Chapter 29: The Senses Flashcards Preview

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Flashcards in Chapter 29: The Senses Deck (52):
1

Sensory Receptor Cells

Detect internal/external stimuli
- located in sense organs
- all nerve impulses are the same, identical

2

Sensation

Awareness of a sensory stimulus
- results when brain integrates new info

3

Perception

More meaningful interpretations and understanding of sensory information
- brain integrates new info w/ previous experiences
- combination of different senses

4

Sensory Transduction

When receptor cells convert stimulus into a nerve impulse
- occurs in plasma membrane of receptor cells
- permeability changes (gated ion channels open)

5

Receptor Potential

Electrical signal produced by sensory transduction, similar to action potential
- not an all or none effect (stronger stimulus, stronger receptor potential)
- receptor cell synapses w/ sensory neurons --> brain

6

Sensory Adaptation

Tendency of sensory receptors to become less receptive if there's too much stimulus
- prevents brain from reacting to normal, useless background info

7

What are the five sensory receptors?

1) Pain Receptors
2) Thermoreceptors
3) Mechanoreceptors
4) Chemoreceptors
5) Electromagnetic Receptors

8

Pain Receptors

Aware of injury/disease
- indicate danger to increase survival
- entire body is filled w/ these but brain

9

Thermoreceptors

Detect heat/cold, monitor temperature of blood
- in vital organs
- hypothalamus is the body's major thermostat

10

Mechanoreceptors

Various forms of energy (stretch, motion, sound, pressure, etc)
- inside muscles, ears

11

Chemoreceptors

Sensitive to chemical stimulation
- nose & tongue
- respond to chemicals dissolved in fluids
- best sense is moths

12

Electromagnetic Receptors

Sensitive to energy of various wavelengths (magnetism, light)
- photoreceptors are most common and detect light waves from electromagnetic spectrum

13

What are the three types of photoreceptors?

1) Eye cups
2) Compound Eyes
3) Single Lens Eyes

14

Eye cups

Found in planar
- detect intensity/direction of light and goes away from light

15

Compound Eyes

Many tiny light detecting units
- Ommatidia = 1 lens, 1 cornea
- Extremely acute motion detectors, excellent color vision

16

Single Lens Eyes

Light enters thru small opening in eyes, regulated by structure (camera type eye)

17

Stretch Receptor

a type of mechanoreceptor sensitive to changes in muscle length; detects the position of body parts

18

Hair Cells

a type of mechanoreceptor that detects sound waves and other forms of movement in air or water (Cilia or Microvilli)

19

Sclera

Tough white coating of eye (outermost)

20

Cornea

Anterior, curved, clear part of sclera
- first structure to focus light

21

Conjuctiva

Thin mucus membrane on cornea

22

Choroid Coat

Darkly colored --> absorb light
- right w/ blood vessels

23

Ciliary muscle

Smooth muscle, where sclera becomes cornea
- attached to lens by suspensionary ligaments to help focus light by contracting

24

Lens

Elastic, biconvex (curves out on both sides)
- positioned behind pupil, surrounded by iris

25

Iris

Ring of pigmented tissue, regulates size of pupil

26

Aqueous Humor

Watery fluid between cornea and lens to provide nutrients

27

Vitreous Humor

Jelly like fluid in chamber behind lens, helps keep shape

28

Retina

Contains photoreceptor cells (stimulus transducers)
- rods and cons

29

Rods (rhodopsin)

Absorb dim light --> black and white image

30

Cons (photopsin)

Absorb bright light --> colored center

31

Optic Nerve

Carries impulses to brain, blind spot

32

Fovea

an eye’s center of focus and the place on the retina where the receptors are highly kind

33

Blind Spot

the place on the retina of the vertebrate eye where the optic nerve passes through the eyeball and where there are no photoreceptor cells

34

Accommodation

the automatic changes made by the eye as it focuses on near objects

35

Visual Acuity

the ability of the eyes to distinguish fine detail

36

Nearsightedness

an inability to focus on distant objects; occurs when the eyeball is longer than normal and the lens focuses distant objects in front of the retina. Also called myopia.

37

Farsightedness

an inability to focus on close objects; occurs when the eyeball is shorter than normal and the focal point of the lens is behind the retina. Also called hyperopia

38

Astigmatism

blurred vision caused by a misshapen lens or cornea

39

What are the 3 regions of the human ear?

Outer ear, middle ear, inner ear

40

Outer Ear

one of three main regions of the ear in reptiles, birds, and mammals; made up of the auditory canal, and in many birds and mammals the pinna

41

Pinna

the flaplike part of the outer ear, projecting from the body surface of many birds and mammals; collects sound waves and channels them to the auditory canal

42

Auditory Canal

part of the vertebrate outer ear that channels sound waves from the pinna or outer body surface to the eardrum

43

Eardrum

a sheet of connective tissue separating the outer ear from the middle ear that vibrates when stimulated by sound waves and passes the waves to the middle ear

44

Middle Ear

one of three regions of the vertebrate ear; a chamber containing three small bones (the hammer, anvil, and stirrup), which convey vibrations from the eardrum to the oval window

45

Oval Window

in the vertebrate ear, a membrane-covered gap in the skull bone, through which sound waves pass from the middle ear into the inner ear

46

Eustachian tube

an air passage between the middle ear and throat of vertebrates, that equalizes air pressure on either side of the eardrum

47

Inner Ear

one of three main regions of the vertebrate ear; includes the cochlea, organ of Corti, and semicircular canals

48

Cochlea

a coiled tube in the inner ear of birds and mammals that contains the hearing organ, the organ of Corti

49

Organ of Corti

the hearing organ in birds and mammals, located within the cochlea

50

Semicircular Canals

fluid filled channels in the inner ear that detect changes in the head’s rate of rotation or angular movement

51

Utricle

a fluid-filled inner ear chamber containing hair cells that detect the position of the head relative to gravity

52

Sccule

a fluid filled inner ear chamber containing hair cells that detect the position of the head relative to gravity