PSICOFISIOLOGIA: English glossary

"Phantom limb” effect: Perception of the sensation that an amputated limb is still connected to our body.
Acetylcholine (ACh): Specific neurotransmitter in the somatic nervous system synapses and the ganglia regions synapses. Synthesized in cholinergic neurons and composed by choline and acetyl-CoA. The main centers where it can be found are the cholinergic nucleus in basal forebrain and the Meynert nucleus.
Adenohypophysis: Endocrine organ, also called anterior pituitary gland, which function is to regulate processes such as growth and reproduction by secreting hormones like oxytocin and vasopressin.
Adrenal gland: Endocrine glands that are located on kidney and its function is producing hormones like adrenaline.
Agnosia: Ability to perceive visually, but not being able to recognize it.
Aldosterone: A mineralocorticoid hormone secreted by the cortex of the adrenal gland. Its function is to regulate the level of minerals and fluid in the kidney.
Alpha motoneurons type 1: They have a slow transmission and innerves aerobic muscle and red muscle.
Alpha motoneurons type 2: They have a fast transmission and innerves anaerobic muscle and white muscle.
Alpha waves: Waves produced during the wakefulness when the subject is relaxed. The frequency is between 8 and 12 Hz.
Amacrine cell: Cell that connects horizontally the bipolar neurons and the ganglion neurons together. It controls the dilation of the pupil depending on the light.
Amplitude: Peak distance of a wave respect the equilibrium position.
Ampulla: Protuberance which contains the “crista”, a layer of cells where the hair cells of the semicircular canals are grouped. The dome, where the cilium are projected, is a gelatinous mass that divides off the ampulla’s canal light.
Amyotrophic lateral sclerosis: Pathology that causes motor neurons loss.
Androgen: Steroid hormones that stimulate and regulate the development of male characteristics as well as the activity of the male sex organs.
Anosmia: Inability to smell. It happens when the tissue surrounds the cribriform plate and cut the olfactory axons because of some injury or shock.
Anterior hypothalamic suprachiasmatic nucleus: Nucleus responsible for the regulation of circadian rhythms. Receives inputs from the retina. The captation of light helps to regulate the rhythms. Their efferents go to pineal gland and the paraventricular area. In this area out axons that synapse with the hypothalamus.
Anterolateral system: Somatosensory pathway dedicated to pain and temperature.
Arousal: Attention warning system that keeps the organism in a state of full consciousness, and helps to follow stimulus.
Ascending reticular activating system (ARAS): System responsible for maintaining wakefulness. It consists of multiple neuronal groups that use different neurotransmitters: locus coeruleus (noradrenaline), Rafe nuclei (serotonin), tuberomamilar nuclei (histamine), brainstem neurons (acetylcholine and glutamate), medulla oblongata neurons (acetylcholine), ventral tegmental area (dopamine) and lateral hypothalamus (hypocretins or orexins). The ascending pathways are responsible for the cortical activation, especially inputs to the thalamus. Descendants pathways activate the autonomic nervous system and motor neurons. This system sends axons to preoptical ventrolateral hypothalamus area to inhibit its inhibitory activity.
Attention: Cognitive mechanism that allows processing relevant stimulus and actions, and ignoring those that may be distracting or not relevant for the organism.
Attenuation reflex: Ear bones’ muscles contraction that prevents its movement because of a loud sound.
Auditive pavilion (or pinna): Cartilaginous structure covered of skin that constitutes the visible part of the ear. It presents a funnel shape with foldings which subserve the stimuli source detection.
Auditory association cortex: Cortex area which covers the primary area. Receives information from the primary area and the geniculate nucleus. Includes the Wernicke area, which is important for the language. This area is specially important for sound combinations’ identification with different frequencies.
Auditory Nerve: Formed by the axons of the neurons of the spiral ganglion, the first neurons of the auditory pathway, which innerve the inner hair cells.
Basal ganglia: large motion controller. Set of subcortical structures consisting of the caudate, putamen (the two form the striatum), the globus pale, the subthalamic nucleus and substantia nigra. Its function is to facilitate movement initiation and filter unwanted movements. Another function is to control procedural memory.
Basilar membrane: Membrane placed inside the cochlea. The end of the cochlea is wide and flexible, while the closest side to the oval window is narrow and rigid. The waves that is produced in the liquid, make the mambrane vibrate, and for ech frequency there’s assigned an end vibration position. The higher the vibration is, the closer to the base will be found its vibration area.
BDNF: Protein that proceeds as a neurotrophic which increases cause the environmental enrichment action, that favours to visual cortex maturation and GABA neuron inhibitory system.
Beta waves: Waves produced during the wakefulness when de subjecte is alert, focused and active. The frequency is between 13 and 30 Hz.
Bipolar neuron: It’s a neuron type that has two extensions, an axon and a dendrite.
Bitter taste: One of the main basic tastes, represented a wide range of substances. It feels unpleasant because many harmful substances to the body have this taste.
