Unit 1 chapter 4 sensory organs and making sense of light

Question 1

What are sensory receptors?

Answer 1

they convert energy of a stimulus into action potentials. Some types of receptors adapt to continuous stimulation (sensory adaptation) and some such as pain, do not.

Question 2

What are some examples of sensory receptor cells?

Answer 2

vision
hearing
touch
smell
taste

Question 3

what are examples of type of energy reception

Answer 3

photoreception: detection of light, perceived as sight
mechano-reception: detection of vibration, perceived as hearing
Mechano reception : detection of pressure perceived as touch
chemoreception: detection of chemical stimuli perceived as smell
Chemoreception: detection of chemical stimuli, perceived as taste.

Question 4

what is sensation ?

Answer 4

sufficient stimulation of the sense organs- to produce an impulse to be sent to the brain

Question 5

What is perception?

Answer 5

meaningful interpretation of sensation

Question 6

What is stereoscopic vision?

Answer 6

eyes out front vertical pupil

Question 7

What is monocular vision

Answer 7

eyes on the side horizontal pupil

Question 8

Label the parts of the eye

Answer 8

Question 9

What are the external features of the eye and the function ?

Answer 9

sclera- layer #3 of the eye, the tough, white layer surrounding the eyeball and gives it shape is called the sclera
Cornea- in the front of the sclera becomes transparent to admit light in. This transparent layer is called the cornea, can bend light towards the pupil.
Optic nerve - sensory information leaving and going to the occipital lobe via the thalamus

Question 10

Label the anterior portion of the internal eye and the functions of each structure?

Answer 10

Aqueous humor- fluid filled chamber infront of the lens which nourishes, lubricates and protects the cornea and lens
Iris - pigmented part of the eye, controls the amount of light entering inside of the eye, when contracts pupil gets smaller when it relaxes pupil gets larger
Pupil- the hole in the iris which admits light into the eye
Lens- focuses the light directly onto the retina (near and far accommodation) by contraction and relaxation of the ciliary muscles

Question 11

Label the posterior portion of internal eye and describe the function of the structures?

Answer 11

Vitreous humor- jelly-like fluid filled chamber behind the lens which nourishes, lubricates and protects the lens and the retina, gives shape
Retina layer- layer #1 of the eye; contains two types of receptors cells that convert light into an action potential.
a) rods- photoreceptors cells are used for nighttime vision
b) Cones- are used for daytime vision (photoreceptor cells)
c) Fovea- is a section of the retina that contains the highest density of cones and has the most acute vision

Blind spot - spot on the retina, where nerves leave the eyeball, does not contain rods or cones, no vision can occur here, location of optic nerve

choroid layer - The middle layer of the eye, contains blood vessels supplying the eye with nutrients and O2, and a dark pigment to prevent the reflection of light. (absorbs excess light)

Question 12

What happens when waves of light enter your eye?

Answer 12

it bends …
role of cornea—-> bend it Iris/pupil—->regulates how much light gets in Lens—->bend it onto retina

Question 13

Discuss the role of the retina. What are rods and cones? What do they allow you to see?

Answer 13

retina —-> converts light into action potential slides
Rods——> are tall and cylindrical, more numerous
Cones—> are conical shaped, shorter than rods
There are two types of photoreceptor cells in the retina: rods and cones. Rods are sensitive to low levels of light and are primarily responsible for vision in dimly lit environments, while cones are responsible for color vision and high acuity vision in bright light.

The retina allows us to see by capturing light and converting it into electrical signals that are sent to the brain. These signals are then processed by the brain to form visual images. The different types of photoreceptor cells in the retina allow us to perceive different aspects of the visual world, such as color, brightness, and contrast.

Question 14

In what area of the retina are cones concentrated _________

Answer 14

fovea

Question 15

under what lighting conditions do cones work best?

Answer 15

-daytime
- cones respond to wave length

Question 16

Draw a flowchart outlining how cones convert light into an electrochemical impulse ?

Answer 16

Question 17

classify the resulting type of vision if the red and green cones are damaged in

Answer 17

colour blindness

Question 18

In what area of the retina are rods concentrated?

Answer 18

periphery

Question 19

Under what condition of rods work best

Answer 19

Dark
grey hues
have to have extra machinery, rods have protein called rhodopsin
-vitamin A is generated to make rhodopsin
-highly sensitive to light and heat sensitive

Question 20

Label a flowchart outlining how rods convert light into an electrochemical impulse?

Answer 20

Question 21

Name two structures that help focus the light rays entering the eye.

Answer 21

Cornea- The cornea is the clear structure that covers the front of the eye, it is the first structure that light encounters when entering the eye. The cornea refracts, and bends the light as it enters the eye.
Lens- The lens is the transparent flexible structure located behind the iris and the pupil. The lens refracts the light as it passes through, helping it focus onto the retina at the back of the eye.

Question 22

Classify the resulting type of vision if the person lacks Vitamin A and can not make the protein rhodopsin in the rod photoreceptors?

Answer 22

night blindness, rods lose ability to respond to light, possibly due to a vitamin A deficiency

Question 23

What are the two diseases of the eye

Answer 23

nearsightedness is called myopia
and farsightedness is called hyperopia

Question 24

What is nearsightedness (myopia)

Answer 24

the eyeball is too long and the image is focused in front of the retina
- concave lens correct the vision
-a condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina

Question 25

What is farsightedness (hyperopia)

Answer 25

here the eyeball is too short so the image gets focused behind the retina)
-convex lens correct the vision
-a condition in which far-away objects are seen more clearly than gear objects because the image of near objects is focused behind the retina.

Question 26

bipolar cells?

Answer 26

Bipolar cells are specialized neurons found in the retina of the eye that receive input from photoreceptor cells and transmit that information to ganglion cells, which then send the visual signal to the brain. They play an important role in processing visual information and detecting contrasts in brightness and color in visual stimuli.

Question 27

What are ganglions?

Answer 27

Ganglion cells are specialized neurons found in the retina of the eye. They are located in the innermost layer of the retina, closest to the center of the eye. Ganglion cells receive input from bipolar cells, which in turn receive input from photoreceptor cells (rods and cones).

The primary function of ganglion cells is to transmit visual information from the retina to the brain via the optic nerve. They generate action potentials in response to visual stimuli and send these signals to the brain, where they are processed to form visual perceptions.