239 terms

A&P 1 Ch. 11 Nervous system and tissues

Study guide for Ch. 11
What are the three Nervous System functions?
Sensory input - gathering information
Integration - process and interpret sensory input
Motor input - response to stimuli
T/F Motor input is a Nervous Sytem function?
What is integration?
processing and interpreting sensory input.
The Nervous sytem gathers information through what process?
Sensory input
What are the two sturctural classifications of the Nervous System?
Central Nervous System
Peripheral Nervous System
The Central Nervous system occupies what body cavity?
Dorsal body cavity
T/F the Central nervous system is not the command center of the entire Nervous system?
False - it is the command center
T/F the Central nervous system includes the Brain and Spinal cord?
T/F The Peripheral Nervous system is outside ofthe Central Nervous system?
How many functions does the Peripheral nervous system have?
Two -
Afferent Division- towards the Central nerovus system
Efferent- away from the Central nervous system
What is the man function of the Afferent Division of the Peripheral nervous system?
collection of sensory input from sensory receptors and sending input to the Central nervous system
The Afferent division of the PNS is also called the ______?
Sensory division
The Efferent division of the PNS is the ______ division.
What is the Main function of the Efferent division of the PNS?
Activates muscles and glands
carry impulses to effector organs
T/F the Efferent division transmits from the CNS to effector muscles?
What are the two main parts of the Effector division?
Somatic Nervous System
Autonomic Nervous System
How many parts does the Effector Division of the PNS have?
T/F The Somatic nervous system is part of the Afferent division?
False - it is part of the Efferent division
T/F the Somatic Nervous system sends impulses to the involuntary muscles?
False - it sends impulses to the skeletal muscles - the voluntary nervous system
What group of muscle does the Somatic Nervous system send impulses to?
Skeletal muscles
What muscle group does the Autonomic Nervous sysyem send inpules to?
Glands, Visceral organs, and Cardiac Muscles
What type of nervous system is the Autonomic nervous system?
Involuntary nervous system
What are the two types of Nervuos tissue?
T/F Neurons are Highly cellular?
What is the main purpose of Neurons?
Conduct nerve impulses
T/F Neurons are not excitable?
False - They are excitable
T/F Neurogila are supporting cells?
What is the main function of Neurogila cells?
Support, protect and insulate
Which cells are smaller?
Neurons or Neurogila?
T/F Neurons outnumber Neugila cells by 10 to 1?
False- Neurogila outnumber neurons
What are the six Gila cell types?
T/F Astrocytes are the most abundant Neurogila cell
Name the functions of Astrocytes.
Help form neuron connections
process local environment
anchor to nutrient site
T/F Astrocytes are not very versetile?
Microgila are the _____ of the CNS?
Microphage/ Defensive cells
T/F Microgila are the microphage of the PNS?
False - the CNS
Ependymal cells line ____ filled cavities in the CNS?
T/F Ependymal cells produce Cilla?
One of the functions of the Ependymal cells is to mix cerebral ____ ____?
Spinal fluid
Oligodendrocytes wrap tightly around_____?
What type of sheaths do Oligodendrocytes form in the CNS?
T/F Astrocytes wrap around neurons?
False- Oligodendrocytes
What is the main function of Satellite cells?
Cushioning and protection
T/F Satellite cells surround cell bodies in the CNS?
False - the PNS
Satellite cells surround cell ___ in the PNS.
_____ cells wrap tightly around neuron axons in the PNS.
T/F Schwann cells wrpa around axons only once to form myelin sheaths?
False - Mnay times
Schwann cells form ____ sheaths.
____ are the structural unit of the nervous system?
T/F Neurons are highly specialized cells?
Neurons conduct messages in the form of _____ _____ to differnt parts of the body.
Nerve impulses
T/F neurons only send impulses to the Brain?
False- many differnt parts of the body
What are the three characteristics of neurons?
extreme longevity
amitotic - lost ability to divide
high metabolic rate
T/F neurons high metabolic rate requires lots of oxygen and glucose?
T/F nuerons die quickly and do not live very long?
False - they live as long as we do.
What are the six parts of a neuron structure?
