Appendix Flashcards
cell
basic biological unit of life, defined by a membrane or wall that encloses cytoplasm and, in eukaryote organisms (including all plants and animals), a nucleus
neuroglial cells
several types of non-neural cells found in the peripheral and central nervous systems that carry out a variety of functions that do not directly entail signalling
cell body/soma
portion of a neuron that houses the cell’s nucleus; axons and dendrites typically extend from the neuronal cell body
organelle
subcellular component visible in a light or electron microscope (e.g., nucleus, ribosome, endoplasmic reticulum)
axon
extension of a neuron that carries the action potential from the nerve cell body to a target
dendrite
extension of a neuron that receives synaptic input; usually branches near the cell body
neural circuit
collection of interconnected neurons mediating a specific function
axon hillock
initial portion of an axon, closest to the cell body; the point where action potentials are typically initiated
ion channels
membrane protein that uses the passive energy of concentration gradients (created by ion pumps) to allow the passage of ions across the cell membrane
ion pump
membrane protein that uses metabolic energy to create ion concentration gradients across neuronal membranes
chemical synapse
synapse that uses a chemical transmitter agent; the most common type of synapse in the mammalian brain
synaptic cleft
small space between a presynaptic and postsynaptic element across which neurotransmitters must diffuse when released
neurotransmitter receptor
molecule embedded in the membrane of a postsynaptic cell that binds a neurotransmitter
synaptic vesicle
organelle at a synaptic ending that contains neurotransmitter agents
afferent neuron
axon that conducts action potentials from the periphery to more central parts of the nervous system
efferent neuron
axon that conducts information away from the central nervous system
interneuron
neuron in a circuit that lies between primary sensory and primary effector neurons;
neuron that branches locally to innervate other neurons
spinal reflex arc
circuit that includes the afferent to efferent components of a response at the level of the spinal cord
sensory neuron
nerve cell that is involved in sensory processing
motor neuron
nerve cell that innervates skeletal or smooth muscle
excitatory
pertaining to a synaptic effect that brings the membrane of the postsynaptic cell closer to threshold, thereby making firing of the postsynaptic cell more likely
inhibitory
pertaining to a synaptic effect that makes the firing of the postsynaptic cell less likely
electrophysiological recording
various methods of recording electrical activity in the nervous system
synaptic potential
membrane potential change (or a conductance change) generated by the action of a chemical transmitter agent. Synaptic potentials allow the transmission of information from one neuron to another
receptor potential
membrane potential change that arises at a sensory receptor in the periphery due to a stimulus from the environment
sensory system
components of the central and peripheral nervous systems concerned with processing information arising from a particular stimulus category (e.g., light, sound stimuli)
motor system
components of the central and peripheral nervous systems that support motor behaviour
effector
muscle or gland that provides the output of neural processing
somatic motor system
components of the motor system that support skeletal movements mediated by the contraction of skeletal muscles
visceral/automatic motor system
very large component of the nervous system that is dedicated to proper functioning of the viscera (all the organs that maintain the well-being of the body and brain)
hyperpolarization
changing the membrane potential of a neuron in the negative direction, driving it away from threshold and making it less likely to initiate an action potential
depolarization
changing the membrane potential of a neuron in the positive direction, which initiates an action potential if threshold is reached
threshold potential
membrane potential at which a nerve cell fires an action potential
central nervous system
brain and spinal cord of vertebrates (by analogy, the central nerve cord and ganglia of invertebrates)
peripheral nervous system
all the nerves and neurons that lie outside the brain and spinal cord
nucleus (pl. nuclei)
anatomically discrete collection of neurons within the brain; typically serves a particular function
subcortical
pertaining to brain structures other than the cerebral cortex
tract
major white matter (axonal) pathway in the brain
myelin
membranous wrapping of axons by certain classes of glial cells that makes brain regions with axonal pathways look whitish
gray matter
regions of the central nervous system that are rich in neuronal cell bodies; includes the cerebral and cerebellar cortices, the nuclei of the brain, and the central portion of the spinal cord
white matter
large axon tracts in the brain and spinal cord; these tracts have a whitish cast when viewed in freshly cut material
sensory ganglia
collections of neurons in the peripheral nervous system that comprise the cell bodies of afferent sensory neurons
dorsal root ganglia
segmental sensory ganglia of the spinal cord that contain the first-order sensory neurons whose axons project centrally
cranial nerve ganglia
sensory or motor ganglia associated with the 12 cranial nerves
autonomic ganglia
collections of autonomic motor neurons outside the central nervous system that innervate visceral smooth muscles, cardiac muscle, and glands
sympathetic division
component of the autonomic motor system that contributes to the mobilization of energy to prepare the body for action
parasympathetic division
component of the autonomic motor system that mediates restorative metabolic functions
enteric division
division of the autonomic motor system that is specifically concerned with regulating the behaviour of the gut
brainstem
portion of the brain that lies between the diencephalon and the spinal cord; comprises the midbrain, pons, and medulla
forebrain
anterior portion of the brain that includes the cerebral hemispheres (the telencephalon and diencephalon)
midbrain
most rostral of the three components of the brainstem; identified by the superior and inferior colliculi on its dorsal surface, and the cerebral peduncles on its ventral aspect
pons
one of the three components of the brainstem, lying between the midbrain rostrally and the medulla caudally
medulla
most caudal of the three components of the brainstem, extending from the pons to the spinal cord
cranial nerves
nerves projecting from the cranial motor nuclei to sense organs or muscles, mostly of the face, head, eyes, or neck
superior colliculi
paired structures that form part of the roof of the midbrain; important in orienting movements of the head and eyes
inferior colliculi
paired structures on the dorsal surface of the midbrain; concerned with auditory processing
substantia nigra
nucleus at the base of the midbrain that receives input from a number of cortical and subcortical structures.
