3. Man and enviromen.pdf

2024-02-20 Man and enviroment Cells in brain 1  2024-02-20 Glia cells Astrocytes Forming the blood-brain barrier (BBB) Regulating ne...

2024-02-20 Man and enviroment Cells in brain 1  2024-02-20 Glia cells Astrocytes Forming the blood-brain barrier (BBB) Regulating neurotransmitters Cleaning up Regulating blood flow to the brain Synchronizing the activity of axons Brain energy metabolism and homeostasis https://biologydictionary.net/glial-cells/ Glia cells Oligodendrocytes help information move faster along axons in the brain myelin sheath Signals along myelinated nerves can travel as fast as 200 miles per second (~322 km/h) https://www.snexplores.org/article/scientists- say-glia 2  2024-02-20 Glia cells Microglia They act as the brain's own dedicated immune system alert to signs of injury and disease detect unnecessary synapses and "prune" them autism https://www.snexplores.org/article/scientists- say-glia Glia cells Ependymal Cells make up the thin membrane lining the central canal of the spinal cord and the passageways (ventricles) of the brain make cerebrospinal fluid https://biologydictionary.net/glial-cells/ an important role in the blood-brain barrier keep the cerebrospinal fluid circulating https://o.quizlet.com/4HHRLnhnRgv0hTs UePM3lA_b.png 3  2024-02-20 Glia cells Radial Glia a type of stem cell can create other cells They provide the long fibers that guide young brain cells into place as brain forms https://biologydictionary.net/glial-cells/ neuroplasticity Glia cells Schwann Cells providing myelin sheaths for axons found in the peripheral nervous system (PNS) rather than the CNS part of the PNS's immune system https://biologydictionary.net/glial-cells/ 4  2024-02-20 Glia cells Satellite Cells similar to astrocytes. found in the PNS, not the CNS regulate the environment around the neurons https://biologydictionary.net/glial-cells/ keep chemicals in balance deliver nutrition to the neuron and absorb heavy metal toxins help transport several neurotransmitters and other substances Cells in brain 5  2024-02-20 Signal sending in nervous system Electrical Chemical Resting and action potential (Ramybės ir veikimo potencialai) 6  2024-02-20 Synapse https://www.youtube.com/watch?v=90cj4NX87Yk Neurons 7  2024-02-20 Nervous system (Nervų sistemos sandara) CNS – central nervous system (brain and spinal cord). PNS – peripheral nervous system, made up of Nervous system sensory and locomotor neurons that connect the CNS to other parts of the body. CNS PNS Afferent – sensory neurons. Information from receptors to CNS Efferent – motor neurons. Information from CNS to Afferent Efferent muscles and glands Somatic – voluntary. Signal from CNS to skeletal muscles Somatic Autonomic Autonomic – involuntary. Information from CNS to heart and glands Sympathetic Parasympathetic Sympathetic – activates at stress Parasympathetic – rest period Autonomic system Arterial pressure Gastrointestinal motions Urinary output Sweating (prakaitavimas) Body temperature General Adaption Syndrome (GAS) 8  2024-02-20 Cranial nerves 1. transmitting olfactory stimuli from the nose to the brain 2. responsible for the transmission of visual stimuli from the eye to the brain 3. controls eye movements and is also responsible for pupil size 4. can make the eyeballs move and rotate 5. carry sensitive information to the face, https://s7i9m6k4.rocketcdn.me/wp- content/uploads/2019/10/%D0%A7%D0%B5%D1%80%D0%B5%D0%BF%D0%BD%D1%8B%D0%B5- %D0%BD%D0%B5%D1%80%D0%B2%D1%8B.jpg information to the chewing process 6. responsible for transmitting motor stimuli to the external rectus muscle of the eye and therefore allows the eye to move in the opposite direction to our nose 9  2024-02-20 Cranial nerves 7. organizes the facial muscles to create facial expressions and sends signals to the salivary and lacrimal glands, collects information about taste through the tongue 8. responsible for balance and orientation in space and hearing function https://s7i9m6k4.rocketcdn.me/wp- 9. gets information about taste and content/uploads/2019/10/%D0%A7%D0%B5%D1%80%D0%B5%D0%BF%D0%BD%D1%8B%D0%B5- %D0%BD%D0%B5%D1%80%D0%B2%D1%8B.jpg sensory information from the pharynx. It leads to the salivary glands and various muscles in the neck that help with swallowing Cranial nerves 10. affects swallowing as well as sending and transmitting signals to our autonomic system to help regulate activation and control stress levels or send signals directly to our sympathetic system. 