TASK 1 and 2 Flashcards
how’s the nervous system composed?
neurons and glial cells
synapses
tiny gaps formed by cells communicating to each others
mithocondria function and where it is located
produces energy - INSIDE CELL
nucleus function and where it is located
contains genetic instructions - INSIDE CELL
ribosomes function and where it is located
translate genetic instructions into proteins - INSIDE CELL
dendrides
receive information from other neurons
soma
(also called cell body) contains cell nucleus
axon
leads away from the cell body and transmits the cell’s output information in form of electrical impulses
axon terminals
ends of the axon , they transmit the neurons activity to to other cells at synapses
types of neurons determined by function
sensory motorneuron interneuron
types of neurons determined by shape
multipolar bipolar unipolar
multipolar neuron
have many dendrites and a single axon (most common) _!!! – in multipolar and bipolar neurons the cell body also receives and so it is also part of the input zone
bipolar neuron
have a single dendrite at one end of the cell and a single axon at the other end (common in sensory systems, such as vision) _!!! – in multipolar and bipolar neurons the cell body also receives and so it is also part of the input zone
unipolar
have a single extension (or process), usually thought of as an axon , that branches in two directions after leaving the cell body
sensory neurons
Sensory neurons are nerve cells within the nervous system responsible for CONVERT EXTERNAL STIMULI FROM THE ORGANISM’S ENVIRONMENT INTO INTERNAL ELECTRICAL IMPULSES
motorneuron
governs movements. A nerve cell that transmits motor messages, stimulating a muscle or gland
interneuron
(make up most of the brain) receive information from other neurons, process it, and pass the integrated information to other neurons (axons are usually short)
gyri
ridges of tissue in cerebral cortex
sulci
furrows between gyri in cerebral cortex
cortical regions
(4) parietal, frontal, occipital, temporal lobes
sylvian fissure
(deep sulcus) – divides temporal lobe from the other regions of the hemisphere
central sulcus
divides frontal and parietal lobes
parietal lobes
Parietal lobe – receive sensory information from the body and participate in spatial cognition Postcentral gyrus – located in parietal cortex, mediates sense of touch. Located behind the central sulcus
occipital lobes
Occipital lobe – process information from the eyes, giving rise to the sense of vision
temporal lobes
Temporal lobe – auditory information, sense of smell and with aspects of learning and memory
frontal lobes
movement and high level cognition Precentral gyrus – located in the frontal lobe, crucial for motor control. Located in front of the central sulcus
Precentral gyrus
located in the frontal lobe, crucial for motor control. Located in front of the central sulcus
Postcentral gyrus
located in parietal cortex, mediates sense of touch. Located behind the central sulcus
white matter
dominated by fibre tracts. Mostly transmits information
grey matter
dominated by nerve cell bodies and dendrite. Primarily processes information
different ways to cut the brain
transverse, sagittal, coronal
developmental subdivision of the brain
forebrain, midbrain, hindbrain
forebrain parts
telencephalon, diencephalon
midbrain parts
tectum, tegmentum
hindbrain parts
metencephalon, medulla (myelencephalon)
telencephalon , parts and location
cortex, basal ganglia, limbic system. Located in forebrain
diencephalon , parts and location
located in forebrain. Formed by thalamus , hypothalamus
tectum, parts and location
superior and interior colliculi , located in the midbrain
reticular formation, function and location
located in the midbrain and hindbrain – network of neurons, implicated in a variety of behaviours, including sleep and arousal, temperature regulation and motor control.
metencephalon , location and parts
located in hindbrain. Composed by cerebellum, pons
medulla, function and location
located in hindbrain. Function: maintains vital body functions, contains nuclei of cranial nerves (contains cell bodies of the neurons that control the neck and tongue muscles), nuclei that regulate heart rate and breathing
basal ganglia parts
_amygdala _striatum (_caudate nucleus_putamen) _globus palldius _substantia nigra _!!! – all connected with the cerebral cortex, forming a looping neural system
Limbic system, function? in what part of the brain? parts of it?
