Name: Hour BE ABLE TO LABEL AN EYE

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1 Quarter 2: Quiz 3 STUDY GUIDE The scientific method. Measurement system - - metric Metric 1. The metric system is a decimal system of measurement scaled on multiples of 10. OR BASE TEN 1. Types of measure: LENGTH= Meter VOLUME = Liter MASS = Grams 2. It takes millimeters to equal centimeter. Be able to solve metric conversions. Kilo 1000 Hecto 100 Deca 10 (BASE) Meter Gram Liter 1.0 Deci 0.1 Centi 0.01 Milli What is a cave? A cave or cavern is a natural underground space large enough for a human to enter. Speleology is the science of exploration and study of all aspects of caves and the environment which surrounds the caves. Exploring a cave for recreation or science may be called caving, potholing, or, in Canada and the United States, spelunking. The key is time millions and millions of years of constant dissolving. Cave Uses Types of Wisconsin Caves 5 Types of Caves Cave Geology Conservation Creed Conservation Tips Bats White Nose Syndrome Learning and Memory Methods of Learning Learning The acquisition of new knowledge and skills. There are several types of memory, and each is processed in a different part of the brain. Memory Retention Emotional - - Fear, anger and happiness Sensory - - We use multiple senses when learning When you combine multiple senses, you tend to learn better Questioning Leading Questions: Questions that assume something is true. You assume in a logical way, but it may not be true. You are creating a fictional scenario. Memory Strategies Senses (the more you combine, the better your remember) Verbal- - Hearing the word being said Sight - - Seeing the word and Seeing the object Touch- Feeling the object and Writing the word Association - When something reminds you of something else. Mnemonic (nee MON ic) Using a phrase, word, acronym, or song to help you remember.

2 THE EYE BE ABLE TO LABEL AN EYE Eyes collect light from the environment and focus that light on a light-sensitive structure inside the eye. In order for any object to be visible, it must either produce light or reflect it. Types of light 1. Radiant light: Sun, candle flame, and a lightbulb all produce 2. Reflected light: Moon, candle stick, and people reflect 3. Transmitted light: When light shines THROUGH an object A lens is a clear, curved object that has a different index of refraction than its surrounding medium When light passes through it bends so all of the rays of light come together at one point called the Concave vs. Convex Two Lenses: Photoreceptors 1. After passing the neurons, the light hits a dense layer of photoreceptors. 2. Photoreceptors are the specialized light-sensitive neurons that that convert light energy to electric impulses. There are two types of photoreceptors. 1. Cones (4 characteristics) 2. Rods (3 characteristics) Field of Vision 1. What you can see with both eyes open is your field of vision. Typically, this is degrees from side to side. 1. Up and down, your field of vision is about degrees. 2. Color vision is seen in a visual field of up to for bright colors 3. Fine detail such as that required for reading, can be seen is a narrow field of vision of about 4. Blind Spots occur where blood vessels and the optic disk block light from reaching the photoreceptors. 1. Blind spots are not easily detected because both eyes work together and compensate for blind spots. 2. In addition to the eyes working together, the brain fills in missing details, making blind spots harder to detect. 5. Peripheral vision: Vision to the sides and top/bottom of our visual field. Provides us mostly with contrast and motion information. Parts of the Eye We are not really looking at the object, but instead we are looking at the reflection from the light of the object. 1. Step 1 Light hits your cornea which focuses the image. Together with the Aqueous Humor they create the exterior lens. a. Cornea The curved outer surface of your eye. b. Aqueous Humor- Watery fluid behind the cornea 2. Step 2 Light enters the eye through the pupil of the iris.