Blind spot: Area where the image which is formed in the retina matches with the optical nerve disk to bring the information from the eye to the brain.
Blindsight: Visual disorder in people with primary visual cortex damage. This people can perceive visually; they can locate objects in the space, but they aren’t able to distinguish these objects.
Brainstem: Rhythmic movements. It starts voluntarily but then keeps in an automatic way (reflex).
Brodmann area 1: Area responsible for discriminating textures and cutaneous stimulus.
Brodmann area 2: Area responsible for distinguishing shapes and sizes and also integrating the cutaneous stimulus and touch.
Brodmann area 3a: Area which is responsible for proprioception.
Brodmann area 3b: Area which is responsible for proprioception.
Catecholamines: Substances synthesized from tyrosine (Tyr) formed by a catechol group and an amino group. The group of catecholamines includes adrenaline, dopamine and noradrenalin.
Central olfactory pathways: Axons from the olfactory tracts are branched and comes in many regions of the forebrain, included the olfactory cortex. Neocortex is reached only through a pathway which synapses in the dorsal nucleus.
Central vestibular pathways: Coordinates and integrates the information about the head and body movements and uses it to control the motoneuron’s activity which adjusts the head, eyes and body’s position.
Cerebellum: Large motion controller. Compares and adjusts what we want to do with what we are doing. Receives information from the somatosensory system and adjusts it to the plan which is formed in prefrontal. Coordinates, adjusts, improves and smooths the movements.
Cerebral Rhythms: Activation pattern of a set of neurons. There are different ones depending on the state of the subject. During sleep, the neurons of thalamus initiate a synchronous rhythmic activity, preventing the processing of external stimuli.
Chemical energy: Energy that activates nociceptors (wounds).
Choroid layer: Brown layer under the sclerotic layer of the eyeball. It has a pigment, melanin.
Circadian rhythms: Rhythm of some physiological processes linked to nearly a day. One of them, sleep propensity, has a peak near 11pm and in 3 pm, but less sharply. These points coincide with the minimum points of the drop in body temperature. Cortisol, on the other hand, is secreted more in the morning, making us to stay awake.
Cochlea: Bone structure with a seashell shape with three cavities, where it is placed the basilar membrane and the corti organ, in charge with the auditory transduction.
Cochlear nuclei (dorsal and ventral): There is a dorsal nucleus and a ventral nucleus in each side of the medulla oblongata and both receive parallel information of the ipsilateral cochlea. They are the second neurones of the auditory pathway.
Coding force: Is conducted through the shock rate of the upper motor neurons. the more is the shock rate, the more is the force.
Collicular pathway: Path that reaches the upper collicles. Its function is to move the eye in function due to a stimulus.
Cone cell: Specialized receptor cells in daytime and color vision. These are more complex than rod cells.
Corticonuclear tract: On trunk motor nucleus. Responsible of muscles’ voluntary movements.
Corticospinal tract: Placed on medulla.
Covert Attention: Attention that causes a physiological response non-manifest.
Cribriform plate: Thin layer of bone where small sets of axons penetrate.
Critical period: Period where neurons presents a high sensitivity for obtain environment signals. During this period, it is established synapses which won’t be made after this period although having the same stimulation.
Decussation: Place where pathways intersect.
Deiters cell: Support cells found in the organ of Corti.
Delta waves: Waves produced during slow waves sleep. They have a lower frequency of 3.4Hz
Dermatome: Portion of skin where a spinal nerve receives information.
Discriminator touch: Touch to distinguish size, shape and structure of objects and their movements on the skin (vibrations, pressure).
Dopamine: Neurotransmitter with motor functions and involved in the regulation of short-term memory, emotional control and reward systems.
Dorsal column system: With the spinothalamic tract, is the natural route where the pain information rises to the brain from the somatosensory system.
Dorsal pathway: Pathway that passes through the parietal lobe and processes the movement and depth.
Dreams: Thoughts, images, acquired memories during the wakefulness which appears in the REM sleep to be activated the cholinergic neurons which activates the cerebral cortex. It activates areas like basal ganglia, limbic system...
Ear canal: Channel which goes from the pinna till the tympanic membrane, where the middle ear starts.
Effector muscle tissue: Set of cells capable to change its structure to become smaller (contraction).
Effector tissue: Set of cells which converts action potentials into muscle contraction (mechanical energy) and make the synthesis and release of substances.
Electroencephalography: Technique that mesures the electrical activity of the neurons of the brain cortex. This technique involves placing electrodes on the head with conductive paste. The relative activation between groups is what you see in the electroencephalogram.
Electromyography: Similar to EEG. This technique measures the electrical activity of the skeletal muscles.
Electrooculography: Technique to measures the eye movements.
Encapsulated receptor: Receptors that have developed a structure without nerves around them, so they can respond to stimulus.
Endolymph: Extracellular liquid with high concentrations of K and low concentrations of Sodium. The concentrations are contrary to the perilymph. This difference helps to the auditory transduction.
