Chapter 14 part 1 Flashcards
Coordination: Neurones, Synapses
What is Coordination?
Coordination is the way all organs and systems of the body work efficiently together.
What is the Endocrine system?
The Endocrine system is where Coordination of chemicals takes place.
- The Endocrine system depends on the release of chemicals called hormones from Endocrine glands.
- Hormones are carried away by the bloodstream.
How does the Endocrine system work VS the nervous system?
The Endocrine system depends on the release of chemicals
Whereas the Nervous system works by sending electrical impulses along nerves.
What are Hormones?
Hormones are chemicals that are released by the endocrine glands and are carried by the bloodstream.
What does the CNS consist of?
The Central Nervous System consists of the Brain and Spinal cord.
What is the role of Nerves?
Nerves carry electrical impulses from the CNS to all parts of the body.
- This makes muscles contract or glands produce enzymes and hormones.
What are electrical impulses?
Electrical impulses are electrical signals that pass along nerve cells (Neurones)
*An impulse is a series of electrical pulses down a nerve fibre.
What is the PNS?
The PNS is the Peripheral Nervous system, which consists of nerves OUTSIDE the brain and spinal cord.
What are Effectors?
Effectors are glands and muscles that go into action when they receive nerve impulses or hormones.
Ex: bicep muscle flexes the arm; salivary gland produces saliva.
What is a nerve impulse?
A nerve impulse is a series of electrical pulses that travel down a nerve fibre.
What are sensory impulses?
Sensory impulses are nerve impulses from sense organs (eyes, ear, nose) to the CNS.
What are Motor impulses?
Motor impulses are those nerve impulses that result in action from CNS to effectors.
What are Neurones/Nerve cells?
The CNS and PNS are made up of nerve cells called Neurones. There are 3 types, Motor, Sensory and Relay.
What are Motor Neurones?
These Neurones carry impulses from the CNS to the glands and muscles.
What are Sensory Neurones?
These Neurones carry impulses from Sense organs to the CNS.
What are Relay Neurones?
These Neurones are neither motor nor sensory. They connect neurones together.
Describe the structure of a Neurone:
A Neurone has a CELL BODY that consists of a Nucleus surrounded by a little Cytoplasm.
- From here there are branching fibres called DENDRITES. These make contact with other neurones.
- A long filament of Cytoplasm surrounded by an insulating sheath called a NERVE FIBRE, goes down the cell body.
*Nerve fibres run in the nerves.
Where are cell bodies located?
Cell bodies are located in the brain and spinal chord.
*Nerve fibres run in Nerves.
What is a Nerve?
A Nerve is a white, tough and stringy that consists of hundreds of nerve fibres bundled together.
Nerves contain a mixture of sensory and motor fibres.
*Sensory fibres travel in 1 direction, motor in the opposite.
What is a Nerve Fibre?
A nerve fibre is the long filament of cytoplasm thats surrounded by an insulating sheath. This is part of a Neurone.
- It carries nerve impulses
How long is the fibre of a Nerve cell?
A nerve cell can have a fibre 1m long.
How long does a nerve pulse last?
Each pulse lasts 0.001 secs and travels at speeds up to 100 m s-1
What is the Reflex Arc?
The reflex Arc is simply where an action is produced. This is by impulses that cross synapses.
*It is the nervous pathway where involuntary reflexes take place.
What does the Reflex Arc contain?
A simple reflex arc contains a receptor,
sensory neurone, relay neurone, motor neurone and effector.
