Download Chapter 35 Directed Reading

Bio. S10
Name _________________________
Chapter 35 Nervous System
35-1
Every cell in the human body is both an independent unit and and interdependent part of a larger
community- the entire ____________________. The organization of the human body enables our cells to work
together. The levels of organization include: cells, tissues, organs, and systems. A __________ is the basic unit
of structure and function in living things. They can be _________________ in multicellular organisms. A group
of cells that perform a single function is called a ________________. There are four basic types of tissue in the
human body: ___________________ (skin, tissue lining internal surfaces, and glands), ___________________
(support for body and connects its parts), ___________________ (transmits nerve impulses), and ___________
(movement). A group of different types of tissues that work together to perform a single function is called an
__________. Our eyes are examples of organs. An organ ________________ is a group of organs that perform
closely related function. Each of the eleven body systems function together to maintain ___________________.
Homeostasis is the process of keeping the internal conditions of the body relatively _________________. (Read
about “feedback inhibition” as it pertains to the heating/cooling of our homes and how it compares to the inner
workings of our bodily heating/cooling system.)
35-2
The ________________ system controls and coordinates functions throughout the body and responds to
internal and external _______________. The nervous system is made up of specialized cells called _________.
These cells carry messages in the form of _________________ signals. Neurons are classified into three types.
________________ neurons carry impulses from the _______________ organs to the ____________ cord and
___________. Neurons that carry impulses from the brain and spinal cord to ________________ and glands are
called _______________ neurons. _____________________ connect sensory and motor neurons and carry
impulses between them. Neurons come in different shapes and sizes, but have certain features in common. A
typical neuron will have a cell ___________, which is the largest part of the neuron and contains the nucleus
and much of the cytoplasm. This is where most of the cell’s metabolic activity occurs. Branching out from the
cell body are short extensions called ___________________, which transmit impulses from the environment or
other neurons ______________ the cell body. The long fiber that extends from the cell body is called the
___________. There is typically only one ________ per neuron, but several _________________. The axon
transmits impulses ____________ from the cell body. At the end of each axon are ___________________
(small swellings). An insulating membrane or _______________ ______________ may surround the axon to
_______________ the speed at which the impulse can travel. This sheath is composed of 80% lipids and 20%
protein. It allows impulses to jump from node to node .
Bio. S10
*Label the diagram on the left using the following terms: cell body, axon, dendrites, axon terminal and
myelin sheath. *Make a drawing of the cell from the microscope set up at the side of the room. Label the
same parts (from) above on your drawing.
The nerve impulse is similar to the flow of electrical current through a metal wire. When a neuron is at
“rest”, the outside of the cell has a net _______________ charge, while the inside has a net ________________
charge. The cell _________________ is electrically charged due to the difference in charge on the outside and
inside. Active __________________ is mostly responsible for this difference. The cell is really not “resting” as
it is constantly producing __________ to fuel active transport.
An impulse begins when a neuron is stimulated by another ______________ or by the _____________.
Once it begins, the impulse travels rapidly down the axon away from the cell body and toward the axon
terminals. ________________ channels open, allowing sodium ions to flow into the cell. This flow of ions
causes the action potential to move and the inside of the membrane to temporarily become more positive than
the outside. At the trailing edge of an action potential, gates in the _________________ channels open,
allowing positive ions to flow_______, restoring the resting potential.
The strength of an impulse is always the same-either there is an impulse in response to a stimulus or
there is not. The minimum level of a stimulus that is required to activate a neuron is called the _____________.
A nerve impulse follows the ________ or ________ principle: either the stimulus will produce an impulse or
not.
When the impulse reaches the axon terminal, it may be passed on to another neuron or other type of cell.
There is a gap between these terminals and the next cell. This gap is called the _______________. Each axon
terminal contains tiny sacs filled with ___________________________, which are chemicals used to transmit
an impulse across a synapse to another cell. These molecules diffuse across the synaptic cleft and attach
themselves to ________________ on the membrane of the neighboring cell causing positive sodium ions to
rush across the cell membrane and stimulating the second cell. The neurotransmitters are then broken down by
enzymes or taken up and recycled by the axon terminal. *Is this adjacent cell always another neuron? ______
Bio. S10
35-3
The human nervous system is separated into two major divisions: ______________ and _____________
nervous systems. The _____________ nervous system (CNS) relays messages, processes information, and
analyzes information and includes the _____________ and the ___________ ___________. The
____________________ nervous system (PNS) receives information from the environment and relays
commands from the CNS to organs and ___________.
Impulses flow to and from the brain. It is made up of several main parts: cerebrum, cerebellum, brain
stem, thalamus, and hypothalamus. The ________________ is the largest and most prominent part of the brain.
