chapter 38 pp Flashcards Preview

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Flashcards in chapter 38 pp Deck (32):
1

Perceptions

Any sensory stimuli of which humans, and perhaps other animals, become conscious

2

Sensory receptors

Specialized cells capable of detecting changes in internal or external conditions, and of communicating that information to the central nervous system
Capable of facilitating sensory transduction (Conversion of an event (stimulus) occurring in the environment into a nerve impulse)
There is no difference between the nerve impulses carried by different types of sensory nerves.

3

Interoceptors

receive stimuli from inside the body.

4

exteroceptors

allow an animal to detect information in its environment

5

Chemoreceptors

Sensory receptors responsible for taste and smell

6

Photoreceptors

Sensory receptors responsible for responding to light

7

Mechanoreceptors

Sensory receptors stimulated by mechanical forces, such as pressure

8

Electromagnetic receptors

Respond to heat or light energy

9

Thermoreceptors

Sensory receptors stimulated by changes in temperature

10

Chemoreception

is found almost universally in all animals.
Thought to be the most primitive sense
Allows organisms to locate food, find a mate, detect dangerous environmental chemicals

11

Housefly chemoreceptors

are on their feet.
Can also detect airborne pheromones
Chemical messages passed between individuals

12

Snakes’ Jacobson’s organs

are in the roof of their mouths.
Send sensory information to the brain

13

taste buds

are located primarily on the tongue.
Taste buds open at a taste pore.
Taste buds have supporting cells and elongated taste cells that end in microvilli.

14

Five primary tastes

Sweet, sour, salty, bitter, and umami (savory)
Taste buds for each are located throughout the tongue, although certain regions may be more sensitive to particular tastes.
A food may stimulate more than one type of taste bud.
Brain surveys overall pattern of incoming impulses.

15

olfactory cells

human sense is dependent on this
Located within olfactory epithelium in the roof of the nasal cavity
Each cell ends in a tuft of cilia with receptor proteins for odor molecules.
Each cell has 1 out of 1,000 different types of receptor proteins

16

Photoreceptors

are sensory receptors that are sensitive to light.

17

Planaria

Eyespots” allow them to sense and move away from light.

18

Arthropods

Contain compound eyes composed of many independent ommatidia
Photoreceptors generate nerve impulses which pass to the brain by way of optic nerve fibers.
Insects have limited color vision compared to humans.
Many insects see some ultraviolet rays.
Allows them to see flower parts, nectar guides

19

camera-type eye

in Vertebrates and certain molluscs
Single lens focuses an image of the visual field on closely packed photoreceptors.

20

vertebrate lense vs mollusk lense

Vertebrate lens changes shape; molluscan lens moves back and forth.

21

Stereoscopic vision

(depth perception)
Found in animals with two eyesfacing forward
Common in predators; also in humans

22

Panoramic vision

(no overlap of images)
Wide visual field
Common in prey animals

23

The Human Eye 3 Layers

Sclera-Opaque outer layer
Choroid – Thin middle layer
Retina – Inner layer

24

Sclera

Fibrous layer covering most of the eye
In front of the eye, the sclera becomes the transparent cornea.
Conjunctiva – covers surface of the sclera and keeps the eyes moist

25

Choroid – Thin middle layer

Contains blood vessels
In front of the eye, the choroid thickens to form the ciliary body and the iris.
The iris regulates the size of the pupil.
The lens helps form images.
Attached to the ciliary body by ligaments

26

Retina – Inner layer

Contains photoreceptors called rod cells and cone cells
Contains the fovea centralis
Region of densely packed cone cells where light is focused
Vision is most acute

27

Blind spot

Where optic nerve exits retina, no vision is possible

28

ciliary muscle

Shape of lens is controlled by the ciliary muscle

29

distant object

ciliary muscle is relaxed; lens remains flat

30

far object

ciliary muscle is contracted; lens becomes more round

31

Rods permit vision in

low light
Peripheral vision and perception of motion

32

Cones permit vision in

bright light
Fine detail and color
Three types of cones, which contain B (blue), G (green), or R(red) pigments