Nervous System Senses (Eye, Ear, Skin, Nose, Tongue)
Where is the sclera and what does it do?
Outer layer, white part of eye at the back of the eye
Serves to shape & protect the eye
Where is the cornea and what does it do?
Outer layer, front part of the sclera
Dome shaped membrane protecting the eye
Where is the choroid and what does it do?
Middle layer, back part of the eye
Nourishes the eye with its blood vessels
Where is the iris and what does it do?
Middle layer, front part of the eye
Colored part of the eye
Where is the pupil and what does it do?
Middle layer, front part of the eye
Black part, hole in the eye that controls how much light enters the eye
Where is the retina and what does it do?
Inner layer, back part of the eye
Loaded with photosensitive cells that absorb light and transform it into nerve signals
Where is the lens and what does it do?
Inner layer, front part of the eye
Focuses light onto the back of the retina so that you can see objects in focus
What is the sensory receptor of the eye?
The retina
Where is aqueous humour located and what does it do?
Between the cornea and the lens
Allows pupil & iris to move
Where is the vitreous humour and what does it do?
In the middle of the eyeball
Hydrates the eye
Where is the pinna and what does it do?
Outer ear
Dome-shaped structure that captures sound waves
Where is the auditory canal and what does it do?
Outer ear
Tube that carries vibrations from pinna to the tympanic membrane. It has hairs & sebaceous glands that make wax to prevent foreign substances from entering the ear
Where is the tympanic membrane and what does it do?
Middle ear
Fibrous membrane that vibrates to the rhythm of the sound waves
Where are the ossicles, what do they do and what are their names?
Middle ear
3 miniature bones found inside the temporal bone
Hammer, anvil, stirrup
Where is the eustachian tube and what does it do?
Middle ear
Connects the middle ear to the pharynx in order to equalize pressure in the head
Where are the semicircular canals and what do they do?
Inner ear
Liquid filled labyrinth in the temporal bone. They regulate balance of the body and are linked to the vestibular nerve
Where is the vestibule and what does it do?
Inner ear
Liquid filled structure linking the semicircular canals to the cochlea
Where is the cochlea and what does it do?
Inner ear
Liquid filled structure, connected to auditory nerve cells which connects to the auditory nerve
What part of the brain analyes sound from the auditory nerve?
Cerebrum
What part of the brain controls balance from the vestibular nerve?
Cerebellum
What is the sensory receptor for sound
Cochlea
What is the sensory receptor for balance
Semicircular canals
What are the 5 flavors analyzed by the tongue
Sweet, sour, salty, bitter, umami
What 3-5 other things the tongue can sense
Hot/cold
Discomfort/spicy
Texture
Where does most of taste come from?
75-95% of taste comes from nose, through smell
What is the papilla for?
Protection and absorbsion
What nerves go from the taste buds to the brain?
3 cranial nerves
Why can infections hinder smell and taste?
They bind receptors on the olfactory bulb and papillae
About how many cells does the olfactory bulb have?
~15 million
What is the sensory receptor for the tongue?
Taste buds
Characteristics of epidermis (3)
Outermost layer of skin
Living and dead layers
Where cells reproduce
Characteristics of dermis (3)
Middle layer
Where most things happen
Defines skin type
What are the 4 things in the dermis?
Sweat glands
Sebaceous glands (attatched to hair follicles)
Hair follicles
Blood vessels (deepest)
Characteristics of hypodermis (3)
Lowest skin layer
Mostly fat
For insulation
What are the 3 functions of skin?
Protection of inside organs
Elimination of waste through sweating
Production of vitamin D
Where are the sensory receptors of the skin?
The dermis
What are the 6 steps for smelling
1. Odorant enters nose through nostril
2. Enters nasal passage (sinuses)
3. Odorant is grabbed by olfactory cilia
4. Olfactory cilia gives the odorant to olfactory epithelium
5. Olfactory epithelium analyzes odorant & passes info to olfactory bulb
6. Olfactory bulb converts sensory stimulus into a nervous signal and sends the signal to the brain via the olfactory nerve
What is the sensory receptor for the nose
Olfactory epithelium