Biology and Behavior                     Mr. Seegers

Perceived light color - for humans is broken down into 3 parts

Hue- the distinct categories of color visible by humans

Brightness- the intensity of the color

Saturation-the purity of the color

Eye Anatomy

Orbits -bony pockets in the front of the skull
-Eyes are suspended in the orbits

Held in place by six extraocular muscles attached to the sclera

Sclera- strong white outer layer of eye. Opaque which allows no
light to enter.

Conjunctiva- Mucus membrane which line the eyelids and attach to eye.
-provide moisture to eyes

Cornea- clear covering over the front of the eye which is transparent

Pupil -controls the amount of light that enter into the eye.
-is an opening in the iris

Iris – pigment ring of muscles behind cornea

Lens- is situated behind the iris
- controlled by micro muscles (ciliary) which change thickness of lens

Accommodation - process of focusing /changing the thickness of the lens

Vitreous humor- clear gelatinous substance contained inside the eye

Retina- interior lining of the back of the eye
- contains the receptor cells (rods and cones)
- rods and cones collectively know as the Photoreceptors

Rods
- 120 million in human retina used for seeing in low light levels

Cones
- 6 million, allows us to see color, detailed vision & daytime

Fovea
- region of retina, which contains highest sharpness of, visions (all cones)

Optic disk- where axons convey visual info and travel into brain via the
optic nerve.

Visual Disorders

Visual agnosia- lose of visual perception caused by brain damage.
-lose the ability to identify common objects by sight but can
identify after touching

Apperceptive visual agnosia
- lose the ability to distinguish between same colored shapes

Prosopagnosia
- lose the ability to recognize faces

Associative Visual Agnosia
- inability to identify objects that are perceived visually,
even though the object can be drawn or matched with similar objects
-
ex. Copy a picture of a fish but cannot name it

Balint’s syndrome
- caused by damage to occipital lobe region
- 3 possible symptoms

1) Optic ataxia- difficulty in reaching for objects under visual guidance
2) Ocular apraxia- difficulty in visual scanning
3) Simultanagnosia- difficulty in perceiving more than one object at a time.


Gustation
-taste
-interact with receptors chemically
-molecules must dissolve in saliva and stimulate taste receptors on tongue

4 qualities of taste
-bitterness
-sourness
-sweetness
-saltiness

FLAVOR IS A COMPOSITE OF OLFACTION AND GUSTATION


Tongue
- contains a10,000 taste buds
- taste buds have 25-50 receptors cells
- taste buds have a life span of 10 days, then replaced
Olfaction (Smell)

Humans can recognize 10,000 different odors

Factors that inhibit olfaction
-smoking
-allergies
-sickness
-genetic deformities (polyps, underdeveloped olfactory bulbs, etc)
-damage to nasal structure
-pollution
-toxins

Sleep Behavior
-2 stages

REM (rapid eye movement)
When dreaming, eye movement, and muscular paralysis occur also called paradoxical sleep

Non REM Sleep
All other forms of sleep besides REM
Why do we sleep?
-as a restorative process
-adaptive trait (some species sleep more than others)

Sleep Disorders

Insomnia-achieving less sleep than body needs

Drug dependency insomnia –caused by the side effects of taking sleeping Medication

Sleep Apnea- breathing stops while sleeping

Narcolepsy- the irresistible urge to sleep during the day
-lasts 2-5 minutes person feels refresh
Symptoms of Narcolepsy
1) Cataplexy –complete paralysis, individual remains awake
2) Hypnagogic hallucination –vivid dreams occurring

REM w/out atonia
-neurological disorder in which person does not
become paralyzed during REM and acts out dreams

Sleepwalking and night terrors occur in non REM sleep

AUDITORY COMMUNICATION DISORDERS

Ceberovascular accident (stroke)
-brain damage caused by rupture of a blood vessel in brain
-causes problems with all forms of communication

Aphasia
-difficulty in producing or comprehending speech caused by brain damage

Broca’s aphasia
-a form of aphasia
-causes difficulty in speech articulation

Anomia
-difficulty in remembering the appropriate word to describe an object, action, or attribute
-a system of aphasia