The dopaminergic cells of the substantia nigra send their output to the caudate or putamen
ventral tegmental area (VTA)
part of the midbrain that contains many dopaminergic neurons and is important for reward and learning
spinal cord
portion of the central nervous system that extends from the lower end of the brainstem (the medulla) to the cauda equina. It sits within a protective tube, or column, created by the vertebrae of the spine
dorsal horn
dorsal portion of the spinal cord gray matter, which contains neurons that process sensory information
lateral horn
lateral portion of the spinal cord gray matter, which mediates sympathetic motor responses
ventral horn
ventral portion of the spinal cord gray matter, which contains the primary motor neurons
cerebral hemisphere
two halves of the forebrain
gyri
ridges in the folded cerebral cortex
sulcus (pl. sulci)
valleys that arise from the folding of the cerebral hemisphere between gyri
fissure
deep cleft in the surface of the brain; can be either between two lobes (e.g., the lateral fissure between the frontal and temporal lobes) or an especially deep sulcus (e.g., the calcarine fissure in the occipital lobe)
cerebral cortex
superficial gray matter of the cerebellum
lobes
four major regions of the cerebral cortex: the frontal, parietal, occipital, and temporal lobes
central sulcus
major sulcus on the lateral aspect of the cerebral hemispheres that forms the boundary between the frontal and parietal lobes. Its anterior bank contains the primary motor cortex; the posterior bank contains the primary sensory cortex
precentral gyrus
gyrus that lies just anterior to the central sulcus; contains the primary motor cortex
motor cortex
region of the cerebral cortex anterior to the central sulcus that is concerned with motor behavior; includes the primary motor cortex in the precentral gyrus, and associated premotor cortical areas in the frontal lobe
lateral/Sylvian fissure
cleft on the lateral surface of the human brain that separates the temporal and frontal lobes
insula
portion of the cerebral cortex that is buried within the depths of the Sylvian fissure (lateral sulcus)
postcentral gyrus
gyrus that lies just posterior to the central sulcus; contains the primary somatosensory cortex
somatosensory cortex
region of the parietal lobe that receives information about touch, pressure and vibration at the body surface
olfactory tracts
projection from the olfactory bulbs to higher olfactory centers
olfactory bulbs
olfactory relay station that receives axons from the olfactory cranial nerve and transmits this information via the olfactory tract to higher centers
olfactory nerve
first cranial nerve; runs from the olfactory mucosa to the olfactory bulb
parahippocampal gyrus
cortical gyrus in the medial temporal lobe adjacent to the hippocampus; plays a role in declarative memory, emotion, and responses to olfactory stimuli
hippocampus
specialized cortical structure located in the medial portion of the temporal lobe; in humans, concerned with declarative memory, among many other functions
uncus
part of the cerebral cortex near the hippocampus and associated with hippocampal function
pyriform cortex
component of the cerebral cortex in the temporal lobe pertinent to olfaction; so named because of its pearlike shape
optic chiasm
crossing of optic nerve axons from the nasal portions of the retinas in humans and other mammals such that the temporal visual fields are represented in the contralateral cerebral hemispheres
hypothalamus
collection of small but critical nuclei in the diencephalon that lies just inferior to the thalamus; governs reproductive, homeostatic, and circadian functions
mammillary bodies
small prominences on the ventral surface of the diencephalon; functionally, part of the caudal hypothalamus
cerebral peduncles
major fiber bundles that connect the brainstem to the cerebral hemispheres
parieto-occipital sulcus
sulcus between the occipital and parietal lobes of the cerebral hemispheres
calcarine sulcus
major sulcus on the medial aspect of the human occipital lobe; the primary visual cortex lies largely within this sulcus
cingulate sulcus
sulcus on the medial aspect of the cerebral hemispheres defined by the cingulate gyrus
cingulate gyrus
gyrus that surrounds the corpus callosum
corpus callosum