11. regulates head and shoulder https://s7i9m6k4.rocketcdn.me/wp- content/uploads/2019/10/%D0%A7%D0%B5%D1%80%D0%B5%D0%BF%D0%BD%D1%8B%D0%B5- movements %D0%BD%D0%B5%D1%80%D0%B2%D1%8B.jpg 12. regulate muscles of the tongue, swallowing and speech. 10  2024-02-20 Reflex Simple, automatic, innate responses to stimuli. Thresholds (slenksčiai) Stimulation Physical Exitation Physiological THRESHOLD Sensation Mental Decision Logical What is relation between sensation and exitation (dirginimas)? 11  2024-02-20 Thresholds (slenksčiai) Absolute Upper maximum irritation that causes an adequate sensation. Lower slightest irritation that causes an adequate sensation. Differential smallest change a person can notice Perceived intensity Over-threshold Irritants that cause an adequate sensation -. Pre-threshold or subsensory. Stimuli that do not cause sensation Intensity of stimul Adaptation Describes how thresholds change to the environmental stimuli. Clothes Living in noisy enviroment Adaption is sometimes referred to as habituation. 12  2024-02-20 Biological control systems Biological control systems employ the principle of „feedback“ Movement Neuro-hormonal feedback Insulin and carbohydrate (angliavandeniai) level Vision perception 380 nm - 760 nm 13  2024-02-20 Eye anatomy Junginė Regos nervas Vyzdys Stiklakūnis Lęšiukas Rainelė Fovea Odena Tinklainė Ragena Eye Lens (lęšiukas) - focuses light rays, changes its curvature (accommodation). The iris (rainelė) is a colored muscle that surrounds the pupil and changes its size. Pupil (vyzdys) - light enters the eye through it. As the diameter of the pupil changes, the flow of transmitted light changes. The diameter of the pupil can vary 16 times: from 2 to 8 mm. Choroid (gyslainė) - made up of blood vessels. Sclera (odena) - protects and strengthens the eyeball. The cornea (ragena) is the transparent part of the fibrous covering of the eyeball. Retina (tinklainė) - contains two types of photoreceptors - cones and rods. Fovea is the location of the retina where the density of cones is highest. Optic nerve (regos nervas) - transmits information by nerve impulses to the brain. 14  2024-02-20 Eye comparison with camera Image reverted and reversed. Not only these distortions in the image on retina Distortions are compensating 15  2024-02-20 Transmission of Visual Stimuli https://www.amnh.org/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/brain/seeing-color/brain-and-eyes/5149386-6-eng-US/brain-and-eyes_full_990.png 16  2024-02-20 Retina (tinklainė) 17  2024-02-20 Accommodation (akomodacija) the lens changes its curvature depending on the distance to the object so that the image in the retina of the eye is sharp Thickened Presbyopia (senatvinė toliaregystė) Flattened Fatigue Retina (tinklainė) Rod Cone Cone Rod Cone – photopic vision Rod – scotopic vision Both – mesopic vision Cone – kūgeliai, kolbelės Rod – lazdelės, stiebeliai 18  2024-02-20 10+5 Absolute Maximum Threshold 10+4 Brightness of the snow which has just fallen on a sunny day Functioning of cones 1000 Brightness of the ground on a sunny day 100 Brightness of the ground on a very cloudy day Photopic vision 10 A sheet of white paper for proper reading under lighting 1 White sheet of paper at a distance of 1 m from 1 candel strong light source Functioning of 10-1 cones and rods 10-2 The snow in the moonlight Mesopic vision 10-3 Brightness at medium moonlight during full moon (in the moonlight) 10-4 Snow in the Light of the Stars Functioning of rods 10-5 Grass in the light of the stars Scotopic vision 10-6 Absolute Minimum Threshold Night vision Receptors (photoreceptors) Cones - 4-5mln. Rods – 77-107 mln. Rod Cone Convert photons into a nerve signal 19  2024-02-20 Blind spot (akloji dėmė) Seeing stars in the sky at night 20  2024-02-20 Central vision - Cones Peripheral vision – Rods Visual field – central vision + Peripheral vision Photoreceptors Cones Rods Active at higher light levels Vision at low light levels (photopic vision) (scotopic vision) – Night vision Color vision Achromatic vision High spatial acuity Low spatial acuity Cones in fovea Cones in periphery 21  2024-02-20 Night vision decrease within altitude 5% at 1 100 m 18% at 2 800 m 35% at 4 000 m 50% at 5 000 m Indifferent zone – from sea level to 3 000 m daytime vision is unaffected Factors affecting night vision Age Mild hypoxia Cabin altitude above 5 000 ft (dentrimental above 12 000 ft) Smoking (20 cigarettes a day – night vision degrade approx. 