Nervous System Flashcards
What are the three main principles/functions of the nervous system?
- Sensory Input
- Integration of information
- Motor Output
What is a reflex?
This is a motor output that is produced by the nervous system that skips the integration/processing section of the nervous system.
Why do we have reflexes?
To allow for faster reactions when necessary.
What is the vertebrate nervous system characterised by?
- A well-developed CNS
- Specialised peripheral nervous system present
- Ventral nerve chords (spinal chords) are unsegmented
- Ganglia (nerve junctions) evident just outside the spinal chord
What is cerebrospinal fluid (CSF) and where can you find it?
It fills the central canal of the spinal cord and ventricles of the brain.
It helps with the supply of nutrients and hormones.
Also helps cushion brain from impact in mammals.
The spinal chord and brain are split into sections of white and grey matter, what do these both represent?
White matter is the myelin associated with nerves.
Grey matter is the dendrites/axons/cell bodies of CNS nerves.
What makes up the peripheral nervous system?
- Nerves (Cranial, Spinal and peripheral)
- Sensory neurons and motor neurons
What part of the peripheral nervous system receives information from both the internal organs, the somatic pathway (skin) and from specialised organs such as eyes and ears then relays this to the brain?
Sensory System
What part of the peripheral nervous system transmits instructions from the brain to various parts of the body
Can do this by the somatic pathway (causes voluntary movement of structures such as skeletal muscle)
Or by the autonomic pathway (less conscious parts of the body such as intestines and other internal organs).
Motor system
What 3 subsystems make up the autonomous nervous system?
- Sympathetic – involved in the “fight or flight” response (promotes escape from danger)
- Parasympathetic – regulates normal body function. Also known as the “rest and digest” system.
- Enteric – is associated with the function of the gastrointestinal system.
What are the 6 main components of a nerve?
- Cell Body
- Dendrites
- Axon
- Axon terminals
- Axon bulb
- Schwann cells
What is the purpose of the cell body of a nerve?
Houses all the components the nerve needs to survive (eg nucleus)
What is the purpose of dendrites in a nerve?
They receive information from other nerves and act as sensory receptors.
What is the purpose of the axon?
They transmit electrical signals from the cell body to the end of the nerve.
What is the purpose of the Schwann cells?
Insulation for the axon, protecting from harm and also allows for the electrical signals to travel faster (jump rather than linear).