large midline fiber bundle that connects the cortices of the two cerebral hemispheres
diencephalon
portion of the brain that lies just rostral to the brainstem; comprises the thalamus and hypothalamus
thalamus
collection of nuclei that forms the major component of the diencephalon. Has many functions; a primary role is to relay sensory information from the periphery to the cerebral cortex
pulvinar
nucleus of the thalamus that mediates interactions among several sensory association areas of the cortex
tegmentum
central gray matter of the brainstem
cerebellum
prominent hindbrain structure that is concerned with motor coordination, posture, balance, and some cognitive processes; composed of a three-layered cortex and deep nuclei, and attached to the brainstem by the cerebellar peduncles
cereberral cortex
superficial gray matter of the cerebral hemispheres
folia (sing. folium)
ridges and valleys that are apparent in the cerebellar cortex
caudate
one of the three major nuclei that make up the basal ganglia in the cerebral hemispheres; together with the putamen, serves as the input structure for the globus pallidus
damage to the caudate nucleus leads to hyperkinetic movement disorders such as Huntington’s disease
putamen
one of the three major nuclei that make up the basal ganglia
striatum
input nuclei of the basal ganglia, consisting of the caudate and the putamen.
so called because of the striped appearance of these structures in brain sections
globus pallidus
one of the three major nuclei that make up the basal ganglia in the cerebral hemispheres; relays information from the caudate and putamen to the thalamus
basal ganglia
group of nuclei lying deep in the subcortical white matter of the frontal lobes that organize motor behavior
the caudate, putamen, and globus pallidus are major components of the basal ganglia; the subthalamic nucleus and substantia nigra are often included
The basal ganglia are mainly associated with movement (primarily learning and remembering how to do something). They are also associated with language, attention, and planning
septal/basal/forebrain nuclei
complex of primarily cholinergic nuclei that lies between the hypothalamus in the diencephalon and the orbital cortex of the frontal lobes; concerned with alertness and memory, among other functions
amygdala
collection of nuclei in the temporal lobe that forms part of the limbic system; its major functions concern autonomic, emotional, and sexual behavior
anterior commissure
small midline fiber tract that lies at the anterior end of the corpus callosum; like the callosum, it connects the two hemispheres
fornix (pl. fornices)
axon tract, best seen from the medial surface of the divided brain, that interconnects the hypothalamus and hippocampus
internal capsule
large white matter tract that lies between the diencephalon and the basal ganglia; contains, among others, sensory axons that run from the thalamus to the cortex and motor axons that run from the cortex to the brainstem and spinal cord
lateral ventricles
major ventricle in each of the two cerebral hemispheres
third ventricle
midline component of the ventricular system at the level of the diencephalon
cerebral aqueduct
portion of the ventricular system that connects the third and fourth ventricles
fourth ventricle
ventricular space that lies between the pons and the cerebellum
cerebrospinal fluid
normally clear and cell-free fluid that fills the ventricular system of the central nervous system; produced by the choroid plexus in the lateral ventricles
choroid plexus
specialized epithelium in the ventricular system that produces cerebrospinal fluid
stroke
clinical and neuropathological result of interruption of the blood supply to one or another region of the brain
brain lesion
localized region of brain damage
ischemia
paucity or complete lack of blood supply; a common cause of stroke
circle of Willis
ring of arteries at the base of the midbrain; connects the posterior and anterior cerebral circulation
reticular formation
core of the brainstem
anterior
in front of
superior
above
inferior
below
posterior
behind
dorsal
back
ventral
front
axial
horizontal (vízszintes)
sagittal
dividing the two hemispheres
coronal
frontal (függőleges)
rostral
direction toward the nose (beak/csőr)
caudal
direction to the base of the skull (tail/farok)
contralateral
on the other side
ipsilateral
on the same side
