Nervous Tissue Flashcards
What kind of cells does nervous tissue contain?
Neurons and several kinds of supporting cells, collectively called neuroglia, or glial cells.
What are the functions of neuroglia? [5]
- Maintain physical and structure of nervous tissue
- Repair nervous tissue framework after injury
- Perform phagocytosis
- Provide nutrients to neurons
- Regulate the composition of the interstitial fluid surrounding neurons.
Describe the structure and function of a neuron.
- They transfer information from place to place and process information.
- Their sizes and shapes vary widely. The longest cells in the body are neurons.
- The dendrites receive information, typically from other neurons.
- The cell body contains a large nucleus and a prominent nucleolus, as well as various organelles. This is the site of information processing and the control centre for the cell as a whole. Most neurons lack centrioles, so they cannot divide under normal circumstances. Nervous tissue therefore has limited ability to repair after injury.
- The axon conducts that information in the form of electrical impulses to other cells. Because axons tend to be very long and slender, they are also called nerve fibres.
What are the three divisions of the nervous system?
Central nervous system
Peripheral nervous system
Enteric nervous system
What does the central nervous system consist of?
The brain and spinal cord
What does the peripheral nervous system include?
All the nervous tissues outside the CNS, except for the ENS.
What are sensory receptors?
Receptors are sensory structures that detect changes in the internal or external environment.
They detect position, touch, pressure, pain, and temperature. Special sense organs are involved with smell, taste, sight, balance, and hearing.
Which division of the PNS brings information to the CNS?
The sensory (afferent) division of the PNS brings information to the CNS from receptors in peripheral tissues and organs.
Where does information processing occur?
In the central nervous system.
It integrates, processes, and coordinates sensory input and motor commands.
Which division of the PNS brings information to the peripheral tissues and systems?
The motor (efferent) division, which includes both the somatic nervous system and the autonomic nervous system.
What is the somatic nervous system?
A component of the motor (efferent) division of the PNS. It is also called the voluntary nervous system because it allows us to consciously control our movement. The effector (i.e., organ/tissue that respond to the neural motor commands) is skeletal muscle.
What is the autonomic nervous system?
This is a component of the motor (Efferent) division of the PNS, also called the involuntary nervous system because it automatically regulates activities. It has two divisions: parasympathetic and sympathetic.
The effectors are smooth muscle, cardiac muscle, glands, and adipose tissue.
Name the effectors of the ANS.
The parasympathetic division effectors are smooth muscle cardiac muscle and glands.
The sympathetic division effectors are all the same a the parasympathetic division with the addition of adipose tissue.
