The nerve cells Flashcards
What are the three types of nerve cells?
Sensory/afferent neurons, motor/efferent neurons and association neurons/interneurons.
What are sensory/afferent neuron’s job?
To carry information from the external world to the brain. So all information heading inwards from the receptors e/gin the eyes and ears, travels on sensory neurons
What are the types of receptors in the body?
Mechanoreceptors, thermoreceptors, nociceptors, electromagnetic receptors and chemoreceptocers
What are mechanoreceptors?
Receptors which detect contact against the skin or against deep tissue e.g muscle
What are types of mechanoreceptors?
-Mesissners corpuscles (which detect light touches and are highly sensitive + found in many skin layers especially the fingertips)
-Pacinian corpuscles (also detect touch)
-Krauses corpucscles (sense vibration and found in the conjunctiva of the eye and in the mucous membranes)
-Merkels discs (detect low frequency vibration and constant touch and are slow adapting)
-Spiral ganglion (group of neurons in the cochlea, the vibration of the tympanic membrane stimulates them to transmit information about sounds to the brain)
-Vestibula receptors (use movement to determine the vertical orientation of the body and are found in the inner ear)
What does the merkels disc being slow adapting mean?
That if the pressure on the disc remains they will continue to register for a long period
What are thermoreceptors?
Cold and warmth sensors found throughout the body
What are nociceptors?
Pain and damage receptors
What are electromagnetic receptors?
The only section of the electromagnetic section able to detect is visible light, they are found within the eyes and divided into rod and cones
What are chemoreceptors?
Taste and smell receptors which also detect blood chemistry as well as other chemical substances
What is the role of motor/efferent neurons?
To carry information from the brain to the effectors.
What is the process the motor neurons go through?
They start at the motor cortex of the brain and then transmit from the spine to a specific effector, which most of the time is a muscle group, and this is how the brain creates movement of the muscles
What is the role of association neurons?
To carry information within the brain and spinal cord and act as a bridge between motor and sensory neurons but are particularly important in reflex actions
How do the association neurons work in action?
Thew dendrites of the interneuron receive signals from the axon terminals of sensory neurons, or from other interneurons. The axon terminal then delivers information to other neurons
