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1.
Int. j. morphol ; 40(2)2022.
Article in English | LILACS | ID: biblio-1385634

ABSTRACT

SUMMARY: The distribution of retinal ganglion cells (RGCs) was observed in the retinal wholemount of native chicken (Gallus gallus domestricus) of Bangladesh by using light microscopy. We considered five different anatomic regions (central, nasal, temporal, dorsal, and ventral) of Nissl stained wholemount, and the RGCs were counted, plotted, and measured accordingly. The average area of the retina was 431.75 mm2 while the total number of ganglion cells was 2124431 on average. Only the central area of the retina was the peak density (10400 cells/mm2) area, signifying the acute visual area, whilst the maximum spatial resolving power was 11 cycles/degree. The overall concentration of RGCs gradually declined towards the periphery but the size of cells generally decreased towards centrally. The size of ganglion cell was not uniform (12 to 180 µm2), specifically the central retina, just above the optic disc was packed with tiny-sized cells. The number, topographic distribution, and size of RGCs in native chicken signified their domesticated or terrestrial characters, uneven visual acuteness, and possibly only the central retina was the area for fine vision as the function of RGCs.


RESUMEN: En este studio se observó la distribución de las células ganglionares en la retina (CGR) de pollo nativo (Gallus gallus domesticus) de Bangladesh mediante el uso de microscopía óptica. Consideramos cinco regiones anatómicas diferentes (central, nasal, temporal, dorsal y ventral). Las muestras de CGR se tiñeron con Nissl, posteriormente, se midieron y contó el número de células totales. El área promedio de la retina fue de 431,75 mm2, mientras que el promedio del número total de células ganglionares fue de 2124431. El área central de la retina fue el área de densidad máxima (10400 células / mm2), señalando el área visual aguda, mientras que el poder de resolución espacial máximo fue de 11 ciclos / grado. La concentración general de CGR disminuyó gradualmente hacia la periferia, sin embargo, el tamaño de las células disminuyó hacia el centro. El tamaño de las CGR no fue uniforme (12 a 180 mm2), específicamente en la retina central, por encima del disco óptico, aumentaron significativamente las células pequeñas. El número, la distribución topográfica y el tamaño de las CGR en pollos nativos determinaron las características domésticas o terrestres, agudeza visual desigual y, posiblemente, la función de las CGR, en la retina central era el área de visión fina.


Subject(s)
Animals , Retinal Ganglion Cells/cytology , Chickens/anatomy & histology , Bangladesh , Microscopy
2.
Article in English | MEDLINE | ID: mdl-34948735

ABSTRACT

Excessive school bag weight may be a modifiable barrier to active transport to school. This study examined correlates of school bag weight and adolescents' perceptions of excessive school bag weight for walking and cycling to school among New Zealand adolescents living in diverse settlement types. Adolescents (n = 1512; 15.0 ± 1.3 years) completed a questionnaire and had their bag weight (n = 1190) and body weight (n = 1038) measured. Adolescents using active transport and rural adolescents had lighter school bags compared to their counterparts. One-third of adolescents reported excessive school bag weight for walking (31.2%) and cycling (37.2%) to school. Positive correlates of relative school bag weight were female gender (regression coefficient (95% CI): 0.53 (0.13, 0.93)), and underweight (2.21 (1.39, 3.02)), whereas negative correlates were Maori ethnicity (-0.87 (-1.41, -0.32)), overweight (-1.84 (-2.35, -1.34)) and obesity (-3.57 (-4.26, -2.87)), and school location in small urban areas (-2.10 (-4.19, -0.01)), and rural settlements (-3.58 (-5.66, -1.49)). Older adolescents, females, those with greater relative school bag weight, and those experiencing school bag-related pain symptoms and/or fatigue were more likely to report excessive school bag weight for both walking and cycling to school. Future initiatives should target reducing excessive school bag weight, particularly in female and urban adolescents.


