Sensory Nervous System - Detecing the enviroment

Question 1

3 types of sensory neuron (receptor) structure

Answer 1

1. sensory receptor with free nerve endings
2. sensory receptors with specialized structure
3. sensory receptor with a receptor cell

Question 2

sensory neuron with free nerve-endings

Answer 2

regular neuron
the sensory receptor is the neuron itself
dendrites take in stimuli - afferent neuron

Question 3

sense organ

Answer 3

sensory receptor involving one dendrite
in a specialized structure - non neural
connective - tissue layer
pressure on skin

Question 4

sensory receptor with afferent neuron

Answer 4

sensory receptor formed by a cell that synapses with an afferent neuron
presynaptic receptor

Question 5

sensory receptor (attached to afferent neuron)

Answer 5

can function as single cells (or with accesory cells - recieves info that neuron needs)
can be grouped in a complex sensory organ - collection in the eye

Question 6

modality

Answer 6

type of sensory info needed

Question 7

mechanoreceptors

Answer 7

respond to mechanical deformation

Question 8

thermoreceptor

Answer 8

respond to cold and heat

Question 9

nocioreceptors

Answer 9

respond to pain - tissue damage

Question 10

electromagnetic receptors

Answer 10

respond to electrical + magnetic fiekd - infared and ultraviolent light

Question 11

photoreceptors

Answer 11

respond to visible light

Question 12

chemoreceptors

Answer 12

respond to various chemicals

Question 13

receptor potential

Answer 13

stimuli causes ion movements across membrane - alters rate at which AP is generated - increases frequency e.g bio lab + inner ear hair cells

Question 14

inner ear cells as AP firing rate

Answer 14

bending of hair cells increase frequency of APs
bending the other way is non-preferred - decreases frequency - no bend will create stable frequency

Question 15

example of mechanoreceptors

Answer 15

stretch receptors
hair cells

Question 16

stretch receptors

Answer 16

in inverts and verts
detect relative position of body structures
has mechaincally gated sodium channels
deforming stimulus depolarizes membrane
perform a variety of roles in animals

Question 17

stretch receptors in the knee-jerk reaction

Answer 17

hitting the knee in that specific spot with stretch receptors moves the extensor muscles which deform the stretch receptors which sends signals to motor neurons to move the leg

Question 18

stretch receptors in wings of insects

Answer 18

wings elevate - connector tissue between body and wing is stretched - deformd the membrane of neurons - leads onto other things

Question 19

neuronal mechanreceptors

Answer 19

stretch receptors

Question 20

non neuronal mechanoreceptors

Answer 20

hair cells

Question 21

process of hair cells working as mechanoreceptors

Answer 21

hair cell with sterocilia detects fluid movements and currents
opens mechanic gated - K+ channels
depolarizes
triggers voltage gated calcium channels which send neurotransmutter into sensory neuron and CNS

Question 22

hair cells as balance in crabs

Answer 22

statolith - calcarious core that will move which then moves hair cells which then triggers k+ channels and sensory neurons
orientation is detected by types of hair cells triggered

Question 23

hair cells as balance in fishes

Answer 23

water goes into the pores of the fish
bends the hair cells
depending on how much water is spread over the surface area of the fish and the amount of hair cells bent - the fish can detect if it’s going straight or turning

Question 24

hair cells as balance in humans

Answer 24

fluid will move the cupula which moves hair cells which triggers K+ channels then sensory neurons

Question 25

hair cells as organs of sound in insects

Answer 25

organs on legs (tympanum) vibrate from pressure which moves hair cells

Question 26

hair cells as organ of sound in humans

Answer 26

eardrum vibrates due to pressure - fluid moves in cochlea - moves basiliar membrane - which moves hair cells - tectorial membrane is not moved - leads to auditory nerve

Question 27

3 types of photoreceptor arrangements

Answer 27

1. eye spots (cups) 2. compound eyes 3. camera eyes

Question 28

eye spots

Answer 28

pigment cups prevent light from one direction of the eye spot - which is why animals need two light reaches photoreceptor cells and is transduced can only see light and dark - no details

Question 29

where are eye spots found

Answer 29

invertebrates - flatworms

Question 30

where are compound eyes

Answer 30

arthropods and some annelides insects, lobsters, segmented worms

Question 31

compound eyes

Answer 31

multiple little eyes each one is a ommatidium which has a lens and focuses the light has accessory cells (light blocking pigment cells) axon leads onto CNS detects complex images which produces evolved brain function

Question 32

Camera eyes are found in

Answer 32

cephlapod molluscs, all vertebrates

Question 33

camera eyes

Answer 33

normal human eyes with retina, cornea, lens, pupil, and iris - also allows for complex images and evolved brain function

Question 34

commonality between all three types of photoreceptors

Answer 34

photopigment

Question 35

photopigment

Answer 35

transduces light energy into a biolelectric signal absorbing energy from light and transducing it

Question 36

rods

Answer 36

in the retina and detect low intensity - gray shades - white and black higher sensitivity - need fewer photons

Question 37

cones

Answer 37

detect high intensity photons - colour

Question 38

photopigments

Answer 38

retinal and an opsin

Question 39

photopigments in rods

Answer 39

rhodopsin

Question 40

photopigments in cones

Answer 40

several kinds of opsins in cones

Question 41

how we see in humans

Answer 41

light comes in from the lens - it's focused - goes to cones and rodes - receptor potentials - goes to horizontal cells - biopolar cells - amacrine cells - ganglion cells - optic nerve

Question 42

retina is

Answer 42

outgrowth of brain - comes from ectoderm

Question 43

what do interneurons do in the retina

Answer 43

assist inr etinal intergration

Question 44

phototransduction in rods and cones (dark)

Answer 44

NA channels are open which depolarizes the plasma membrane glutamate is released in the cell keeps gates open

Question 45

phototransductin in rodes and cones (light)

Answer 45

NA channels close hyperpolarizes plasma membrane glutamate is not released cis retinal is converted to trans retinal which triggers metabolic process cGMP is converted into GMP keeps sodium channels closed

Question 46

example of receptor potential in retina

Answer 46

when photon enters cones and rods and NA closes and hyperpolarization occurs

Question 47

examples of action potentials in retina

Answer 47

when ganglion cells send signals up to brain with the optic nerve

Question 48

retinal intergration by interneurons

Answer 48

modify original signal from receptor cells assist in defining boundaries, changing retinal sensitivity identifying object movement colour of object allows for well-developed sensory system

Question 49

example of chemoreception

Answer 49

taste and olfaction

Question 50

taste in flies

Answer 50

each leg has chemoreceptor cells with dendrites that reach the tip of the leg with a pore - eeach taste receptor responds to a diff stimulus neuronal!!

Question 51

taste in humans

Answer 51

non-neuronal receptor cells grouped into taste buds each receptor has a preferred chemical sensitivity salt and sour are simple compounds - bound by ionotropic receptors sweet, umami, and bitter - complex compounds bound by metabotropic receptors

Question 52

mouth olfaction

Answer 52

binding of odorant leads to membrane depolarization - involves less concentrated molecules

Question 53

thermoreception in vampire bats

Answer 53

noseleaf creates an infared image of

Question 54

crotalid snakes

Answer 54

pit organs form infared image of rat

Question 55

electroreception in electric fish

Answer 55

produces electric field and if it is distrubed, they know