function: controls emotional behaviour located: forebrain- telencephalon
amygdala, function and location
functions as emotion regulation and odor perception location: forebrain- telencephalon- LIMBIC SYSTEM
hippocampus, function and location
contribute to learning and memory . location: forebrain- telencephalon- LIMBIC SYSTEM
fornix, function and location
contribute to learning and memory. location: forebrain- telencephalon- LIMBIC SYSTEM
cingulate gyrus, function and location
implicated in many cognitive functions , as direction of attention. location: forebrain- telencephalon- LIMBIC SYSTEM
olfactory bulb, function and location
function: implicated in smell functions location: forebrain- telencephalon- LIMBIC SYSTEM
Thalamus, function and location
trade information with the cortex , directs all incoming sensory info to the appropriate regions of cortex for further processing location: forebrain-diencephalon
Hypothalamus, function and location
helps to govern highly motivated behaviours, like sex and aggression, and regulate the hormonal system of the body (because it controls the pituitary gland) location: forebrain-diencephalon
caudate nucleus , location
located: forebrain-telencephalon-basal ganglia connected with the cerebral cortex, forming a looping neural system
putamen
located: forebrain-telencephalon-basal ganglia connected with the cerebral cortex, forming a looping neural system
globus palladius
located: forebrain-telencephalon-basal ganglia connected with the cerebral cortex, forming a looping neural system
substantia nigra
located: forebrain-telencephalon-basal ganglia connected with the cerebral cortex, forming a looping neural system
superior colliculi, function and location
(rostral pairs - in each hemisphere, bumps on the dorsal surface) process visual information location: midbrain-tectum
inferior colliculi
(caudal bumps) – process information about sound location: midbrain-tectum
cerebellum, function- parts and location
(attached to the pons) aids motor coordination and control , it’s a folded sheet (devided in 3 layers) _purkinje cell layer _granule cell layer _molecular cell layer location: midbrain-metencephalon
purkinje cell layer, definition and location
(middle) enourmous amount of neurons location: hindbrain-metencephalon-cerebellum
granule cell layer, definition and location
(last one, under purkinje cell) , forms parallel fibers and brings them to outermost layer location: hindbrain-metencephalon-cerebellum
molecular cell layer, definition and location
composed by the parallel fibers location: hindbrain-metencephalon-cerebellum
Pons
connects midbrain to medulla. location: hindbrain-metencephalon
Brainstem, what is it and composition
refers to medulla and pons combined _red nucleus
red nucleus, function and location
structure related to motor control, communicates with motoneurons in the spinal cord location: midbrain-tegmentum
Precentral gyrus location and function
located in the frontal lobe, crucial for motor control. Located in front of the central sulcus
Postcentral gyrus location and function
located in parietal cortex, mediates sense of touch. Located behind the central sulcus
tegmentum, components and location
reticular formation and red nucleus location: midbrain
Directions in the brain
Anterior/rostral Towards the nose end (Latin rostrum=nose) Posterior/caudal Towards the tail end (Latin cauda=tail) Dorsal Towards the back or top of the head (Latin dorsum=back) Ventral Towards the chest or bottom of the head (Latin venter=abdomen) Medial Towards the middle Lateral Away from the middle Inferior Lower or below Superior Upper or above
Anterior/rostral view
Towards the nose end (Latin rostrum=nose)
Posterior/caudal view
Towards the tail end (Latin cauda=tail)
Dorsal view
Towards the back or top of the head (Latin dorsum=back)
Ventral view
Towards the chest or bottom of the head (Latin venter=abdomen)
Medial view
Towards the middle
Lateral view
Away from the middle
Inferior view
Lower or below
Superior view
Upper or above
central nervous system CNS
the brain and spinal cord
peripheral nervous system PNS
the part of the nervous system outside the brain and spinal cord, including the nerves attached to the brain and spinal cord
meninges
protective membrane formed by _Pia mater _Arachnoid _Dura mater
Pia mater
inner part of meninges
Arachnoid
middle part of meninges
Dura mater
outer part of meninges
cerebrospinal fluid CSF
fluid where the brain is suspended (it gives it a bath ahah)
meningitis
an inflammation of the meninges caused by viral infection (in the worst case can form a meningiomas, a large benign tumor)
meningiomas
large benign tumor
ventricular system function
Inside the brain is a series of chambers filled with CSF, that circulates and creates 2 main functions 1. It acts as a shock absorber for the brain (brain is protected from sudden movements of the head that would smash it against the inside of the skull) 2. It provides a medium for the exchange of materials, including nutrients, between blood vessels and brain tissue
lateral ventricle
each hemisphere contains one
choroid plexus what does it do, where it is located and what is it?
