Homeostasis and Neuronal communication Flashcards
What is meant by Homeostasis
The maintenance of a relatively constant internal environment
Why is it important to keep a stable internal environment?
It is vital for cells to function normally and to stop them from being damaged
What is meant by stimulus
any change in the internal or external enviornment
Why is coordination needed
Cells have become specialised to perform specific functions. Therefore, organisms need to coordinate the function of different cells and systems to operate effectively
What detects stimuli?
Receptors
Receptors are..
Specific
What are effectors?
Cells that bring about a response to a stimulus, to produce an effect
What is the role of receptors and effectors
Communicating information from one part of an organism to another
How is the response between receptors and effectors carried out?
Cell signalling
What are the three types of neurones? and what are there functions
Sensory neurone - transmit nerve impulses from receptors to the CNS
Motor neurone - Transmit nerve impulses from the CNS to the effectors
Relay Neurone - Transmit nerve impulses between sensory neurones and motor neurones
What is the function of the myelin sheath
Acts as an insulating layer and allows electrical impulses to be transmitted quickly.
What is the function of the axon?
carries nerve impulses away from the cell body
What is the function of the dendron?
carries nerve impulses to the cell body
What is the function of the cell body?
Within the cell body the organelles are surrounded by the cytoplasm - this contains the endoplasmic reticulum and mitochondria which are involved in the production of neurotransmitters.
What are dendrites?
they receive the electrical impulses
What is the node of ranvier
Gaps between the myelin sheath which allows the faster generation of electrical impulses along the axon.
What are Schwann cells
They form the myelin sheath around the axon.
What are sensory receptors?
They are specialised receptors which are able to detect changes in the environment.
What is a transducer?
They convert a type of energy into a different type of energy
What are the two features of sensory receptors?
- Specific to a single type of stimulus
- Act as transducer
How does sensory neurone act as a transducer?
The receptor converts the stimulus into a generator potential
Pacinian corpuscle
They specific sensory receptors that detect mechanical pressure.
What are the layers of connective tissue separated by?
Gel
