Simple Reflex Flashcards
Nervous communication – GCSE review
A stimulus is detected by _________ cells and an ________impulse is sent along a ________neurone. Stimuli can be external or ________.
A stimulus is detected by receptor cells and an electrical impulse is sent along a sensory neurone. Stimuli can be external or internal.
Nervous communication – GCSE review
DEFINITIONS
Receptor = an energy ___________– changes energy from one form to another. Receptors are ________. Receptors in the retina of the eye will only detect _____ energy.
Sensory neurone = _____________cell carries nerve impulses from __________to the coordinator.
Motor neurone = transmit ___________impulses from ___to effectors
Relay neurone AKA ______________neurones = transmit electrical impulses between __________and ______neurones
Stimulus = a change (chemical or physical) that can bring about a __________in an organism
Receptor = an energy transducer – changes energy from one form to another. Receptors are specific. Receptors in the retina of the eye will only detect light energy.
Sensory neurone = specialised cell carries nerve impulses from receptors to the coordinator.
Motor neurone = transmit electrical impulses from CNS to effectors
Relay neurone AKA intermediate neurones = transmit electrical impulses between sensory and motor neurones
Stimulus = a change (chemical or physical) that can bring about a response in an organism
Nervous communication – GCSE review continued
When an ________impulse reaches the end of a neurone chemicals called ____________ take the information across the gap (called a _________) to the next ________, where another electrical impulse is generated.
The central nervous system (CNS) is the ___________ which processes the information and sends ________ along _____ neurones to an __________.
When an electrical impulse reaches the end of a neurone chemicals called neurotransmitters take the information across the gap (called a synapse) to the next neurone, where another electrical impulse is generated.
The central nervous system (CNS) is the coordinator which processes the information and sends impulses along motor neurones to an effector.
The blink reflex is a reflex which is designed to naturally protect the eyes. Most animals with eyes have some form of this reflex, and the reflex is present from the time that an animal first opens its eyes.
Reflexes are ________actions. They allow the body to react very _______to potentially ___________situations by taking defensive action of some form. In the case of the blink reflex, the blink is often over before someone is consciously aware that there was a risk.
The blink reflex is a reflex which is designed to naturally protect the eyes. Most animals with eyes have some form of this reflex, and the reflex is present from the time that an animal first opens its eyes.
Reflexes are involuntary actions. They allow the body to react very quickly to potentially dangerous situations by taking defensive action of some form. In the case of the blink reflex, the blink is often over before someone is consciously aware that there was a risk.
A simple reflex is a rapid, _____(unlearned) response to a stimulus. The pathway of communication is through the ______cord or brain - but not through the conscious parts of the brain, so the response happens _______and is the same every time. Simple reflexes are _________– they help the organism to avoid damage to the body because the response happens so quickly.
The pathway of _______linking receptors to effectors in a simple reflex is called a ______arc. Three neurones are involved – a ______neurone, an ___________or relay neurone and a ______neurone.
A simple reflex is a rapid, innate (unlearned) response to a stimulus. The pathway of communication is through the spinal cord or brain - but not through the conscious parts of the brain, so the response happens rapidly and is the same every time. Simple reflexes are protective – they help the organism to avoid damage to the body because the response happens so quickly.
The pathway of neurones linking receptors to effectors in a simple reflex is called a reflex arc. Three neurones are involved – a sensory neurone, an intermediate or relay neurone and a motor neurone.
The knee jerk reflex action involves lightly tapping a person on the patellar tendon (just below the kneecap) with a tendon hammer. When this happens, the quadriceps muscle 9in the thigh) immediately contracts causing the person’s lower leg to jerk forward.
This response is a reflex. Suggest one way in which the response would differ if it was not a reflex
E.g. the response would be slower/ response would be voluntary
Name the stimulus and the effector in the knee jerk response.
Stimulus = light touch. Effector = quadriceps muscle
The knee jerk reflex is unusual because the sensory neurone synapses directly onto the motor neurone in the spinal cord.
Describe how this differs from a simple reflex such as the hand-withdrawal response to heat
Suggest what effect tapping the patellar tendon might have in someone with a spinal cord injury. Explain your answer
the quadriceps muscle may not contract/there may be no response. If the spinal cord is damaged then the sensory neurone may not be able to transmit nervous impulses to the motor neurone/ the motor neurone may not be able to transmit nervous impulses to the leg muscle.