20%) Alcohol Minor illnesses Deficiency of vitamin A 22  2024-02-20 Adaptation to dark Cone – photopic vision Rod – scotopic vision Both – mezopic vision To light – shorter About 15 min 10 sec To dark – longer 30-35 min Avoid bright light 30 min prior to a night flight Adaptation Slow regulatory processes: Change in pupil size; Use of different receptors; Regulation of pigment content at receptors. Under normal conditions, the amount of pigments in the receptors does not change. Changes only in extremely high light. Quick adjustment process: R-H-B triads by altering the receptor-bipolar cell binding threshold. 23  2024-02-20 Visual acuity Detection Recognition CAE Separation, Distinguishing Localization Visual acuity – ability to discriminate at varying distance 6/12 – see at 6 m what normal see at 12 m. Visual acuity Depends on: Light; Place in the retina, where the stimulus projects Best acuity in the central retina (fovea) Aprox 2 deg visual angle Higest density of cones, absent rods Visual acuity of scotopic vision is low Depends if stimulus is moving. Visual acuity for static stimulus is better than dynamic. > Visual acuity 24  2024-02-20 Visual acuity Scotopic vision Visual acuity does not change with increasing illumination Photopic vision Visual acuity increase with increasing illumination but till some level Limitations of visual acuity Angular distance from fovea Physical imperfections within visual system Age Hypoxia Smoking Alcohol Visibility (dust mist, etc.) Amount of light available Size and contours of an object Distance of the object from viewer Contrast of an object within its surroundings Relative motion of a moving object Drugs or medications 25  2024-02-20 Hyperacuity (hiperaštrumas) 0,3 Receptors responce 0,2 0,1 0 -3 -2 -1 0 1 2 3 4 -3 -2 -1 0 1 2 3 26  2024-02-20 Cortical magnification factor Periphery central part Periphery Retina Cortex (žievė) Visual field (Regėjimo laukas) The bigger nose – the less vision field in nasal side 27  2024-02-20 Depth perception Monocular vision – seeing one eye. Binocular vision – seeing two eyes. The arrangement of objects in space can be perceived by seeing it with one eye. However, both eyes are needed to accurately perceive the position of objects in space. 28  2024-02-20 Sources of information about depth Oculomotoric Optic Accommodation Binocular Monocular (primary) (secondary) Convergence Static Motion paralax Interposition Size Perspective Linear Aerial Shadows perspective perspective Texture Accomodation 29  2024-02-20 Convergence-divergence Oculomotoric depth cues Accommodation Convergence Related with distance between eyes and object (absolute distance) Information from the tension of muscles of eyes. 30  2024-02-20 Static monocular (secondary) depth cues Interposition – objects that are in front of other objects may partially block our view of the rearmost object. Because we know what the object should look like, and because we see only part of it, we interpret the obstructed object as being farther away Static monocular (secondary) depth cues Size: Familiar objects; Unfamiliar objects. 31  2024-02-20 Ames room 32  2024-02-20 Ames room 33  2024-02-20 Moon illusion Explanation of moon illusion Changes perceived distance, because human perceives the arch of the sky not as a sphere, but as an egg - the length is greater than the height. 34  2024-02-20 Static monocular (secondary) depth cues Perspective - objects are visible at a smaller viewing angle if they are at different distances from the observer Linear perspective Perspective Texture – further objects are visible smaller, the distance between them decreases. 35  2024-02-20 Perspective Aerial perspective – the objects far are visible as if through a fog, the image is less vivid. Perspective Shadows The perceived image depends on: Light source; Observer position. The brightness distribution provides information about the spatial shape of the object, especially if the location of the light source is known. 36  2024-02-20 http://www.michaelbach.de/ot/fcs_hollow-face/index.html Monocular (secondary) depth cues Motion parallax – if objects are moving at the same speed, then the visible speed of movement of further objects is lower (the sixth Euklidean theorem). We often move our heads unconscious to determine the distance between objects more accurately. Objects closer to the fixation point move in the opposite direction, further – in the same direction. 