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Health & Nutrition
Apologia-Module 5: Your Senses
Question | Answer |
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Natural Eye Defense | The bones of the orbit are dense and unlikely to break, and the eye is cushioned from contact with the orbit by fat, tear glands, and connective tissue. |
conjunctiva (structure in the eye) | pink eye (infection of the conjunctiva) Also called conjunctivitis |
cornea (structure in the eye) | abrasion (the most common eye injury)-a scratch on the outside layer of the cornea |
eyelid (structure in the eye) | stye (eye infection)-this is a pimple, a bacterial infection of a sebaceous (oil) gland near the edge of an eyelid |
lens (structure in the eye) | cataract (condition)-due to long-term exposure to UV light-it is a condition of cloudiness in the lens that makes clear vision difficult |
retina (structure in the eye) | macular degeneration (condition)-the deterioration of the macula MACULA (definition): the reddish-brown area in the middle of the retina |
vitreous humor (structure in the eye) | floaters (condition)-harmless strings of protein floating in the vitreous humor |
What is true about a normal retina? | 1. It is richly supplied with blood vessels. 2. It has a blind spot (the optic disk). 3. It contains millions of photoreceptor cells. |
snow blindness | As UV light bounces off sand, water, or snow, it can sunburn corneas and conjunctivae. This "sunburn" is called snow blindness (or photokeratitis). |
night blindness | Cannot see in low light due to not enough photo pigment |
color blindness | An inability or decreased ability to distinguish between colors typically due to underdevelopment before birth of one of the types of cones-a genetic malformation. |
a blind spot | optic disk-found here-a natural blind spot on the retina |
What do you do if you suspect a foreign body in the eye (on the cornea)? | foreign body: an object sticking to or embedded in the surface of the eye or the inside of the eyelid (1) Grasp the eyelashes of the upper eyelid, and gently lift the eyelid away from the cornea and over the eyelashes of the bottom lid. (2) Fight wincing and examine the eye's surface for any object. If you find something, try to remove it with a dry corner of a clean tissue. (3) Flush out the eye with lots of saline or water to try to dislodge the foreign body. |
Hyperopia (farsightedness): | You will see distant objects clearly but have difficulty focusing on objects nearby. Reading glasses might bring relief. |
Myopia (nearsightedness) | You will see nearby objects clearly but have difficulty focusing on objects more than 20 feet away. They are blurry. |
Amblyopia (lazy eye) | A condition in which one eye is used in preference to the other, perhaps because the focus is better in the stronger eye. |
Study Figure 5.13, pg. 124 in the textbook. Sound Waves | Sound Wave #2: high amplitude and a little faster in frequency, which means its sound would be louder and higher in pitch. Sound Wave #3: lower amplitude and higher frequency than Sound Wave #2, which means that the sound would be softer in volume but higher in pitch than the sound of Sound Wave #2 |
How do we hear the sound waves? There are many structures that vibrate. Here's the order of how the sound travels through each structure of the ear: | (1) eardrum (2) auditory ossicles (3) oval window (4) fluid in the cochlea (5) fibers and hair cells in the spiral organ |
Damage to Hearing: sensorineural hearing loss | Permanent hearing loss due to the hair cells (the sensory receptor) being damaged. This damage can happen in many ways: (1) loud noise by one very loud blast or by repeated exposure to loud noise (above 90 dB) (2) head injury in an auto accident (3) lifesaving medications or antibiotics (4) aging (5) genetic tendency toward hearing loss |
Temporary Hearing Loss: conductive hearing loss due to (flip card) | (1)eardrum rupture (once) (2) fluid in the middle ear (3) excessive wax in the ear canal |
bony labyrinth contains the following structures within the inner ear: | semicircular canals & the vestibule: these organs deal with balance cochlea (snail shell shape): responsible for hearing vestibule: where we find the oval window & the round window |
When is it important to wear hearing protection? | If you know you will be around something louder than a vacuum cleaner (70 dB) or a blender (80 dB) such as a power mower or motorcycle (both 90 dB), shooting range, or live music concert (110 dB), you need to wear earplugs, earmuffs, or both. |
vestibular system | is made up of the vestibule and the semicircular canals These sensory organs are responsible for sensing head position and head movement, essential to our ability to maintain balance. This alerts you to your head's orientation with respect to gravity. |
