neuro 1

  1. stimulus
    change in environment, either internal or external, tt detected by receptor = elicits response
  2. response
    • change in organism, produced by stimulus
    • e.g. drop in temp/change in day length causes animals to hibernate, thirsty = drink
  3. reflex
    • rapid, unconscious response to stimulus (reflexes are all innate behaviours, and are simplest type o coordination)
    • e.g. knee jerk reflex, pupils constrict/dilate (pupillary reflex), pain withdrawal, diving reflex
  4. basic parts o reflex arc, explain roles receptors
    Used to detect stimulus; can be sensory cells or nerve endings o sensory neurons
  5. Sensory neurons
    • Used to receive messages fr receptors
    • across synapses; carry message to CNS (spinal cord or brain)
  6. Relay neurons
    • Used to receive messages fr sensory neurons, across synapses;
    • pass message to motor neurons tt cause an appropriate response
  7. Motor neurons
    Used to receive messages fr CNS relay neurons, across synapses; carry message to effectors
  8. effectors
    • Used to carry out response after receiving message fr motor neuron;
    • ***2 types o effectors· Muscles: respond by contracting·
    • Glands: respond be secreting substances such as hormones
  9. synapses
    Spaces b/twn adjacent neurons; neurotransmitters carry message fr presynaptic neuron to postsynaptic neuron
  10. draw and label diagram reflex arc pain withdrawal reflex (7)spinal cord, spinal nerves, receptor cell, sensory neuron, relay neuron, motor neuron, effector
    Image Upload 1
  11. explain how animal responses can be affected by natural selection, 2 examples
    • innate responses and behaviors develop by natural selection/ det survival + genes passed on
    • if certain response / behav patter n= advan at survival / reprod = more offspring = cont
    • freq gene in pop increases
    • respon and behav patterns are adaptive
  12. mate selection mating white tailed deer
    • males fight in fall = breed stronger more deter males
    • females ovulate in fall, stimulated by photoperiod (shortening day length)
    • mating late so fawns in spring, food / temp
    • easier escape preds
    • survival fittest = natural selection
  13. innate behavior northern cardinals
    • non migrat species where both male/fem call to each other
    • comm in winter w/ whistles, male in spring change calls
    • mate in march again may-july
    • lay eggs when weather warmer, food avail
    • fem sings fr nest, give male info when to bring food
    • timing gives chicks time mature and fledge b4 winter
    • studies show brighter males hold better territories, more food, greater reprod, more veg
  14. distin innate and learned behaviour
    innate develops indep o environmental context, learned develops as result o exp

    innate: normally occurs in all members o species despite natural variation in environmental influences (=species-specific behaviour)

    develop by natural selection and they improve animal’s chances o survival and reproduction

    learned: develops beh through trial and error, experience, indiv pop show variation behav
  15. Discuss how the process of learning can improve the chance of survival.
    • Learning is modification o behaviour, resulting fr specific experiences during animal’s dvlpmnt.
    • diverse and changing environ, animals can improve their chance o survival by learning new behaviour patterns.
    • Learning can help animals to respond in way to incr chances o survival
    • To become more frequent in the population ‘learning’ behaviour must have a genetic component
    • e.g. chimps catching termites, poking mounds with sticks
    • foxes avoiding electric fences
  16. Outline Pavlov's experiments into conditioning of dogs.
    inclu unconditioned stimulus, conditioned stimulus, unconditioned response, conditioned response
    • Classical conditioning = alteration in bhvr o animal due to association o external stimuli
    • Ivan Pavlov observed dogs secrete saliva when see/taste food 
    • Unconditioned stimulus: sight/taste o food
    • Unconditioned response: secretion o saliva·
    • Gave dogs neutral ext. stim., e.g. ringing bell/ticking metronome, before gave unconditioned stimulus (food)
    • Repeated proc found dogs secreted saliva when heard bell/metronomeo
    • Conditioned stim: sound bell/metronome
    • Cond Resp: secretion o saliva (same; timing learned) b4 presen.
    • unconditioned stimulus: Dogs learned to associate two external stimuli, sound bell/metronome (conditioned stimulus) arrival o food (unconditioned stimulus)
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  17. Outline the role of inheritance and learning in the development of birdsong in young birds.
    • Probably partially innate, partially learned in most species
    • Many birds, learning + experience
    • Many species basic “template” inherited; young birds have unrefined subsong, changes w/ practice + listening to parents perform
    • Birds raised in isolation fr other membrs same spec. often sing songs similar, sometimes identical, to those normal birds, w/ correct length/# notes, w/o ever hearing another bird sing song; ability = innate
    • Birds raised in normal environ can also have greater range o frequencies and more distinctive phases o song, which must be learned by listening to other birds sing
    • Very few species do young birds never hear song o their parents (cuckoos exception)
    • cuckoo song must be instinctive/mimics
  18. Outline the diversity of stimuli that can be detected by human sensory receptors. (4)
    • function of receptors is to transform the stimuli into a nerve impulse that can be sent to the central nervous system which in turn coordinates an appropriate response
    • all stimuli -> nerve impulses
    • mechanoreceptors: Mechanical energy in frm mvmnt, sound, pressure, gravity e.g. skin, ear
    • chemoreceptors: Chemical substances dissolved in water (tongue) o detected as vapours diffusing through air/nose e.g. tongue, nerve cells nostrils
    • thermoreceptors: temperature e.g. skin nerve 
    • photoreceptors: Electromagnetic radiation, usually frm o light e.g. rod/cone cells eyes
  19. label diagram structure human eye (14)
    Image Upload 3
  20. Annotate a diagram of the retina to show the cell types and the direction in which light moves.
    Image Upload 4
  21. annotations
    • cone cells: yellow, synapses with ONE bipolar neuron, 3 types sens. to red, green, blue light
    • rod cell: blue: more light senstive but gives monochrome vision
    • bipolar neuron: purple, synapse with single cone cell, multiple rod cells
    • ganglion cell (body): green, each synapses with bipolar neurones, becomes depol by transmission o AP fr bipolar neurons, init nerv imp transmitted to optic nerv fib
    • nerve fibres o ganglion cells: form optic nerve tt goes to brain
    • layer pigmented cells: inclu sclera choroid, absorbs extra light + prevents reflection back
Card Set
neuro 1
neuro bio