Apraxia of Speech
- impairment in the ability to program movements of the tongue, lips, and throat

Wernicke’s aphasia
-a form of aphasia resulting in poor speech comprehension and fluent but meaning less speech

Pure word deafness
-ability to hear, speak, read, and write without being able to comprehend the meaning of speech

Transcortical sensory aphasia
-speech disorder in which a person has difficulty comprehending speech

Conduction aphasia
-inability to repeat words that are heard but normal speech ability is present

DISORDERS OF READING AND WRITING

Pure Alexia
-lose ability to read but still can write

Surface Dyslexia
-read words phonetically but has difficulty reading irregularly spelled words by the whole-word meaning

Word-form dyslexia
-read word only after spelling out the individual letters

Direct dyslexia
-language disorders caused by brain damage in which individual can read words aloud without understanding them

Phonological dysgraphia
-writing disorder in which the person cannot sound out words

Orthographic dysgraphia
-writing disorder in which the person can spell regularly spelled words but not irregularly spelled words.



Biology and Behavior 335 Mr. Seegers
Notes 5

Audition

-We here sounds produced by objects that vibrate and set molecules of air into motion
-this phenomenon is known as sound waves
-sound waves travel away from objects at approximately 700mph
-if the vibrations ranges between approximately 30 and 20,000 times per second our ears can detect it.
Humans cannot hear any sound outside this range.


Sounds
-sounds have three components (or dimensions) pitch, loudness and timbre

Pitch
-one of the three dimensions of sound
-is determined by the frequency of vibration which is measured in hertz
hertz-means is cycles per second

Loudness
-the second dimension of sound
-is function of intensity
-the more vigorous an object vibrates the greater the intensity,
meaning louder sounds are produces

Timbre
-the third dimension of sound
-provides information about the nature of the sound
-is the sounds mixture and complexity

The ear is an analytical organ meaning that when two different frequencies of sound waves
are mixed we hear both original tones In contrast the eye is a synthetic organ
meaning it can mix different wavelengths to perceive a single color.

Ear Anatomy

Pinna
-called the external ear
Is there a benefit to having a pinna?

The pinna shape allows sound to be funneled into the ear canal

Ear canal
- canal that starts at the ear opening and ends with the tympanic membrane.
- Directs sounds down to the tympanic membrane

Tympanic Membrane
-membrane that vibrates with sounds as they enter ear canal
-better known as eardrum

Middle ear
- consists of open region behind the tympanum
- contains the ossicles

Ossicles
-consists of three bones
-the malleus (hammer), incus (anvil), and stapes (stirrup)
-View fig 7.3

Why 3 bones not two or one?

Inner Ear

Oval window
is a membrane opening in the cochlea where the stapes attaches

Cochlea
-spiral shaped structure of the inner ear that contains auditory transducing mechanisms
-liquid filled
-contain the basilar membrane

Basilar Membrane
-membrane in the cochlea
-contains the organ of corti

Organ of Corti
(contains the auditory hairs, which are the receptive
cells of the auditory apparatus)
-contains auditory nerve

Tectorial membrane
-membrane in which the cilia of the auditory hair cells move

Round Window
-membrane covered window use to regulate pressure
-expands and contracts depending on sound heard

Middle Ear Disease
-ear bone grows over the oval window and causes severe hearing loss
-surgical methods can correct

Cochlear implants
-electronic device surgically implanted in inner ear that can enable some deaf patients to hear

Biology and Behavior 335 Mr. Seegers Notes 6

What is the largest organ in the body?

Skin
-protects body-first layer of defense
-thermoregulation
-certain parts of the body contain skin that:
-produces mucus
-produce hair
-produce smooth thick layers such as the soles on feet

-contains subcutaneous tissue, dermis and epidermis

Glabrous Skin
-smooth skin
-hairless

Pacinian corpuscles
-largest sense organs in skin
-sensitive to touch and high frequency vibration

Sebaceous Glands
-produce sweat

What skin areas of the body contain the most nerves? Why?

Skin can adapt to ignore stimuli? Think of examples?

-it is not the pressure we sense it is the vibration

Skin and the sense of touch helps analyze shapes and textures

Pain
-caused by mechanical stimulation
-most pain causes tissue damage