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Grasp
A grasp is an act of taking, holding or seizing firmly with (or as if with) the hand. An example of a grasp is the handshake, wherein two people grasp one of each other's like hands. In zoology particularly, prehensility is the quality of an appendage or organ that has adapted for grasping or holding. Grasping is often preceded by reaching, which is highly dependent on head and trunk control, as well as eye control and gaze. Development The development of grasping is an important component of child development stages, wherein the main types of grasps are: * ''Raking grasp'', wherein the fingers, but not including the thumb, do all the holding.Page 176, section "Grasp" in: * ''Palmar grasp'', wherein the fingers squeeze against the palm, instead of against themselves as in the ''raking grasp''. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Child Development Stages
Child development stages are the theoretical milestones of child development, some of which are asserted in nativist theories. This article discusses the most widely accepted developmental stages in children. There exists a wide variation in terms of what is considered "normal", caused by variation in genetic, cognitive, physical, family, cultural, nutritional, educational, and environmental factors. Many children reach some or most of these milestones at different times from the norm. Holistic development sees the child in the round, as a whole person – physically, emotionally, intellectually, socially, morally, culturally and spiritually. Learning about child development involves studying patterns of growth and development, from which guidelines for 'normal' development are construed. Developmental norms are sometimes called milestones – they define the recognised pattern of development that children are expected to follow. Each child develops in a unique way; however, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palmar Grasp Reflex
Palmar grasp reflex (or grasp reflex) is a primitive and involuntary reflex found in infants of humans and most primates. When an object, such as an adult finger, is placed in an infant's palm, the infant's fingers reflexively grasp the object. Placement of the object triggers a spinal reflex, resulting from stimulation of tendons in the palm, that gets transmitted through motor neurons in the median and ulnar sensory nerves. The reverse motion can be induced by stroking the back or side of the hand. A fetus exhibits the reflex ''in utero'' by 28 weeks into gestation (sometimes, as early as 16 weeks), and persists until development of rudimentary fine motor skills between two to six months of age. Evolutionary significance Biologists have found that the reflex is significantly more frequent in infants of fur carrying primate species. It is theorized that the grasping reflex evolved as it is essential to survival in species, usually primates, where the young are carried in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hand
A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each "hand" and fingerprints extremely similar to human fingerprints) are often described as having "hands" instead of paws on their front limbs. The raccoon is usually described as having "hands" though opposable thumbs are lacking. Some evolutionary anatomists use the term ''hand'' to refer to the appendage of digits on the forelimb more generally—for example, in the context of whether the three digits of the bird hand involved the same homologous loss of two digits as in the dinosaur hand. The human hand usually has five digits: four fingers plus one thumb; these are often referred to collectively as five fingers, however, whereby the thumb is included as one of the fingers. It has 27 bones, not including the sesamoid bone, the numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primitive Reflexes
Primitive reflexes are reflex actions originating in the central nervous system that are exhibited by normal infants, but not neurologically intact adults, in response to particular stimuli. These reflexes are suppressed by the development of the frontal lobes as a child transitions normally into child development. These primitive reflexes are also called infantile, infant or newborn reflexes. Older children and adults with atypical neurology (e.g., people with cerebral palsy) may retain these reflexes and primitive reflexes may reappear in adults. Reappearance may be attributed to certain neurological conditions including dementia (especially in a rare set of diseases called frontotemporal degenerations), traumatic lesions, and strokes. An individual with cerebral palsy and typical intelligence can learn to suppress these reflexes, but the reflex might resurface under certain conditions (i.e., during extreme startle reaction). Reflexes may also be limited to those areas affected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehensility
Prehensility is the quality of an appendage or organ that has adapted for grasping or holding. The word is derived from the Latin term ''prehendere'', meaning "to grasp". The ability to grasp is likely derived from a number of different origins. The most common are tree-climbing and the need to manipulate food. Examples Appendages that can become prehensile include: Uses Prehensility affords animals a great natural advantage in manipulating their environment for feeding, climbing, digging, and defense. It enables many animals, such as primates, to use tools to complete tasks that would otherwise be impossible without highly specialized anatomy. For example, chimpanzees have the ability to use sticks to obtain termites and grubs in a manner similar to human fishing. However, not all prehensile organs are applied to tool use; the giraffe tongue, for instance, is instead used in feeding and self-cleaning Government procurement or public procurement is undertaken by the pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Handshake
A handshake is a globally widespread, brief greeting or parting tradition in which two people grasp one of each other's like hands, in most cases accompanied by a brief up-and-down movement of the grasped hands. Customs surrounding handshakes are specific to cultures. Different cultures may be more or less likely to shake hands, or there may be different customs about how or when to shake hands.Fist bump can pound out flu transmission __TOC__ History The handshake may have originated in prehistory as a demonstration of peaceful intent, since it shows that the hand holds no weapon. Another possibility is that it originated as a symbolic gesture of mutual commitment to an oath or promise: two hands clasping each other represents the sealing of ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoology
Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. The term is derived from Ancient Greek , ('animal'), and , ('knowledge', 'study'). Although humans have always been interested in the natural history of the animals they saw around them, and made use of this knowledge to domesticate certain species, the formal study of zoology can be said to have originated with Aristotle. He viewed animals as living organisms, studied their structure and development, and considered their adaptations to their surroundings and the function of their parts. The Greek physician Galen studied human anatomy and was one of the greatest surgeons of the ancient world, but after the fall of the Western Roman Empire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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