3 a. Pupil A small opening that adjusts with the amount of light. b. Iris The wall that covers your lens but is open for your lens. 3. A pupil will adjust to a variety of lights. a. The less light there is, the bigger your pupil. b. The more light there is, the smaller your pupil. 4. Step 3 Once the light passes through the pupil, it becomes more focused at the lens. a. Lens A focuser that lies just behind the pupil. 5. Step 4 Light then passes through the vitreous humor and projects onto the retina. a. Vitreous Humor The jelly that fills the bulk of the eye. b. Retina A delicate tissue filling the back half of the eye which light is reflected upon. 6. Step 5 The retina transforms light into electrical signals which travels to the brain through the optic nerve. a. Optic Nerve a tough white cordlike structure connecting the back of the eye to the brain. Human Eyes 1. Pupils are round. 2. No tapetum in a human eye. 1. Tapetum a second lining that helps you see better in the dark. Cow Eyes 3. Pupils are oval. 4. A blue-green tapetum is present in a cow eye helping it see better at night. 1. This usually reflects light better making their eyes more shiny when light is flashed on them, like a cat eye. Perception How we see things is determined by what we gather through our senses and then push into our brain. We perceive depth because of the following factors: Two eyes or binocular vision. As an object gets closer, our eyes begin to cross as they focus on the object. The brain takes information about the angle of each eye to calculate how far away the object is. Depth, Motion, and Color are all taken in the eyes differently but then combined together in the mind making us see. Illusions Perspective Illusions: Lines that begin to converge (grow closer) tend to look like it is further away. Misconceptions: Perceiving something that does not correspond to what is real. Types of illusions Ambiguous Figures: Two or more different figures in one figure. Unstable Figures: Different parts of a figure appear to be closer to the viewer. Figure-Ground Illusions: Difficult to distinguish figures from their background. Illusory Figure: Seeing something that is not there. Opposite color images after staring and looking away. Impossible Figures: Logical, but impossible to manufacture in three dimensions. Shape, Size & Length Distortion: Shape, size, or length distortion is due to field interference. Perceptual Set: Perceptions influenced by expectations. Word Perceptions: Words in a nonphonetic languages are subject to some form of distortion.

4 Orientation Illusion: Totally different images are seen when viewing one picture from a different angle or distance. From the Eyes to the Brain Once the optical system projects an image on the retina, a series of electrochemical interactions begins. The photoreceptors (cones and rods) transform the image (light energy) into electric messages. These messages are transmitted through neurons (nerve cells). The neurons converge at the optic disk where the optic nerve (a thick bundle of nerves) is connected to the eye. Both optic nerves extend into the skull and join at a point called the optic chiasm. The optical nerves continue to the back of the brain. Processing of the images begin in the lateral geniculate nucleus (LGN) Images from both eyes are processed together to form a complete image. How we view the Brain Types of Brain scans: Computerized axial tomography (CAT) produced with a computerized x-ray device. Magnetic resonance imaging (MRI)- As a person is slid into a tunnel-shaped scanner, a magnetic field surrounds them. Radio waves are beamed to the area. Electroencephalography (EEG)- measures electric activity in the brain by attaching electrodes to a patient s head. Positron emission tomography (PET) Low-dose radioactive isotope is detected by injecting a substance into the patient. This substance is detected in the brain by the scanner. Parts of the Brain Cerebrum: The large wrinkled portion that makes up most of the brain. Has two halves or hemispheres Left and Right These two halves look symmetrical and communicate with each other. Organized into four major lobes Frontal: behind the forehead. Temporal: Along the side in from the ear. Occipital: In the back. Parietal: On the top Cerebellum: underneath the cerebrum, this smaller part of the brain is found in the center of the brain. Brain stem: An extension of the spinal cord. It is found in front of the cerebellum and below the cerebrum. Brainstem: Oldest part of brain, Basic Functions Medulla: Controls heartbeat and breathing, Close your eyes and be quiet Pons: Coordinates movement Thalamus: The Hub, Receives information from all senses (except smell) and sends it to different lobes of the brain Cerebrum Corpus Callosum: Connects Left and Right hemispheres Lobes Occipital- vision and how you interpret what you see Parietal- sensory input for touch and body position Temporal- auditory areas Frontal- speaking, muscle movement, planning, and judgment Phineas Gage Sensory and Motor Cortex Cerebellum: Coordinates voluntary movement, Happens without conscious effort Hypothalamus- hunger, thirst, temperature Amygdala- aggression and fear Hippocampus- memory

5 Neurons Central Nervous System: What is a Neuron? Neuron Communication Neurons send electric messages Which is faster, a message traveling through neurons or electricity through wires? Numbers... Sensory neurons = a few million Motor neurons = a few million Neurons in your brain = 100,000,000,000! Vocabulary Dendrites cell body axon terminal fibers neurotransmitters receptors dendrites cell body axon Drugs and the Nervous System Heroine- floods system with opiates we stop producing them naturally endorphins runner s high Cocaine- blocks re-uptake of dopamine and serotonin Pain Medicine (Tylenol, Advil)- blocks receptor