neuro 1

change in environment, either internal or external, tt detected by receptor = elicits response

• change in organism, produced by stimulus
• e.g. drop in temp/change in day length causes animals to hibernate, thirsty = drink

• 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

Used to detect stimulus; can be sensory cells or nerve endings o sensory neurons

• Used to receive messages fr receptors
• across synapses; carry message to CNS (spinal cord or brain)

• Used to receive messages fr sensory neurons, across synapses;
• pass message to motor neurons tt cause an appropriate response

Used to receive messages fr CNS relay neurons, across synapses; carry message to 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

Spaces b/twn adjacent neurons; neurotransmitters carry message fr presynaptic neuron to postsynaptic neuron

• 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

• 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

• 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

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

• 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

• 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)
• 

• 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

• 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

• 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