37  2024-02-20 Binocular (primary) depth cues Binocular depth features are related to differences in images of the same objects in the retina of the eye. Describe the differences between the viewing angles of the object in the left and right eyes. Disparity - the difference between the images of objects in the retinas of the left and right eyes. We can calculate disparity only when the same object is visible to both eyes at the same time. The visual system evaluates the depth of the object according to the disparity, the direction of the object according to the parallax. F 38  2024-02-20 F F F 39  2024-02-20 F F – fixation point A – object α and β left and right eyes sees object A Disparity = α - β Disparaty: Cross or negative - the object is closer to the fixation point. Non-cross or positive - the object is farther from the fixation point. β Zero - The object is at the same depth as α  the fixation point. O2 O1 O1AO2 – convergence angle (absolute distance) O Dar vienas parametras, kuris nusako objekto padėtį erdvėje yra paralaksas. Paralaksas – regimoji kryptis. Paralaksas – horizontalus ir vertikalus. 40  2024-02-20 A Another parameter that determines the position of an object in space is parallax. F Parallax - the visible direction. Parallax - horizontal and vertical. Horizontal Parallax - Defines the direction of the object's projection in O1 α the horizontal plane.  Vertical Parallax - Defines the angle β above or below the horizontal plane O O2 of the visible object. The visual system evaluates the depth of the object according to the disparity, the direction of the object according to the parallax. 41  2024-02-20 Stereograms 42  2024-02-20 Stereovision Fusion Diplopia Area of Panum Stereopsis Horopt Stereopsis useless for depth perception at distance beyond 60 m Empty field Fixation point 1-1,5 m The area where objects do not diplopic at a certain point of fixation is the area of the Panum. In the area of Panum, a person accurately identifies changes in depth, hence the area of fine stereopsy. The area beyond the Panum area, where the subject can estimate the distance to the object, is the area of quantitative stereopsy. Even further is the area where the subject can tell if the object is closer to or further from the fixation point, but the distance cannot be estimated - the area of qualitative stereopsy 43  2024-02-20 High light levels High energy blue Damage to retina Ultra violet Damage to lens 44  2024-02-20 Sunglasses characteristics Be impact resistant. Have thin metal frames (minimum obstruction of the visual field). Be coated with polycarbonate for strength. Be of good optical quality. Have a luminance transmittance of 10-15%. Have appropriate filtration characteristics. Visual Defects Hypermetropia - a shorter than normal eyeball along the visual axis results in the image being formed behind the retina and, unless the combined refractive index of the cornea and the lens can combine to focus the image in the correct plane, a blurring of the vision will result when looking at close objects. A convex lens will overcome this refractive error by bending the light inwards before it meets the cornea 45  2024-02-20 Visual Defects Myopia - the eyeball is longer than normal and the image forms in front of the retina. If accommodation cannot overcome this, then distant objects are out of focus whilst close up vision may be satisfactory. A concave lens will correct the situation by bending the light outwards before it hits the cornea. Pilots with either hypermetropia or myopia may usually retain their licences provided that their corrected vision allows them to read normal small print in good lighting at a distance of 30 cm and have at least 6/9 vision in each eye, but with 6/6 vision with both eyes. Visual Defects Presbyopia The ability of the lens to change its shape and therefore focal length (accommodation) depends on its elasticity and normally this is gradually lost with age. After the age of 40 to 50 the lens is usually unable to accommodate fully and a form of long-sightedness known as presbyopia occurs. The effects start with difficulty in reading small print in poor light. The condition normally requires a minor correction with a weak convex lens. Half lenses or look-over spectacles will suffice 46  2024-02-20 Visual Defects Astigmatism is usually caused by a misshapen or oblong cornea and objects will appear irregularly shaped Visual Defects Cataracts are normally associated with the ageing process though some diseases can cause cataracts at any age. With time, the lens can become cloudy causing a marked loss of vision. For severe cases, traditional surgery is carried out in which a section of the lens is removed and replaced with an artificial substitute. Surgery utilizes local anaesthesia on an outpatient basis and, following successful treatment, pilots will normally be allowed to return to flying. 