Final- Bio and Neuro Flashcards
What are neurons
the basic unit of communication in the nervous
What are neurons
the basic unit of communication in the nervous
What is the communication process between neurons called
Its an electrochemical process.
Describe the 3 steps a neuron takes to communicate
- When it wants to communicate, it fires by sending an electrical impulse (aka action potential)
- The action potential causes the release of neurotransmitters
- The release of neurotransmitters deliver the message from one neuron to another
What are the 8 important structures of the neuron
- Soma
- Dendrites
- Axon
- Axon terminals
- Terminal buttons
- Myelin Sheath
- Synapse
- Synaptic Cleft
What is the soma and what is its role
The cell body of a neuron. It contains the nucleus and DNA. It manufactures everything the neuron needs to survive
What are the 2 roles of dendrites
- they increase the surface area of the soma without taking up too much space
- Receive messages from other neurons
What is an axon and what is its role
Its a thin tube in the neuron. It carries the electrical impulse
What is an axon terminal and what is its role
Its a part of the axon in the neuron. It carries the action potential (electrical impulse) until it reaches the terminal buttons
What are the terminal buttons and what are their roles
little nobs at the end of axon branches in a neuron. They release neurotransmitters when the action potential reaches them
What is a myelin sheath and what is its role
a white fatty-like substance on the axon of a neuron. It speeds up the transmission of the information.
What is a synapse
the place where neurons need to communicate
What is a synaptic cleft
a little gap at the synapse between two neurons. It is where the communication happens.
What is a presynaptic neuron
the neuron that sends out messages
What is a post synaptic neuron
a neuron that receives messages
The more dendritic branches a neuron has, the greater the ___________
the greater the number of other neurons the cell communicates with.
Dendrites have proteins called _____ embedded on their membranes that bind with ________
receptors, neurotransmitters.
The ____ is the location of metabolic processing in the neuron cell and contains the cell’s organelles.
soma
What and where is the axon hillock
Protruding from the neuron’s cell membrane, you will also find the axon hillock. It is the intersection between the soma and the axon, and is the beginning of the axon.
terminal buttons house ______, which are little bubbles containing the neurotransmitters.
vesicles
What are the nodes of Ranvier
gaps in the myelin sheath that increase the effectiveness of signal transmission by allowing ions to enter and change the charge inside the cell.
What percent of a neuron is water?
80%
What is intracellular fluid?
fluid dissolved inside neuron
What is extracellular fluid?
fluid outside the neuron
What are the 3 dissolved chemicals in neurons?
Na+ (sodium), Cl- (chloride), K+ (potassium)
What is happening with the dissolved chemicals inside a neuron when the neuron is AT REST?
When neuron is at rest, there is a higher concentration of negative neurons on the inside. There is a higher concentration of positively charged ions on the outside.
What does a inhibitory message mean to the neuron?
Not to fire. Not to produce an active potential
How will an inhibitory message keep the neuron from not firing?
message will change the concentration of ions to make it MORE negative inside the neuron. As a result, neuron is less likely to fire
What does it mean when a neuron is hyperpolarized?
the inside is made MORE negative than normal. it will be less likely to fire.
What does an excitatory message mean to the neuron?
Instructs the neuron to fire. To produce an action-potential
How will an excitatory message get the neuron to fire?
It will change the concentrations of the inside of the neuron to be LESS negative. As a result, it is more likely to fire
What does it mean when a neuron is depolarized?
When the inside is LESS negative than normal. More likely to fire.
At what charge will a neuron most likely to fire at?
About -50 mv
What are the nodes of Ranvier in a neuron and why are they there?
they are gaps in the myelin sheath that covers the axons. Ions use them to get in and out of the neuron
Explain the movement of ions in the neurons during an inhibitory response
Chloride (Cl-) channels open which causes an influx of chloride ions in the neuron. When this happens, there is an excess of negative ions inside the neuron, making the neuron more negative (hyperpolarized)
Explain the movement of ions in the neurons during an excitatory response
Sodium (Na+) channels open, causing sodium channels to rush into the cell. This increase the amount of positive ions in the neuron, causing it to be less negative (depolarization)
What is the threshold of excitation and how is it reached?
