B. The system of nerves which carries instructions from the CNS to the body's smooth muscles, cardiac muscle and glands.
b.The system of nerves which carries information from the body's receptors
to the CNS.
c. The system of nerves which carries instructions from the CNS to the skeletal muscles.
What are the two main types of cells in the human nervous system?
neurons and neuroglia
Identify the structures pointed of in this diagram of a neuron.
c. cell body
What do dendrites do?
Dendrites carry electrical signals to the cell body.
What do axons do?
Axons carry electrical signals away from the cell body.
What is a synapse?
A synapse is a small gap between the axon of a neuron and the receiving end of another cell.
Explain how a signal crosses from the axon of a neuron to the receiving cells.
When the electrical signal reaches the end of axon, neurotransmitters are released which travel across the synapse. Once they reach the receiving cell, they create a new electrical signal.
What is the function of neuroglia?
neuroglia support the neurons by performing tasks which make it possible for the neurons to do their job.
A nerve runs down the leg, carrying signals to the foot. Is it a part of the PNS or the CNS?
the nerve is part of the PNS
What two Things Protect the brain?
the skull and the cerebrospinal fluid protect the brain.
What is the brain's gray matter composed of?
Gray matter is made up mostly of neuron cell bodies.
What is the brain's white matter composed of?
white matter is made up mostly of the axons of neurons.
What is the function of the corpus callosum?
the corpus callosum allows the two sides of the brain to communicate with one another.
What does the cerebellum primarily control?
the cerebellum is mostly in charge of voluntary muscle movements.
What part of the deals mostly with the higher level thinking skills?
the cerebrum is in charge of most higher level thinking skills.
Do the two sides of the brain do exactly the same things?
they do not.
What side of the PNS does the left side of the brain control?
the left side of the brain controls the right side of the PNS.
What is the blood-brain barrier and why is it so important?
the blood-brain barrier is a system that insulates the brain from the blood. It is important because many of the chemicals in our blood are toxic to brain cells.
What does the sympathetic division of the autonomic nervous system do?
The sympathetic division increases the rate and strength of the heartbeat and raises the blood pressure. It also stimulates the liver to release more glucose in the blood, producing quick energy for the "fight or flight" response that we experience when we are frightened or angry.
What does the parasympathetic
division of the autonomic nervous system do?
The parasympathetic system slows the heart the heart rate and lowers the blood pressure. In addition it takes care of "housekeeping activities such as causing the stomach to churn while its digesting a meal.
What are the four basic tastes that we can detect?
sweet, salty, bitter, sour,
What portion of the tongue is the least sensitive to taste? Why is it so insensitive?
the tongue is least sensitive to taste at the center, because there are few taste buds there.
When we smell something, what are we actually detecting?
When we smell, we are actually detecting chemicals which are in the air.
What is the function of the eye's pupil?
The pupil regulates how much light get into the eye.
What is the function of the eye's lens?
The lens focuses light on the retina.
What is the function of the eye's ciliary muscle?
The ciliary muscle deforms the lens, changing its focus.
What cells of the retina detect light?
the rods and cones detect light.
What causes an eye's blind spot?
Where the optic nerve enters the eye, there are no rods and cones.
Which part of the body has the most nerves related to touch: the fingers or the arm?
What is the function of the ear drum?
The ear drum converts vibrations in the air into vibrations of the ossicles, which moves the cochlea back and fourth.
what is the function of the cochlea?
The cochlea converts the back and fourth motion of the ossicles into electrical signals which can be received by the brain and interpreted as sound.