99 relations: Absolute threshold, Acetylcholine, Action potential, Adaptation (eye), Adenosine triphosphate, Adenylyl cyclase, Adequate stimulus, Adrenal gland, Adrenaline, Auditory cortex, Axon, Axon hillock, Axon terminal, Baroreceptor, Blood pressure, Brain, Carotid artery, Cell (biology), Central nervous system, Cephalic phase, Chemoreceptor, Cilium, Cochlea, Cribriform plate, Cyclic adenosine monophosphate, Dendrite, Depolarization, Digestion, Ear, Eardrum, Endocrine system, Enteric nervous system, Environment (systems), Epithelium, Excitatory postsynaptic potential, Fight-or-flight response, G protein–coupled receptor, Gamma-Aminobutyric acid, Glutamic acid, Group C nerve fiber, Gustducin, Hair cell, Homeostasis, Homeostatic emotion, Hormone, Human digestive system, Hypotension, Hypovolemia, Inhibitory postsynaptic potential, Lamina propria, ..., Larynx, Light, Mechanoreceptor, Merkel nerve ending, Motor neuron, Myocyte, Nasal septum, Nerve, Nervous system, Neuromuscular junction, Neuron, Neurotransmitter, Nicotinic acetylcholine receptor, Nociceptor, Occipital lobe, Olfaction, Olfactory epithelium, Olfactory receptor neuron, Organ (anatomy), Organ of Corti, Organism, Peripheral nervous system, Pharynx, Photoreceptor cell, Physiology, Postcentral gyrus, Quinine, Receptor potential, Reflex, Retina, Second messenger system, Sensory neuron, Soma (biology), Somatosensory system, Sound, Stimulation, Stimulus (psychology), Synaptic vesicle, Taste, Taste bud, Temporal lobe, Thermoreceptor, Threshold potential, Tongue, Transduction (physiology), Type Ia sensory fiber, Vasopressin, Vestibulocochlear nerve, Visual cortex. Expand index (49 more) » « Shrink index
In neuroscience and psychophysics, an absolute threshold was originally defined as the lowest level of a stimulus – light, sound, touch, etc.
Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals, including humans, as a neurotransmitter—a chemical message released by nerve cells to send signals to other cells.
In physiology, an action potential occurs when the membrane potential of a specific axon location rapidly rises and falls: this depolarisation then causes adjacent locations to similarly depolarise.
In ocular physiology, adaptation is the ability of the eye to adjust to various levels of light.
Adenosine triphosphate (ATP) is a complex organic chemical that participates in many processes.
Adenylyl cyclase (also commonly known as adenyl cyclase and adenylate cyclase, abbreviated AC) is an enzyme with key regulatory roles in essentially all cells.
The adequate stimulus is a property of a sensory receptor that determines the type of energy to which a sensory receptor responds with the initiation of sensory transduction.
The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol.
Adrenaline, also known as adrenalin or epinephrine, is a hormone, neurotransmitter, and medication.
The primary auditory cortex is the part of the temporal lobe that processes auditory information in humans and other vertebrates.
An axon (from Greek ἄξων áxōn, axis) or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that typically conducts electrical impulses known as action potentials, away from the nerve cell body.
The axon hillock is a specialized part of the cell body (or soma) of a neuron that connects to the axon.
Axon terminals (also called synaptic boutons or terminal boutons) are distal terminations of the telodendria (branches) of an axon.
Baroreceptors (or archaically, pressoreceptors) are sensors located in the blood vessels of all vertebrate animals.
Blood pressure (BP) is the pressure of circulating blood on the walls of blood vessels.
The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals.
Carotid artery may refer to.
The cell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known living organisms.
The central nervous system (CNS) is the part of the nervous system consisting of the brain and spinal cord.
The cephalic phase of gastric secretion occurs even before food enters the stomach, especially while it is being eaten.
A chemoreceptor, also known as chemosensor, is a specialized sensory receptor cell which transduces (responds to) a chemical substance (endogenous or induced) and generates a biological signal.
A cilium (the plural is cilia) is an organelle found in eukaryotic cells.