membrane in lateral ventricle, produces CSF by filtering blood
third ventricle position
up the fourth ventricle
fourth ventricle position
lies between cerebellum and the pons
_glial cells (glia) function and types
– make additional contributions to information processing, protect neurons, remove dead neurons 1. astrocyte 2. oligodendrocytes 3. microglia
_astrocyte , location and function
– (star cell) provides physical support to neurons and clean up debris within the brain. They also produce chemicals that neurons need to fulfil their functions it is a glia cell
_oligodendrocytes , location and function
– provide support to axons and to produce myelin sheath (insulates most axons from one another) it is a glia cell
_microglia, location and function
– smallest cells, they “eat” dead and dying neurons, and they also serve as one of the representatives of the immune system in the brain it is a glia cell
Shwann cells, function
– produce myelin
_node of Ranvier
-bare portion of an axon, unmyelinated parts between myelin sheaths
_myelin sheath
-(myelinated axon) insulate axons from one another , helps to transmit information faster
HOW DO NEURONS TRANSMIT INFORMATION?
_action potential – electric impulse traveling down the axons terminal (whether or not is myelinated) _saltatory conduction – when an electric impulse goes from an unmyelinated part to a myelinated one, because it changes in voltage across a plasma membrane
_endoplasmic reticulum , what and where are they?
a system of folded membranes in the cell body, rough portions (with ribosomes) play a role in synthesis of proteins, smooth portions (without ribosomes) play a role in the synthesis of fats inside neuron
_nucleus , what and where are they? WHAT DOES PRODUCE?
– spherical DNA- containing stricter of the cell body, produces ribosomes inside neuron
_mitochondria , what and where are they?
– energy release (oxygen-consuming) inside neuron
_cytoplasm , what and where are they?
– the clear internal fluid of cells inside neuron
_ribosomes , what and where are they?
– internal cellular structures on which proteins are synthesized; they’re located on the endoplasmic reticulum inside neuron
_golgi complex , what and where are they? WHAT DOES PRODUCE?
– a connected system of membranes that packages molecules in vesicles , , wraps the products of a secretory cell, produces lysosome inside neuron
_microtubules , what and where are they?
– tubules responsible for the rapid transport of material throughout neurons inside neuron
_buttons , what and where are they?
– buttonlike endings of axon branches, which release chemical into synapses end of the neuron
_synaptic vesicles , what and where are they?
– spherical membrane packages that store neurotransmitter molecules ready for release near synapses in buttons (inside neuron)
_neurotransmitters , what and where are they?
– molecules that are released from active neurons and influence the activity of other cells in buttons (inside neuron)
fissure
big and deep sulcus
_calcarine fissure , where is it and function
– located in the occipital lobe, most of the primary visual cortex is located along its upper and lower banks
_primary visual cortex , position
(inner surface of the brain at the back, surrounds calcarine fissure) in the cortex
_primary auditory cortex , position
(located in the lower surface of the lateral fissure, or sylvian fissure) in the cortex
_primary somatosensory cortex, position and function
(receives information from the body senses, in front of central sulcus) in the cortex
_primary motor cortex , position
(in the back of central sulcus) in the cortex
stratium, location and parts
_caudate nucleus _putamen located: forebrain-telencephalon- BASAL GANGLIA
_septum , function and location
– midline nucleus located: forebrain, telencephalon, limbic system
_mammillary bodies , function and location
– pair of spherical nuclei located on the inferior surface of the hypothalamus located: forebrain, telencephalon, limbic system
_Major fissures and location
– central, lateral, longitudinal fissures located: forebrain, telencephalon
_Major gyri and location
– precentral gyrus , postcentral gyrus, superior temporal gyrus, cingulate gyrus located: forebrain, telencephalon
_Four lobes and location
– frontal, temporal, occipital, parietal lobes located: forebrain, telencephalon
_cerebral commissures , location and function
– tracts that connect the two cerebral hemispheres directly, the corpus callosum is the largest located: forebrain, telencephalon
Thalamus parts
_massa intermedia _lateral geniculate nuclei _medial geniculate nuclei _ventral posterior nuclei
_optic chiasm , what and where (???) is it?
