmental rates
- Disruption of food webs including food abundance and phenology
- Secondary effects on aquatic O2 and CO2 levels
- Populations that swim furthest have bigger hearts