47  2024-02-20 Visual Defects Glaucoma is a disease of the eye which causes a pressure rise of the liquid in the eye (aqueous humour). The fluid protects the lens and nourishes the cornea. It passes through a small shutter which can either be flawed or can become jammed causing a rise in pressure of the eye. The normal pressure range is 10 - 20 mm Hg. Glaucoma damages the optic nerve and may cause severe pain and if left untreated, blindness. Symptoms: Acute pain in the eye - in extreme cases. Blurred vision. Sensitivity to high light levels. Visual field deterioration. Red discolouration of the eye. Visual perception cascade Perception Total reaction time visual input → brain reaction → perception → recognition → evaluation → decision → ac on → response 5-7 s Prolonged due workload, fatigue Visual perception cascade 48  2024-02-20 Colour vision Cones Sensitive to red light, Red, Long Sensitive to green light, Green, Medium Sensitive to blue light, Blue, Short. Lighting Described by a spectrum (D65) Object Described by the reflection function Described by absorption Cones spectrum Responce Three spectral measurements. Information about color is of cones transmitted to the brain through opposing channels 49  2024-02-20 The number and arrangement of cone types differ in the retina: R:G:B ratio 10:4:1 B cones are absent in the central part of the retina R 700 nm. G 564,1 nm. B 435,8 nm. 50 2024-02-20 51  2024-02-20 Three Dimensions of Color Hue (atspalvis) represents the color being displayed Value (lightness) (skaistis, ryškis) describes overall intensity to how light or dark a color is Saturation (sodris) The distance from white. Longer distance – more saturated color. How women can distinguish more colors? Perception of red color related with genes in X chromosome. This gene has many variantions. Women have 2 X chromosomes. Women can receive one chromosome with the typical configuration of the red vision gene while the other chromosome receives a slight variation. The combination of a normal and variant gene, which occurs in about 40 percent of women, that may provide a broader spectrum of color vision in the red-orange range. 52 2024-02-20 53 2024-02-20 54 2024-02-20 55 2024-02-20 56 2024-02-20 57 2024-02-20 58  2024-02-20 Color blidness Name Physiology Pojūtis Man/Woman Protanomaly Missing L badly 2% / 0,02% cones distinguishes red color Deuteranopia Missing M badly 4,9% / 0,038% cones distinguishes green color Tritanopia Missing S badly 0,01% / 0,01% cones distinguishes blue color 59 2024-02-20 60 2024-02-20 61 2024-02-20 62 2024-02-20 63  2024-02-20 The trichromatic theory does not explain why dichromatic color blindness (red and green, blue and yellow) exists, why in such pairs. The trichromatic theory does not explain the color yellow. According to this theory, it is not pure, but obtained additively by mixing red and green. However, we perceive it pure (eg orange looks like a mixture of yellow and red). The trichromatic theory does not explain the afterimages. 64 2024-02-20 65  2024-02-20 Oponent process theory (E.Hering) Hering suggested three processes: Red - green Yellow - blue Chromatic system Ewald Konstantin Black - white Hering 1834-1918 Achromatic system Carry information about hue and Carry information saturation about value (lightness) 66  2024-02-20 S cones Achromatic channel M cones L cones [M+L] S cones Blue - yellow channel M cones [(M+L) vs. S] L cones S cones Red – green channel M cones [(L+S) vs. M] L cones Signals are summed if two solid arrows. S - B M - G Between solid and dashed arrow system looks the L - R differences. Simultaneous contrast The brightness of the square increases 67  2024-02-20 Lighness intensivity 10 10 10 5 5 5 Input Receptors +1 +1 +1 +1 +1 +1 -0.2 -0.2 -0.2 -0.2 -0.2 -0.2 -0.2 Neurons 6 6 7 2 3 3 Output Neurons activity Simultaneous contrast is explained by lateral inhibition. 68  2024-02-20 In the center inhibition occurs from four sides. - - + - - 69  2024-02-20 Color simultaneous contrast Color contrast 70 2024-02-20 71 2024-02-20 72  2024-02-20 Color adaptation Observing a certain color for a long time reduces the sensitivity to that color. 73  2024-02-20 Color adaptation Color adaptation 74