– the point at which the optic nerves from each eye come together
_pituitary gland what and where (???) is it?
– synthesises and secretes hormones
_somatic nervous system
interacts with the environmental stimuli (voluntary) -sensory= input -motory= output
_autonomous nervous system
involuntary
_substantia nigra location and function
– the substantia nigra is an important player in brain function, in particular, in eye movement, motor planning, reward-seeking, learning, and addiction position: midbrain-tegmentum
_periaqueductal gray location and what is it
– gray matter around cerebral aqueduct position: midbrain-tegmentum
_cerebral aqueduct function and location
connects the third ventricle in the diencephalon to the fourth ventricle position: midbrain-tegmentum
_reticular formation
– set of interconnected nuclei location- hindbrain
_Blood-brain barrier, what is it function and position
– a semipermeable barrier between the blood and the brain produced by the cells in the walls of the brain’s capillaries, protects the brain
_layers where and what they are
cortex divided in 6 horizontal layers segregated by cell type. More or less uniform
_columns where and what they are
vertical structures. These columns are often thought as the basic repeating functional units of the neocortex (doesn’t make sense to understand neocortex in terms of columns because there are too many definitions in terms of anatomy, size, or function)
CFS flows where?
lateral ventricle- third and fourth ventricle- subarachnoid space- arachnoid granulations-superior saggittal sinus
arachnoid granulations
pouch shaped structures where CFS flows
_Obstructive hydrocephalus
if the fluid is interrupted at some point in its route of passage (by a tumor or baby with too little celebral aqueduct ) it generates occlusion and results in greatly increased pressure within the ventricles, because the choroid plexus continues to produce CFS. IF THE OBSTRUCTION REMAINS AND NOTHING IS DONE TO REVERSE THE INCREASED INTRACEREBRAL PRESSURE BRAIN (FATAL) DAMAGE WILL OCCUR.
_superior sagittal sinus
blood vessel that drains into the veins serving the brain
Contralateral
controls the opposite part of the body
_axon hillock
– a cone-shaped area from which the axon originates out the cell body. Functionally, the integration zone of the neuron
_ions what they are and types
dissolved in intracellular fluid (separated by the cell membrane from the extracellular fluid) _cations – positively charged _anions – negatively charged
Resting membrane potential
– resting neuron is more negative on the inside and in the outside more positive , potential difference of about -50, -80 millivolts (mV) ,or thousandths of volts. -negative polarity – mines sign before number of millivolts
_lipid bilayer
two layers of linked fatty molecules that made up cell membranes
selective permeability
cell membrane of a neuron lets in just some stuff, not everything. Throught Channels.
