PSY 260 Exam 1
What is the resting potential?
-70mV The difference in electric charge between the inside and outside of a neuron's cell membrane
What are oligodendrocytes and what is their primary function?
A cell that forms the myelin sheath (a layer that covers and protects nerve cells) in the brain and spinal cord. An oligodendrocyte is a type of glial cell.
What is the basic "story" of cell signaling (aka neurotransmission or how neurons communicate)?
A neuron sending a signal (i.e., a presynaptic neuron) releases a chemical called a neurotransmitter, which binds to a receptor on the surface of the receiving (i.e., postsynaptic) neuron. Neurotransmitters are released from presynaptic terminals, which may branch to communicate with several postsynaptic neurons.
What is meant by the presynaptic neuron/cell? Postsynaptic neuron/cell?
A presynaptic neuron transmits the signal toward a synapse, whereas a postsynaptic neuron transmits the signal away from the synapse.
The temporal lobe?
A region of the cerebral cortex responsible for hearing and language.
Nodes of Ranvier?
Because the myelin sheath is largely composed of an insulating fatty substance, the nodes of Ranvier allow the generation of a fast electrical impulse along the axon. Gaps in the myelin sheath of a nerve
What do the CNS and PNS consist of?
CNS: brain and spinal cord PNS: nerves that branch off from the spinal cord and extend to all parts of the body.
What are the anatomical directions?
Caudal: directed toward the back of the head Dorsal: toward the top Ventral: toward the bottom Rostral: directed towards the nose RCDV - Ranch Causes Diabetes Viciously
What is CSF and what is its primary function?
Cerebrospinal fluid is made by tissue that lines the ventricles (hollow spaces) in the brain flows in and around the brain and spinal cord to help cushion them from injury and provide nutrients.
What is depolarization? (what neurotransmitter? what are the effects of sodium influx?)
Depolarization is when a change occurs inside a cell that causes the distribution of electric charges to alter, leaving the cell with a less negative charge than the outside. when acetylcholine is released at the synapse between a nerve and muscle (called the neuromuscular junction) by a presynaptic neuron, it causes postsynaptic Na+ channels to open. Na+ enters the postsynaptic cell and causes the postsynaptic membrane to depolarize. glutamate (excitatory)
How can we record those PSPs (that is, synaptic neural activity)?
EEG reflects voltages generated (mostly) by excitatory postsynaptic potentials from apical dendrites of massively synchronised neocortical pyramidal cells.
What are the basic features of the principal brain research methods? (EEG, MEG, fMRI, structural MRI, DTI?)
EEG: a test that measures electrical activity in the brain using small, metal discs (electrodes) attached to the scalp. MEG: a test that uses sensors to form an image of magnetic fields produced within the brain. fMRI: measures the small changes in blood flow that occur with brain activity. structural MRI: scans image anatomical structure DTI: a novel imaging technique that can reveal non-invasively unique information of white matter (WM) microstructures within the central nervous system (CNS)
What are the basic features of the main neurotransmitters: Glutamate, GABA, acetylcholine, dopamine, serotonin? Which neurotransmitters have major excitatory/ inhibitory functions?
Glutamate: excitatory - anxiety, depression, restlessness, inability to concentrate, headaches, insomnia, fatigue, and increased sensitivity to pain. GABA: inhibitory - calming Acetylcholine: excitatory/both - muscle control, autonomic body functions, and in learning, memory, and attention Dopamine: both - a chemical released in the brain that makes you feel good. Serotonin: inhibitory - regulate mood, sleep patterns, sexuality, anxiety, appetite and pain.
What is the gyrus/(plural: gyri) and sulcus (plural:sulci)?
Gyrus: a ridge on the surface of the brain./folds and bumps Sulcus: fissures that surround the gyri/indentations and grooves
What is hyperpolarization? (what neurotransmitter? what are the effects of chloride influx?) IPSPs
Hyperpolarization is when the membrane potential becomes more negative at a particular spot on the neuron's membrane GABA usually causes hyperpolarization of the postsynaptic neuron to generate an inhibitory postsynaptic potential (IPSP) (inhibitory)
What two primary structures constitute the diencephalon? Their functions?
