The nervous system Flashcards
Homunculus
a representation of a human whether size of the body part shows the number of receptors
Sense & sensitivity - sight
Stimulus – light
sense organ – eye
receptor - photoreceptor
Sense & sensitivity - hearing
Stimulus – sound
sense organ – ears
receptor - cochlea
Sense & sensitivity - taste
Stimulus – chemical
sense organ – tongue
receptor - chemoreceptors
Sense & sensitivity - smell
Stimulus – chemical
sense organ – nose
receptor - chemoreceptors
Sense & sensitivity - touch
Stimulus – pressure movement
sense organ – skin
receptor - sensory nerve endings
Sense & sensitivity - balance
Stimulus – change in position
sense organ – inner ear
receptor - semicircular canals
How the nervous system works e.g. flash of light
Stimulus (change in the environment) - flash of light
Receptor (detection of the change) – eye (retina)
sensory neuron:
coordinator (CNS) (integration of information) – brain
motor neurone:
effector (muscle or gland) - circular muscles in iris
response (contraction or secretion) - Iris contracts to reduce size of pupil to let less light in.
How the nervous system works e.g. hot object
Stimulus (change in the environment) - Hot object
Receptor (detection of the change) – heat receptor in skin
sensory neuron:
coordinator (CNS) (integration of information) – spine
motor neurone:
effector (muscle or gland) - arm muscles
response (contraction or secretion) - hand is withdrawn.
sensory neurone
A sensory neuron is a type of neuron that carries sensory information from the sensory receptors (such as those in the skin, muscles, and internal organs) to the central nervous system (CNS), including the brain and spinal cord. Sensory neurons are responsible for detecting various stimuli such as temperature, pressure, pain, touch, and light.
motor neurone
A motor neuron is a type of neuron that carries signals from the central nervous system (CNS) to muscles, glands, and other effector organs. Motor neurons are responsible for controlling muscle movements and are essential for all voluntary and involuntary movements.
relay neurone
A short neurone found in the CNS that links sensory neurons and motor neurones - allows control over reflex arcs
neural pathway
A neural pathway is a series of interconnected neurons that transmit signals between different parts of the nervous system. These pathways are responsible for carrying information throughout the body and are involved in controlling various physiological and behavioral functions.
reflex arc
A reflex arc is a neural pathway that mediates a reflex action. A reflex arc is a rapid, involuntary response to a stimulus that does not require conscious thought. Reflexes are important for protecting the body from harm, maintaining posture, and allowing for rapid responses to changes in the environment.
reflex arc / action after touching a hot object with a finger
- coordinated by spinal chord - NOT brain - this makes the reflex quick to minimise damage
- response is muscle contracting and pulling the hand away
synapse
A synapse is a junction between two nerve cells or between a nerve cell and a muscle cell, where information is transmitted from one cell to the other, in one direction. It is the point where the axon of one neuron meets the dendrite or cell body of another neuron.
The chemical travels across the gap by diffusion. The chemical is called a neurotransmitter.
cerebral cortex
The cerebral cortex is the largest, outermost layer of the brain and plays a crucial role in many important functions, including sensation, perception, movement, cognition, and consciousness. It is divided into four main lobes: the frontal lobe, parietal lobe, temporal lobe, and occipital lobe.
cerebellum
The cerebellum is a structure located at the base of the brain, beneath the cerebrum, and it is primarily involved in coordinating and fine-tuning movements, balance, and posture.