Content - Central Nervous System Flashcards
What do Bio-psychologists assume that behaviour is caused by?
experiences in the nervous system
Define the nervous system
a specialised network of cells in the human body and is our primary internal communication system
Name the 2 main functions of the CNS (2)
1) To collect, process and respond to information in the environment.
2) To co-ordinate the working of different organs and cells
Define the CNS
made up of the brain and spinal cord and is the origin of all complex commands and decisions
Name 3 facts about the brain (3)
- This is the centre of all conscious awareness.
- The brain’s outer layer, the cerebral cortex, is highly developed in humans.
- The brain is divided into two hemispheres
Name 3 facts about the spinal chord (3)
- The spinal cord is an extension of the brain.
- One thing it is responsible for is reflex actions such as pulling your hand away from a hot plate.
- Passes messages to and from the brain and connects nerves to the PNS.
Define the Peripheral Nervous System
The PNS transmits messages via millions of neurons (nerve cells), to and from the central
nervous system
What’s the PNS further subdivided into? (2)
- the somatic nervous system (SNS)
2. the autonomic nervous system (ANS)
Define the somatic nervous system
This is the part of the PNS that is responsible for
carrying sensory and motor information to and from the spinal cord. It is involved in skeletal muscle contraction
Define the autonomic nervous system
This governs vital functions in the body such as
breathing, heart rate, digestion, sexual arousal
and stress responses
Name the 2 main divisions of the ANS (2)
- The sympathetic nervous system (SNS)
2. The parasympathetic nervous system (PNS)
What do the SNS and PNS control?
Fight of flight response
What happens to your gut?
Digestion slows/increases
What happens to the salivary glands?
Saliva production inhibits/increases
What happens to the heart?
Heart rate increases/decreases
What happens to the liver?
Glucose production stimulated/bile production stimulated
What happens to the bladder?
Urination stimulated/inhibits
What happens to the eye?
Pupils dilate/constrict
What happens to the lungs?
Bronchi dilates/constricts
What’s another name for nerve cells?
Neurons
Define neurons
a unit of nervous tissue
How many neurons are in the nervous system?
100 billion
What percentage of neurons are located in the brain?
80%
How do neurons allow the nervous system to communicate by?
transmitting an electro-chemical signal (i.e. part of it is electrical and part of it is chemical)
Define cell body?
Contains the nucleus (DNA) and mitochondria (provides energy).
Define dendrite
Branches on the cell body of each neuron that receive information from neighbouring neurons to trigger an action potential
Define axon hillock
Where the nerve impulse is triggered from
Define axon
A tube-like structure; carries impulses away from the cell body down the length of the neuron
Define myelin sheath
Layers of fatty deposits that provide insulation for protection and help speed up the rate of message transmission. Formed from
special cells called glial cells
Define axon terminal
End of the axon, separated from other neurons by a tiny gap (known as the synapse)