Nervous System and Nervous Tissue Flashcards
What are the 2 major regions of the Nervous System:
Central nervous system (CNS)
Peripheral nervous system (PNS)
What organs are located in the CNS:
Brain: contained within the cranial cavity of the skull
Spinal cord: Contained within the vertebral cavity of the vertebral column
What organs are located in the PNS:
Everything else (ganglia and nerves)
Named because it is on the periphery—meaning beyond the brain and spinal cord
What are the two types of cells:
- Neurons
- Glial cells
Describe neurons:
Neuron
- Functional units of the nervous system
- Cell body (soma) rich in rough endoplasmic reticulum (Nissl substance)
- Short afferent cell processes (dendrites), responsible for receiving most of the input from other neurons
- Main efferent cell process (the axon), fiber that connects a neuron with its target
What is gray matter:
Regions with many cell bodies and dendrites
What is white matter:
- The regions with many axons
- White matter is white because axons are insulated by a lipid-rich substance called myelin
What are the 2 peripheral Nervous System functions:
- Somatic (voluntary)
- Autonomic (involuntary)
Somatic nervous system (SNS)
- voluntary motor responses
- Means the contraction of skeletal muscle
Autonomic nervous system (ANS)
- Responsible for involuntary control of the body
- Homeostasis (regulation of the internal environment)
What are the divisions of the Nervous System:
Brain (CNS)
Spinal Cord (CNS)
Nerves (PNS)
Ganglia (PNS)
Digestive Tract (ENS)
What are the specialized support cells (Glial cells):
Astrocytes
Oligodendrocytes
Microglia
Ependymal cells
Neuron responsibility:
Electrical signals that communicate information about sensations, and that produce movements in response to those stimuli, along with inducing thought processes within the brain
What is the most important part if the function of the neurons:
Structure
Shape
What is the main part of the Neuron:
Cell body, which is also known as the soma which contains the nucleus and most of the major organelles
What insulating substance are wrapped around axons:
Myelin produced from glial cells
Node of Ranvier:
- Gaps in the myelin covering of an axon
- Important to the way that electrical signals travel down the axon
Axon segment:
Length of the axon between each gap
Axon terminal:
At the end of the axon
Several branches extending toward the target cell, each of which ends in an enlargement called a synaptic end bulb
Synaptic end bulb:
Bulbs are what make the connection with the target cell at the synapse
what are other processes of the neuron:
Dendrites, which receive information from other neurons at specialized areas of contact called synapses
How does information flow:
Information flows through a neuron from the dendrites, across the cell body, and down the axon.
