Coordination Flashcards
What does a coordinated response require?
- Stimulus
- Receptor
- Coordination
- Receptor
- Effector
- Response
- Effector
What is at the base of the brain?
Pituitary gland (secrets a number of chemical ‘messengers’ called hormones into the blood) just below the hypothalamus
Name the receptor and type of energy transduced
eye (retina) - light ear (organ of hearing) - sound ear (organ of balance) - kinetic tongue (taste buds) - chemical nose (organ of smell) - chemical skin (touch/pressure/pain receptors) - kinetic skin (temperature receptors) - heat muscle (stretch receptors) - kinetic
What do receptors do?
- Receptors change the energy into electrical energy of the nerve impulses (transduction)
- All receptors are transducers of energy
Give an example of the system?
light intensity–>eye(retina)–>neurones–>iris muscles–>change pupil size
What can be a stimulus?
A change in the organisms surroundings
What is a receptor?
Specialised cells that detect stimuli
What does the coordination do?
Links the stimuli and the response
What is the effector?
An organ carrying out the action
What is the response?
The reaction to the change
What is in the central nervous system? (CNS)
The brain and the spinal cord and is linked to sense organs by nerves
Sensory neurones carry information to the CNS whereas the motor neurones carry information from the CNS
What happens when receptors detect a stimulus?
- When the receptors detect a stimulus they send electrical impulses along sensory neurones to the CNS
- The CNS then sends electrical impulses to the effectors along a motor neurone
- The effector then responds accordingly. The CNS coordinates the response
- Because neurones transmit information using high speed electrical impulses the nervous system is able to bring about a very rapid response
What are synapses?
Synapses are gaps between two nerve cells, electrical signals are converted into chemical signals back into electrical signals
What happens in a synapse?
- Electrical impulses arrive down the axon of the first neurone
- Neurotransmitters diffuse across the synapse
- Neurotransmitters attach to the membrane of the second neurone
- Electrical impulses start in the second neurone
- Neurotransmitters are broken down by an enzyme from the second neurone after it has ‘passed on the message’
Other chemicals such as drugs may imitate neurotransmitters or block its action for good or bad.
What is a reflex action?
- A rapid involuntary response to a stimulus, the purpose is often to protect the body
- They are not started by impulses from the brain, but you are still aware (you feel pain). A voluntary action is under conscious control
What are examples of involuntary actions?
- Knee jerk
- Pupil reflex
- Hot surface
- Balancing and catching ones self