The cochlea is the part of the inner ear involved in hearing.
In human anatomy, the cribriform plate of the ethmoid bone (horizontal lamina or lamina cribrosa) is received into the ethmoidal notch of the frontal bone and roofs in the nasal cavities.
Cyclic adenosine monophosphate (cAMP, cyclic AMP, or 3',5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes.
Dendrites (from Greek δένδρον déndron, "tree"), also dendrons, are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project.
In biology, depolarization is a change within a cell, during which the cell undergoes a shift in electric charge distribution, resulting in less negative charge inside the cell.
Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma.
The ear is the organ of hearing and, in mammals, balance.
In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear.
The endocrine system is a chemical messenger system consisting of hormones, the group of glands of an organism that carry those hormones directly into the circulatory system to be carried towards distant target organs, and the feedback loops of homeostasis that the hormones drive.
The enteric nervous system (ENS) or intrinsic nervous system is one of the main divisions of the autonomic nervous system (ANS) and consists of a mesh-like system of neurons that governs the function of the gastrointestinal tract.
In science and engineering, a system is the part of the universe that is being studied, while the environment is the remainder of the universe that lies outside the boundaries of the system.
Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue.
In neuroscience, an excitatory postsynaptic potential (EPSP) is a postsynaptic potential that makes the postsynaptic neuron more likely to fire an action potential.
The fight-or-flight response (also called hyperarousal, or the acute stress response) is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival.
G protein–coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptor, and G protein–linked receptors (GPLR), constitute a large protein family of receptors that detect molecules outside the cell and activate internal signal transduction pathways and, ultimately, cellular responses.
gamma-Aminobutyric acid, or γ-aminobutyric acid, or GABA, is the chief inhibitory neurotransmitter in the mammalian central nervous system.
Glutamic acid (symbol Glu or E) is an α-amino acid with formula.
Group C nerve fibers are one of three classes of nerve fiber in the central nervous system and peripheral nervous system.
Gustducin is a G protein associated with taste and the gustatory system, found in some taste receptor cells.
Hair cells are the sensory receptors of both the auditory system and the vestibular system in the ears of all vertebrates.
Homeostasis is the tendency of organisms to auto-regulate and maintain their internal environment in a stable state.
A homeostatic emotion, primordial emotion or primordial feeling is an attention-demanding sensation and motivation (e.g., thirst, pain, fatigue) evoked by an internal body state that drives behavior (drinking, withdrawing and resting in these examples) aimed at maintaining the body's internal environment in its ideal state.
A hormone (from the Greek participle “ὁρμῶ”, "to set in motion, urge on") is any member of a class of signaling molecules produced by glands in multicellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behaviour.
The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder).
Hypotension is low blood pressure, especially in the arteries of the systemic circulation.
Hypovolemia is a state of decreased blood volume; more specifically, decrease in volume of blood plasma.
An inhibitory postsynaptic potential (IPSP) is a kind of synaptic potential that makes a postsynaptic neuron less likely to generate an action potential.
The lamina propria is a thin layer of connective tissue that forms part of the moist linings known as mucous membranes or mucosa, which line various tubes in the body, such as the respiratory tract, the gastrointestinal tract, and the urogenital tract.
The larynx, commonly called the voice box, is an organ in the top of the neck of tetrapods involved in breathing, producing sound, and protecting the trachea against food aspiration.
Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum.
A mechanoreceptor is a sensory receptor that responds to mechanical pressure or distortion.
Merkel nerve endings are mechanoreceptors, a type of sensory receptor, that are found in the basal epidermis and hair follicles.
A motor neuron (or motoneuron) is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, and whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly or indirectly control effector organs, mainly muscles and glands.
A myocyte (also known as a muscle cell) is the type of cell found in muscle tissue.
The nasal septum separates the left and right airways in the nose, dividing the two nostrils.
A nerve is an enclosed, cable-like bundle of axons (nerve fibers, the long and slender projections of neurons) in the peripheral nervous system.
The nervous system is the part of an animal that coordinates its actions by transmitting signals to and from different parts of its body.
