Biology and Neuroscience - Will Flashcards
1
Q
What are the two types of cells in the nervous system?
A
Neurons and Glial cells
2
Q
Where are dendrites located?
A
They are extensions of the cell body membrane.
3
Q
What proteins are bound to the dendrites?
A
Receptors
4
Q
What are the molecules called that bind to receptors on the dendrites?
A
Neurotransmitters
5
Q
What two parts of a neuron work together to send messages?
A
The axon and the soma.
6
Q
What is the cell body of a neuron called?
A
The soma.
7
Q
What are the “dendrite looking” structures at the end of the axon? What is located at the end of them?
A
Axon Terminals, terminal buttons
8
Q
What are vesicles in the axon?
A
They are little bubbles that contain neurotransmitters.
9
Q
What structures interact between the presynaptic vs postsynaptic neuron? What separates them?
A
The presynaptic terminal button is separated from the postsynaptic dendrite by the synaptic cleft.
10
Q
Where do neurotransmitters bind?
A
Postsynaptic receptors
11
Q
What structure surrounds the axon and acts as insulation?
A
The myelin sheathe.
12
Q
What are the breaks in the myelin sheathe called? What are they there for?
A
The nodes of Ranvir allow for ions to enter and charge the inside of the cell, leading to more efficient signal transmission.
13
Q
What are the three important ions in the process of neural signal transmission? (indicate charges)
A
Potassium (K+)
Chloride (Cl-)
Sodium (Na+)
14
Q
What is the charge of a polarized ion? Will it fire in this state?
A
Around -70mV. It is less likely to fire.
15
Q
When will a neuron be more likely to fire?
A
When the inside of a neuron gets more positively charged farther away from polarization.
16
Q
What structure in the neurons allow for ions to move in and out of the cell?
A
The channels.
17
Q
What ion is introduced into the cell to induce an action potential?
A
Sodium
18
Q
What are the states of voltage gated channels determined by?
A
The voltage of the neuron.
19
Q
What is the propagation process responsible for?
A
Bringing the electric impulse to the end of the neuron.
20
Q
What happens when an electrical impulse reaches the end of a neuron?
A
Neurotransmitters are released.
21
Q
At resting stage, what is the state of the voltage controlled gates? What is the Na/K transporter doing?
A
The Na gates are are closed and most of the K gates are closed. The Na/K transporter is pumping Na out of the neuron and K in.
22
Q
What ions enter the cell in response to depolarization? What threshold does this lead to?
A
Na+ ions enter the cell as the voltage gates open. This brings the cell closer to the threshold of excitation.
23
Q
What happens at the threshold of excitation?
A
All Na channels open.
24
Q
What happens during the peak action potential?
A
The Na channels close and the K channels open, releasing K ions into the extracellular fluid. The cell becomes hyperpolarized.
25
What are the 5 stages of the action potential? Lightly describe them.
1. Threshold- Enough Na ions enter the cell, triggering the opening of voltage gated Na channels.
2. Depolarization- At the nodes of Ranvir, the charge inside the axon is higher than the surrounding extracellular fluid.
3. Repolarization - Na channels close, and K channels open allowing K ions out of the cell. This brings the charge of the cell down closer to its polarized state.
4. Refractory period - The K channels stay open long enough for the cell to become hyperpolarized (too negative).
5. Resting state - The neuron stabilizes at its resting polarity.
26
What is the difference between excitatory and inhibitory neurotransmitters?
Excitatory neurotransmitters increase the probability of the neuron firing and inhibitory ones do the opposite.
27
What does the synapse encompass?
The presynaptic terminal button, the postsynaptic dendrite, and the synaptic cleft.
28
What is an agonist drug?
It is a drug that mimics the action of a neurotransmitter produced by the body.
29
What is the name of a neurotransmitter naturally produced by the body?
An endogenous neurotransmitter.
30
What is an antagonist drug? What are the two types of them?
A drug that inhibits the action of the endogenous transmitter. Two types of antagonist drug are competitive and non-competitive.
31
What is the difference between a competitive and non-competitive antagonist?
A competitive antagonist binds to the same receptor as the endogenous neurotransmitter, non-competitive (passive-aggressive) ones bind to other receptor sites but still inhibit receptor function in a way.
32
What is a partial agonist/antagonist?
A drug that binds to a receptor site for less time, being less effective.
33
What kind of neurotransmitter is glutamate? What is it responsible for?