How should you effectively deal with motion sickness? | in a car: focus on a distant object down the road ahead in a boat: move to where you can see the horizon and visually process the motion of the boat in an airplane: look outside the window You can always close your eyes and try to sleep. Motion sickness is caused by conflict between your vestibular system and your vision. Closing your eyes takes vision out of the conflict. |
The Senses of Touch: Your skin There are different cutaneous receptors on our skin, but they are not evenly distributed. | Pain receptors respond to excess stimulation, including crushing, poking, and extreme temperature. These receptors adapt very slowly. |
Equilibrioception: the body's ability to PHYSICALLY BALANCE in space and not fall over when moving, standing, or sitting. Balancing is a skill that can be developed or lost. It is not really a separate sense, but rather it relies on several senses working together. The following are needed to keep balance-- (FLIP CARD) | (1) Vestibular System: keeps you apprised of head position and movement-it lets you know when your head is level, when it's moving, or when it's starting to lean dangerously to one side. (2) Posture: the head leads, and its position defines posture, the position of the rest of the body (3) Proprioception: the sense of knowing where each limb is (4) Balance is dependent upon vision and aided by sensory receptors for touch. |
frostbite | damage to bodily extremities due to cold |
heat stroke | illness with high body temperature (105 degrees Fahrenheit) |
hypothermia | illness with low body temperature (95 degrees Fahrenheit) |
vasoconstriction | narrowing action of blood vessels to conserve body heat |
hypothalamus | part of the brain controlling body temperature |
shivering | reflexive and quick contractions and relaxations of skeletal muscles to generate body heat |
papillae (on the tongue)- little projections, like tufts in a carpet. These are not taste buds but folded mucosa, which greatly increases the surface area of the tongue. Papillae make it easier for the tongue to moisten food and manipulate it into a bolus (a soft wad) which can be swallowed. (FLIP CARD) | Papillae does not need to be present for the sense of taste to function. |
You eat a hot pepper. Your mouth is on fire! What do you do? | You need something that will absorb or dissolve the waxy oil (capsaicin) found in the white membranes of the chili pepper. Fatty dairy products work well such as milk, yogurt, cheese, butter, sour cream, or ice cream. Also, bread or rice can absorb the oil. |
What is needed for you to smell something? | (1) olfactory epithelium: this is responsible for the sense of smell (2) chemoreceptors: much like the receptors in the taste buds--they bind to the molecules of odorant (any substance that you can smell). (3) substances that can dissolve in air (4) substances that can dissolve in mucus |
natural gas and propane are odorless (fuels used for heating & cooking in homes) Why do gas companies add a "bad breath" smell to them? | To make their customers aware of leaking gas within their home |
What do you do when you are aware that the building you are in is on fire? | Get yourself and other people out immediately! DO NOT WAIT for firefighters to arrive or try to save any of your possessions. |
What do you do if you wake up in the middle of the night and smell smoke, but the smoke detector isn't alarming? | Turn on the lights, walk through the house, and look for smoke. |
What do you do if your only escape from a house fire is through a smoky corridor? | Get on your hands and knees and crawl under the smoke to get out of the house. |
THE 7 TRUTHS ABOUT ELECTRICITY (pgs. 142-144) | (1) Electricity coming into your home is very dangerous. (2) Have respect for power cords and their plugs. Never pick up an appliance by its power cord or unplug an appliance by pulling on the cord. The stress weakens the wires in the cord and damages the cord's insulation. (3) Any damaged or frayed power cord with bare wires can spark and start a fire. |
THE 7 TRUTHS ABOUT ELECTRICITY (cont.) | (4) When doing house remodeling projects, make it a habit to shut off the electricity for the room you are working in whenever you install fixtures, cut into a wall, or even pound a nail into a wall. You need to know exactly where the house wires run. (5) Water conducts electricity! Never let a power cord or an extension cord for yard equipment run through a puddle of water. |
THE 7 TRUTHS ABOUT ELECTRICITY (cont.) | (6) Ground Fault Circuit Interrupter (GFCI): It is an electric outlet that detects when a short circuit happens and interrupts that electric circuit in a fraction of a second. It has saved many lives! (7) A human body can conduct (carry) electricity and become part of an electric circuit. Electricity will take the easiest route to reach the ground even if it means traveling through a person. |