Coordination and Control Flashcards
What are all living organisms able to do?
- respond to change
- make coordinated response
What does coordinated mean?
body able to make things happen in different parts of body at right time
What are the two organ systems that humans have?
endocrine
nervous
What is the endocrine system?
hormones
How do humans make coordinated responses?
endocrine and nervous systems
How do plants make coordinated responses?
plant growth substances
What are the three things that are required for a coordinated reponse?
stimulus
receptor
effector
What is a stimulus?
change in surroundings
What is a receptor?
organ that detects change in surroundings
What is an effector?
muscles that contract to make a coordinated response
How are the stimulus and coordinated response linked?
endocrine system
How do receptors work?
detect change then change energy into nerve impulses
What do receptors use?
energy conversion
What is the central nervous sytem?
brain and spinal chord
What responses does the central nervous system coordinate?
movement and reflexes
What is the peripheral nervous system?
contains all other nerves
What does the peripheral nervous system do?
sends impulses to effectors
What are nerve cells called?
neurones
What are neurones?
nerve cells
What are the three types of neurones?
sensory neurones
relay neurones
motor neurones
What is the role of sensory neurones?
carry impulses from receptors to central nervous system
Which neurone carries impulses from receptors to central nervous system?
sensory neurones
Which neurones act immediately after the stimulus is received?
sensory neurones
What is the role of the relay neurones?
connect the receptor to the effector via the central nervous sytem
Which neurones connect the receptor to the effector?
relay neurones
What is the role of the motor neruones?
pass electrical impulse to effectors from central nervous system
Which neurones pass the electrical impulse from the central nervous system to the effectors?
motor neurones
What is the order of the relay neurones?
- sensory
- relay
- motor
What does the body use to send messages to respond to the environement?
electrical impulses
What does the body use electrical impulses for?
sending messages around the body to respond to the environment
What is a nucleus?
Contains genetic information of cell
What is a dendrite?
Tree like projections which connect to different neurones
What is a cell body?
main section of cell
Where is the nucleus found in a neurone cell?
cell body
What is an axon?
long section of neurone cell that allows electrical impulses to travel long distances
What is myelin sheath?
surrounds axon
What is the role of the myelin sheath?
insulates axon to speed up transmission of impulse
What are reflexes?
automated actions that do not involve the brain
What is the speed of reflexes like?
very fast
Which neurones are involved in reflexes?
sensory, relay and motor
What does a reflex not include?
central nervous system
What is a reflex arc?
movement from receptor to effector
What is the movement from receptor to effector called?
reflex arc
What is the gap between neurones called?
synapse
What are synapses?
gaps between neurones
Do neurones ever touch?
no they do not - they have synapses
What travels along the axon?
electrical impulses
What does the electrical impulse travelling along the axon trigger?
nerve ending of neurone releases chemical messengers
What causes chemical messengers to be released?
electrical impulse travelling along the axon
What are chemical messengers released from the nerve endings called?
neurotransmitters
Where are neurotransmitters released from?
nerve endings of neurones
How do neurotransmitters move?
diffuse
What do neurotransmitters bind with?
bind with receptor molecules of the next neurone
How are neurotransmitters specific?
binding only occurs between specific chemical messengers from the first and second chemical messnegers
What stimulates the second neurone to transmit the electrical impulse?
binding of neurotransmitters in the synapse
What does the binding of neurotransmitters stimulate?
electrical impulse
Give an example of a sensory organ
the eye
What is the eye an example of?
sensory organ
What makes the eye a sensory organ?
detects light and sends impulse to the brain
What is the cornea?
curved transparent disc at the front of the eye
Where is the cornea located?
front of the eye
What shape is the cornea?
curved transparent disc
What is the role of the cornea?
focusing of eye
What is the pupil?
circular opening in the eye
What controls the size of the pupil?
iris
What does the iris control?
size of pupil
What is the iris?
ring of muscles with pupil in the middle
What is controlled by the iris?
amount of light entering the eye
What is the lens like?
soft, flexible and transparent
What changes the shape of the lens?
ciliary muscles
What does the lens focus the light on to?
retina
What are the ciliary muscles?
ring of muscles at the edge of the eye which circle the lens
What happens when the ciliary muscles contract?
lens gets fatter
What happens when the ciliary muscles relax?
lens gets thinner
What are suspensory ligaments?
strong fibres which attach the lens to the ciliary muscles
What attaches the lens to the ciliary muscles?
suspensory ligaments
What is the retina?
contains light sensitive cells