_ion channel what it is and types
– tube-like pore that allows ions of a specific type to pass through the membrane They selectively let potassium ions (K+) and sodium to cross the membrane _Leak channel _Gated channel
_Gated channel what it is
– selective channel that opens or closes in response to changes in the voltage of the local membrane potential; it mediates the action potential _IT IS A ION CHANNEL
_Leak channel what it is
– either potassium or sodium channel, potassium one is the most widely distributed type of channel _IT IS A ION CHANNEL
_diffusion , what it is
– force that causes molecules of a substance to diffuse from regions of high concentration to regions of low concentration _concentration gradient – variation of the concentration of a substance within a region, molecules tend to move down their concentration gradient
_concentration gradient , what it is
– variation of the concentration of a substance within a region, molecules tend to move down their concentration gradient WHEN TALKING ABOUT diffusion
_electrostatic pressure, why happens and what it is
– arises from the distribution of electrical charges rather than the distribution of molecules, it is the propensity of charged molecules or ions to move via diffusion, toward areas with the opposite charge (cations attracted to the negatively charged inside of the cell and anions are repelled by the cell interior)
_sodium-potassium pump, what is it and why it happens
– happens across a neuron’s cell membrane, it is a mechanism that pumps three sodium ions (Na+) out of the cell per every two K+ pumped in _equilibrium _Nernst equation
_equilibrium , what it is and what it explains
– equilibrate amount of ions K and Na (around -60 mv, but could be also -50, -80) _explains sodium potassium pump
_Nernst equation , what it is and what it explains
– mathematical function predicting the voltage needed to just counterbalance the diffusion force pushing an ion across a semipermeable membrane from the side with a high concentration to the side with a low concentration _explains sodium potassium pump
_potential , definition
– separation of charges
_action potential , what it is and how it is triggered
– brief and large changes in neuronal polarization, electric impulse that travels along the axon to the presynaptic axon terminals Triggered by: _hyperpolarization: increase in membrane potential, it increases negative distance from zero _depolarization: decrease in membrane potential, it decreases negative distance from zero (makes the inside of the neuron more like the outside)
_hyperpolarization: what it is and what it triggers
increase in membrane potential, it increases negative distance from zero TRIGGERS ACTION POTENTIAL
_depolarization: what it is and what it triggers
decrease in membrane potential, it decreases negative distance from zero (makes the inside of the neuron more like the outside) TRIGGERS ACTION POTENTIAL
_local potential what it is
– graded and diminish over time and distance, also arise at synapses in response to other neurons. It is initiated by stimulation at a specific site, which is a graded response that spread passively across the cell membrane, decreasing in strength with time and distance
_Threshold point
– stimulus intensity that is just adequate or trigger an action potential
_all or none property
– the fact that the amplitude of the action potential is independent of the magnitude of the stimulus
_after potential
– it is difficult after an action potential to go back to the baseline membrane, many axons exhibit electrical oscillations immediately following the spike
_voltage-gated Na+ channel
– sodium selective channel that opens or closes in response to changes in the voltage of the local membrane potential; it mediates the action potential
_Axonal membrane when is it refractory and what does refractory means? What are the phases?
it is refractory (unresponsive) to second stimulus , apply pairs of stimuli that are spaced closer together reveals that , beyond a certain point only the first stimulus is able to elicit an action potential Refractory phases _absolute refractory phase _relative refractory phase
_absolute refractory phase WHAT IS IT?
– brief period immediately following the production of an action potential where there is complete insensitivity to stimuli IT IS THE FIRST REFRACTORY PHASE
_relative refractory phase WHAT IS IT?
– a period of reduced sensitivity during which only strong stimulation produces an action potential IT IS THE SECOND REFRACTORY PHASE
_conduction velocity WHAT IS IT
– speed at which an action potential is propagated along the length of an axon
_saltatory conduction WHAT IS IT
– the form of conduction that is characteristic of myelinated axons, in which the action potential jumps from one node of Ranvier to the next
_neurotransmitter (or synaptic transmitter)
– the chemical released from the presynaptic axon terminal that serves as the basis of communication between neurons
_postsynaptic potentials WHAT IS IT
– local potential that is initiated by stimulation at a synapse (liberation of neurotransmitters at synapse), can vary in amplitude, and spreads into passively across the cell membrane, decreasing in strength with time and distance
_synaptic delay WHAT IS IT
– the brief delay between the arrival of an action potential at the axon terminal and the creation of a postsynaptic potential
_Excitatory postsynaptic potential (EPSP) WHAT IS IT
– a depolarizing potential in the postsynaptic neuron that is caused by excitatory connections. EPSPs increase the probability that the postsynaptic neuron will fire an action potential TYPE OF SYNAPSE
_inhibitory postsynaptic potential (IPSP) WHAT IS IT
– a hyperpolarizing potential in the postsynaptic neuron that is caused by inhibitory connections. IPSPs decrease the probability that the postsynaptic neuron will fire an action potential TYPE OF SYNAPSE
_spatial summation
– the summation at the axon hillock of postsynaptic potentials from across the cell body. If this summation reaches threshold, an action potential is triggered
_temporal summation
– the summation of postsynaptic potentials that reach the axon hillock at different times. The closer in time that the potentials occur, the more complete the summation
_phagocytosis what it is and where it happens
– the process by which cells engulf and digest other cells or debris caused by cellular degeneration -glia cells, astrocyte
Telencephalon/Diencephalon DEVIDED BY ???