Subject(s)
Schools , Walking , Adolescent , Bicycling , Female , Humans , New Zealand , Rural Population
3.
Int. j. morphol ; 39(2): 378-385, abr. 2021. ilus, tab
Article in English | LILACS | ID: biblio-1385376

ABSTRACT

SUMMARY: We studied the bones of forelimb of four adult lions (Panthera leo) of both sexes to record the gross anatomical and morphometrical features of the scapula, humerus, radius and ulna. We observed some unique anatomical features that will be helpful for radiographic interpretation and forensic investigations. The lateral surface of scapula was unequally divided into supraspinous (fossa supraspinata) and infraspinous fossa (fossa infraspinata) by a well developed spine (spina scapulae). The acromion process was subdivided into suprahamate process (processus suprahamatus)and hamate process (processus hamatus); the later one was over hanged the glenoid cavity (cavitas glenoidalis), but the supraglenoid tubercle (tuberculum supraglenoidalis) was absent. The shaft (diaphysis) of humerus was compressed craniocaudally in proximal part, rounded to oval in middle part and compressed mediolaterally in distal part. A long, narrow supracondyloid foramen was found at distal limb just above the medial epicondyle (epicondylus medialis) which didn't connect the radial fossa (fossa radialis) with the olecranon fossa (fossa olecrani). The radius and ulna were twin bones where radius was articulated craniolateral to the ulna proximally and craniomedial to the ulna distally. However, the ulna was the longest bone in the forelimb of lion. The olecranon tuberosity of this bone had three prominences - two were cranially, whereas the caudal one was the largest and rounded. Distally projected styloid processes (processus styloideus) were found in the distal limb of both radius and ulna.


RESUMEN: Estudiamos los huesos de las miembros torácicos de cuatro leones adultos (Panthera leo) de ambos sexos para registrar las características anatómicas y morfométricas macroscópicas de la escápula, el húmero, el radio y la ulna. Se observaron algunas características anatómicas únicas que serán útiles para la interpretación radiográfica y las investigaciones forenses. La superficie lateral de la escápula se dividió de manera desigual en fosa supraespinosa y fosa infraspinosa por una columna bien desarrollada (espina de la escápula). El proceso del acromion se subdividió en proceso suprahamato (processus suprahamatus) y proceso hamato (processus hamatus); el tubérculo supraglenoideo (tuberculum supraglenoidalis) estaba ausente. La diáfisis (diafisis) del húmero estaba comprimida craneocaudalmente en la parte proximal, redondeada a ovalada en la parte media y comprimida mediolateralmente en la parte distal. Se encontró un foramen supracondileo largo y estrecho en la extremidad distal, por encima del epicóndilo medial (epicondylus medilaris) que no conectaba la fosa radial (fosa radial) con la fosa olecraneana (fossa olecrani). El radio y la ulna eran huesos idénticos en los que el radio se articulaba craneolateral a la ulna proximalmente, y craneomedial a la ulna distalmente. Sin embargo, la ulna era el hueso más largo del miembro torácico del león. La tuberosidad del olécranon de este hueso tenía tres prominencias: dos eran craneales, mientras que la caudal era la más grande y redondeada. Se encontraron procesos estiloides proyectados distalmente (processus styloideus) en la extremidades distales del radio y la ulna.


Subject(s)
Animals , Male , Female , Forelimb/anatomy & histology , Lions/anatomy & histology , Radius/anatomy & histology , Scapula/anatomy & histology , Ulna/anatomy & histology , Humerus/anatomy & histology
4.
Article in English | MEDLINE | ID: mdl-33287302

ABSTRACT

The school neighbourhood built environment (BE) can facilitate active transport to school (ATS) in adolescents. Most previous studies examining ATS were conducted in large urban centres and focused on BE of home neighbourhoods. This study examined correlations between school-level ATS rates among adolescents, objectively measured school neighbourhood BE features, and adolescents' perceptions of the school route across different urbanisation settings. Adolescents (n = 1260; 15.2 ± 1.4 years; 43.6% male) were recruited from 23 high schools located in large, medium, and small urban areas, and rural settings in Otago, New Zealand. Adolescents completed an online survey. School neighbourhood BE features were analysed using Geographic Information Systems. School neighbourhood intersection density, residential density and walkability index were higher in large urban areas compared to other urbanisation settings. School-level ATS rates (mean 38.1%; range: 27.8%-43.9%) were negatively correlated with school neighbourhood intersection density (r = -0.58), residential density (r = -0.60), and walkability index (r = -0.64; all p < 0.01). School-level ATS rates were also negatively associated with adolescents' perceived safety concerns for walking (r = -0.76) and cycling (r = -0.78) to school, high traffic volume (r = -0.82), and presence of dangerous intersections (r = -0.75; all p < 0.01). Future initiatives to encourage ATS should focus on school neighbourhood BE features and minimise adolescents' traffic safety related concerns.


