Pages in this set

Page 1

Preview of page 1
The Nervous System & Neurones
The Nervous System Sends Information as Nerve Impulses

1. The nervous system is made of a complex network of cells called neurones. There are 3 main
types of neurone:
Sensory neurones ­ transmit nerve impulses from receptors to the central nervous system
(CNS) ­ the…

Page 2

Preview of page 2






The Structure of Sensory Neurones

1. All neurones have a cell body with a nucleus (plus
cytoplasm and all other organelles you usually get in a
cell)
2. The cell body has extensions that connect to other
neurones ­ dendrites carry nerve impulses towards the
cell body & axons carry…

Page 3

Preview of page 3
The sodiumpotassium pumps move sodium ions out of the neurones, but the membrane isn't
permeable to sodium ions, so they can't diffuse back in. This creates a sodium ion electrochemical
gradient (a concentration gradient of ions) because there are more positive sodium ions outside
the cell than inside.
The sodiumpotassium…

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all resources »