CHIASMA OPTICUM (optic nerves)
_cerebral commissures, what is it
– tracts that connect the two cerebral hemispheres directly, the corpus callosum and the anterior commissure are the largest
corpus callosum, what is it
one of the largest cerebral commissures together with anterior commissure
anterior commissure, what is it
one of the largest cerebral commissures together with corpus callosum
cerebral aqueduct, what and where is it
is within the mesencephalon (or midbrain), contains cerebrospinal fluid (CSF), and connects the third ventricle in the diencephalon to the fourth ventricle within the region of the mesencephalon and metencephalon, located dorsal to the pons and ventral to the cerebellum.
_area postrema, where and what is it
– a region of the medulla where the blood- brain barrier is weak, poisons can be detected there and can initiate vomiting
_axoplasmic transport
– an active process by which substances are propelled along microtubules that run the length of the axon
_anterograde axoplasmic transport (same as orthodromic conduction)
– movement from the soma (cell body) to the terminal bottoms IT IS AN AXOPLASMIC TRANSPORT
_retrograde axoplasmic transport (same as antidromic conduction)
– movement from the terminal bottoms to the soma (cell body) IT IS AN AXOPLASMIC TRANSPORT
_cytoskeleton , what is it and parts
– formed of microtubules and other protein fibres, linked to each other and forming a cohesive mass that gives a cell its shape. PARTS: microtubule
_microtubule, what is it and location
– a long strand of bundles of protein filaments arranged around a hollow core, part of the cytoskeleton and involved in transporting substances from place to place within the cell
_enzymes, what is it
– molecule that controls a chemical reaction, combining two substances or breaking a substance into two parts
_Chromosomes (long strands of DNA), what is it
– contain genetic information, and when active portions of chromosomes cause production of another molecule,
_ messenger ribonucleic acid (mRNA) , what is it
– a macromolecule that delivers genetic information concerning the synthesis of a protein from a portion of a chromosome to a ribosome
_deoxyribonucleic acid , what is it?
DNA
_exocytosis , what is it and where it happens
– a process that includes the secretion of a substance by a cell through means of vesicles, the process by which neurotransmitters are secreted HAPPENS IN GOLGI COMPLEX
_lysosome , what is it and location
– an organelle surrounded by membrane, contains enzymes that break down waste products LOCATED IN GOLGI COMPLEX
_interneurons , what are they
– their function is to integrate the neural activity within a single brain structure, not to conduct signals from one structure to another. They have a short axon or no axon
_electrode , what is it
– a conductive medium that can be used to apply electrical stimulation or to record electrical potentials
_microelectrode, what is it
– a very fine electrode, generally used to record activity of individual neurons
_graded responses , what are they and types
– the amplitudes are proportional to the intensity of the signals that elicit them (weak signals cause small postsynaptic potentials, strong ones cause big ones) TYPES: _inhibitory postsynaptic potential (IPSPs) _Excitatory postsynaptic potential (EPSPs)
_membrane potential
– the electrical charge across a cell membrane, the difference in electrical potential inside and outside the cell
_resting potential
– the membrane potential of a neuron when it is not being altered by excitatory or inhibitory postsynaptic potentials
ACTION POTENTIALS NOT GRADED RESPONSES, but…………………….?
ALL OR NONE response
_all or none property
– the principle that once an action potential is triggered in an axon, it is propagated, without decrement, to the end of the fibre Supported by _rate law
_rate law
– the principle that variations in the intensity of a stimulus or other information being transmitted in an axon are represented by variations in the rate at which that axon fires SUPPORTS ALL OR NONE PROPERTY
_conduction velocity
– speed at which an action potential is propagated along the length of an axon
_neurotransmitter (or synaptic transmitter)
– the chemical released from the presynaptic axon terminal that serves as the basis of communication between neurons
_saltatory conduction
– the form of conduction that is characteristic of myelinated axons, in which the action potential jumps from one node of Ranvier to the next.
SYNAPTIC TRANSMITION, steps and what is it?
Transporting information across a synapse