Endplate: Membrane region of the muscle fiber where the synapses occurs..
Environmental enrichment:Manipulation process of environment’s conditions which is used to improve environmental quality and intensity. Stimuli are complex. This stimulation improve provokes Central Nervous System changes. This process implies gene’s expression changes.
Epigenetic: Heritable changes in DNA and histones which it doesn’t implicate alterations in the nucleotides’ sequence and modifies the chromatin structure and condensation, which affects the gene expression and fenotip.
Estrogens: Steroidal hormones. In people with female genitalia, the role of estrogens (estradiol and estriol) is stimulating the development of different characteristics during puberty (breast growth, increased adipose tissue, widening hips ...) and regulating processes such as menstruation. In people with male genitalia, estrogens (such as estradiol) are presented in smaller quantities, and are important in the development of sperm.
Eustachian tube: Canal which links the tympanic cavity with the bucal cavity. It is controlled by a valvule. Its function is to balance the air pressure with the tympanic cavity regard the outside pressure.
Evoked potential: Set of noninvasive tests that are used to study the electric activity of neurons.
Execution: Brainstem and medulla.
Experience: The fact of having seen , felt or known something.
Exteroceptive signals: Environment objects position.
Extra-striate cortex: Cortex that separates the information and then distributes it in successive analyses.
Eyeball: Vision organ composed by the iris, the pupil and the cornea.
Facial Nerve: Also known as the cranial nerve VII, is a nerve that contains sensory and motor fibers. This nerve controls the facial expression muscles and is responsible for receiving taste information perceived in the anterior part of the tongue.
Final common pathway: Pathway where motor pathways ends.
Flavorings: Components of the substances we eat reporting on nutritional aspects of these.
Flavour: Impression caused by substances perceived by the chemical senses (smell and taste) and the somatosensory system.
Flexion and extension cross reflex: Reflex that enables that when we lift up one leg, the other remains stretched to avoid us to fall.
Flexor withdrawal reflex: Reflex that make us retire a member making a contraction when we receive a painful stimulus.
Flexor-extensor rule: The most ventral areas of the medulla controls the extensor muscles and simultaneously, the most dorsal ventral areas horn controls the flexor muscles.
Fovea: Retina area with a high level of cone cells which is specialized in color vision.
Free receptor: Termoceptors and nociceptors. Mielinized axons have a small diameter so the action potential is driven slow. It is located in the archaic pathways.
Fusiform gyrus: Neurons that only respond to faces, located in the area specialized in processing faces in the inferior temporal cortex.
GABA (γ-aminobutyric acid): Neurotransmitter related to the regulation of neuronal excitability.
Ganglion neuron: First order sensory neurons that form the optic nerve.
Geniculate-striate pathway: Primary visual pathway divided into two paths y ganglion cells.
Glomeruli: Spherical Structures of each bulb entry’s layer. Each Glomeruli converge the terminations of 25000 primary olfactory axons (reception cells’ axons, which comes from a wide region of the olfactory epithelium), on the dendrites of about 100 second level’s olfactory neurons. It only receives entries from receptor cells that express a gene from a determinate receptor protein. Each Glomeruli measures about 50-200mm diameter.
Glossopharyngeal nerve: Also known as the cranial nerve IX, is a nerve whose function is to receive sensitive information from the posterior mouth area (including the pharynx, tongue ...) and the middle ear and ear tube. It also receives sensory information about the arterial pression, and provides parasympathetic fibers to the parotid gland.
Golgi tendon organ: Propioceptor located in the tendons.
Hair cells of the otoliths organs: The taller cilium of the hair cells is called kinocilium. When the cilium bends to the kinocilium direction, it makes a depolarizing receptor potential (excites). If it bends to the other side, the cell is hyperpolarized (inhibited). Due to the sacculi and utricle’s mirror arrangement, when a given movement excites the hair cells to a side, it tends to inhibit the hair cells of the other side, making any movement or acceleration provoke excitation or inhibition in some hair cells.
Hair Cells: Cells with stereocilia that allow with their deflection the transduction from a mechanic signal to a neural signal. They are located on the basilar membrane and the reticular lamina (vertical plane) and between the pillars of Corti (horizontal). Cells between Mediolus and pillars are the inner cells and the cells that are between the pillars are the outer cells. The stereocilia of the outer hair cells arrive above the reticular lamina, penetrating the endolymph.
Hair follicle: Phasic receptor that provides information about the hair sensations which is a form of touch sensation.
Helicotrema: Orifice of the basilar membrane that connects scala vestibuli with scala tympani. It is located at the end of the basilar membrane.
Horizontal cell: Cells that connect horizontally the receptor cells. Its function is to define the contrasts and contours.
Hypnogram: Graphical representation of the measured data in a polysomnography.
Hypocretin neurons: Neurons in the lateral hypothalamus. They are ecitatory, kept wakefulness, stailizing the activity of ARAS. They avoid sudden changes of state.