Subject(s)
Built Environment , Schools , Transportation , Adolescent , Built Environment/statistics & numerical data , Cross-Sectional Studies , Environment Design , Female , Humans , Male , New Zealand , Residence Characteristics , Schools/statistics & numerical data , Surveys and Questionnaires , Transportation/statistics & numerical data , Urbanization , Walking
5.
Article in English | MEDLINE | ID: mdl-32397592

ABSTRACT

Active transport to or from school presents an opportunity for adolescents to engage in daily physical activity. Multiple factors influence whether adolescents actively travel to/from school. Creating safe walking and cycling routes to school is a promising strategy to increase rates of active transport. This article presents a comprehensive conceptual framework for modelling safe walking and cycling routes to high schools. The framework has been developed based on several existing relevant frameworks including (a) ecological models, (b) the "Five Es" (engineering, education, enforcement, encouragement, and evaluation) framework of transport planning, and (c) a travel mode choice framework for school travel. The framework identifies built environment features (land use mix, pedestrian/cycling infrastructure, neighbourhood aesthetics, and accessibility to local facilities) and traffic safety factors (traffic volume and speed, safe road crossings, and quality of path surface) to be considered when modelling safe walking/cycling routes to high schools. Future research should test this framework using real-world data in different geographical settings and with a combination of tools for the assessment of both macro-scale and micro-scale built environment features. To be effective, the modelling and creation of safe routes to high schools should be complemented by other interventions, including education, enforcement, and encouragement in order to minimise safety concerns and promote active transport.


Subject(s)
Bicycling , Built Environment , Environment Design , Walking , Adolescent , Humans , Male , Residence Characteristics , Schools , Transportation
6.
Int. j. morphol ; 34(3): 909-917, Sept. 2016. ilus
Article in English | LILACS | ID: biblio-828962

ABSTRACT

Bones of forelimb were studied from a prepared skeleton of an adult female Asian elephant (Elephas maximus) in Anatomy Museum of Chittagong Veterinary and Animal Sciences University to understand the morphological form and structure of Asian elephant forelimb. The angle was approximately 123 between caudal border of scapula and caudal border of humerus. The scapula, humerus and bones of the antebrachium (particularly the ulna) were massive bones. The bones of manus were the short and relatively small. The dorsal border of scapula extended from the level of proximal extremity of first rib to the middle of the 6th rib. Ventral angle of scapula articulated with humerus by elongated shaped glenoid cavity (cavitas glenoidalis) of scapula and head of humerus (caput humeri). The major tubercle (tuberculum majus) of humerus was situated laterally to the head, which had smaller cranial part with large caudal part and extended cranially to the head. The crest of minor tubercle (tuberculum minus) was present as the rough line on the mediocaudal surface of humerus that ends in a slight depressed or elevated area, known as teres major tuberosity (tuberositas teres major). The lateral supracondyler crest (crista supra condylaris lateralis) at the caudal surface of the shaft limit the musculo-spiral groove in body of humerus. The radius and ulna are twin bones of forearm and the attachment between ulna and radius occurs in such a way, the radius articulates craniomedially with the ulna in the proximal part. But the shaft spirals laterally over the cranial surface of the ulna to articulate distally with the medial aspect of the ulna. There were 8 carpal bones, 5 metacarpal bones and 5 digits. The comparative size of the proximal and distal raw of carpal bones were ulnar carpal > radial > intermediate > accessory carpal and IV > III > II > I respectively. The gradual lengths of the metacarpal bones were III > IV > II > V > I. Digits I and V were vertical and digit II, III and IV were horizontal.


