Organization of nervous system 2

Question 1

flatworm (planarian) nervous system

Answer 1

nerve nets; longitudinal nerve cords; brain present, but other ganglia lacking; sensory structures

Question 2

flatworm (planarian) sensory structures

Answer 2

pigment-cup type eyes; sensory cells on head responds to touch, temperature, light and water chemistry

Question 3

flatworm (planarian) behaviour

Answer 3

active predators and scavengers; wrap body around prey or impale prey with modified penis; regenerative ability; learning; sexual reproduction

Question 4

flatworm’s pharynx

Answer 4

located in middle of ventral side; mouth at tip; extends into food, begins digestion externally

Question 5

differentiate food types (leaves vs stems) through trial and error

Answer 5

earthworms (annelids)

Question 6

example of annelid learning

Answer 6

show habituation to a stimulus such as light and touch

Question 7

Annelid nervous system

Answer 7

CNS; PNS; sensory structures

Question 8

Annelid CNS

Answer 8

brain; pair of ventral nerve cords; giant fibres; subesophageal ganglion

Question 9

Annelid PNS

Answer 9

on average 3 or 4 pairs of lateral nerves/ganglion

Question 10

annelid brain

Answer 10

dorsal, anterior; involved in correlation of movement with external conditions

Question 11

annelid paait of ventral nerve cords

Answer 11

in most annelids, two cords fused; typically on ganglionic swelling/segment

Question 12

PNS

Answer 12

peripheral nervous system

Question 13

annelid sensory structures

Answer 13

dispersed photo- and chemoreceptors; mechanoreceptors; statocysts; eyes may be present

Question 14

annelid eye capabilities (when present)

Answer 14

determine light intensity and light source; some capable of image formation

Question 15

arthropod behaviour in a nut shell

Answer 15

primarily innate behaviour with many reflex actions and stero-typed stimulus-bound behaviour yet capable of complex behaviours

Question 16

Examples of arthropod behaviour

Answer 16

predation, migration, courtship strategies, sociality

Question 17

capable of classical conditioning to positive and negative stimuli

Answer 17

arthropods

Question 18

tool construction and use, self-medication, farming

Answer 18

arthropods

Question 19

arthropod nervous system

Answer 19

CNS; PNS; sensory structures

Question 20

arthropod CNS

Answer 20

dorsal, anterior brain; ventral nerve cord with ganglia; may have medial and lateral giant fibres; subesophageal ganglion

Question 21

arthropod PNS

Answer 21

on average 2-4 pairs of lateral nerves/ganglion

Question 22

arthropod sensory sturctures

Answer 22

simple and compound eyes; auditory system; chemoreceptors; mechanoreceptors; gravitational organs

Question 23

greater diversity of receptors than vertebrates

Answer 23

arthropods e.g. humidity receptors, strain receptors, osmotic receptors

Question 24

show reflex behaviour, simple conditioning, habituation, learning, and in some, reasoning

Answer 24

molluscs

Question 25

can learn a T-maze and remember is for a month

Answer 25

snails

Question 26

greatest cephalization of all invertebrates

Answer 26

cephalopods

Question 27

mollusc nervous system

Answer 27

specialization of ganglia, including brain regions (lobes); reduction of nerve cords

Question 28

organism repeatedly and at regular intervals exposed to stimulus of constant strength –> responds less and less vigourously and eventually not at all

Answer 28

habituation

Question 29

dishabituation

Answer 29

immediate recovery of response upon delivery of a strong stimulus of a different type

Question 30

characteristics of habituation

Answer 30

spontaneous recovery; dishabituation

Question 31

learning

Answer 31

change in behaviour due to experience

Question 32

gill-withdrawal reflex (Aplysia)

Answer 32

stimulus –> sensory neuron –> transmitter release –> motor neuron –> gill withdrawal

Question 33

gill-withdrawal reflex habituation

Answer 33

repeated stimulus –> sensory neuron –> decreased transmitter release –> motor neuron –> decreased or no withdrawal

Question 34

gill-withdrawal reflex dishabituation

Answer 34

serotonin –> sensory neuron –> increased transmitter release

Question 35

Mediterranean octopus

Answer 35

observational learning; associative learning and long-term memory

Question 36

observational learning in Mediterranean octopus

Answer 36

some octopods can open jar, other can’t; octopus that can’t open jar will learn how by observing con-specific that can

Question 37

associative learning and long-term memory in Mediterranean octopus

Answer 37

provide food reward or negative stimulus during presentation of human faces; after 6 months, octopus remembers event and shows predictive response to each image

Question 38

Mollusc CNS (tendency towards)

Answer 38

fusion; reduction of ventral nerve cords; subdivision of ganglia into lobes; specialized ganglia; increased brain volume

Question 39

Mollusc sense organs

Answer 39

eyes (highly developed in cephalopods); chemoreceptors; mechanoreceptors

Question 40

mollusc chemoreceptors

Answer 40

general chemical receptors; chemotactile receptors; distance chemoreceptors (olfaction)

Question 41

mollusc mechanoreceptors

Answer 41

statocysts; touch and pressure receptors; lateral line analogue in some cephalopods