Tag: neural tissues

The nerve cells stop dividing after the birth of the child. There are no centrosomes in the neurons. Since there are no centrosomes the formation of the spindle apparatus cannot take place. The spindle fibres are necessary for the cell division to take place because they help in the attachment of the chromosomes

The neurotransmitter substance found between a motor neuron and a muscle cell is acetylcholine. In the autonomic nervous system, acetylcholine (ACh) is the neurotransmitter in the preganglionic sympathetic and parasympathetic neurons. ACh is also the neurotransmitter at the adrenal medulla and serves as the neurotransmitter at all the parasympathetic innervated organs. ACh is also the neurotransmitter at the sweat glands, and at the piloerector muscle of the sympathetic ANS. 

The average length of muscle fibers is of a few centimeters. 
The average size of epithelial cells is of few microns. 
Nerve cells possess a cell body and one to many thin, fiber-like axons.

• The axon terminals are the end of axon fiber and located close to the dendrites of another neuron, forming a connection known as a synapse and allowing them to send messages from neuron to neuron with the help of neurotransmitter. 
• So, a nerve cell transmits it's impulse to another through its axons. 

In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron. Synapsis is the fusion of chromosome pairs at the start of meiosis. A cell junction (or intercellular bridge) is a type of structure that exists within the tissue of some multicellular organisms, such as animals. Cell junctions consist of multiprotein complexes that provide contact between neighbouring cells or between a cell and the extracellular matrix. Synapticula is one of the numerous calcareous processes which extend between, and unite, the adjacent septa of certain corals.

The myelin sheath of neurons provides them with an insulating covering. It allows rapid transmission of signals from the nervous system to the body and vice-versa. Any damage to the myelin sheath will cause hindrance and slowing down of the transmission of signals to the axons.

So, the correct answer is 'Action potentials would be conducted too slowly along the neurons'.

The four segments of the spinal cord, going from top to bottom, these are the cervical, thoracic, lumbar and sacral segments. Injury to a certain segment of the cord will generally affect the parts of the body below the point of injury. Depending upon the severity and extent of the injury, there will be varying loss of movement and sensation. Damage to the spinal cord can also affect bodily functions such as breathing, bowel and bladder function, hormone release, temperature control, and movement of food through the stomach and intestines. It bears repeating that no two spinal cord injuries behave exactly alike. 

A unipolar neuron is a type of neuron, in which only one neurite or protoplasmic process extends from the cell body. Bipolar neuron is a type of neuron, which has two processes extending from the cell body. Pseudounipolar contains an axon, that has split into two branches, one branch runs to the periphery and the other to the spinal cord. A multipolar neuron is a type of neuron that possesses a single, long axon and many dendrites. The majority of the neurons are multipolar.