Its about -50mv. Its the electrical charge that the neuron must get to for it to fire. It is achieved through depolarization.
What is resting potential?
Around -70mv. Its the electrical charge that a neuron rests at.
After a neuron is fired, it has to go back to resting membrane potential. How does it return?
AFTER sodium channels open and sodium has rushed inside cell, potassium channels open. Potassium (K+) ions start leaving the neuron. Potassium ions leaving = less positive ions inside cell = less positive charge = back to resting potential
What is a refractory period?
During this period, the neuron will not fire when stimulated. The membrane is hyperpolarized.
What are the 7 steps of a presynaptic neuron firing?
- Presynaptic neuron decides to send a message to another neuron. It fires, producing an action potential.
- Action potential travels down the axon until it reaches the terminal buttons
- It goes inside the terminal buttons, where it reaches the terminal neurons.
- When it arrives at the terminal neurons, the synaptic vesicles attach the the membrane of the neuron.
- Synaptic vesicles burst open and release neurotransmitters into synaptic gap.
- Neurotransmitters cross the gap and attach to receptor sites of the synaptic neurons
- Once they attach to receptor sites, they send the message to the postsynaptic neurons.
The neurotransmitters MUST attach to ________ otherside it cannot deliver the message.
Receptive sites
What are two ways that we get rid of the neurotransmitters once the message has been delivered?
- Reuptake
- Degradation
What is the reuptake of neurotransmitters?
the neurotransmitter is reabsorbed into the neuron that released it
What is the degradation of neurotransmitters?
Once message is delivered, an enzyme comes and breaks down the neurotransmitters.
Why do neurotransmitters have to be removed once they have delivered the message?
If they are not removed, it is going to remain active, delivering the same message over and over again. This can overexcite the nervous system or over-inhibit it.
What is propagation
the process by which electrical impulses get sent to the end of a neuron
Why are Glial Cells called ‘Nannies of the neurons’
They provide neurons with everything they need to survive: protection, insulation, nutrition, clean after them
What are the 4 types of glial cells
- Oligodendrocytes 2. Schwann Cells 3. Astrocytes 4. Microglia
What are Oligodendrocytes and Schwann Cells both involved in
the production, laying down, and repair of the myelin sheath
What is the difference between Oligodendrocytes and Schwann Cells
Oligodendrocytes repair the myelin sheath in the central nervous system and Schwann Cells repair the myelin sheath outside the brain and spinal cord
What is the function of microglia and astrocytes?
They both form the immune system of the brain
What are neural networks
complex connections between the dendrites and axons of many neurons.
What are Efferent axons
carrying electrical impulses away from the CNS
What are afferent axons
carrying impulses back to the CNS from the organs and muscles.
What is the neocortex? Function? Location?
outer layer of your brain with all the ridges. The conscious, high-level processing of sensory input.
What is the medulla? Function? Location?
Located in brain stem. Closest to spinal cord. Help control basic life-support functions like breathing, heart rate, and reflexes
The modulation of neural networks in the lower-brain centers like the medulla and spinal cord is made possible by _____ that extend from the cortex to connect with neurons in the medulla.
axons
What is the main job of the PNS
carry information between body to CNS and vise-versa
What are the two main divisions of the PNS
Somatic and Automatic
what are the 2 main functions of the somatic system
- Sensory
- Motor function
What does the autonomic NS consist of
glands, organs, and involuntary muscles
What are the 2 divisions of the ANS
Sympathetic and Parasympathetic
What is the function of the Sympathetic system
Fight or Flight system
What is the function of the Parasympathetic system
Rest and Digest
What is the CNS and what does it consist of
The central nervous system (CNS) is all the cells and supporting structures inside the skull and vertebral column. In short, the CNS is the brain and the spinal cord.
The central nervous system contains both ____ and ____ matter. What is the function of the 2
Gray matter: local processing of information (neurons and ganglia)
White matter: helps different areas of the brain share information by connecting neurons via axons and dendrites (myelinated axons)
where does the brainstem start
starts where the spinal cord ends
Why is the brainstem a relay station
all the info coming to the brain will have to go through it and all the
information leaving the brain will have to go through it
Why is the brainstem called the crossover point
The information coming from the left side of the body will cross over to the right side of
the brain and vice versa.