En el Museo de Anatomía de la Universidad de Veterinaria y Ciencias de Animales de Chittagong fueron estudiados los huesos del miembro torácico de un esqueleto preparado de un elefante asiático (Elephas maximus), hembra adulta, para analizar su morfología y estructura. El ángulo entre el margen caudal de la escápula y el margen caudal del húmero era de aproximadamente 123°. La escápula, húmero y los huesos del antebrazo (en particular la ulna) eran huesos macizos. Los huesos de las manos eran cortos y relativamente pequeños. El margen dorsal de la escápula se extendía desde el nivel de la porción proximal de la primera costilla para la parte media de la sexta costilla. El ángulo ventral de la escápula está articulado con el húmero por la cavidad glenoidea (cavitas glenoidalis), de forma alargada, de la escápula y la cabeza del húmero (caput humeri). El principal tubérculo (tuberculum majus) del húmero estaba situado lateralmente a la cabeza, que tenía una parte craneal pequeña y una mayor parte caudal, extendiéndose cranealmente en la cabeza. La cresta del tubérculo menor (tuberculum minus) estaba presente como la línea áspera sobre la superficie mediocaudal del húmero que termina en una pequeña zona deprimida o elevada, conocida como tuberosidad redonda mayor (tuberositas teres major). La cresta supracondilar lateral (crista supra condylaris lateralis) en la superficie caudal del eje limita la ranura músculo-espiral en el húmero. El radio y la ulna son huesos gemelos del antebrazo y la unión entre la ulna y el radio se produce de tal manera, que el radio articula, craneal y medialmente, con la ulna en la porción proximal. Pero el eje en espiral está ubicado lateralmente sobre la superficie craneal de la ulna para articular distalmente con la cara medial de la ulna. Se identificaron 8 huesos del carpo, 5 metacarpianos y 5 dígitos. El tamaño comparativo de las porciones proximal y distal de los huesos del carpo fue ulna > radial > Intermedio> carpiano accesorio y IV > III > II > I, respectivamente. Las longitudes graduales de los huesos metacarpianos eran III > IV > II > V > I. Dígitos I y V eran verticales y dígitos II, III y IV fueron horizontales.


Subject(s)
Animals , Female , Elephants/anatomy & histology , Humerus/anatomy & histology , Scapula/anatomy & histology , Ulna/anatomy & histology , Asia , Radius/anatomy & histology
7.
Int. j. morphol ; 33(1): 100-104, Mar. 2015. ilus
Article in English | LILACS | ID: lil-743771

ABSTRACT

A histological and morphometric study was conducted to evaluate the seasonal testicular variations in the adult Japanese quail (Coturnix coturnix japonica) in Bangladesh. The weight of birds and testes, volume, length, circumference, seminiferous tubule diameter, circumference and height of germinal epithelium of testes were measured. Sections of testes obtained from studied birds were stained with H&E and images were taken by J software. Weight and volume of paired testes of quails significantly heavier (P<0.05) in long day period of summer and rainy season (March ­ September) than the short day period of autumn and winter (October ­ February). Seasons had no significant effect on live weight gain of quails. The weight and diameter of testes or height of the germinal epithelium of the seminiferous tubule were positively correlated (r=0.84; r=0.88). Spermatogenic activity was pronounced during summer and rainy season than that of autumn and winter (P<0.05).


Se realizó un estudio histológico y morfométrico para evaluar las variaciones testiculares estacionales de la codorniz japonesa adulta (Coturnix coturnix japonica) en Bangladesh. Se midieron el peso de las aves y sus testículos; el volumen, longitud, circunferencia y diámetro de los túbulos seminíferos, y la circunferencia y altura del epitelio germinal testicular. Secciones de testículos obtenidos de las aves estudiadas fueron teñidas con H&E y las imágenes fueron analizadas con el programa ImageJ. Se registró un aumento significativo en peso y volumen de los testículos de codornices (P<0,05) en el periodo día de verano y en la temporada de lluvia (marzo-septiembre) al período del día corto de otoño e invierno (octubre-febrero). El período estacionario no tuvo efecto significativo sobre el aumento de peso vivo de las codornices. El peso y el diámetro de los testículos, y la altura del epitelio germinal del túbulo seminífero se correlacionaron positivamente (r=0,84; r=0,88). La actividad espermatogénica fue más pronunciada durante el verano y durante la temporada de lluvias que en otoño e invierno (p<0,05).


Subject(s)
Animals , Male , Coturnix/anatomy & histology , Testis/anatomy & histology , Bangladesh , Photoperiod , Seasons , Seminiferous Tubules/anatomy & histology , Temperature
8.
Int. j. morphol ; 31(4): 1473-1478, Dec. 2013. ilus
Article in English | LILACS | ID: lil-702336

ABSTRACT

Recent excavated skeleton of an adult female Asian Elephant (Elephas maximus), died in dystokia in Bangladesh was used for macro anatomical study. Some unique morphological features of bones of hind limb were observed. Pelvic canal was more oval and the wings of ilium were wider. Rump slope was about 36°. Angle between femur and tibia was close to 180°. In Femur, the major trochanter was located at the lower level of head. Minor trochanter, fovea capitis and trochanteric ridge were absent. Supracondyloid fossa was shallow but the intercondyloid fossa was deep. Posterior surface of patella possessed a blunt vertical ridge. The articular surfaces of both tibial condyles were clearly concave. The tibia and the fibula were articulated proximally and distally with keeping a wide interosseous space. Instead of tibial tuberosity, there was an elongated triangular depression in proximal part. There were six tarsal bones arranged in three rows. The comparative size of the distal tarsal bones were III+IV > I > II. The comparative lengths of the metatarsal bones were III > II > IV > V> I. Digits I and V were the most vertical and digit III was the most horizontal. The proximal phalanx was the biggest of all.


