chapter 10 the senses

Question 1

anatomy of the eye: retina

Answer 1

contains photoreceptors: sensory cells of the eye

Question 2

anatomy of the eye: Lens

Answer 2

focus light onto retina

Question 3

anatomy of the eye: Cornea

Answer 3

helps focus image on retina

Question 4

anatomy of the eye: optic nerve

Answer 4

• coming from each eye
• collects the light, sends it to the retina, and the light is converted into action potentials which can be sent down to neurons

Question 5

rods

Answer 5

respond to low levels of light

Question 6

cones

Answer 6

respond to bright light signals (red, blue, green)

Question 7

neural pathways of vision

Answer 7

• Light signals are converted into action potentials through the interaction of photoreceptors w/ bipolar cells & ganglion cells.
• ->Glutamate is neurotransmitter released
• Photoreceptor and bipolar cells only undergo graded responses, they lack the voltage-gated channels that mediate action potentials
• Ganglion cells are the first cells in the pathway where action potentials can be initiated.

Question 8

from the back of the retina to front

Answer 8

-effective light traps, bipolar cells, ganglion cells

Question 9

photoreceptors cells-in the retina

Answer 9

Contain Photopigments arranged for effective light trap

Question 10

Metabotropic receptor eye

Answer 10

: initiates formation of second messengers when bound with ligand (neurotransmitter), found in neurons

Question 11

Ionotropic receptor eye

Answer 11

binding of neurotransmitter controls the protein for the ion to move through

Question 12

neural pathways in the brain

Answer 12

• Optic nerve (cranial 2) from each eye meet at the optic chiasm, project to many areas mainly the thalamus
• Other inputs come in from brainstem & visual cortex
• Some visual pathway neurons project to areas other than visual cortex, like hypothalamus
• Information is coded in spatial and temporal electrical activity-we perceive it all as a visual image consisting of lines, colors, contrast and movement

Question 13

ear: tympanic membrane

Answer 13

• air molecules push against it at same frequency as sound wave
• Pressures and movement of the membrane indicate pitch and volume

Question 14

ear: 3 bones

Answer 14

• malleus, incus, stapes

- Transduce sound by amplifying it through middle ear to the oval window

Question 15

ear: Cochlea

Answer 15

• Waves of pressure are created against the scala vestibuli- transmits sound to cochlear duct
• Cochlear duct to cochlea

Question 16

ear: Organ of corti

Answer 16

contains ears receptor cells

Question 17

ear: receptor cells

Answer 17

• Receptor cells called Hair cells(mechanoreceptors)
• The hairs on the cell called Stereocilia (!) are bent back and forth as sound waves vibrate
• K+ channels open, Bursts of neurotransmitters are then released onto afferent neurons
• Glutamate (neurotransmitter) binds and causes action potentials in neurons making up the vestibulocochlear nerve

Question 18

fluid in the cochlea is highly ___(+/-)

Answer 18

+

more K, K moves down gradient in (??)

Question 19

neural pathways in hearing

Answer 19

• Cochlear nerve fibers synapse with interneurons in the brainstem.
• Different arrival times from each ear and intensity help determine sound source also the shape of the outer ear and head movements

-vestibulocochlear nerve–>brainstem (medulla oblongata)–>thalamus–>auditory cortex

Question 20

steps for neural pathway

Answer 20

vestibulocochlear nerve–>brainstem (medulla oblongata)–>thalamus–>auditory cortex

Question 21

Chemicals binding to specific ______ are responsible for the detection of taste and smell.

Answer 21

chemoreceptors

Question 22

taste responds to chemicals ……

Answer 22

dissolved in food and drink

Question 23

smell responds to chemical……

Answer 23

molecules from the air

Question 24

taste buds located in bumps on the lounge called _____

Answer 24

papillae

Question 25

what does microvilli do

Answer 25

increase the surface area of taste receptor cells. Microvilli come into contact with chemicals.

Question 26

To enter the pores of the taste buds and come into contact with taste-receptor cells, food molecules must be …

Answer 26

dissolved in liquid, either ingested or provided by secretions of the salivary glands.

Question 27

salt taste

Answer 27

sodium ions

Question 28

sour taste

Answer 28

high acid content (H+ ions)

Question 29

sweet taste

Answer 29

glucose

Question 30

bitter flavor

Answer 30

quinine

Question 31

umani

Answer 31

amino acid glutamate

Question 32

pathway for taste

Answer 32

Pathways for taste go from glossopharyngeal nerve->medulla->thalamus->gustatory cortex (also prefrontal cortex) in the brain

Question 33

true or false: All areas of the tongue are able to respond to all five categories

Answer 33

true

Question 34

Independent coded pathways lead from the receptors, afferent neurons, to the CNS

This means a particular taste cell is sensitive to only one category

Answer 34

ok??

Question 35

Olfactory receptors

Answer 35

-The olfactory receptor neurons lie
in the olfactory epithelium, in the
upper part of the nasal cavity.

• Each odorant is determined by the activation of a certain combination of receptors (affinity is higher for some receptors than others)
• Axons of these cells synapse in the olfactory bulb of the cerebra cortex then onto the olfactory cortex & interconnects with the amygdala, hippocampus, and limbic system