CNS Class 2 - Sensory Review Flashcards
Information carried from the body’s tissues via receptors (about its internal and external environments) to the CNS.
Afferent/Sensory
T/F - There are about 20 times more efferent than afferent neurons in the human body.
False - There are about 20 times more AFFERENT than EFFERENT neurons in the human body.
Transmission of directive signals from the CNS to effectors in the body tissues, such as muscles or glands.
Efferent/Motor
The purpose of ________ data is to inform the CNS about what is happening inside the body and external to it so that this information can be processed or evaluated.
Afferent Data
The most straight forward type of response where incoming sensory information triggers an automatic efferent reaction without having to reach the brain.
Reflex
Reflexes can be very simple or more complex and their neural pathway of afferent neuron to interneuron to efferent neuron is called a ______ ___.
Reflex Arc
T/F - Spinal or withdrawal reflexes are able to initiate a response without input from the brain.
True
Afferent information that arrives in the brain processing centres receives more complex types of analysis relating to _______ and cognition.
Emotion
Data that is carried as afferent transmission along the neurons of the sensory system into the CNS for interpretation and response.
Sensory Input/Afferentation
Conscious awareness of sensation.
Sensory Experience (aka. Sensory Perception)
Since most afferentation does not rise to consciousness because it is filtered out or suppressed, only a percentage results in sensory __________.
Sensory Experience (aka. Sensory Perception)
_________ receptors detect ambient molecules and inform the CNS. If this data is selected for experience, the perception of it is called a _____.
Olfactory Receptors
Scent
___________ detect tissue stress or damage and convey this information to the CNS. At this transmission stage it is referred to as __________. Only when the person has a sensory experience of it is it called ____.
Nociceptors
Nociception
Pain
T/F - The presence of afferentation from the tissues means there will be sensation.
False - The presence of afferentation from the tissues DOES NOT mean there will be sensation.
All sensation is assigned by the _____.
Brain
Stimuli are detected in the tissues by receptors that are specialized for specific stimulus types. These receptors are the distal ends of afferent neurons called the _______ or _____ _____ neurons.
Primary/First Order
Neurons that convey the transmission to the spinal cord and their synapses occur either in the dorsal horn or farther up in the brainstem via cranial nerves.
Primary/First Order Neurons
Neurons in the chain that carry the afferentation data to the thalamus.
Secondary/Second Order Sensory Neurons
A reception or relay station for the brain and its crucial role in sensation is to convey data via the ________ or _____ _____ neurons.
Thalamus
Tertiary/Third Order Neurons
Neurons in the chain that convey data to the somatosensory cortex, which is part of the system that consolidates sensory experience, as well as to related brain areas for memory, emotion, cognition and autonomics.
Tertiary/Third Order Neurons
The anatomy can be different for the special senses and ________ sensation, compared to the pathway for somatosensation.
Visceral Sensation
The typical first order neuron is attached to one or more receptors (its specific type) that are embedded in tissue. These receptors have stimulus __________, and if the stimulus is strong enough an ______ _________ is initiated.
Stimulus Thresholds
Action Potential
The resulting depolarization wave from a stimulus travels along the axon of a first order neuron, which sits in the dorsal ____ ________.
Dorsal Root Ganglion
The axon from the receptor to the cell body of a first order neuron located in the peripheral nerve, and then the spinal nerve, that corresponds with their supply tissue.
Peripheral Branch/Process
The axon of a first order neuron that enters the spinal cord’s dorsal horn in the CNS.
Central Process
Each first order neuron’s receptor is located in the tissue it is responsible for sensing and reporting about, meaning that it generates information about a specific stimulus type occurring in a discrete location, referred to as its _________ _____.
Receptive Field
The peripheral branches of the first order neurons for a tissue area are bundled together into _________, which are then grouped together into a __________ nerve that is responsible for that tissue zone.
Fascicles
Peripheral Nerve
A tissue zone and its associated peripheral nerve give rise to an identified pattern of sensation responsibility that is called the nerve’s “______ _______.”
Supply Tissues
In relation to nerve supply tissues, there are smaller areas for which the nerve exclusively carries the ________ neurons, and larger zones where the nerve is the primary but not _________ supplier.
Afferent Neurons
Exclusive Supplier
First order neurons are in a different configuration once their __________ branches enter a ______ nerve.
Peripheral Branches
Spinal Nerve
Each ascending dorsal root axon, before reaching the spinal cord, __________ into ascending and descending branches entering several segments _____ and _____ their own segment.
Bifurcates
Below
Above
T/F - Peripheral nerves each carry a group of neurons that do not sense the same tissue zone, but report to the same spinal cord segment.
False - Peripheral nerves each carry a group of neurons that DO sense the same tissue zone, but DO NOT report to the same spinal cord segment.
The nerve that contains all the neurons whose functions correspond to one spinal cord level.
Spinal Nerve
The supply zone pattern is different for the same body tissues, depending on whether the ______ nerve or the __________ nerve pattern is what is clinically relevant in a case.
Spinal Nerve
Peripheral Nerve
A spinal nerve’s pattern of skin responsibility.
Dermatome
A spinal nerve’s pattern of responsibility relating to deeper structures such as bone, periosteum and joints.
Sclerotome
A term meaning “of the root.”
Radicular
The spinal nerve is the combination of the nerve _____ from that spinal segment.
Nerve Roots
The idea that humans have 5 senses has been around since Aristotle, but in fact there are at least __ identified sensory modalities.
17
Sometimes sensory modalities are viewed by the experts as ________ senses (e.g. itch), while other believe in _________ senses that integrate several sub-modalities (e.g. itch is a sub-category of pain).
Separate Senses
Principal Senses
The term used when a sense has receptors distributed throughout the body in various tissue types.
General Sense