Hypothalamus: controls emotions. It also regulates your body's temperature and controls crucial urges — such as eating or sleeping. Thalamus: acts as a gatekeeper for messages passed between the spinal cord and the cerebral hemispheres
Neurotransmitter vesicles are located ____
in presynaptic axon terminals
When a neuron's membrane is at rest, the concentration gradient tends to move sodium ___ the cell and potassium ___the cell
into; out of
Why do we say that cell signaling is neurochemical in nature? What part is electrical vs. chemical?
ions - electrical neurotransmitters - chemical
What is the blood-brain barrier (BBB)? What cells form the BBB?
is both a structural and functional roadblock to microorganisms, such as bacteria, fungi, viruses or parasites, that may be circulating in the bloodstream. The BBB is formed by microvascular endothelial cells lining the cerebral capillaries
Why are the basal ganglia important?
it controls your body's voluntary movements., and damage could cause problems controlling speech, movement, and posture. This combination of symptoms is called Parkinsonism.
The resting potential is mainly the result of ___
negatively charged proteins inside the cell
What does the neural tissue consist of? (note: neurons, glia, blood vessels)
nerve cells or neurons and glial cells
What type of channel is the primary "leakage" ion channel?
non-gated/passive
What is the concentration gradient/ difference and how does it affect ion distribution inside/outside of the cell?
occurs when the concentration of particles is higher in one area than another.
When the potential across a membrane reaches threshold, the sodium channels ____.
open to let sodium enter the cell rapidly
EPSPs result from an__
outflow of Na+ out of the cell
Together, the somatic nervous system and the autonomic nervous system make up the ____ nervous system.
peripheral
The All-or-None Law?
principle that the action potential in a neuron does not vary in strength; the neuron either fires at full strength or it does not fire at all
What are ion channels?
proteins that create specific pathways for charged molecules
Also, be able to recognize the 4 views of the brain
sagittal: middle vertically lateral: from the side Superior: from the top inferior: from the bottom Coronal: middle horizontally?
The somatic nervous system carries signals from the _ and is part of the _.
senses; central nervous system
What are some examples of brain lesions? (e.g. what is TBI? stroke?)
stroke occurs when something blocks blood supply to part of the brain or when a blood vessel in the brain bursts. brain aneurism epilepsy
Where are neurotransmitters stored before release?
synaptic vesicles
The basal ganglia are a related cluster of cell bodies that are lateral to the _____.
thalamus
What are the basic forces acting upon ions?
the concentration gradient and the electrical gradient.
What is the synapse? What purpose does it serve? What happens in the synapse?
the junction between the axon of one neuron and the dendrite of another, through which the two neurons communicate. Synapses are part of the circuit that connects sensory organs, like those that detect pain or touch, in the peripheral nervous system to the brain. Synapses connect neurons in the brain to neurons in the rest of the body and from those neurons to the muscles
What does the pyramidal cell look like and what are its primary features? (apical/basal dendrites, axon etc)
the most common neuron in the cerebral cortex. They are the major source of intrinsic excitatory cortical synapses, and their dendritic spines are the main postsynaptic target of excitatory synapses
A person who has been diagnosed with cortical blindness has had damage to _____.
the occipital cortex
What is the cortex?
the outer layer that lies on top of your cerebrum.
What is its voltage? How is it formed?
the pressure from an electrical circuit's power source that pushes charged electrons (current) through a conducting loop,
A membrane produces an action potential whenever the potential across it reaches what level?
the threshold of excitation
Temporal lobe is located ____ with respect to the primary somatosensory cortex.
ventrally
Superior colliculus is to _ as inferior colliculus is to _.
vision; hearing
What is the purpose of the axon?
where electrical impulses from the neuron travel away from the soma to be received by other neurons.
A temporary hyperpolarization is known as an __.
IPSP
What happens if the cell membrane is sufficiently depolarized? ( action potential)
If the depolarization is sufficiently large, voltage-dependent sodium channels will be opened, and an action potential will be initiated
Which action would depolarize a neuron?
Increasing membrane permeability to sodium
What are the locations and basic functions of the 3 brain stem structures (medulla oblongata, pons, and midbrain)?
Medulla Oblongata: it's where your brain and spinal cord connect, making it a key conduit for nerve signals to and from your body. It also helps control vital processes like your heartbeat, breathing and blood pressure Pons: coordinates facial movements, hearing and balance Midbrain: vision, hearing, motor control, sleep/wake, arousal (alertness), and temperature regulation, acting as a sort of relay station for auditory and visual information.
What are the electrical forces pulling ions in/out of the cell?
Membrane potential is a potential gradient that forces ions to passively move in one direction: positive ions are attracted by the 'negative' side of the membrane and negative ions by the 'positive' one.
What are action potentials?
Nerve Impulses. Electrical impulses that are carried along the lengths of the axons. Always the same regardless of the stimulus.
What are postsynaptic potentials (PSPs)? What do excitatory PSPs (EPSPs) do?
