Axons are long nerve processes which carry nerve impulses from the Soma to other neurons, they vary in length but can become almost as long as half of the human body.
The soma (body) of the neuron contains the nucleus which acts as the cell's control centre, these contain many small neurofibrils which project from the nucleus into the dendrites.
Dendrites are short, thick processes which branch out of the soma in a tree like manor. They conduct nerve impulses to the soma.
The three categories of neurons:
Afferent (Sensory) Neurons have the dendrites connected to receptors such as the eyes, ears etc. These receptors change the information they receive into electrical impulses that are transmitted to other neurons. In sensory neurons the axons are connected to other neurons.
Efferent (Motor) Neurons have the dendrites connected to other neurons, the axons are connected to effectors. Effectors are either glands or a muscle cell that is the receiving end of the nerve impulse. The nerve, when excited will cause the effector to react (move, contract, or secrete etc).
Internuncial Neurons have both the dendrites and the axons are connected to other neurons. They are sometimes referred to as connector neurons.
Internuncial neurons are found throughout the body, but especially in the spinal cord and brain.
Properties and characteristics of Neurons:
Normally the electrical impulses (messages) travel through a neuron in only one direction.
The axon may be surrounded by a 'coat' of lipids (fats) and proteins known as the myelin sheath which acts as an insulator.
Neurons are specialist cells that have lost the ability to reproduce themselves. Once the soma of a neuron has died the entire neuron dies, and can never be replaced.
Repair of damaged neurons only occurs in myelinated neurons.
white matter are coloured by myelin, consisting of many neurons supported by neuroglia.
grey matter is soma and dendrites or bundles of unmyelinated axons and neuralgia.
Explanation:
Risk-Taking—Research shows the brain keeps developing well into the twenties, during which time it continues to establish important communication connections and further refines its function. Scientists believe that this lengthy developmental period may help explain some of the behavior which is characteristic of adolescence—such as their propensity to seek out new and potentially dangerous situations. For some teens, thrill-seeking might include experimenting with alcohol. Developmental changes also offer a possible physiological explanation for why teens act so impulsively, often not recognizing that their actions—such as drinking—have consequences.
this is a muscle disease that mainly has to do with chickens and turkeys so it is deadly for humans you can get fever,vomiting,headaches, and also muscle and joint pain and also rashes
Too much hard work with zero results can cause stressful death..:/
Answer:
Explanation:
Puberty is when a child's body begins to develop and change as they become an adult. Girls develop breasts and start their periods. Boys develop a deeper voice and facial hair will start to appear. The average age for girls to begin puberty is 11, while for boys the average age is 12.