Hypothalamic pathway: Pathway that reaches the suprachiasmatic nucleus, responsible for the regulation of day/night cycle.
Incus: The middle ear second bone. It is linked with malleus and stapes.
Indirection: Proceeds on tracts (medial and lateral) which starts at brainstem.
Inferior Colliculus: Nucleus located in the tectal part of the midbrain. Integrates the processed information in the olivary nucleus and lemniscal. They are very important to process the specific stimulus properties.
Inhibition of return: Attentional mechanism that allows to make an efficient exploration of the environment, avoiding to explore areas that have already been attended.
Inner ear: ear’s segment which includes the cochlea and the labyrinth.
Insomnia: Difficulty tostart or maintain the sleep, waking up early or not having a restful sleep. It can be caused by stressful situations. It’s related with high levels of cortisoland cerebral waves alterations.
Insular cortex: Structure located deep in the lateral surface of the brain, in the Sylvian fissure. It has an important role in emotions and feelings.
Intensity: Pressure difference between the air blocks. It is perceived thanks to the variation of the cochlear nerve’s axons activation rate.
Involuntary attention: A reflexive attentional subprocess caused by an external stimulus that attracts the attention of the organism.
Ionotropic receptors: Proteins that form a ion channel that allows the entrance of molecules in the cell modifying the permeability of the cell membrane.
Iris: Colored and circular membrane that separates the eye of the previous camera above the later.
K Complexes: Sharp and sudden waves that appear in Stage 2. They have a large amplitude in the EEG.
Knee jerk: Shows that the stretch reflex works well. When we hit the patella tendon, this relaxes and the stretch reflex leaves it into an adequate standard of contraction again.
Lateral corticospinal tract: Begins at cerebral cortex and ends at the medulla. Controls limbs muscles’ voluntary movements
Lateral inhibition: Mechanism that avoids the activation of neural pathways when the activation is insufficient.
Lateral line organs: It is present in every vertebrate aquatic animal. Small cavities located along the animal’s sides. Each cavity contains accumulated sensorial hair cells. It is used to perceive vibrations or pressure changes in the water. Its mechanical sensitivity of the hair cells were being adapted till being used in the internal ear’s structure which were derived from the lateral line.
Law of reciprocal innervation: It is the law which requires that when a muscle contracts, the antagonistic muscle relax.
Limbic system: System composed by several brain structures (hypothalamus, hippocampus, thalamus, amygdala...) managing physiological responses to emotional stimulus. Its function is related to memory, attention, sexual instincts, emotions, personality and behavior.
M ganglion cell: Cells that project information to parvocellular cell layers in the thalamus.
Malleus: Bone from the middle ear which is adjusted to the tympanic membrane and to the incus, with which it makes a rigid connection.
Mechanical energy: Energy that activates mechanoreceptors.
Mechanical nociceptors: Nociceptor related to mechanical energy.
Mechanoceptor: Type of encapsulated receptor.
Medial routes: It controls the body axis (posture and global trunk movements).
Mediolus: Central pillar of the cochlea.
Meissner corpuscles: Phasic receptors that provide information about texture.
Melanin: Pigment derived from tyrosine. It can be found on the choroid layer of the eye.
Melaninergic neurons: Neurons that has a neurotransmitter, the melanin. They are located in the pineal gland. It promotes the sleep
Merkel discs: Tonic receptor that brings information about pressure on a surface.
Metabotropic receptors: Proteins that form a channel that allows the entrance of molecules in the cell indirectly through secondary messengers.
Midbrain pathway: Path that reaches the pretectum (or pretectum area, which is a hypothalamic region) and controls the contraction and relaxation of the iris.
Middle ear: part between the outer ear and the inner ear. It forms the tympanic cavity, which contains the specific bones and muscle chain coupled to its chain and allows its movement.
Monoaminergic neurons: Locus coeruleus neurons, Rafe nucleus and tuberomammillary nucleus that activates the wakefulness in the flick-flock system of the sleep. They belong to ascending reticular activating system
Monosynaptic reflexes movement: Correspond to a sensory neuron plus a motor neuron.
Motor cortex: Generates voluntary movements.
Motor pathways: Related with the transmission of efferent information, in other words: from the central nervous system to the periphery.
Motor system: Nervous System part that controls the effector tissue’s activity.
Motor unit: It’s equivalent to a motor neuron plus all the muscle fibers which innerves. Depending on innervated fibers proportion regard motor neuron, it will have a more or less precise movement.
Movement of the hair cells: The movement of the basilar membrane causes a movement of all structures of the organ of Corti. When this movement occurs, the lamina is moved while the hair cells that are in the tectorial membrane do not. This makes the hair cells bend following the movement. This causes the opening of the ionic channels and the despolarization of the cell.
Movement: Muscle contraction caused by motor neuron which innerves it. A muscle never shrink or relax, neither excites or inhibits the motor neuron which innerves it. There must be a constant coordination of antagonist muscles with each and simultaneously between synergistic muscles each.