A neuromuscular junction (or myoneural junction) is a chemical synapse formed by the contact between a motor neuron and a muscle fiber.
A neuron, also known as a neurone (British spelling) and nerve cell, is an electrically excitable cell that receives, processes, and transmits information through electrical and chemical signals.
Neurotransmitters are endogenous chemicals that enable neurotransmission.
Nicotinic acetylcholine receptors, or nAChRs, are receptor proteins that respond to the neurotransmitter acetylcholine.
A nociceptor is a sensory neuron that responds to damaging or potentially damaging stimuli by sending “possible threat” signals to the spinal cord and the brain.
The occipital lobe is one of the four major lobes of the cerebral cortex in the brain of mammals.
Olfaction is a chemoreception that forms the sense of smell.
The olfactory epithelium is a specialized epithelial tissue inside the nasal cavity that is involved in smell.
An olfactory receptor neuron (ORN), also called an olfactory sensory neuron (OSN), is a transduction cell within the olfactory system.
Organs are collections of tissues with similar functions.
The organ of Corti, or spiral organ, is the receptor organ for hearing and is located in the mammalian cochlea.
In biology, an organism (from Greek: ὀργανισμός, organismos) is any individual entity that exhibits the properties of life.
The peripheral nervous system (PNS) is one of the two components of the nervous system, the other part is the central nervous system (CNS).
The pharynx (plural: pharynges) is the part of the throat that is behind the mouth and nasal cavity and above the esophagus and the larynx, or the tubes going down to the stomach and the lungs.
A photoreceptor cell is a specialized type of neuroepithelial cell found in the retina that is capable of visual phototransduction.
Physiology is the scientific study of normal mechanisms, and their interactions, which work within a living system.
The postcentral gyrus is a prominent gyrus in the lateral parietal lobe of the human brain.
Quinine is a medication used to treat malaria and babesiosis.
A receptor potential, also known as a generator potential, a type of graded potential, is the transmembrane potential difference produced by activation of a sensory receptor.
A reflex, or reflex action, is an involuntary and nearly instantaneous movement in response to a stimulus.
The retina is the innermost, light-sensitive "coat", or layer, of shell tissue of the eye of most vertebrates and some molluscs.
Second messengers are intracellular signaling molecules released by the cell in response to exposure to extracellular signaling molecules—the first messengers.
Sensory neurons also known as afferent neurons are neurons that convert a specific type of stimulus, via their receptors, into action potentials or graded potentials.
The soma (pl. somata or somas), perikaryon (pl. perikarya), neurocyton, or cell body is the bulbous, non-process portion of a neuron or other brain cell type, containing the cell nucleus.
The somatosensory system is a part of the sensory nervous system.
In physics, sound is a vibration that typically propagates as an audible wave of pressure, through a transmission medium such as a gas, liquid or solid.
Stimulation is the encouragement of development or the cause of activity generally.
In psychology, a stimulus is any object or event that elicits a sensory or behavioral response in an organism.
In a neuron, synaptic vesicles (or neurotransmitter vesicles) store various neurotransmitters that are released at the synapse.
Taste, gustatory perception, or gustation is one of the five traditional senses that belongs to the gustatory system.
Taste buds contain the taste receptor cells, which are also known as gustatory cells.
The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals.
A thermoreceptor is a non-specialised sense receptor, or more accurately the receptive portion of a sensory neuron, that codes absolute and relative changes in temperature, primarily within the innocuous range.
In neuroscience, the threshold potential is the critical level to which a membrane potential must be depolarized to initiate an action potential.
The tongue is a muscular organ in the mouth of most vertebrates that manipulates food for mastication, and is used in the act of swallowing.
In physiology, sensory transduction is the conversion of a sensory stimulus from one form to another.
A type Ia sensory fiber, or a primary afferent fiber is a type of afferent nerve fiber.
Vasopressin, also named antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin, is a hormone synthesized as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP.
The vestibulocochlear nerve (auditory vestibular nerve), known as the eighth cranial nerve, transmits sound and equilibrium (balance) information from the inner ear to the brain.
The visual cortex of the brain is a part of the cerebral cortex that processes visual information.