Neurones and nervous coordination Flashcards
What are the two main forms of coordination in animals?
The nervous system and the hormonal system
How does the nervous system communicate?
The nervous system uses nerve cells to pass electrical impulses along their length
How does the nervous system communicate with it target cells?
The hormonal system produces hormones that are transported in the blood plasma to target cells.
The target cells have specific receptors on their cell surface membranes and the change in hormone concentration stimulates them
Which results in a slower, less specific form of communication between the parts of an organism
How does the nervous system communicate with its target cells?
The nervous system uses nerve cells to pass electrical impulses along their length
They stimulate targeted cells by secreting neurotransmitters onto them directly, which results in rapid communication between specific parts of an organism
What are neurones?
Nerve cells that are specialised cells adapted to rapidly carrying electrochemical changes nerve impulses from one part of the body to another
1) What is the cell body of a neurone?
2) What are dendrons and what do dendrons subdivide into?
3) What are axons and what function do they perform?
1) The cell body contains all the usual cell organelles, including the nucleus and large amounts of rough endoplasmic reticulum
2) Dendrons are extensions of the cell body which subdivide into smaller branched fibres called dendrites
3) Axons are the single long fibres that carry the nerve impulses away from the cell body
Look at your notes and cover the structure of a myelinated neuron and identify each structure
OR
Label the structure of a myelinated neuron
Look at your notes and cover the structure of a myelinated neuron and identify each structure
OR
Label the structure of a myelinated neuron
What is the motor neuron made up of? (6 components)
1* Cell body
2* Dendrons
3* Axon
4* Schwann cells
5* Myelin sheath
6* nodes of Ranvier
What are Schwann cells and what do they do?
What is the myelin sheath and what is it’s function?
What are the nodes of Ranvier?
The Schwann cells are cells that wrap around the axon to protect it, provide electrical insulation, carry out phagocytosis and play a part in nerve regeneration
The myelin sheath forms a covering of the axon and are made up of Schwann cells
The nodes of Ranvier are constrictions between adjacent Schwann cells where there is no myelin sheath
What is the function of dendrites?
Dendrites carry nerve impulses towards the cell body
What is the structure and function of the sensory neurone?
The sensory neurone transmits nerve impulses from the receptor to the motor neurone
The sensory neurone has one very long dendron, which carries impulses towards the cell body and one axon which carries the impulse away fro. the cell body
What is the structure and function of the motor neurone?
Motor neurons transmit nerve impulses from the relay neuron to the effector
Motor neurons have a long axon and many short dendrites
What is the structure and function of the relay (intermediate) neurone?
The relay neurone transmits impulses between neurons and carries out many short processes