Multiple sclerosis: Disease that causes myelin loss in motor neuron.
Muscle contraction: Is given by physiological sinapsi between motor neuron and the muscle fiber. The muscle fiber contains two proteins (actin and myosin) which are interlaced. When contraction occurs, the myosin filaments climbs between the actin filaments.
Muscle fiber: Single cell that is capable to reduce its tridimensional structure. It is grouped forming muscles.
Muscle spindle: Propioceptor found inside the muscle.
Neuroendocrine system: Combination of the nervous system and the endocrine system, which is responsible for responding to stimuli releasing hormones.
Neuromodulators: Substances that regulate synaptic transmission in interaction with a receptor.
Neuropeptides: Molecules composed by amino acids but smaller than proteins, with sedative or analgesic function.
Neuroplasticity: Changes in neural connections. Experiences reorganize neural pathways in the brain. When we learn new information, that causes long lasting functional changes in the brain.
Neurotransmitters: Substances that induce the opening of ion channels in interaction with a receptor.
Nociception: Sensory information that regulates tissue injury or chemical irritation (itching and pain).
Nociceptor: Type of receptor that gives information about tissue injuries.
Non-REM sleep: Sleep with no rapid eye movements. It predominates in the first half of the night. The cortical activity is low and the body can move, with a low muscular tone. The Non-REM sleep has four phases.
Noradrenalin: Neurotransmitter synthesized from tyrosine (catecholamine) with implications in the processes of excitation, alert, learning and memory. It’s also associated with depression and anxiety.
Oculovestibular reflex: Ability to keep staring toward a certain direction, even if we are moving around. It is necessary that the image remains stable in the retina, even if the head is moving. As the oculovestibular reflex receives information from the head, it orders a compensatory eye movement to the opposite direction. The movement helps to remain sight’s line to be fixed to a visual target. Both in light or dark (or even closed eyes), it works just as well. Its efficacy is based on its semicircular canals’ connections to the vestibular nucleus and the cranial nerves.
Odor: Property which has a substance that activates the olfactory system.
Odorants: Mechanical Stimuli which are dissolved in water base with dissolved mucopolysaccharides (long sugar chains), some proteins, antibodies, enzymes and odorants union proteins, which are small and soluble and allows the odorant concentration in mucus.
OFF ganglion neuron: Type of ganglion neurons that are deactivated if the light hits the center of the bipolar cells and ganglion center "ON".
Olfactory Bulb: Structure full of neuronal circuits with dendrites disposition, non-habitual reciprocate synapses and high levels of lots of neurotransmitters.
Olfactory cortex: One of the most important targets where axons from the olfactory bulb courses through the olfactory tracts and directly projects on them.
Olfactory epithelium: Thin layer made of mucus which constantly flows and it’s being replaced about each 10 minutes. The size can tell its animal olfactory’s sharpness. In humans: The olfactory capacity is relatively low. It only measures ten square centimeters.
Olfactory maps: Organization where neurons from an specific place of the bulb response to determinate odors.
Olfactory nerve: Olfactory axons set which forms the first cranial nerve.
Olfactory receptor cells: This is where transduction is made. They're neurons and axons which penetrate in Central Nervous System. Those are constantly growing, dying and regenerating in a 4-8 week cycle. Also, those neurones are among the few that regenerates.
Olfactory transduction: Pathway which makes the Odorant till central nervous system.
Olfactory’s population codification: The olfactory system is able to differentiate a citrus odor when combines the three olfactory cells’ response, provoking the brain being able to distinguish odors from other odors. Due to this, thousands of odors can be recognized, since the olfactory system have 1000 different receptors.
Olithics organs: Chambers called Saccule and Utricle, situated near the labyrinth centre. The Saccule and the Utricle detects changes of the head’s angle, as well as the head’s linear acceleration. Detects the gravity’s power and the head’s inclination.
Olivary nuclei: Located in the medulla oblongata, they receive contralateral and ipsilateral projections from the cochlear nuclei, integrating information from the two ears. They are very important for the sound origin localization. This is because they integrate information of the two sides and they can compare which pathway is firstly activated and therefore locate where is the origin of the stimuli. Olivary nuclei axons ascend by the lateral lemniscus to the inferior colliculus.
ON ganglion neuron: Type of ganglion neurons that are activated if the light hits the center of the bipolar cells and ganglion center "ON".
Optic illusion: Any illusion of vision leads us to perceive reality in several ways
Optic tract: Extension of the optic nerve that carries information from the eye to the brain.
Organ of Corti: Structure that has hair cells and supporting structures (columns, cells) located on the basilar membrane.
Ossicle’s muscles: Tympanum tensor muscle and Stapes tensor muscle (stirrup) are in charge of the regular bones moviment and allows to hinder the chain movement in the attenuation reflex.
