Senses and Reflexes Flashcards
Why do we need to be able to sense changes in our environment?
So that we can respon - for safety
What do we call changes in the environment?
Stimuli
How do we detect stimuli/ changes in the environment?
Using receptors
Name the sense organ and stimulus to the sense: touch
Sense organ: skin
Stimulus: pressure, pain, temperature
Name the sense organ and stimulus to the sense: taste
sense organ: tongue
stimulus: chemicals in food & drink
Name the sense organ and stimulus to the sense: smell
sense organ: nose
stimulus: chemicals in the air
Name the sense organ and stimulus to the sense: sight
sense organ: eyes
stimulus: light
Name the sense organ and stimulus to the sense: hearing
sense organ : ears
stimulus: sound
how are organisms able to respond to changes in their environment?
- using receptors to detect the stimuli
The Central Nervous System
- CNS made up of the spinal chord and the brain
- Peripheral nervous system carries information to or from the CNS
- When a stimulus is detected by a receptor, impulses pass down neurones to the CNS which sends more impulses out along neurones to an effector which causes a response
label a diagram of a sensory and motor neurone
MOTOR NEURONE: - dendrites - nucleus - cell body - axon - electrical impulse - insulating sheath SENSORY NEURONE: - dendrites - nucleus - cell body - axon - electrical impulse - insulating sheath
what are synapses
- the gaps between neurones are called synapses
- the impulse is transmitted from one side to the other using neurotransmitters, which travel across the gap via diffusion
- synapses mean that nerve impulses are unidirectional, meaning they only travel in one direction
- they can also connect more than one neurone
label a diagram of a synapse
include:
- end of neurone
- neurotransmitters
- neurone
- sacs containing neurotransmitters
- synapse
What are neurones?
- specialised cells which make up nerves
- sensory neurones carry impulses from sense organ to CNS
- relay neurones are found inside the CNS and connect sensory and motor neurones
- motor neurones carry impulses from the CNS to effectors (muscles or glands)
draw a diagram of the reflex arc
include:
- sensory neurone
- motor neurone
- relay neurone
- spinal chord
- impulse
- receptor
- effector
what is a reflex
a reflex is an automatic and rapid response, such as when you touch something hot or sharp.