Cells Body
Axon Hillock
Axon Terminals
Myelin Sheath
Label the parts of the neuron structure
T/F Most neuron cell bodies are locates in the PNS?
False - CNS
T/F the rough endoplasmic reticulum of the cells bodies are call Nissl bodies?
Cell bodies are also called?
Soma or Perikaryon
Cell bodies have? Three things...
Large neucleus
Neurofibrils in cell bodies _____? function
Maintain shape and integrity
T/F Dendrites have organelles?
What is the function of Dendrites?
Conduct impulses to cell bodies through graded potential
T/F Dendrites are located in the receptive or input region?
Short highly branched process of the neuron are called _____.
T/F Dendrites use Graded Potential?
The long proces of the neuron is called the _____?
T/F the axon can be up to 10ft. long?
False - 3 to 4 feet long
The axon transmits signal _____ from the cell body?
T/F the axon makes up most of the length of the neuron?
Branches off the main axon are called ____?
Axon Collaterals
T/F Axons will not greatly branch at the terminal end?
False- will greatly branch
The connection point between the cell body and the axon is called ____?
Axon Hillock
T/F The axon Hillock is branched?
Where is the connection point btween the cell body and the axon located?
Axon Hillock
The axon terminal is at the ____ tip of the axon?
The main function of the axon terminal is to? two things
hold and release neurontransmitter
T/F axon terminals will connect to other neurons at snapses?
T/F axon terminals are connected to the dendrites?
False - distal tip of the axon
Fatty segments layered around the axon are called?
Myelin Sheaths
T/F Myelin sheaths are pink or red in color?
False - they appear white
myelin sheaths are elecric insulators which make impulses conduct? (Faster/Slower)
T/F Myelin sheaths are made the same way in both the PNS and CNS?
False -Schwann cells in the PNS Oligodendrocytes in CNS
T/F Schwann cells can wap around axons up to 200 times?
What are the gaps between myelin sheaths called?
Nodes of Ranvier
T/F In the CNS the gaps between myelin sheaths are called Oligodendrocytes?
T/F Nervous tissue that looks whote to the naked eye is called gray matter?
False - White matter
What are myelinated nervous fibers called?
White matter
Unmyelinated fibers and cell bodies are called_____?
Gray matter
T/F Gray matter is nervous tissue that looks gray to the naked eye?
A nucleus can be defined as?
a group of neuron cell bodies in the CNS
What is a group neuron cell bodies in the CNS called?
What is a group of cell bodies in the PNS called?
T/F a Ganglion is a group of cell bodies in the CNS?
False- PNS
What is a bundle of neuron extensions in the CNS called?
Where is a bundle of neuron extension in the CNS usually found?
T/F A tract is group of cell bodies in the CNS?
False - neuron extensions
What is a bundle of neuron extension in the PNS called?
A nerve is made up of mostly _____.
What is the function of Interneurons?
Connect sensory and motor neurons
T/F Interneurons connect to the CNS?
False do not connect to or from the CNS
Where are interneurons found?
T/F interneurons are not very common?
False - very common
Where is the charge transfered from in man-made electricity?
T/F electrons transfer electricity in the human body?
False - man-made electricity
Charged particles are called ______ in the human body?
How is electricity transfered in the body?
With ions
What are the four charged ions that transfer electricity in the human body?
What is voltage?
the measure of the potential energy of separated charges
T/F voltage can separate using plasma membranes?
What would an example of voltage be?
The height of a waterfall
Whate are the four basic principles of electricity?
Ohms Law
Current is the measure of the flow of charged particles from _____ ___ to ___.
One point to another
T/F current is measured in Amperes?
The measure of the flow of charged particles from one point to another is called?
What is resistance?
The opposition to the flow of ions
Resistance is measured in ?
T/F High resistance means it is harder for ions to flow ?
If current is having a hard time formn then resistance is _____(high/Low)?
The opposition to the flow of ions is?
The formula for Ohms law is?
T/F Ohms law shows the relationship between voltage, current and resistance?
Current is formed when ____ happens?
A channel is opened and charged particles flow
T/F If current (I) is formed, voltage(V) has to change?