It is responsible for voluntary (________________) activities of the body. This is the site of intelligence,
______________, and judgment. Each half of the cerebrum controls the ________________ side of the body.
The cerebellum is the second largest region of the brain and is located at the _________ of the skull.
This portion of the brain is responsible for _____________________ and _________________. The brain and
spinal cord are connected by the __________ __________. This region of the brain regulates information
between the brain and the body. Your blood ________________, heart rate, breathing and _______________
are controlled by the brain stem. The ________________ receives messages from all of the sensory receptors
throughout the body and then relays the information to the proper region of the cerebrum for further processing.
The hypothalamus is the control center for _____________________ and analysis of _____________, thirst,
fatigue, anger and body temperature. It also controls _____________________ of the nervous and endocrine
systems.
The spinal cord is responsible for linking the _____________ with the rest of the body. _____________
or quick automatic responses are processed directly in the spinal cord to speed up your response to danger.
Animals in the wild rely heavily on reflexes.
Remember that the peripheral nervous system lies outside the CNS (brain and spinal cord). The PNS can
be divided into two subdivisions: sensory and motor. The sensory division transmits impulses from __________
organs to the CNS, while the motor division transmits impulses from the CNS to the ______________ or
_____________. The Motor division is further divided into: somatic and autonomic. The ______________
nervous system regulates activities under _____________ control, like movement and/or reflexes. The
autonomic nervous system regulates activities that are automatic or __________________, like heart rate,
sweating.... The autonomic nervous system is subdivided into the _________________ and________________.
These two have opposite effects on the same organ system, which helps to maintain __________________.
Heart rate is increased by the _________________ system, while it is _______________ by the
parasympathetic system.
Bio. S10
*Label the brain with the following terms: cerebrum, cerebellum, brain stem, thalamus, &
hypothalamus.
*Construct a concept map using the following terms: nervous system, central nervous system, peripheral
nervous system, brain, spinal cord, sensory, motor, somatic nervous system autonomic nervous system,
sympathetic and parasympathetic.
*Complete the chart noting the effect of the sympathetic and parasympathetic nervous systems.
Part of Body
Effect of Sympathetic Nervous System
Pupil of Eye
Dilate
Liver
Release ______________
Urinary Bladder
Effect of Parasympathetic Nervous System
None
Contracted
Muscle
Muscle of Heart
Bronchi of Lungs
Increase rate and flow
Constricted
Bio. S10
35-4 The Senses
______________________ receptors are neurons that react directly to stimuli from the environment.
They are located ______________________ the body, but are concentrated in _______________ organs (eyes,
nose, mouth, skin). The five general categories of sensory receptors are: _____________________ receptors,
thermoreceptors, mechanoreceptors, chemoreceptors and ______________________ receptors.
Vision (p. 906-907) *Match the following parts of the eye with its function.
_____ 1. Here photoreceptors convert light energy into nerve impulses.
A. Pupil
_____ 2. Respond to light of different colors, producing color vision.
B. Cornea
_____ 3. Small opening that allows light to enter the eye.
C. Lens
_____ 4. Outer layer of eye that maintains they shape.
D. Retina
_____ 5. In addition to muscles, it helps you focus on near/distant objects.
E. Rods
_____ 6. Extremely sensitive to light; do not distinguish color.
F. Cones
_____ 7. Tough transparent layer of cells.
G. Sclera
Hearing & Balance (p.909) *Fill in the blanks in the following paragraph. You are tracing the pathway of
sound.
As your favorite song begins playing on the radio, the sound coming out of the speakers causes the air to
vibrate. Your ______________ ear collects these vibrations and channels them into the _______________
_______________. The tiny hairs and wax in your ________________ canal prevent foreign objects (which
might interfere with your hearing) from entering your ears. The sound vibrations strike your _______________
and are transmitted to the bones of the middle ear: the ___________________, ___________________, and
_________________. The _______________ then vibrates against the thin membrane covering __________
window, which then transmits the vibrations to the fluid-filled ___________________. As the fluid in your
______________ vibrates, tiny hairs are pushed back and forth, providing stimulation that is turned into nerve
impulses. These nerve impulses are carried to the brain by the _______________ nerves, and you are able to
enjoy your favorite song. When the song is over, you decide to change the radio station. When you get up off
the floor, the fluids and otoliths in the _________________________ canals of your middle ear send impulses
to your brain that help you maintain your balance.
Smell (p.909)
What are chemoreceptors? ___________________________________________________________________
_________________________________________________________________________________________
Bio. S10
Taste (p. 909)
List the 4 types of tastes detected by taste buds:
1. ________________________
3. _____________________________
2. ________________________
4. _____________________________
Touch & Related Senses (p. 909)
The largest sense organ is: __________________________
List type of sensory receptors:
1.______________________
2. ______________________
3. ______________________
The most touch-sensitive areas of the body are found on your:
1.______________________
2. ______________________
3. ______________________