The Body Flashcards
what are eyes?
Eyes are light receptors that are sensitive to light. These cells have a nucleus, cytoplasm and cell membrane
what are ears?
Ears are sound receptors that are sensitive to sound they are also balance receptors sensitive to changes in position
what are noses?
Noses are smell receptors sensitive to chemical stimuli
what are tongues?
Tongues are taste receptors and are sensitive to bitter, salt, sweets and sour and savoury - It is a chemical stimuli
what is skin?
Skin is touch, pressure, pain and temperature sensitive
what are receptors?
Receptors are groups of cells which are sensitive to a stimulus. They change stimulus energy into electrical pulses
what is the central nervous system?
The central nervous system is where all the information from the sense organs is sent, and where reflexes and actions are coordinated. The central nervous system consists of the brain and spinal chord only
what are the sensory neurones?
Sensory neurones are the nerve cells that carry signals as electrical impulses from receptors in the sense organs to the central neurone system
what is the relay neurone?
The nerve cells that carry signals from sensory neurones to motor neurones
what are motor neurones?
Motor neurones are nerve cells that carry signals from the central nervous system to the effector muscles of glands
what are effectors?
Muscles and glands are known as effectors - they respond in different ways. Muscles contract in response to a nervous impulse, whereas glands secrete hormones
what are reflexes?
Reflexes are automatic responses to certain stimuli which reduce the chances of being injured
what are the stages of the reflex arc?
- Accident happens
- Stimulation of the pain receptor
- Impulses travel along the sensory neurone
- Impulses are passed along a relay neurone, via a synapse
- Impulses travel along a motor neurone via a synapse
- When impulse reaches the muscle it contracts
