Science 14 Flashcards
(19 cards)
What are the organs of the central nervous system? What are the divisions of the peripheral nervous system?
The brain and the spinal cord make up the central nervous system, while the peripheral nervous system is composed of the sensory division and the motor division.
What are the three main parts of the brain and what are their major functions?
The cerebrum receives sensory information, interprets that information, and determines the response, if necessary. The cerebellum controls subconscious motor functions, muscle sequencing, and muscle preset. The brain stem controls vital functions.
What makes up the gray matter in the brain? What about the white matter?
Gray matter contains neuron cell bodies, while white matter is made up of neuron axons.
What side of the brain controls the motor function of the right hand?
The left side of the brain controls the motor function of the right hand.
List the parts of the body that tend to be dominated by one hemisphere of the brain.
The hands, legs, eyes, and ears.
While the brain sends most of the commands down the motor division of the peripheral nervous system, which kinds of commands are sent directly from the spinal cord?
The spinal cord issues reflex commands.
The images in your eye appear upside down. Why don’t you see the world upside down?
When you are an infant, your other senses allow you to understand the actual direction of objects, and your brain gets trained to flip the images so that you see the world properly.
Where does the lens focus the light coming from the objects you are looking at?
The images are focused on your retina.
How does the lens change the way it is focusing light?
It changes its shape.
What is the name of the tissue that holds the neurons that are sensitive to smell?
The olfactory epithelium contains the neurons sensitive to smell.
If something has no scent, what can you conclude about the chemicals it releases into the air?
The neurons in the olfactory epithelium cannot interact with them.
What structures hold gustatory cells? Where are these structures found?
Gustatory cells and found in taste buds, which are found on the tongue.
Your sense of taste mixes five basic sensations together to make all the flavors you taste. What are those five basic sensations?
The sensations that make up all flavors are sweet, salty, bitter, sour, and umami.
What other special sense does your sense of taste depend on?
Your sense of taste also depends on your sense of smell.
What two senses are controlled by the ear?
The sense of hearing and balance both come from the ear.
Explain what happens to the tympanic membrane, the ossicles, and the liquid in the cochlea when sound enters the external ear. How does that lead to the sense of hearing?
When sound waves enter the external ear, they cause the tympanic membrane to vibrate. That causes the ossicles to rock, which causes the fluid in the cochlea to vibrate. Nervous tissue in the cochlea senses those vibrations and sends signals to the brain, which interprets them as sound.
What two structures provide the sense of balance? Which tells the brain how the head is moving, and which tells the brain about the position of the head, even when it is not moving.
The semicircular canals provide information about how the head is moving, while the vestibule provides information about the position of the head, even when it is not moving.
Compare signal speeding in the nervous and endocrine systems as well as how long the effect lasts.
Signals from the nervous system are faster and do not last as long.
What two things are necessary for a cell to be able to respond to an endocrine system signal?
There must be a hormone that sends the signal and a receptor on the cell that the hormones can bind to.
