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.
You can avoid spreading it by: Do not use antibiotics to treat viral infections, such as influenza, the
common cold, a runny nose or a sore throat
Use antibiotics only when a doctor prescribes them.
Never share antibiotics with others or use leftover prescriptions.
Answer: Your first prenatal care visit is usually the longest one. You'll talk with your doctor about your medical history, the other parent's medical history, and your family's' medical history. Your doctor will give you a complete check-up, usually with a physical exam and blood and urine tests to make sure you're healthy.
Explanation:
