chapter 9 Flashcards
what part of the body is part of the central nervous system
the brain and spinal cord only!!!
This part of the nervous system is responsible for transmitting to the brain input from the somatic and special sensory receptors and somatic sensory neurons, touch pressure temperature etc… it is voluntary and the brains response is through the somatic motor neurons that send messages to the skeletal muscles.
SNS Somatic Nervous System
This part of the nervous system is responsible for transmitting to the brain input from the autonomic sensory receptors and autonomic (automatic) sensory neurons (internal organs, blood vessels, and glands) such as fluctuations in blood pressure, oxygen, etc… it is non-voluntary and the brains response is to the autonomic motor neurons sympathetic and parasympathetic (internal organs, blood vessels, and glands) divisions send messages to smooth muscle, cardiac muscle, and glands.
ANS Autonomic Nervous System
This part of the nervous system gets no direct output from the CNS It is mostly it’s own system in which the enteric sensory receptors and enteric sensory neurons in the GI tract and enteric plexuses send messages to the brain and to the enteric motor neurons in the enteric plexuses which in turn send messages to the smooth muscles, glands, and endocrine cells of the GI tract all involuntarily - it also receives some input from the ANS.
ENS - Enteric Nervous System
The SNS, ANS, and ENS are all part of what nervous system?
the PNS - Peripheral Nervous System - which controls all nervous tissue outside the CNS
what are the three functions of the nervous system?
sensation
integration
motor function - effectors
detecting internal and external stimuli and transmitting information to the CNS such as touch a hot pan or a rise in blood pressure falls under what function of the nervous system
sensation
this function of the nervous system analyses sensory information and makes decisions for appropriate responses
integration
this function of the nervous system is carried out when effectors are activated by nerves to contract a muscle or activate a gland
motor function
the main cell of the nervous system
neuron
arms coming off of the neuron that receive action potentials from other neurons
dendrites
signals come into this part of the neuron
the cell body
longer extension or arm (usually only one) that transmits signals away from the cell body
axon
the ends of an axon release chemical signals called ______ that tell the next cell what it should do
neurotransmitters
this classification of neurons carries information toward the CNS; each one is connected to specialized receptors which each detect a different kind of stimulus
sensory neuron
This classification of neurons carries information away from the CNS, going towards a receptor, synapses with a muscle or a gland
motor neuron
This classification of neurons is located between sensory and motor neurons and are found only in the CNS.
Interneurons
what are the three classifications of neurons
sensory
motor
interneurons
these special cells in the CNS help neurons communicate effectively
neuroglial cells
what are the five types of neuroglial cells (another monkey eats olives)
astrocytes
microglia
ependymal cells
oligodendrocytes
these neuroglial cells support neurons and maintain proper chemical environment
astrocytes
these neuroglial cells are immune cells
microglia
these neuroglial cells produce and circulate cerebrospinal fluid (csf) - line cavities in the brain
ependymal cells
these neuroglial cells produce myelin sheath in CNS
oligodendrocytes
these neuroglial cells produce myelin sheath in PNS
Schwann cells
This insulating outer layer is created by Schwann cells (PNS) and oligodendrocytes (CNS) and allows action potential to “jump” quickly down the axon - wraps around the axon and makes communication from the brain move faster
myelin sheath
the gaps in the myelin sheath that the action potential jumps between down the axon
nodes of ranvier
produces myelin sheath in CNS by processes of one cell producing myelin sheath on many axons
oligodendrocytes
produces myelin sheath in PNS by one cell wraps around the axon many times
Schwann cells
this nervous tissue is composed mostly of cell bodies and also axons with no myelin (myelin is white)
grey matter
this nervous tissue is composed mostly of myelinated axons
white matter
neurons communicate with each other and the body’s other components through electrical impulses used to communicate from one cell to the next - called ?
action potentials
during the action potential what happens to the charge on the inside and the outside of the axon?
it flips
what is the charge in a resting neuron
the inside is negative and the outside is positive so no signal is being transmitted at this time
what is the unequal distribution of charges on the inside and outside of the cell called
polarized
what is used to create the flip in the charge of the neuron?
two very important ions:
sodium Na+ and potassium K+
describe the 4 steps involved in the action potential
1) THRESHOLD is met - there is a minimum amount of stimulus that must be met to cause the reaction - the stimulus must be strong enough to cause a response in the neuron. once this happens there is no going back it is all or nothing.
2) DEPOLARIZATION - the inside of the cell becomes more positive which is caused by the flow of sodium (NA+) ions into the cell.
3) REPOLARIZATION - the inside of the cell returns towards the original state which is caused by the flow of potassium (K+) ions out of the cell.
4) HYPERPOLARIZATION - the cell becomes too negative and no action potentials can be generated this is intentional so that the flow of the action potential continues forward along the axon and does not move backwards.
there is a minimum amount of stimulus that must be met to cause the reaction - the stimulus must be strong enough to cause a response in the neuron. once this happens there is no going back it is all or nothing.
Threshold is met
the inside of the cell becomes more positive which is caused by the flow of sodium (NA+) ions into the cell
depolarization
the inside of the cell returns towards the original state which is caused by the flow of potassium (K+) ions out of the cell.
repolarization
the cell becomes too negative and no action potentials can be generated this is intentional so that the flow of the action potential continues forward along the axon and does not move backwards.
hyperpolarization
which ion is used during depolarization, and what does it do
sodium (NA+) flows into the cell
which ion is used during repolarization
potassium (K+) flows out of the cell
what are the labels on the x and y axis of the diagram for action potential
x - membrane potential in millivolts
y - time in milliseconds
what is the name for the connection between the neuron and the adjacent cell (effector or another neuron)
synapse
This requires the release of a specific chemical, a neurotransmitter
synaptic transmission
what are the two actions that a synaptic transmission can cause
excite or inhibit the neuron or effector
a tiny space filled with interstitial fluid, that separates the plasma membrane of the presynaptic and postsynaptic neurons.
synaptic cleft
why do neurotransmitters need to be removed from the synaptic cleft?