Fue utilizado para su estudio anatómico macrocroscópico, el esqueleto de un elefante asiático (Elephas maximus) hembra adulta, excavado recientemente y con muerte por distocia en Bangladesh. Se observaron algunas características morfológicas únicas de los huesos de los miembros posteriores. El canal pélvico era más ovalado y las alas del ilion eran más amplias. La pendiente de la rabadilla era de unos 36° aproximadamente; el ángulo entre el fémur y la tibia era próximo a los 180°. En el fémur, el trocánter mayor se encontraba en el nivel inferior de la cabeza. El trocánter menor, la fovea capitis y cresta del trocánter estuvieron ausentes. La fosa supracondílea era superficial, mientras que la fosa intercondílea era profunda. La superficie posterior de la patela poseía una cresta vertical sobresaliente. Las superficies articulares de ambos cóndilos tibiales eran claramente cóncavas. La tibia y la fíbula se articulan proximal y distalmente, manteniendo un amplio espacio interóseo. En lugar de la tuberosidad tibial, había una depresión triangular alargada en parte proximal. Se observaron seis huesos del tarso dispuestos en tres filas. El tamaño relativo de los huesos del tarso distal eran III + IV > I > II. Las longitudes comparativas de los huesos metatarsianos fueron III > II > IV > V > I. Los dígitos I y V fueron los más verticales y el dígito III fue el más horizontal. La falange proximal fue la de mayor tamaño.


Subject(s)
Animals , Elephants/anatomy & histology , Pelvic Bones/anatomy & histology , Hindlimb/anatomy & histology
9.
Okajimas Folia Anat Jpn ; 87(3): 75-83, 2010 Nov.
Article in English | MEDLINE | ID: mdl-21174936

ABSTRACT

In this study, the pecten oculi of a diurnally active bird, the Japanese jungle crow (Corvus macrorhynchos), was examined using light and electron microscopy. In this species, the pecten consisted of 24-25 highly vascularized pleats held together apically by a heavily pigmented 'bridge' and projected freely into the vitreous body in the ventral part of the eye cup. Ascending and descending blood vessels of varying caliber, together with a profuse network of capillaries, essentially constituted the vascular framework of the pecten. A distinct distribution of melanosomes was discernible on the pecten, the concentration being highest at its apical end, moderate at the crest of the pleats and lowest at the basal and lateral margins. Overlying and within the vascular network, a close association between blood vessels and melanocytes was evident. It is conjectured that such an association may have evolved to augment the structural reinforcement of this nutritive organ in order to keep it firmly erectile within the gel-like vitreous. Such erectility may be an essential prerequisite for its optimal functioning as well as in its overt use as a protective shield against the effects of ultraviolet light, which otherwise might lead to damage of the pectineal vessels.


Subject(s)
Capillaries/ultrastructure , Crows/anatomy & histology , Melanocytes/ultrastructure , Retinal Vessels/ultrastructure , Animals , Basement Membrane/ultrastructure , Capillaries/cytology , Capillaries/metabolism , Collagen Type I/metabolism , Female , Male , Microscopy, Electron, Transmission , Retinal Vessels/cytology , Retinal Vessels/metabolism
10.
Zoolog Sci ; 27(6): 514-21, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20528159

ABSTRACT

The topography of cone oil droplets and their carotenoids were investigated in the retina of jungle crow (Corvus macrorhynchos). Fresh retina was sampled for the study of retinal cone oil droplets, and extracted retinal carotenoids were saponified using methods adapted from a recent study, then identified with reverse-phase high-performance liquid chromatography (HPLC). To assess the effects of saponification conditions on carotenoid recovery from crow retina, we varied base concentration and total time of saponification across a wide range of conditions, and again used HPLC to compare carotenoid concentrations. Based on colors, at least four types of oil droplets were recognized, i.e., red, orange, green, and translucent, across the retina. With an average of 91,202 /mm(2), density gradually declines in an eccentric manner from optic disc. In retina, the density and size of droplets are inversely related. In the peripheral zone, oil droplets were significantly larger than those of the central area. The proportion of orange oil droplets (33%) was higher in the central area, whereas green was predominant in other areas. Three types of carotenoid (astaxanthin, galloxanthin and lutein), together with one unknown carotenoid, were recovered from the crow retina; astaxanthin was the dominant carotenoid among them. The recovery of carotenoids was affected by saponification conditions. Astaxanthin was well recovered in weak alkali (0.06 M KOH), in contrast, xanthophyllic carotenoids were best recovered in strong alkali (0.6 M KOH) after 12 h of saponification at freeze temperature.