Ossicles: Bones from the middle ear which allows the transmission of the sound vibrations transmitted by the air to the liquid medium. The bones are: stapes, incus and malleus.
Otoliths: Small calcium carbonate crystals which are incrusted in the surface of the gelatinous macula’s cover. Its density is higher that the surrounded endolymph. When the head leans or accelerates, exerts a force to the otoliths, which provokes a force to the same direction on the gelatinous cover, making the hair of the cells bend.
Outer ear: Outermost part of the ear which is in charge of collecting and transport the sound till the middle ear. Between middle ear and outer one, there’s the tympanic membrane.
Oval window: Membrane placed in the cochlea’s base and which it moves thanks to the stape’s action.
Overt Attention: Attention that causes a physiological response which is manifest.
Oxytocin: Hormone that acts as a neurotransmitter secreted by the pituitary nerve endings, present in both sexes. In women, it has a reproductive function but it also stimulates the milk ejection in front of the stimulation of the mammary gland. This hormone is released during orgasm in both sexes, so it’s related to pair bonding.
P ganglion cell: Cells that project information to magnocellular cell layers in the thalamus. They bring information about color.
Pacinian corpuscles: Phasic receptors that bring information about deep pressure.
Perilymph: Liquid of the scala vestibuli and scala tympani . It has low concentrations of potassium and high in sodium. The compositions is similar to the cerebrospinal fluid.
Pheromones: Important signals for sexual behaviors. Also useful for mark territory, identify individuals and indicate aggression or submission.
Phototransduction: It’s the process by which the information captured by the photoreceptors becomes an electrical signal (action potential).
Pitch: We captivate the tone’s difference thanks to the stimulation of different neurons and its tonotopic processing in cortex.
Polymodal cortex: 5 and 7 Brodmann Areas that process the tactile and proprioceptive information.
Polymodal nociceptors: Nociceptors related to outages and tissue damage.
Polysomnography: Combined technique that mesures the sleep activity in an EEG, an electromyogram and electrooculogram
Premotor area: Collects information from the limbic system and prefrontal and elaborates a motor plan.
Premotor cortex: Motor cortex area located in the frontal lobe. It’s functions are diverse, it has a role in direct behavior control, , body muscles, planning and in spatial and sensory orientation movement.
Primary auditory cortex: Area placed in temporal lobe which receives the geniculate nucleus afferents. This area is distributed in a tonotopic way and increases the number of stimulus’ characteristics that processes.
Primary motor area: Corresponds to Brodmann area 4 and is located next to sillon de Rolando. It controls the movements execution by the muscle sending its engine plan.
Primary motor cortex: Brain region that is in the back of the frontal lobe. It works with the premotor areas to plan and execute movements.
Primary somesthesic cortex: Areas 1, 2, 3a, 3b Brodmann in the postcentral gyrus (somatotopic organization). It. receives projections from the thalamus.
Primary visual area: The image that reaches the retina is inverted after passing through all the visual pathways, reaches the primary visual cortex, striate cortex or V1.
Propioceptor: Type of encapsulated receptor to distinguish the body members position and movement.
Proprioception: Sensation that helps to distinguish the static position and movement of the limbs and body.
Proprioceptive signals: Body segments relative position.
Proximal-distal rule: Medial ventral areas of the medulla bathe control the muscle next to the body (the body axis), the dorsal and ventral areas of distal musculature control bathe (limbs).
Pupil: Structure of the eye which is a hole located in the center of the iris, that leads the light into the inside the eyeball.
Pyramidal Neurons: The activation of big groups of these neurons of the cortex is the neural activity that we can record in an EEG.
Receptor cell: Glycoprotein that allows the interaction of certain substances with the mechanisms of cellular metabolism.
Reflex arc: Neuronal circuit wchich causes a reflex movement.
Reflex movements: Unintentional action provoked by an excitation, it allows reactions with suitable motor actions to different signal types.
REM off Neurons: Neurons which desactivates the REM state. It is located in the periaqueductal gray matter. They are monoaminergic. When they are activated, REM on ones cannot be activated as well.
REM on neurons: Neurons which activates the REM sleep state. They are located in the protuberance, in the sublateral dorsal. They are cholinergic. When they are activated it cannot be activated the REM off ones.
REM Sleep: Sleep stage with high cortex activity, muscular weakness (inhibition of spinal motor neurons) and rapid eye movement occurs.
Reticulospinal tract: Begins at reticular formation and ends at medulla. It controls postural reflex.
Retina: The most important layer of the visual system, because it contains receptors vision: rod cells and cone cells.
Retinotopia: Distribution of the stimulus in the retina, so the point perceived in the visual field is always projected in the same area on the retina, regardless of the image.
Rod cell: Specialized receptor cells in color and night vision. These are quite rudimentary.
Round window: Membrane placed in the cochlea’s base, under the oval window. This membrane moves to compensate the cochlea’s liquid movement produced by the oval windows movement.