It is excitatory and responsible for learning and movement.
34
What kind of neurotransmitter is GABA? What is it responsible for?
It is inhibitory and related to learning and anxiety regulation.
35
What kind of neurotransmitter is acetylcholine? What is it responsible for?
It is excitatory and responsible for learning and muscle action.
36
What kind of neurotransmitter is dopamine? What is it responsible for?
It is excitatory and inhibitory. It is responsible for learning and reward systems.
37
What kind of neurotransmitter is seratonin? What is it responsible for?
It is excitatory and inhibitory. It is responsible for mood regulation.
38
What kind of neurotransmitter is norepinephrine? What is it responsible for?
It is excitatory and inhibitory. It is responsible for mood regulation.
39
What kind of neurotransmitters are endorphins and enkephalins? What are they responsible for?
They are excitatory and inhibitory. They are responsible for pain regulation.
40
What kind of cell is most common in the nervous system?
Glial cells.
41
What four functions do glial cells carry out?
1. Structural support
2. Waste removal/dead neuron removal
3. Nutrient provision
4. Speeding up electrical impulses.
42
What is the function of ogliodendrocytes?
They wrap the axons of the central nervous system with the myelin sheathe.
43
What cells are responsible for the myelin sheathes of neurons outside the central nervous system?
Schwann Cells
44
What glial cells are involved in the immune function of the brain?
astrocytes and microglia
45
What is the difference between an efferent axon and an afferent axon?
An efferent axon takes impulses away from the CNS, and afferent axon brings impulses back.
46
What is a neural network?
Connections between the dendrites and axons of many neurons.
47
What does neuroplasticity entail?
Brains can grow new branches on dendrites change amounts of receptors and neurotransmitters, and can also get rid of neurons that are damaged or ineffcient.
48
What are the neocortex and medulla responsible for?
The neocortex is responsible for conscious thought and directives, the medulla is responsible for basic life functions.
49
What is the difference between white and grey matter in the CNS?
White matter consists of bundled myelinated axons and is responsible for the communication of different areas of the brain by connecting neurons. Grey matter is responsible for local processing of information and is made up of neurons and glial cells.
50
What are the two divisions of the peripheral nervous system?
Somatic and autonomic divisions.
51
Which division of the PNS contains the flight or flight response?
The autonomic system
52
Which division of the PNS controls skeletal muscles?
The somatic divison.
53
Which division of the PNS is more heavily myelinated?
The somatic divison.
54
What are the two systems within the autonomic system? What are they responsible for?
The sympathetic and parasympathetic systems are responsible for action responses and relaxation, respectively.
55
What systems use which neurotransmitters? (3 systems)
The somatic system uses acetylcholine. The parasympathetic system uses acetylcholine. The sympathetic system uses norepinephrine and epinephrine.
56
What is the bundle of nerves in the limbic system, ganglia, and cerebellum?
The ganglion.
57
Is the postganglionic axon myelinated?
No
58
When is a sympathetic neuron linked to blood vessels?
When the sympathetic neuron has its ganglion at the adrenal medulla, it releases epinephrine and norepinephrine into the bloodstream.
59
Where is the adrenal gland located?
The kidneys.
60
Where are the neurons and nerves of the parasympathetic nervous system located?
Mostly in the lower brain and sacral region of the spinal cord.
61
Where are the neurons and nerves of the sympathetic nervous system located?
Mostly in the spinal cord.
62
What are the frontal lobes responsible for?
Decision making (anterior) and movement (posterior)
63
What is located in the most anterior part of the frontal lobes?
The prefrontal cortex.
64
What are the parietal lobes responsible for?
The integration of sensory information from around the brain.
65
Where is the postcentral gyrus found? What sensory inputs are it responsible for?
It is found on the most anterior part of the parietal lobes and is responsible for the tactile sensory system.
66
What is the part of the frontal lobe that is responsible for movement and is at the very posterior part of the frontal lobe?
The precentral gyrus.
67
What is the function of the temporal lobes?
It is responsible for memory and sound processing. It is also the home of the olfactory cortex and Wernicke's area.
68
What are the occipital lobes responsible for? What are 2 other names for them?
They are responsible for sight and processing the visual sensory inputs. It is also referred to as the striate or striped cortex.
69
How many lobes is the cerebellum divided into? What is its function?
It is divided into 2 lobes. It controls voluntary movement, balance, and muscle tone.
70
What is the medulla responsible for?
