ciało-człowieka: Brain

Evidence: 100 • authority: 72

The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for special senses such as vision, hearing, and olfaction. Being the most specialized organ, it is responsible for receiving information from the sensory nervous system, processing that information (thought, cognition, and intelligence) and the coordination of motor control (muscle activity) and the endocrine system. While invertebrate brains arise from paired segmental ganglia (each of which is only responsible for the respective body segment) of the ventral nerve cord,…

Evidence: 72 • authority: 72

Evidence: 62 • authority: 72

Arthropods ( AR-thrə-pod) are invertebrates in the phylum Arthropoda. They possess an exoskeleton with a cuticle made of chitin, often mineralised with calcium carbonate, a body with differentiated (metameric) segments, and paired jointed appendages. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. They form an extremely diverse group of up to ten million species. Haemolymph is the analogue of blood for most arthropods. An arthropod has an open circulatory system, with a body cavity called a haemocoel through which haemolymph circulates to the interior organs. Like their exteriors, the internal organs of a…

Evidence: 55 • authority: 72

Evidence: 42 • authority: 92

Preservation and early evolution of scalidophoran ventral nerve cord.. Ecdysozoan worms (Nematoida + Scalidophora) are typified by disparate grades of neural organization reflecting a complex evolutionary history. The fossil record offers a unique opportunity to reconstruct the early character evolution of the nervous system via the exceptional preservation of extinct representatives. We focus on their nervous system as it appears in early and mid-Cambrian fossils. We show that some of the oldest known representatives of the group either preserved in carbonaceous compression (early and mid-Cambrian Burgess-type preservation) or secondarily phosphatized in three dimensions (e.g., basal Cambr…

Evidence: 41 • authority: 92

Evidence: 40 • authority: 92

A common modular design of nervous systems originating in soft-bodied invertebrates.. Nervous systems of vertebrates and invertebrates show a common modular theme in the flow of information for cost-benefit decisions. Sensory inputs are incentivized by integrating stimulus qualities with motivation and memory to affect appetitive state, a system of homeostatic drives, and labelled for directionality. Appetitive state determines action responses from a repertory of possibles and transmits the decision to a premotor system that frames the selected action in motor arousal and appropriate postural and locomotion commands. These commands are then sent to the primary motor pattern generators cont…

Evidence: 40 • authority: 72

Evidence: 37 • authority: 72

Cephalization is an evolutionary trend in bilaterian animals in which, over a sufficient number of generations, special sense organs and nerve ganglia concentrate towards the front of the body, often producing an enlarged head. This is associated with the animal's movement direction and bilateral symmetry. Cephalization of the nervous system has led to the formation of a brain with varying degrees of functional centralization in three phyla of bilaterian animals, namely the arthropods, cephalopod molluscs, and vertebrates. Hox genes organise aspects of cephalization in the bilaterians.

Evidence: 37 • authority: 72

In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events. Nervous tissue first arose in wormlike organisms about 550 to 600 million years ago. In vertebrates, it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of long fibers, or axons, that connect the CNS to…

Evidence: 37 • authority: 80

Evidence: 37 • authority: 92