Ruffini corpuscles: Tonic receptor that brings information about stretching in the skin.
Salty taste: One of the main basic tastes represented by mineral salts; mainly sodium and chlorine ions. These minerals are useful to the body in regulating the water balance in cells, regulating muscle activity, and bone growth.
Scala vestibuli, media and tympani: Cavities of the cochlea. The scala vestibuli is above the scala media and this one is above the scala tympani . Each one has liquid.
Sclera: Outermost layer of the eye and responsible of the white color in the eye.
Secondary visual cortex: The information passes from the secondary to the primary visual cortex (V2) and then activates the two-way process of information.
Semicircular canals: They’re sensitive to head’s rotation. It detects the head’s rotary movements. They’re also sensitive to acceleration. The angular acceleration is generated by sudden rotary movements and it is constituted as primary stimulus of the canals. They’re full of endolymph. The three semicircular canals of one head’s side collaborate because we perceive every possible rotation angle.
Sensorial Map: Array of neurons that are correlated with determinate characteristics from the environment.
Sensory transducer: Set of cells that converts energy into action potentials.
Serotonin (5HT): Neurotransmitter synthesized from tryptophan (Trp) related to depression and schizophrenia, that regulates cycles of sleep and waking, saciety after eating and mood control.
Side roads: Limbs control. All end up in the final common pathway, and most of the side roads don’t decussate.
Sleep debt: homeostatic process that depends on the previous day sleep. The body during wakefulness accumulates peptides that cause a need for sleep. During the slee, the level of acumulation decreases.
Sleep: Reversible state where occurs a disconnection in the environment perception and response. During the night, non-REM and REM phases alternate, forming a cycle that it is repeated approximately six times per night.
Slow Wave Sleep: This is the third and fourth stage of the Non-REM sleep. This stage is characterized by the presence of delta waves and the synchrony of neural activity, which indicates little activity.
Smell: It’s combined with the taste in order to help us identify aliments and increase our delight
Solitary nucleus of the brainstem: Also known as the nucleus of the solitary tract is a set of gray matter located in the brainstem where the fibers of the facial nerve, the glossopharyngeal nerve and the vagus nerve match.
Somatic motor/nervous system: It’s in charge of the observable behavior. It’s related to the external medium and striated skeletal muscle tissue effector.
Somatic sensation: Subjective perception derived from the processing of touch, pain, temperature body position information.
Somatosensory pathway: Pathway formed by the anterolateral system and the trigeminal thermoalgic system.
Somatotopic arrangement: Point by point correspondence of a body area with a specified central nervous system area.
Sound frequency: Number of compressed air masses which reaches the ear every second.
Sound: Perceptible variation of the ear in the air pressure.
Sour taste: One of the main basic tastes, represented by hydrogen ions. It feels unpleasant because some harmful substances have this taste.
Specific G protein: Protein which activates an enzyme that catalyzes cyclic AMP's synthesis, and this, opens sodium channels, making a depolarization of the olfactory cell's membrane.
Spinal cord: Reflex movements. Those movements can also be controlled by the brainstem.
Spinal reflexes movement: Correspond to a sensory neuron plus an interneuron plus a motor neuron.
Spinal/mixed nerves: It contains various types of motoneurones.
Spindles: Short frequency waves groups between 12 and 14 Hz taking place in periods of few minutes between phase 2 and 4 of NoREM sleep.
Spiral Ganglion: Formed by the first neurons of the pathway, which inervate the hair cells.
Stage 1Non-REM: First phase in which the waking threshold is low. Theta waves appear.
Stage 2 Non-REM: Second phase of the Non REM. There is theta waves activity. Appear spindles and K complexes.
Stapes: Ear bone which is flexible linked with the incus and moves the oval window.
Stereocilia: Apical specializations of the cells of the organ of Corti in the auditory system.
Strategy: Premotor cortex/supplementary motor area and basal ganglia.
Stress: set of responses from the organism towards changes and stimuli which attempts against homeostasis.
Stretch reflex: Mechanism which our motor systems makes to relax our muscle.
Supplementary motor area: Initiates the body movements.
Support cells: They collaborate on mucus' production. It is similar to glia.
Sweet: One of the main basic tastes universally associated with pleasurable experiences and represented by glucose. Foods rich in carbohydrates are usually associated with a sweet taste. The sweet taste feels pleasant in humans because carbohydrates our main source of energy.
Synchronic Rhythm: Joint activation of a set of neurons at the same time, following the same pattern. It can arise from the guidance of pacemaker or by the joint interaction.
Synchronizers: Physical or social stimuli that interfere in the circadian rhythms adjustment
Tactic: Motor and cerebral cortex.
Target: Stimulus in which the attention is focused.
