Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
9.14 Quiz 8
Vocab from Schneider Chapters 20-23
| Term | Definition |
|---|---|
| Optic Tract | The axons from the retina after they pass through the optic chiasm become the optic tract. |
| Frontal Eye Spot | The light sensitive region near the anterior end of the CNS of amphioxus (Branchiostoma). It contains neurons, receptor cells, and pigmented cells. |
| Parietal Eye (Pineal Eye) | Also known as the pineal eye, the parietal eye is a single eye-like region that responds to light, which times the production of melatonin. |
| Lamellar Body | A partially light sensitive structure in the epithalamic region of amphioxus. |
| Suprachiasmatic Nucleus | A small cell group of the CNS located just above the optic chiasm which receives direct input from retinal ganglion cells. Some of these neurons have an endogenous circadian cycle of activity. |
| Pineal Gland | A small endocrine gland located on the midline above and attached to the epithalamus. The pineal produces secretes melatonin, normally varying in a 24-hr cycle. This melatonin release is important in circadian rhythms and reproduction. |
| Paraventricular Hypothalamic Nucleus (PVH) | A cell group in the medial anterodorsal hypothalamus. Magnocellular PVH axons in the posterior pituitary release oxytocin and vasopressin into the bloodstream. Parvocellular axons release peptides that influence the anterior pituitary. |
| Superior Cervical Ganglia (SCG) | The most rostral ganglion of the sympathetic paravertebral ganglia is called the SCG. The neurons of these ganglia have axons that provide the sympathetic innervation of smooth muscle and glands of the head region, including the Pineal Gland. |
| Zona Incerta (ZI) | Neurons of the subthalamic region that are not included in the subthalamic nucleus or the ventral nucleus of the lateral geniculate body. ZI neurons receive input from neocortex and midbrain while projecting to pallidal structures and paleothalamus. |
| Pupillary Eye Reflex | The narrowing of the pupils in response to more light reaching the eyes. The reflex pathway goes: retina, pretectal area, parasympathetic preganglionic motor neurons, to the ciliary ganglion behind the eye which innervates the iris. |
| Nucleus of the Optic Tract (NOT or nOT) | Neurons embedded in the optic tract fibers. They are activated large visual field movements in temporal to nasal direction, and are inhibited by the reverse. The neurons are sensitive to any changes in horizontal head direction. |
| Innate Releasing Mechanisms | An ethological term for inherited brain mechanisms that respond selectively to particular stimulus configurations and can trigger particular movements depending on the motivational state. |
| Nucleus Centralis Lateralis (CL) | CL is one of the intralaminar cell groups, which is part of the paleothalamus, located just lateral to the mediodorsal thalamic nucleus in mammals. |
| Hypothetical Stages of the Origins of Vision | 1. Detection of light/shadow. 2. Ability to separate different light intensities coming from the left or the right. 3. Eyes have lenses and topographic projections to the optic tract. 4. Evolution of visual pathways to the endbrain. |
| Lateral Posterior Nucleus (LP) | Part of the lateral nuclei of the mammalian thalamus. The LP receives a strong projection from the superficial layers of the superior colliculus, and a sparse projection from the retina. It projects to areas near the primary visual cortical area. |
| Neuraxis | The orientation of the rostro-caudal axis of the central nervous system. Early in development this axis bends in specific places (the flexures). |
| Monocular Crescent | The most temporal part of the visual field of each eye—the part which does not overlap with the visual field of the opposite eye. |
| Posterior Pretectal Nucleus | The posterior pretectal nucleus is densely innervated by optic-tract axons. The nucleus is located just ventral to the superficial optic tract but is traversed by deeper lying optic-tract axons. |
| Superficial Grey Layer | The most superficial cell layer of the mammalian superior colliculus overlying the optic tract. Its cells receive dense projections from the retina and visual cortex while projecting to deeper tectal layers, LP, and the external layer of the LGBv. |
| Pulvinar Nucleus | The enlarged posterior lateral nuclei in the primates. The ventral part (inferior pulvinar) receives input from the superior colliculus and sparse projections from the retina. The pulvinar projects to posterior association areas of the neocortex. |
| Accessory Optic Tract (AOT) | Axons that leave the main portion of the optic tract and innervate the nuclei of the accessory optic tract. The neurons of these nuclei are activated by simultaneous and matching movements of all objects and contours in large parts of the visual field. |
| Stria Terminalis (ST) | A major output of the amygdala which projects to the basal forebrain and hypothalamus. These axons follow a course in the mammalian endbrain that is mostly parallel to the course of the fornix fibers from the hippocampus. |
| Ray-finned Fish Midbrain Tectum Lamina | This group of fishes has well developed optic tecta with multiple layers (laminae), as defined by cell and fiber arrangements seen in histological sections, and by dendritic and axonal arborizations. |
| Retinal Maps | Shorthand for topographically organized retinal terminations. On a such a map, each position receives terminals of axons from one small part of the retina, with the entire pattern in each structure forming a map of the retinal surface. |
