neuro / eyes week 9

Question 1

what is the nervous system?

Answer 1

the nervous system allows communication between the brain and the rest of the body

Question 2

what specialized cells make up the nervous system?

Answer 2

neurons

Question 3

what is the function of axons?

Answer 3

Axons are pathways that carry action potentials from the body of one neuron to the body of another neuron

Question 4

what happens when an electrical signal reaches a synapse?

Answer 4

the electrical signal is converted to a chemical signal, which can then cross the synapse

Question 5

What body parts make up the central nervous system?

Answer 5

the brain and the spinal cord

Question 6

neurons are?

Answer 6

special cells that translate information to the brain and within the brain along pathways called nerves

Question 7

The best way for most people to visualize the nervous system is to think of a ????

Answer 7

highway that runs through all the other organ systems

Question 8

Neurons are ___________ that vary in shape,
depending on their role in the body.

Answer 8

living cells

Question 9

A ________ triggers your sense of touch sight,

Answer 9

stimulus

Question 10

The iris is the

Answer 10

Colorful, flexible part of the eye that
controls the pupil with smooth muscles

Question 11

the cornea is the ?

Answer 11

outer protective layer

Question 12

the lens is….

Answer 12

Flexible and soft, focuses images
with the help of smooth muscles

Question 13

Images are
projected here onto
numerous visual
cells and neurons

Answer 13

what is the RETINA

Question 14

WHAT determines
HOW and WHERE an image is focused?

Answer 14

The shape of the LENS

Question 15

The small area on the back of your retina
where the images are projected when you
look DIRECTLY at something is called the ???

Answer 15

Fovea

Question 16

BLACK-AND-WHITE vs. COLOR is
detected by light-sensitive visual cells
embedded in your retina.

These are known as what?

Answer 16

RODS
Black & white
(night vision)

CONES
Color
vision

Question 17

what are more densely
packed in the FOVEA near the
center of your retina?

Images are
projected there when you look
directly at something.

Answer 17

CONES

CONES and
RODS are
embedded in
the RETINA.
Neurons link
them to the
optic nerve.

Question 18

CONES (for COLOR vision) are most common
in the CENTER of your retina (FOVEA)
(in back, where most images are projected).

What do rods do?

Answer 18

RODS (for BLACK & WHITE vision) are more
common around the EDGES
Less detail, but you can still things in the “corner of
your eye…”

Question 19

CONES are of 3 types:

Answer 19

some respond to RED
light, some to BLUE,
some to GREEN.
Your BRAIN reads the
signals and INVENTS
the other colors

Question 20

WHAT IS THE TAPETUM LUCIDUM??

Answer 20

A shiny layer in the retina that lies
BEHIND the rods and cones.
It helps AMPLIFY dim images in darkness.
If any light rays MISS your rods or cones, the tapetum
lucidum can mirror them back outwards so they pass
through the rod-cone layer again for a second try at making an image.

Question 21

do humans have a tapetum lucidum?

Answer 21

NO!

Question 22

What condition can result from different
mixes of rods and cones in the retina, or damage
to an area of the brain where colors are perceived.

It occurs in MEN more often than in WOMEN.

Answer 22

Color blindness

Most common is
red-green deficiency.
It can involve trouble with
telling red from orange or
green, or distinguishing
colors on the spectrum
from red to green.

Question 23

Your EYES see things ___________
so your BRAIN has to FLIP the images.

Answer 23

UPSIDE DOWN…