5.1.3 Neuronal communication Flashcards
What is a stimulus?
Change in the internal or external environment of an organism
What are the structures within a neurone?
- Cell body
- Dendrons
- Dendrites
- Axons
- Myelin sheath
- Schwann cells
- Node of Ranvier
What is the cell body?
Contains the nucleus and organelles to produce neurotransmitters
What is the dendron?
Short extensions from cell body
What are dendrites?
Branches of dendrons
What is the axon?
Singular extension from cell body
What is the myelin sheath?
Fatty layers of insulation produced by Schwann cells that surround axon multiple times
Why is the myelin sheath needed?
Provides insulation for the electrical impulse to allow for a faster transmission of impulse
What are Schwann cells?
Cells that produce layers of membrane making up myelin sheath
What are the Nodes of Ranvier?
Unmyleinted gap between myelin sheath
Electrical impulse can _______ from one node to the next in a myelinated neurone
Jump
What does sensory neurone do?
Transmit impulse from sensory receptor cells to CNS
Is sensory neurone afferent or efferent neurone?
Afferent neurone
Where is the cell body located on a sensory neurone?
In the middle of the neurone
What does relay neurone do?
Transmit impulse between neurones e.g. between sensory and motor neurones
Which neurones are myelinated and which are unmyelinated?
Myelinated - sensory & motor
Unmyelinated - relay
What type of neurone makes up the brain and spinal cord?
Relay neurone
What does motor neurone do?
Transmit impulses from CNS to effector cells
Is motor neurone afferent or efferent neurone?
Efferent neurone
Where is the cell body found on motor neurone?
At the start of the neurone
What is the direction of impulse?
Dendrites to axon
What is the electrical impulse pathway?
Sensory receptor -> sensory neurone -> relay neurone -> motor neuorne -> effector
What are the features of sensory receptor?
- Specific to a single type of stimulus
- Act as a transducer
What does a transducer do?
Coverts stimulus (light, heat, sound or pressure) into nerve impulse called the generator potential
What is a generator potential?
Nerve impulse created when detected by sensory receptor
Describe mechanoreceptor with example?
- Stimulus: pressure and movement
- Example: Pacinian corpuscle
- Example of sense organ: skin