Regulating life functions (e.g. breathing, heartbeat)
71
What is the pons responsible for?
Sending information from the brain to the body and from the spinal cord to the prefrontal cortex. It also deals with arousal and connects senses to the cerebellum. It controls facial expressions and eye movement as well.
72
Aside from the function organization of the brain, what is another recognized organization of the brain structures?
It can be organized based on how the brain developed in the fetus. These structures are the forebrain, midbrain, and hind/lower brain.
73
What does RAS stand for?
Reticular activating system
74
What two brain structures is contains the RAS
the pons and medulla
75
What two functions do the RAS allow us to do?
1. Arousal control (excitement/energy)
2. focus/attention on tasks
76
What are other words for the fore/mid/hind brain?
prosencephalon, mesencephalon, rhombencephalon
77
What does the forebrain differentiate into? (2)
The telencephalon and diencephalon.
78
What does the hindbrain differentiate into? (2)
Metencephalon and myelencephalon.
79
Where is the limbic system located?
The midbrain(mesencephalon) and the cortex(telencephalon).
80
What is the limbic system responsible for? (3)
It is responsible for the regulation of the endocrine system as well as the regulation of the emotional systems and emotional memory.
81
What is the amygdala responsible for?
Reponses to threats/strong emotions.
82
What is the hippocampus responsible for?
The formation of new memories, and imagination.
83
What is the cingulate gyrus responsible for?
Focuses attention on pain and unpleasant things.
84
What is the hypothalamus responsible for?
hunger, sexual response, temperature, aggression. it is responsible for homeostasis in the body, and produces oxytocin, which is associated with social bonds.
85
What is the basal ganglia responsible for?
the modulation of movement commands, initiating or terminating a movement, making a complex movement automatic
86
What part of the brain would be damaged for a patient to have an uncoordinated gait or loss of balance?
The cerebellum
87
True or false: the cerebellum coordinates thought and problem solving and emotional regulation
true, the cerebellum connects parts of the neocortex with the hypothalamus
88
What is the thalamus responsible for?
What we pay attention to, it filters sensory information and chooses what isn't important
89
Where is the visual cortex located?
The occipital lobes
90
Where is the auditory cortex located?
the temporal lobes
91
Where is the sensory cortex located?
In the parietal lobes.
92
Where is the motor cortex located?
In the frontal lobes.
93
Define association cortex
parts of the neocortex that merge primary sensory input
94
Where is Wernicke's area and what is it responsible for?
It is located in the temporal lobe and is responsible for speech processing.
95
How do we know about functional asymmetry? (3)
Neural imaging
Clinical observation
Split brain patients
96
What is a generalization of the roles of the right and left side of the brain?
The right brain typically sees thing on a larger scale, and the left brain is more focused on details.
97
What is the bundle of fibers responsible for transferring information between hemispheres?
The corpus callosum
98
What part of the brain controls the endocrine system?
The hypothalamus.
99
What does the pineal gland secrete?
Melatonin
100
Where is the pituitary gland located and what does it secrete?
It is located in the CNS and secretes hormones responsible for many things including hunger, aggression, and sexual behaviour.
101
Why is oxytocin important?
It is associated with bonding and love.
102
What are the 4 ways we can study the brain?
1. Dissection
2. Observation
3. Structural Imaging
4. Functional Imaging
103
What was the first way of measuring electrical potential in specific areas of the brain?
EEG (electroencephalograph)
104
How does an MRI work? What are advantages and disadvantages?
It measures oxygen level changes related to blood flow to visualize the neurons firing. It provides good detailed images, is noninvasive, and there is no radiation but it is expensive and patients cannot have metal in them.
105
How does a PET scan work? What are advantages and disadvantages?
A stained competitive neurotransmitter is ingested and thereby displaced by the levels of neurotransmitters released. Changes can be seen in real time, but there is radiation exposure.
106
What is a CT scan? What are advantages and disadvantages?
It is x-rays that pass through the body. It is fast, cheap, and noninvasive, but exposes the subject to radiation.
107
What is the difference between an MRI and an fMRI?
the F stands for functional, so it is a measurement taken during a function, however cardiovascular problems can alter the readings.
108
What is a DTI imaging? What are advantages and disadvantages?
It tracks and images water movement in the brain as well as the density of neural tracks. It is also non invasive but it can be difficult to interperet.
109
What is the limbic system responsible for?
behavioral and emotional responses
110