If the NT is not removed the membrane will be continuously inhibited or excited, without stopping.
what are the three ways for a neurotransmitter to be removed from the synaptic cleft?
1) diffuses away
2) Enzymes can make the NT inactive
3) the NT can be pumped back into the axon.
name the five neurotransmitters. (a girl needs dresses, shoes)
acetylcholine GABA Norepinephrine Dopamine Serotonin
this neurotransmitter is used to initiate muscle contractions
acetylcholine
this neurotransmitter has an inhibitory effect on CNS
GABA
this neurotransmitter causes the fight or flight response )increased heart rate, etc.)
Norepinephrine
this neurotransmitter plays a role in dreaming
Norepinephrine
this neurotransmitter is active during pleasurable experiences, and during addictive behaviors.
Dopamine
this neurotransmitter is involved in complex movements like walking
Dopamine
this neurotransmitter is responsible for feelings of happiness, and decreases appetite
Serotonin
a decrease in this neurotransmitter is linked to depression
Serotonin
an increase in this neurotransmitter plays a role in a type of schizophrenia
Dopamine
a disorder that results in the death of dopamine - releasing neurons which leads to a drop in dopamine levels
Parkinson’s disease
what are the symptoms associated with Parkinson’s disease?
- resting tremors (involuntary muscle contractions)
- slow movement
- shuffling gait
What is the treatment for Parkinson’s disease?
Treated with drugs that turn into dopamine, or inhibits an enzyme that breaks down dopamine.
releases neurotransmitters
axonal terminal
conducts electrical currents towards the cell body
dendrite
increases the speed of impulse transmission
myelin sheath
location of the nucleus
cell body
generally, conducts the impulses away from the cell body
axon
helps provide nutrients to neurons
astrocyte
protects the CNS from disease through phagocytosis
Microglial cell
produces myelin sheath around an axon of a PNS neuron
Schwann cell
Produces myelin sheath around an axon of CNS neuron
oligodendrocyte
forms cerebrospinal fluid
ependymal cell
The plasma membrane of a neuron at rest is ______, meaning that there are fewer positive ions sitting on the inner face of the ell than there are on the outside of the cell.
polarized
In the first part of the nerve impulse, the ______ ion moves to the inside of the neuron, this event is known as _____.
sodium
depolarization
As a nerve impulse passes through an axon, the charge inside of the cell changes from ______ to ______.
negative to positive
After a nerve impulse passes through an axon the cell regains the resting potential by pumping _____ out of the cell. This event is known as ________.
potassium
repolarization
The junction between one neuron and another s called a _____.
synapse
When the action potential reaches the end of a neuron a ________ is required to move the potential on to the next neuron.
neurotransmitter
The central nervous system contains the _____ and ______.
brain and spinal cord
Cells that conduct messages toward the CNS are known as _______ neurons and cells that conduct messages from the CNS are known as ______ neurons.
sensory
motor
The muscle that is stimulated by a neuron is known as the _____.
effector
Which type of neuron performs integration?
a - interneuron
b - All of these can perform integration
c - sensory neuron
d - motor neuron
b - All of these can perform integration
At the height of an action potential, the inside of the neuron is \_\_\_\_\_ and the outside is \_\_\_\_\_\_\_. a - positive, positive b - negative, positive c - positive, negative d - negative, negative
c - positive, negative
All of the following are functions of the nervous system EXCEPT a - senses changes. b - stores potassium. c - integrates impulses. d - responses to changes. e - analyzes changes.
b - stores potassium.
The portion of the nervous system that is considered involuntary is the a - peripheral nervous system. b - somatic nervous system. c - central nervous system. d - motor nervous system. e - autonomic nervous system.
e - autonomic nervous system.
Neurons that conduct nerve impulses from the receptors to the central nervous system are \_\_\_\_\_\_\_ neurons. a - motor neurons b - integrating neuron c - sensory neurons d - efferent neurons
c - sensory neurons
Which division of the nervous system sends impulses to smooth muscles, cardiac muscle, and glands? a - Enteric Nervous System b - Autonomic Nervous System c - Somatic Nervous System d - Central Nervous System
b - Autonomic Nervous System
How are neurotransmitters removed so as not to cause continuous signaling?
a - active transport back into the neuron
b - diffusion
c - All of the above
d - enzymatic destruction
c - All of the above
Which is not true of neurotransmitters? a - They are released at the synaptic cleft b - They can trigger action potentials c - They are always excitatory d - They are small chemical signals
c - They are always excitatory
Trace the neuron pathway that is followed when you touch a sharp object with your finger then pull your finger away.
a - sensory neuron, motor neuron, interneuron
b - sensory neuron, interneuron, motor neuron
c - motor neuron, sensory neuron, interneuron
d - motor neuron, interneuron, sensory neuron
b - sensory neuron, interneuron, motor neuron
Which portion of the neuron releases neurotransmitters?
a - node of Ranvier
b - cell body
c - dendrite
d - axon
d - axon
Blocking which of the following neurotransmitters would most likely cause a decrease in heart rate?
a - serotonin
b - acetylcholine
c - norepinephrine
d - dopamine
c - norepinephrine