Subject(s)
Carotenoids/metabolism , Crows/anatomy & histology , Crows/physiology , Oils/metabolism , Retinal Cone Photoreceptor Cells/cytology , Retinal Cone Photoreceptor Cells/physiology , Animals , Retina/cytology , Retina/physiology
11.
Anat Sci Int ; 83(4): 239-46, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19159352

ABSTRACT

This study was intended to determine the number and density of both retinal ganglion cells and the oil droplets of cone photoreceptor cells in brown-eared bulbul (Hypsipetes amaurotis). For this study birds were killed with proper dose of anesthetic (pentobarbital, 30 mg/kg), and the eyes were removed from the orbital cavity to isolate the retina. For the ganglion cell study retinal whole-mount specimens were prepared and stained with 0.1% cresyl violet. The different types of oil droplets were counted from color microphotographs of freshly prepared retinal samples. The mean total number of ganglion cells was estimated at approximately 2.5 x 10(6); with an average density of 16 523 cells/mm(2). Two high-density areas, namely the central area (CA) and the dorso-temporal area (DTA), are located in the central and dorso-temporal retinas, respectively, in bulbuls (24 032 cells/mm(2) in the CA; 23 113 cells/mm(2) in the DTA). Small ganglion cells persisted in the highest density areas, whereas the largest soma sizes were found in the lowest density areas of the retina. Four types of different colored oil droplets - red, orange, green and clear - were identified with an average density of 29 062/mm(2). Among the different colors, the green oil droplets had a significantly higher population (13 083/mm(2)) than the others across the retina. The central retina had a significantly higher number of all types of oil droplets, at a density of 60 552/mm(2). The density and size of the different colored oil droplets were inversely related across the regions of the retina. Taken together, it is concluded that the CA of the retina is an excellent quality area for visual perception due to peak density of ganglion cells and oil droplets. Moreover, each specific oil droplet makes a distinct contribution to visual perception, thereby ensuring that the bird has a retina that best matches its natural environment and feeding behavior.


Subject(s)
Oils , Passeriformes/anatomy & histology , Photoreceptor Cells, Vertebrate/cytology , Retina/cytology , Retinal Ganglion Cells/cytology , Animals , Cell Count , Female , Male , Visual Perception
12.
Anat Sci Int ; 81(4): 253-9, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17176961

ABSTRACT

A retinal ganglion cell density map was generated using Nissl-stained retinal whole mounts from the jungle crow (Corvus macrorhynchos). The total number, distribution and size of these cells were determined in the area centralis, as well as in temporal, nasal, dorsal and ventral retinal regions. The mean total number of ganglion cells was estimated to be 3.6 x 10(6). The highest densities were found in the area centralis (25 600 /mm2) and the dorso-temporal part of the retina, suggesting the highest quality of vision. This density diminished nearly concentrically from the central area towards the retinal periphery. The number of ganglion cells was highest in the temporal retina followed, in order, by the nasal, dorsal and ventral retinal regions. Based on ganglion cell size, the retina seemed to consist of the following five regions: central, temporal, nasal, dorsal and ventral. Ganglion cell size ranged from 16 to 288 microm2, with smaller cells predominating in central regions above the optic disc and larger cells comprising more of the peripheral regions. The present study showed two highly populated areas of ganglion cells in the crow retina and it is expected that the crow retina provides well-developed monocular and binocular vision.


Subject(s)
Crows/anatomy & histology , Retinal Ganglion Cells/cytology , Visual Fields/physiology , Animals , Axons/physiology , Axons/ultrastructure , Brain Mapping , Cell Count , Cell Size , Crows/physiology , Female , Fovea Centralis/cytology , Fovea Centralis/physiology , Male , Neural Pathways/cytology , Neural Pathways/physiology , Optic Disk/anatomy & histology , Optic Disk/physiology , Optic Nerve/cytology , Optic Nerve/physiology , Retinal Ganglion Cells/physiology , Species Specificity , Vision, Binocular/physiology , Visual Pathways/cytology , Visual Pathways/physiology
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