The information coming from the right side of the body will cross over to the left side of
the brain and vice versa
Why is the brainstem the life center of the brain
it contains structures that control vital functions that are
essential for survival. These structures include the medulla, the pons and the RAS
What are the 3 functions of the medulla and pons and where are the located
Located in brainstem
1. critical for sustaining basic life functions
2. to regulate basic life functions in the background.
3. connecting the peripheral and central nervous systems to regulate what we do and pay attention to.
What is the reticular activating system (RAS)
a network of neurons spanning the center of the medulla and pons. It bridges the functions of the body and brain via connections to the spinal cord and thalamus.
What are the two main function of the RAS
- our level of arousal (excitement/energy)
- the focus of our attention on tasks, people, or objects.
(ex// being able to focus solely on your friends at a loud party)
What is the limbic system linked to
a variety of functions. ex// emotion, memory, learning, motivation
What 2 things are the hippocampus linked to
- formation of new memories
- formation and maintenance of cognitive maps
How many amygdala do we have
2, one of left and one on right
What is the amygdala associated with
- aggresion 2. emotion 3. fear 4. perception of emotion 5. emotional memories
Why is the amygdala the alarm system of the body?
it activates and informs us when there is a threat, real or imaginative
Why is the hypothalumus called the “The brain within the brain”
controls and regulates a variety of functions essential for survival
What are the 3 main functions of the hypothalamus
- Drives (hunger, sex, thirst)
- Homeostasis (balance)
- Social bonds (produces oxytocin)
What are the 6 structures associated with the limbic system
prefrontal cortex, the olfactory (smell) cortex, the amygdala, the hippocampus, the cingulate gyrus, and the hypothalamus
If animals got an amygdalectomy (the removal of the amygdala), what would the animal show?
The animal would become docile. It will not have a fear of its predatory animals. It will not longer have proper emotions.
What is the cingulate gyrus
the network that becomes more active when we when people experience physical pain and when they are excluded socially.
What does the cerebellum control
Controls voluntary movements. Regulates balance and muscle tone
What is the cerebellum involved in
with motor movements that become automatic (typing, writing)
Where are half of the neurons in the brain located?
cerebellum
What are the basal ganglia
interconnected groups of neurons that serve to modulate movement commands in the brain before they reach the spinal cord
What are the 2 parts that make up the basal ganglia
- dorsal and ventral striatum
- globus pallidus and substantia nigra
What is the function of the dorsal and ventral striatum
where inputs for movement to the basal ganglia come in.
What is the function of the globus pallidus and substantia nigra
send inhibitory outputs to the thalamus to help integrate sensory and motor information with motor planning. (ex// which height should you swing the bat to hit the ball)
One part of the basal ganglia in particular is implicated in Parkinson’s
substantia nigra. in Parkinson’s, these cells die off, and people lose part of the circuit that initiates and terminates movements.
What are the 3 divisions of the cerebellum and what are their functions
spinocerebellar: match sensory input with motor plans to fine-tune movement patterns.
vestibulocerebellar: processes information from the inner ear to help adjust your posture and balance.
cerebrocerebellar: manages connections with the pons and thalamus to adjust the timing and planning of movements.
What is the endocrine system and what does it consist of
a major communication network. consists of gland and hormones
what are hormones
Hormones are chemicals and they carry messages from the endocrine system to the
body system, as well as to the brain. Hormones influence both physical processes, as well as mental processes.
What are the 3 types of hormones:
- homeostasis. ex// insulin
- reproductive. ex// testosterone
- Stress. ex// epinephrine
what is the pituitary gland?
It is the master gland of the endocrine system. It is the master gland because it
is the boss of almost all the other glands of the endocrine system
how does the nervous system and endocrine system affect each other
The nervous system controls the endocrine system via the hypothalamus. The hormones of the ES (endocrine system) influence and affect the NS (nervous
system), including the brain.
what is the function of the frontal lobe
tasked with decision making (anterior, frontal portion) and movement (posterior, back regions). The prefrontal cortex (most anterior portion) receives input from across the cerebral cortex and helps us decide when, why and how we do things.
