Nervous tissue consists of two main types of cells: neurons and neuroglia. Nerve cells, or neurones (also written 'neurons') transmit nerve impulses that move information around the body. Neuroglia are also known simply as 'glia' and have various functions in support of nerve cells but do not transmit nerve impulses themselves.
What are the types of cells the make up the nervous tissue?
Nervous tissue consists of two main types of cells: neurons and neuroglia. Nerve cells, or neurones (also written 'neurons') transmit nerve impulses that move information around the body. Neuroglia are also known simply as 'glia' and have various functions in support of nerve cells but do not transmit nerve impulses themselves.
What are the cells called within the nervous system?
The nervous system is composed of two basic cell types: glial cells (also known as glia) and neurons. Glial cells, which outnumber neurons ten to one, are traditionally thought to play a supportive role to neurons, both physically and metabolically.
What is special about the cells in a tissue?
Cells are enclosed by a special tissue or skin called a semi-permeable membrane. The word permeable means porous or penetrable. Semi-permeable means that the membrane only allows certain things to pass through it. The membrane around cells
What are the three types of nervous tissue?
What are the Different Types of Nervous Tissue
- Cyton or cell body. The cell body contains the major concentration of the cytoplasm and the central nucleus of the neuron. ...
- Dendrons. These are short much-branched and tapering projections arising from the cell body. ...
- Axon (Nerve fibre). The axon is a long cylindrical process of uniform diameter that arises from the axon hillock of the cyton. ...
What is the role of nerve tissue in the body?
It is responsible for coordinating and controlling many body activities. It stimulates muscle contraction, creates an awareness of the environment, and plays a major role in emotions, memory, and reasoning.
What are the cells that conduct electrical impulses called?
The cells in nervous tissue that generate and conduct impulses are called neurons or nerve cells. These cells have three principal parts: the dendrites, the cell body, and one axon.
Which part of the cell carries impulses away from the cell body?
Dendrites are extensions, or processes, of the cytoplasm that carry impulses to the cell body. An extension or process called an axon carries impulses away from the cell body. Nervous tissue also includes cells that do not transmit impulses, but instead support the activities of the neurons.
What are the two types of cells that make up nervous tissue?
All of the other types of neuroglia above are larger and collectively called macroglia. This diagram shows the two types of cells, neurons and neuroglia, that make up nervous tissue.
What is the function of nerve tissue?
Nervous tissue is the term for groups of organized cells in the nervous system, which is the organ system that controls the body’s movements, sends and carries signals to and from the different parts of the body, and has a role in controlling bodily functions such as digestion. Nervous tissue is grouped into two main categories: neurons ...
What are the two main categories of nerve tissue?
Nervous tissue is grouped into two main categories: neurons and neuroglia. Neurons, or nerves, transmit electrical impulses, while neuroglia do not; neuroglia have many other functions including supporting and protecting neurons.
What does activation of the SNS do to the body?
Activation of the SNS causes the pupils of the eyes to dilate, inhibits digestion, increases sweat secretion, and increases the heart rate.
What is the cell that transmits signals called?
Neurons are cells that can transmit signals called nerve impulses, or action potentials. An action potential is a quick rise and fall in the electrical membrane potential of the neuron, which transmits signals from one neuron to the next. These are the different types of neurons:
Which system is responsible for controlling the movement of specific parts of the body?
It connects the CNS to the rest of the body and is directly responsible for controlling movements of specific parts of the body; for example, just before arm movement the CNS sends nerve impulses to the PNS nerves in the arm, which causes the arm to move. Another subdivision of the nervous system is into the sympathetic nervous system (SNS) ...
Where are sensory neurons located?
Sensory neurons are found in the peripheral nervous system (PNS) and send information from the PNS to the central nervous system (CNS). Certain sensory neurons can detect heat, light, or pressure and relay this information to the brain.
What are the two types of cells in the nervous system?
Nervous tissue is composed of two types of cells, neurons and glial cells . Neurons are the primary type of cell that most anyone associates with the nervous system. They are responsible for the computation and communication that the nervous system provides. They are electrically active and release chemical signals to target cells. Glial cells, or glia, are known to play a supporting role for nervous tissue. Ongoing research pursues an expanded role that glial cells might play in signaling, but neurons are still considered the basis of this function. Neurons are important, but without glial support they would not be able to perform their function.
Which cells support the neurons of the CNS?
The CNS has astrocytes, oligodendrocytes, microglia, and ependymal cells that support the neurons of the CNS in several ways.
How long is a myelin sheath?
Because a micrometer is 1/1000 of a millimeter, this means that the length of a myelin sheath can be 100–1000 times the diameter of the axon. [link], [link], and [link] show the myelin sheath surrounding an axon segment, but are not to scale. If the myelin sheath were drawn to scale, the neuron would have to be immense—possibly covering an entire wall of the room in which you are sitting.
Why are bipolar cells a direct relay?
Bipolar cells, because they have one dendrite that receives input and one axon that provides output, would be a direct relay between two other cells.
What is the main part of a neuron?
As you learned in the first section, the main part of a neuron is the cell body, which is also known as the soma (soma = “body”). The cell body contains the nucleus and most of the major organelles. But what makes neurons special is that they have many extensions of their cell membranes, which are generally referred to as processes. Neurons are usually described as having one, and only one, axon—a fiber that emerges from the cell body and projects to target cells. That single axon can branch repeatedly to communicate with many target cells. It is the axon that propagates the nerve impulse, which is communicated to one or more cells. The other processes of the neuron are dendrites, which receive information from other neurons at specialized areas of contact called synapses. The dendrites are usually highly branched processes, providing locations for other neurons to communicate with the cell body. Information flows through a neuron from the dendrites, across the cell body, and down the axon. This gives the neuron a polarity—meaning that information flows in this one direction. [link] shows the relationship of these parts to one another.
How many types of glial cells are there?
There are six types of glial cells. Four of them are found in the CNS and two are found in the PNS. [link] outlines some common characteristics and functions.
How to classify neurons?
They can be classified by many different criteria. The first way to classify them is by the number of processes attached to the cell body. Using the standard model of neurons, one of these processes is the axon, and the rest are dendrites. Because information flows through the neuron from dendrites or cell bodies toward the axon, these names are based on the neuron’s polarity ( [link] ).
What are the two groups of the nervous system?
Anatomically, the nervous system is divided into two groups. CNS. PNS. Organs that make up the CNS. brain and spinal cord . Function of the CNS. integrates, processes, and coordinates sensory data about conditions inside and outside the body. The CNS is also the source of. thoughts, emotions, and memories.
Where does the nerve impulse travel?
the nerve impulse travels in an axon in a saltatory propagation. Jumping from one node of ranvier to the next and so on....
Which type of cell performs several functions in support of neurons?
star shape cells that perform several functions in support of neurons
Which neurons transmit information from somatic & special sensory receptors to the CNS?
consist of somatic censor neurons that transmit info (input) from somatic & special sensory receptors to the CNS
What are the two types of neurons that make up the motor neurons?
consist of autonomic visceral sensory neurons and autonomic motor neurons
Where are the neurons located in the GI tract?
Networks of neurons located in the walls of organs of GI tract, help regulate digestive system activities
What is the axon surrounded by?
most axons are this and is surrounded by a myelin sheath
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