Unit 2_Intro to Sensory Systems Flashcards
Where does perception begin?
At the receptor level
What triggers an electrical signal in a sensory receptor?
A stimulus
Once a stimulus triggers an electrical signal in a sensory receptor, information is then relayed/processed from cell to cell with the ultimate goal of reaching the cortex for what?
conscious perceptions
It is important to note sensations are needed to trigger responses like what?
reflexes, movements, and alertness
Almost all sensory information is sent to the cerebral cortex for perception via what?
The thalamus (Smell is the exception)
This large ovoid mass is the largest of the four components and each half of the brain contains one. In many individuals there is a short inter-thalamic adhesion that connects the two thalami across the third ventricle that lies between them. Contains nuclei that may be divided into 5 functional nuclear groups.
Thalamus
What comprises the nuclei of Group 1 - Sensory Group?
- lateral geniculate (LG) – Eye
- medial geniculate (MG) – Ears
- ventral posterolateral (VPL) – Body
- ventral posteromedial (VPM) - Face
These nuclei have connections with the basal ganglia and the cerebellum and are involved in motor control?
GROUP 2 – Motor Group
These nuclei have important connections with limbic system structures and are involved in emotions such as anxiety and also in memory?
GROUP 3 – Limbic Group
These nuclei are likely involved in the complex processing of sensory information?
GROUP 4 – Multimodal Group
Recent evidence suggests that these nuclei are involved in the regulation of consciousness along with roles in movement control and pain?
GROUP 5 – Intralaminar Group
What kind of neurons are sensory nerves?
Pseudounipolar
Sensation is transmitted via what type of nerves?
Peripheral nerves
The morphological distinction between _______ and _______ is blurred.
Axons
Dendrites
Where are cell bodies residing in the peripheral nervous system for sensory neurons?
Ganglions in the spinal cord
Having myelin on the peripheral nerve will do what?
Decrease capacitance and allow EPSP or IPSP to have same magnitude when it reaches cell body
What is a specialized cell or group of cells that transform a type of physical energy into an electrical signal?
Somatosensory Receptors
What are two structure types of Somatosensory Receptors?
Free nerve ending
Special receptor cell
A sensory neuron in a sensory ganglion whose peripheral process is specialized for reception?
Free nerve ending
A sensory neuron in a sensory ganglion whose peripheral process is connected to what?
Special receptor cell
Axons (fibers) with the largest diameter and most myelin have the greatest what?
conduction velocities