Taste bud: Taste receptor organ. The chemical molecules that come from what we ingest, in contact with chemoreceptors cause a depolarization in the taste cell membrane. This depolarization will cause the activation of first order sensory neurons, starting the gustatory sense pathway. Depending on its situation on human anatomy, taste receptors can perceive five tastes: sweet, salty, sour, bitter and umami
Taste: Chemical sense that allows to detect hydrosoluble molecules in saliva that usually come from the substances we ingest, through structures called chemoreceptors. See also: chemical sense, chemoreceptor
Tectospinal tract: It begins at the trunk tectum and ends in medulla. Controls postural movements and orientation movements toward stimuli.
Thalamus medial geniculate nucleus: This Thalamus nucleus receives axons from the inferior colliculus, and there keeps processing following a tonotopic disposition.
Thermal energy: Energy that activates thermoreceptors and nociceptors and if the stimulus is strong.
Thermal nociceptors: Nociceptor related to thermal energy.
Thermoceptor: Type of receptor activated by thermal energy.
Theta waves: Waves produced during the non-REM that have a frequency between 3.5 and 7Hz.
Thyroid: Endocrine gland located in the neck that regulates metabolism by secreting thyroid hormones such as thyroxine (T4), and triiodothyronine (T3).
Tonotopy: Spatial arrangement where the sound is processed regard the frequency
Touch trigeminal system: System formed by the touch sense and proprioception.
Trigeminal nerve: Controls the feeling of pain when an irritant chemical substance is smelled, like ammonia.
Trigeminal thermoalgic system: Somatosensory pathway dedicated to pain and temperature.
Tympanic cavity: Space filled with air of the middle air that contains the ear bones.
Tympanic membrane: Elastic membrane in a conical shape where the hammer bones are adjusted. It keeps away the ear canal and the middle ear.
Umami taste: Umami, (from the Japanese うま味) means "pleasant taste" or "tasty". One of the main basic tastes, represented by monosodium glutamate (MSG). Umami is not a particular taste, but MSG has the property to enhance the taste of a nice substance, so the food is nice in a relatively narrow margin of concentration of this amino acid. However, low-salt foods can have a satisfying taste of umami with the appropriate amount. In addition, the umami taste can be promoted if it is combined, for example, with smells that support this taste in a chemical level.
Unimodal cortex: Brodmann area 43 (special sensitivity of the face). It receives projections from the thalamus and the primary somatosensory cortex.
Vagus nerve: Also known as the cranial nerve X, is a nerve whose function is the sensitivity in the inner ear area, larynx, and throat.
Vasopressin: Also called antidiuretic hormone, is responsible for regulating the balance of water molecules in the concentration of urine. It is also associated with aggressive behavior, social relationships of hierarchy and social dominance.
Vegetative motor/nervous system: It is in charge of the physiological behavior. Related to the internal environment, the cardiac and smooth muscle tissue effect, exocrine glands and the adrenal endocrine.
Ventral corticospinal tract: Begins at cerebral cortex and ends at medulla. It controls body axis muscles’ voluntary movements.
Ventral pathway: Pathway passes through the inferior temporal lobe that processes form, color and depth.
Ventrolateral preoptic area: It receives inputs from retina, and with the thalamus and olivary nuclei , they regulate the biological rhythms. The neurons in this area inhibited, causing sleep. They synthesize GABA and send axons to ARAS.
Vestibular labyrinth: It has two structures: the otolith organs and the semicircular canals. Its function is to transmitter mechanical energy from the head’s movements to its ciliated cells. Each cell is sensitive to different types of movements because of its specialized structures.
Vestibular macula: Sensorial epithelium which is oriented vertically in the sacculi and horizontally in the utricle when the head is in a vertical position. It contains hair cells that are arranged over a bed of supporting cells which cilia are projected inside a gelatinous cover.
Vestibular nucleus: Receives afferents from the brain, cerebellum, visual and somatic systems and other sensory modalities. It consists of subdivisions that are projected in different places above the brainstem and below the spinal cord. It also happens with other sensory systems; axons from the vestibular nucleus are sent to the posterior ventral nucleus of the thalamus, which is projected near the representation of the face in the somatosensory areas and primary motor cortex regions. It is produced a considerable integration of information relating to the movements of the body, eyes and the visual field. It also controls the extraocular muscles.
Vestibular System: Registers the head’s position and movement, it proportionate balance and it helps to coordinate the head’s and eye’s movement as well as regulate the body’s posture.
Vestibulocervical reflex: Remains a safe position wherever the body goes. It positionates us well to not fall.
Vestibuloespinal reflex: It helps to maintain the balance of our body. For example, when you walk over a tree trunk.
Visual camp: Spatial portion that the eye is able to perceive. It is defined by the sum of the visual camp in the left eye and the visual camp in the right eye.
Visual field: Portion of space that the eye can see. It’s defined by the sum of the visual field of the left eye and the visual field of the right eye.
Voluntary attention: It is a selective attentional subprocess (endogenous) that allows focusing on a particular stimulus.
Vomeronasal organ: organ which almost every mammal has and responses to olfactory stimuli.
Wavelenght: Distance between the points of maximum electric field. It’s measured in meters.