| Medial Terminal Nucleus of the AOT | The most ventral terminal nucleus of the AOT, located in the ventral midbrain between the ventral tegmental area and the substantia nigra. |
| Lateral Terminal Nucleus of the AOT | A small group of neurons located at the lateral edge of the midbrain just ventral to the axons from the inferior colliculus as they near their terminal sites in the medial geniculate body of the thalamus. |
| Dorsal Terminal Nucleus (DTN) of the AOT | A small clump of neurons located just caudal to the main optic tract, caudolateral to the NOT in the pretectal area. Neurons are activated by visual stimuli resulting from lateral deviations of the head—as are neurons in the NOT. |
| Inferior Fasciculus of the AOT | Retinofugal axons traveling caudally below the cerebral peduncle at the lateral margin of the hypothalamus. They terminate in the medial terminal nucleus of the AOT. In many non-mammals, these axons are called the basal optic root. |
| Superior Fasciculus of the AOT | Retinofugal axons found in a small bundle between the dorsal and lateral terminal nuclei of the accessory optic tract. |
| Trans-pedundular Tract | Retinofugal axons that course in one or several small bundles over the surface of the cerebral peduncle between the lateral and medial terminal nuclei of the AOT. |
| Optic Radiations (Geniculostriate Pathway) | The axons from the lateral geniculate body (dorsal nucleus of LGB) through the internal capsule and neocortical white matter to the striate cortex in the occipital lobe. |
| Parcellation by Competition | Progressive separation of two or more projections to a structure during evolution or development. In the beginning, the different projections overlap, but by the end they are segregated. |
| Striate Visual Cortex | The primary visual cortex of the occipital lobe, known to electrophysiologists as V1. It may have been preceded by a more primitive visual area represented in mammals by area “prostriata” which is connected to parahippocampal areas. |
| Extrastriate Visual Cortex | Visual receptive neocortical areas located outside the striate area. Multiple areas have been mapped. Most of them show a complete topographic representation of the opposite visual hemifield. |
| Nucleus Rotundus | A cell group of the dorsal thalamus in birds and reptiles that receives visual input from the optic tectum of the midbrain and projects to part of the dorsal ventricular ridge (nidopallium of birds). |
| Dorsolateral Cortex | In reptiles, the dorsal cortex receives sensory projections from the thalamus. The dorsolateral part of this cortex receives visual input from the dorsolateral optic nucleus, similar to the pathway from the LGBd to V1 in mammals. |
| Nidopallium | A large region located below the endbrain ventricle. Connections from visual, auditory and somatosensory systems show the nidopallium to be similar in function to lateral parts of the neocortex in mammals. |
| Entopallium | The part of the nidopallium in birds that receives visual inputs from nucleus rotundus of the thalamus. |
| Calcarine Fissure | A deep sulcus in the medial surface of the occipital lobe of primates, in the middle of area 17 (primary visual cortex). In monkey and human, the upper visual field is represented below the fissure, and the lower field above. |
| Secondary Optic Radiations | Fibers from the visual cortex that terminate in brainstem structures: thalamus, pretectal area, and superior colliculus. |
| Sylvian Fissure | The deep fissure in primate brains that separates the temporal lobe cortex from the frontal and parietal lobe cortex. Hidden in the fissure is the insular cortex, which overlies the putamen. |
| Meyer's Loop | Axons of the optic radiations found in the white matter of the neocortex of the temporal lobe. The “loop” forms during the development of the temporal lobe. These axons represent the upper part of the opposite visual field. |
| 1st Transcortical Visual Pathway | This pathway is often called the “dorsal stream” by neuroscientists, concerned with egocentric “where is it?”. The striate cortex projects to prestriate and posterior parietal areas which project rostrally in stages until the frontal eye fields. |
| 2nd Transcortical Visual Pathway | This pathway is called the “ventral stream”, concerned with “what is it?” information. The striate area projects to prestriate areas, which project to ventral temporal lobe (inferotemporal cortex), and on to the amygdala and ventral prefrontal cortex. |
| 3rd Transcortical Visual Pathway | This pathway is concerned with “where am I? and “where am I heading?” information, thus dealing with allocentric localization and direction of the animal’s position in the environment. Visual information goes to parahippocampal areas. |
| Prestriate Areas | Visual cortical areas just outside the striate cortex, always including areas 18 and 19 of Brodmann. Sometimes all the unimodal visual association areas (extra-striate visual areas) are included. |
| Parahippocampal Gyrus (Hippocampal Gyrus) | This gyrus includes several cortical areas near the hippocampus, including entorhinal cortex and presubiculum. The subiculum is sometimes included in the parahippocampal gyrus but it is more properly a part of the hippocampus itself. |
| Areas TF, TH, and TL | Areas of the posterior parahippocampal gyrus often distinguished in large primates. They receive projections from visual, auditory, or somatosensory association areas or multimodal areas, and are connected to entorhinal and other parahippocampal areas. |
