Ch 43

Question 1

What is involved in the sensation process?

Answer 1

sensory receptors transmit coded signals, the brain then interprets the signals

Question 2

What is sensory adaptation?

Answer 2

it is a decrease in frequency of action potentials in a sensory neuron, it ocurs even when the stimulus is maintained, and it decreases the body’s response to the stimulus, it’s when we recieve a sensory signal over and over again and our bodies become accustomed to the signal, example: we aren’t constantly aware that we’re wearing clothes

Question 3

sensory receptors

Answer 3

detect information about changes in the external and internal environment, these receptors consist of specialized neuron endings or specialized cells in close contact with neurons; sensory receptors, along with other types of cells, make up complex sense organs, such as eyes, ears, nose, and taste buds

Question 4

accesory cells

Answer 4

support, connect, and integrate sensory receptors and neurons

Question 5

mechanoreceptors

Answer 5

respond to deformation, mechano=touch&hearing, examples of mechanoreceptors: hair follicle receptor, pacinian corpuscle, merkel disc, meissner corpuscle, free nerve endings, Ruffini corpuscle (be able to recognize these as mechanoreceptors), balance, acceleration, and hearing are all mechano-

Question 6

photoreceptors

Answer 6

respond to light

Question 7

chemoreceptors

Answer 7

respond to concentration changes of chemical stimuli, ex: taste buds

Question 8

nociceptors

Answer 8

respond to painful stimuli

Question 9

thermoreceptors

Answer 9

respond to heat and cold

Question 10

vestibular apparatus

Answer 10

responds to acceleration

Question 11

proprioceptors

Answer 11

respond to muscle and joint position, being able to recognize where your body is based on joint position, a sense of where you are

Question 12

electroreceptors

Answer 12

respond to electric currents or magnetic fields

Question 13

interoceptors

Answer 13

respond to internal pH, salt, and gas

Question 14

lateral lines

Answer 14

respond to water currents (found in fish, not humans), this is how fish ‘hear’ underwater, senses vibrations and water movement, the lateral line organ is a canal that extends the length of the body, the canal has numerous groupings of hair cells and openings to the outside environment, the receptor cells are hair cells, each hair cell has steriocilia and a kinocilium that are covered with a gelatinous cupula, the hair cells respond to waves, currents, and other disturbances in the water

Question 15

statocysts

Answer 15

respond to gravity (hair cells that respond to gravity), a sense of where you’re going, similar to vestibular apparatus

Question 16

vestibular apparatus

Answer 16

helps with balance, in human’s ears there is the ‘jello’ like hill or cupula with otoliths (little stones) on top. when you tilt your head the stones move the cupula and give you a sense of where your body is

Question 17

organ of corti

Answer 17

in the inner ear, helps us hear, there are hair cells and certain pitches activate different rows of the hair cells, this is in the cochlea

Question 18

what do vertebrate hair cells do?

Answer 18

detect movement, ther are found in lateral line of fishes, vestibular apparatus, cochlea, and skin

Question 19

How does taste work? what are the 4 taste receptors?

Answer 19

the nose and tongue work together and interact with smell, texture, and temperature to form the taste, the taste receptors are salt, sweet, sour, and bitter

Question 20

How does the chemical process of taste work?

Answer 20

1) chemical contact, 2-5) membrane proteins activate second messengers, 6) second messengers close K+ channels, 7) sensory receptor cell membrane depolarizes releasing the neurotransmitter, 8) action potential induced in neighboring sensory neurons; potassium channels are normally open in taste receptors, so K+ is always leaking out, the way the cell depolarizes is by closing the K+ channels

Question 21

What is the chemical process of smell?

Answer 21

1) chemical contact, 2-4) membrane proteins activate second messengers, 5) second messengers open Na+ membrane channels, 6) sensory receptor cell membrane depolarizes, releasing neurotransmitter, 7) action potential induced in neighboring sensory neurons; very similar to taste, how to tell them apart? you taste a banana which has potassium (K+), if someone gets knocked out you use smelling salts (Na+)

Question 22

sight

Answer 22

absorbs light energy, transduces it into electrical energy, produces receptor potentials, which produce polarizations or depolarizations of the membrane or graded responses

Question 23

What are ocelli?

Answer 23

ocelli are eyespots, the are found in cnidarians and flatworms, they detect only light, do not form images

Question 24

Ommatidia of insects and crustaceans

Answer 24

insects such as flies have visual units called ommatidia that produce a mosaic image

Question 25

How do human eyes work?

Answer 25

light enters through the cornea, light is focused by the lens, the image is produced on the retina, the iris regulates the amount of light

Question 26

What are the photoreceptor cells in the retina?

Answer 26

rods and cones

Question 27

What are the steps of the human vision process?

Answer 27

1) absorb light energy, 2) internal membrane proteins activate second messengers, 3) second messengers close Na+ membrane channels, 4) rod cells signal to bipolar cells via reduced neurotransmitter, 5) bipolar cells signal to ganglion cells; at rest, sodium channels are open and the photoreceptor is depolarized

Question 28

Human vision process: take 2

Answer 28

light strikes the rhodopsin, the rhodopsin signals to close the Na+ channels, the rod cell (photoreceptor) depolarizes, bipolar cell depolarizes, ganglion cell depolarizes