T/F current change is easier to track than voltage change?
False- voltage is easier to track
Voltage changes if _____ is formed?
If a channel is opened and charged particles flow _______ is formed?
What are the three types of gated channels?
Voltage gated
Chemically gated
Mechanically gated
Ions (charged particles) _______ (can/cannot) pass through membranes on thier own?
cannot - need protien channels
T/F All channels are always open?
False- some are always open, and some require something to open/close
Once gated channels are open, what do ions move along?
Concentration gradient and/or Electrical gradient
T/F Ions only move along the Electrical gradient when gated channels are open?
False - Both concentration and electrical gradients
What is the Electrochemical gradient?
The influence on ion movement based on the combination of electrical and chemical gradients
T/F The electromagnetic gradient influences the movemnt of ions?
False- Electrochemical gradient
T/F Intracellular and Extracellular fluids are electrically neutral?
What changes the electrical charge in intracellular and extracellular fluids?
The amount of Na+ and K+ inside or outside the membrane
Resting potential (voltage) is created at about ___ mv?
How do excitable cells communicate?
Membrane potentials
What are the two ways to change membrane potentials?
Change membrane permeability to any ion
alter ion concentration on either side of the membrane
T/F Memebrane potential cannot be changed?
False- can be changed
The reduction of membrane potential is called ____?
Hyperpolarization _____ membrane potential?
Hyperpolarization makes membrane potential (more/less) negative?
How does depolarization affect membrane potential?
Becomes less negative
T/F Graded potential is a long lived, local membrane disturbance?
False - Short lived
T/F Graded potential can occur in either Hyperpolarization or Depolarization?
In graded potential current_____ with distance?
When do graded potentials occur?
When environmental change near the neutron causes gated ion channels to open
T/F In graded potential the magnitude varies with the intensity of stimuli?
Current in graded membrane is lost with distance due to ions _____?
Being lost through leaky membranes
T/F Current can be lost through leaky membranes?
True - in graded potentials
Dendrites and Cell bodies use ___ potential?
T/F axons use action potential to cover long distance?
T/F Graded potential used by dendrites and cell bodies covers long distances?
False - short distance
T/F Action potential decreases in strength over distance?
False - does not decrease
Action potential occurs in axons and is also called ____ ____?
Nerve impulse
Action potential is a brief reversal of _____ _____?
Membrane potential
T/F graded potential occurs on the axon?
False- Axon hillock
Where does action potential happen?
What are the 4 steps to generate action potential?
Resting state
Depolarization phase
Repolarization phase
Hyperpolarization phase
T/F in the Resting state all gated ion channels are open?
False - Closed (-70mv)
What is the state called if all gated ion channels are closed?
When Na+ channels begin to open the action potential is entering the ____ ____?
Depolarization phase
What mv threshold does the membrean have to hit in order for depolarization to become self perpetuation?
T/F K+ floods the membrane until it reaches +30mv during depolarization?
False - Na+
Repolarization starts when ____ ___ close?
Na+ channels
___ channels open and ___ rushes in to drop the membrane potential in the repolarization phase?
T/F Membrane potential drops duriing repolarization?
T/F In hyperpolarization the mv levels drop more than needed before resting state is achieved?
True- Na+ and K+ pumps restore normal levels
What happens during hyperpolarization?
membrane potential drops mopre than needed
What propogates Action potential (AP)?
A disturbance of voltage moving down the length of the axon
A wave of ____ follows AP to prevent backwards movement.
The act of AP moving from one area to another to another to another is called?
Propogation of action potential
T/F Action potential is propogated when a voltage disturbance moves down the cell body?
False- the length of the axon
Action potential (AP) uses the ___ or ___ phenomenon?
All or Nothing
T/F if graded potential is strong enough it will reach the axon hillock?
If threshold is reached at the axon hillock then ____ _____ is produced?
Action potential
Graded potential ____ with distance?
T/F Action potential either happens completely or not at all?
If threshold is not reached ___ happens?
New action potentials are created at the ____ _____?
Axon hillock
T/F Action potentials move towards the cell body?
