11.1 Nervous System Flashcards
(28 cards)
What is a neuron
a specialized nerve cell that is the functional unit of the nervous system
Neural Signalling is
the process by which an animal respons appropriately to stimuli
4 components of Neural Signaling
Reception, Transmission, Integration, Response
Reception
Detection of a stimulus
Transmission
movement of a message along a neuron to another neuron, muscle, or gland
Integration
Sorting and interpretation of multiple neural messages and determination of appropriate response
Response
Action resulting from the integration of neural messages
3 Classes of Neurons
- Afferent
- Interneurons
- Efferent
Afferent Neurons
Also called sensory, transmit stimuli collected by sensory receptors to interneurons
Interneurons
Integrate the information to formulate an appropriate response
Efferent Neurons
carry the response signal away from the interneurons to the effectors (muscles, or glands)
When are efferent neurons called motor neurons?
If they carry the signal to a muscle
What is the cell body
contains the nucleus and most of the organelles in the cell
What is a dendrite
Has highly branched projections at the end of a neuron. Receives signals and transmits them towards the cell body
What are axons
specialized projections that conduct signals away from the cell body to another neuron or an effector.
What are Glial Cells
cells that do not conduct electrical signals, but provide support and nutrition
What is an example of a Glial Cell
Shwann Cells
What are Shwann Cells
they form tightly wrapped layers of plasma membrane called the myelin sheath around axons and act as electrical insulators due to their high lipid content
What are the gaps between schwann cells
Nodes of Ranvier. They expose the axon membrane directly to extracellular fluid
Do glial cells or neurons reporduce?
glial cells. They are the source of nearly all brain tumours
What are the two ways axons can deliver information
through the axon or jump node to node which is faster
The nervous system is divided into two parts
the central nervous system and the peripheral nervous system
Central Nervous System consists of
spinal cord and brain. Most interneurons are located here.
How many pairs of spinal nerves are there
31