PSPs: Membrane potential change due to the binding of neurotransmitter to postsynaptic membrane receptors. EPSPs: Excitatory postsynaptic potentials (EPSPs) are synaptic inputs that depolarize the postsynaptic cell, bringing the membrane potential closer to threshold and closer to firing an action potential.
Excitory vs. inhibitory
Red = excitatory
What are the two subsystems that constitute the Autonomic NS and what are their basic functions?
Sympathetic Nervous System: controls "fight-or-flight" responses; this system prepares the body for strenuous physical activity. Parasympathetic Nervous System: regulates "rest and digest" functions.
How do EPSPs and IPSPs combine? (in time - temporal summation in space: spatial summation)
Temporal summation involves a single presynaptic neuron rapid-firing signals to a single postsynaptic neuron's synapse. Because the signals are received in rapid succession, they compound into a greater signal. Spatial summation involves multiple presynaptic neurons simultaneously sending signals to a single neuron.
What are the basic components of the human nervous system?
The Central Nervous System (CNS) and the Peripheral Nervous System (PNS)
What do the corpus callosum and anterior commissure have in common?
The anterior or ventral white commissure is a collection of nerve fibers that cross the midline of the spinal cord and transmit information from or to the contralateral side of the brain. They both connect two hemispheres
What determines whether a neuron has an action potential?
The combined effects of EPSPs and IPSPs
What is the limbic system, what are the primary limbic structures and their overall functions?
The limbic system is a set of structures in the brain that deal with emotions and memory Hippocampus: learning and memory Amygdala: processing fearful and threatening stimuli
How do they affect the resting membrane potential?
The resting potential is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion.
What ions are outside vs inside the cell?
The sodium and chloride ion concentrations are lower inside the cell than outside, and the potassium concentration is greater inside the cell.
Where are the primary cortical areas responsible for vision, audition (hearing), somatosensation (touch), motor function? What is the "motor strip"?
The visual cortex primary auditory cortex primary somatosensory cortex primary motor cortex/precentral gyrus (PCG)/Motor strip: a strip of brain tissue located in the frontal lobe. It is responsible for initiating purposeful and intentional movements.
How are they cleared from the synaptic cleft?
This is accomplished mainly through two processes: neurotransmitter transport and/or degradation. Transport physically removes the neurotransmitter molecule from the synaptic cleft. Degradation breaks down the neurotransmitter molecule by enzyme activity. Glial cells: astrocytes remove neurotransmitters from the synaptic cleft. 4. Reuptake: the whole neurotransmitter molecule is taken back into the axon terminal that released it.
How is the brain protected?
Three layers of membranes known as meninges
Voltage-gated channels?
Voltage-gated ion channels are a class of transmembrane proteins that form ion channels that are activated by changes in the electrical membrane potential near the channel.
White matter?
White matter is found in the deeper tissues of the brain (subcortical). It contains nerve fibers (axons), which are extensions of nerve cells (neurons). Many of these nerve fibers are surrounded by a type of sheath or covering called myelin. Myelin gives the white matter its color
The cortex (gray matter): how many layers? What are the primary types of cells?
Your cerebral cortex consists of six layers of nerve cells made of primarily excitatory projection neurons: and inhibitory interneurons:
What is meningitis?
a disease caused by the inflammation of the protective membranes covering the brain and spinal cord known as the meninges.
What is the basic function of the dendrites?
appendages that are designed to receive communications from other cells.
An action potential is generated at the ______
axon hillock
How are the two hemispheres connected?
by the corpus callosum
In order to produce an IPSP, there needs to be an increase in permeability for __
chloride
What does the human cerebrum contain?
consists of two cerebral hemispheres. Each hemisphere has an inner core composed of white matter, and an outer surface - the cerebral cortex - composed of grey matter.
Each hemisphere of the cerebral cortex receives most of its input from the _ side of the body and controls the muscles on the _ side.
contralateral; contralateral
What higher functions are subserved by the prefrontal cortex?
decision making, reasoning, personality expression, and social cognition.
An EPSP is to ___ as an IPSP is to __.
depolarization; hyperpolarization
A person who has been diagnosed with Parkinson's disease probably has damage to his/her _ neurons in the ____.
dopamine; substantia nigra
What are the 3 meninges?
dura mater, arachnoid mater, pia mater
What are the 4 lobes of the human cortex?
frontal, occipital, parietal, temporal lobes
This brain image was taken in the __ plane
horizontal
Inhibitory synapses on a neuron________
hyperpolarize the cell