False - Away from
T/F stronger stimuli cause AP more often than weaker stimuli?
Independent of stimuli strength all ____ ____ are the same.
Action potentials
What 2 factors is conduction velocity dependent on?
Axon diameter
Degree of myelination
T/F Axons with larger diameters have faster velocities?
The more ____ cells (myelin) the faster the velocity?
The conduction pattern along an axon with myelin is called____?
Saltatory conduction
____ ____ prevent "leakage" of charge from axon and increase membrane resistance.
Myelin sheaths
T/F Ion channels are only at the Nodes of Ranvier?
AP travels ___ (faster/slower) along a myelinated axon compared to an unmyelinated axon?
T?F Action potentials "skip" from node to the next node during saltatory conduction?
Why does AP travel faster along a myelinated axon compared to an unmyelinated axon?
the ion channels at the Nodes of Ranvier allow the AP to not have to open every gated channel and instead skip to the next node
An example of Homeostatic imbalance is____?
Multiple sclerosis (MS)
Multiple sclerosis is an _____ disease?
T/F If a person has MS, their immune sytem kill its Schwann cells, resulting in a loss of myelin sheaths?
MS affects ___ neurons?
T/F MS can cause uncoodination, muscle weakness, and eventual paralysis?
There are ___ groups of nerve fibers based on conduction velocity.
Nerve fibers in group A are characterized by being ____and ____?
Large diameter axons
Heavily myelinated
T/F Group A nerve fibers conduct at over 300mph?
T/F Group A nerve fibers are used by the autonomic nervous system?
False - Somatic Nervous System
What muscle group do the group A fibers serve?
Skeletal muscles
T/F Group B nerve fibers are not myelinated?
False- they have some, but not a lot
About how fast do group B fibers conduct?
About 30mph
Which nervous system uses group B fibers?
Autonomic nervous system
T/F Group B fibers are larger than Group A fibers?
False - smaller
Which group of nerve fibers has the smallest diameter?
Group C
T/F Group C fibers are used by both the Somaticand Autonomic nervous system?
False - Autonomic
How fast do Group C nerve fibers conduct?
About 2mph
Are group Cf fibers myelinated?
No they are not
Waht is a junction that mediates information transfer from a neuron to another neuron or to an effector cell?
T/F A synapse mediates information to affector cells?
False - Effector cells
Where are presynaptic cells located?
Before the synapse
T/F presynaptic cells hold the formed AP?
What are used at synnapse in pre-synaptic cells?
Axon terminals
T/F post-synaptic cells are located befor the synapse?
False- after the synapse
Post-synaptic cells ___ (may/May not) form an action potential?
May form an Action potential
T/F dendrites are used at post-synaptic synapse?
What are the three type of synapse?
Electrical synapse
Chemical synapse
T/F electrical synapse is bidirectional?
In electrical synapse substances can move in_____ directions?
T/F electrical synapse is fairly commmon?
False- fairly rare
Electcal synapse ______ activities?
T/F Chemical synapse use a neurotransmitter?
Chemicla synapse is ____ directional?
uni - one way
In chemical synapse presynaptic cells ____ control post- synaptic cells.
T/F Post-synaptic cells always communicate with presynaptic cells?
False - Never
Describe the chemical synapse process.
Electric signals reach axon terminal
converted to chemcal signal
chemical signal sent to synpatic neuron
chemical signal converted to electrical signal- gated potential
if it is strong enough it starts AP
How many steps are there in the chemical synapse process?
What are the steps in removing neurotransmitter from the synaptic cleft?
diffused away from synaptic cleft
T/F Emzymes can destroy neurotransmitter in order to remove it from the synaptic ceft?
What is re-uptake?
the reobsorbtion of neurotransmitter by the presynaptic terminal
Post-synaptic potential are _____ gated, not voltage sensative?
______ initiate graded potentials?
Post-synaptic potentials
T/F In post-synaptic potentials the strength is based on the amount of neurotransmitter and time in synapse?
post-synaptic potentials can be both ____ and ____?
excitatory and inhibitory
In Excitatory postsynaptic potentials (EPSP) neurotransmitter causes ____ of postsynaptic membrane?