| Postsubiculum | A dorsal portion of the subiculum in rodents that receives visual inputs from several neocortical areas as well visual input from the thalamus. |
| Area Prostriata | A visual cortical area between visual neocortex and the posterior cingulate and parahippocampal areas. It receives thalamic input and projects to retrosplenial and parahippocampal cortical areas, and to more rostral cingulate areas with motor functions. |
| Lateral-dorsal nucleus (Anterior part of the Lateral Thalamus, or LD) | Receives input from the pretectal area. It is adjacent to the anterior nuclei of the thalamus, in particular the anterodorsal nucleus. Input from the cortex represents head-direction in the local environment. |
| Cingulate Gyrus | Located just above the corpus callosum. Its structure indicates its transitional nature between neocortex and hippocampus. The anterior part includes motor areas that may interface motivational systems, cognitive areas and motor outputs of the neocortex. |
| Proportional Connectivity | Connectivity between neurons that is 100%, so every neuron is connected to every other neuron in a structure. Axons increase exponentially as number of neurons increases linearly. |
| Absolute Connectivity | Connectivity only between neighboring neurons in a structure. |
| Small World Architecture | Absolute connectivity plus a limited number of longer range connections. Modelers depict these longer connections as random. |
| Dorsalateral Placodes | Local thickenings of the epithelium of the embryonic head that form the peripheral portions of the auditory, vestibular, lateral line, and trigeminal systems. |
| Otic Placodes | Local thickenings of the epithelium of the embryonic head that form the peripheral portions of the auditory and vestibular systems. |
| Octaval System | In mammals, the auditory and vestibular systems. The peripheral structures give rise to the two portions of the 8th cranial nerve: the auditory and vestibular portions. |
| Torus Semicircularis | The major midbrain cell group of the auditory pathway in non-mammalian vertebrates, similar to the inferior colliculus of mammals. This structure receives lateral line inputs in animals with mechanosensory or electrosensory lateral line systems. |
| Lateral Nucleus of the Amygdala | Dderived from the embryonic pallium, the lateral nucleus receives visual, auditory and somatosensory inputs and projects not only to other amygdalar regions but also to the ventral prefrontal cortex. |
| Cochlear Nuclei | The secondary auditory cell groups, located in the alar plate of the rostral hindbrain. There are two main cell groups, the dorsal and the ventral cochlear nuclei, which can be further divided into the anteroventral and posteroventral cochlear nuclei. |
| Post-Orbital Bar | A bone that prevents distortion of the eyes during chewing. A post-orbital bar was lost in the earliest mammals, apparently because of reduction in eye size and importance together with increased reliance on olfaction and audition. |
| Quadrate and Articular Bones | Small jawbones in reptiles that underwent changes in the cynodonts, instead acquiring functions in hearing. In the transition to mammals, the articular bone became the malleus of the middle ear, and the quadrate became the incus. |
| Impedance | When impedances match, transfer of energy is optimized. This kind of matching between conduction of sound in air and in fluids is accomplished by the middle ear bones, attached to each other in lever arrangements. |
| Ossicles | The tiny bones of the middle ear in mammals |
| Oval Window | The oval-shaped membrane where the stapes of the middle ear in mammals attaches. The membrane separates the air-filled middle ear cavity from the upper part of the fluid-filled cochlea. |
| Round Window | Similar in size to the oval window, this separates the lower part of the fluid-filled cochlea from the middle ear cavity. Its presence lowers impedance of the cochlear fluids to sound vibrations. |
| Scala Tympani | The chamber of the fluid-filled cochlea (filled with perilymph) that is attached to the scala vestibuli only at the cochlear apex—farthest from the oval and round windows. |
| Scala Vestibuli | The chamber of the fluid-filled cochlea that is continuous with the fluid of the vestibular canals. Throughout the length of the cochlea the Organ of Corti sepaates the scala vestibuli from the scala tympani. |
| Organ of Corti | Structural complex running down the center of the cochlear tube containing auditory receptor cells and the endings of 8th nerve axons. Vibrations in the cochlear fluid result in shearing forces on the hair cells. |
| Cochlear Duct | The third fluid-filled portion of the cochlea, filled with endolymph, is separated from the vestibular duct by Reissner’s membrane. The cochlear duct is separated from the scala tympani by the Organ of Corti. |
| Vestibular Canals | The three semicircular canals in the temporal bone, arranged in three different planes. Movement of fluid in these canals during head movement is detected by the vestibular receptors. |
| Frequency Coding | The code for sound frequencies is based on rhythmic firing of auditory nerve axons that matches low sound frequencies, and on differential firing of axons from different parts of the cochlea for higher frequencies. |
| Intensity Coding | In auditory nerve axons, different intensities are coded by different rates of firing of action potentials, and also by differences in the number of axons firing, since these axons have different thresholds. |
Created by:
9.14
Popular Biology sets