Somatosensation and Sensory Pathways

These flashcards cover key concepts related to somatosensation, sensory pathways, and associated terminology from the lecture notes.

What is somatosensation?

Somatosensation refers to the body's senses, including touch, pain, temperature, and proprioception.

What are the main receptors involved in touch sensation?

The main receptors for touch sensation include free nerve endings, Meissner's corpuscles, Pacinian corpuscles, and Merkel's discs.

What type of sensory information do A-delta fibers transmit?

A-delta fibers transmit sharp pain and temperature sensations.

What are the two pathways for somatosensory information?

The two pathways are the dorsal column-medial lemniscus pathway (for touch and pressure) and the spinothalamic tract (for pain and temperature).

Where do touch sensations first synapse in the spinal cord?

Touch sensations first synapse in the dorsal column nuclei of the medulla.

What happens to pain and temperature information in the spinal cord?

Pain and temperature information first synapses in the dorsal horn of the spinal cord.

What is the role of the thalamus in sensory pathways?

The thalamus processes and relays sensory information to the appropriate regions of the cortex.

What do you call the syndrome affecting one side of the body due to half spinal cord damage?

Brown-Séquard syndrome.

What sensory information does the trigeminal nerve carry?

The trigeminal nerve carries somatosensory information from the face.

How does adaptation in sensory receptors occur?

Adaptation occurs when receptors become less sensitive to a constant stimulus over time.

What type of pain is transmitted by C fibers?

C fibers primarily transmit dull, aching pain.

What are encapsulated nerve endings?

Encapsulated nerve endings are sensory receptors with a membrane covering that specific for pressure and vibration detection.

What type of information is processed by the dorsal posterior medial (VPM) nucleus of the thalamus?

VPM processes somatosensory information from the face.

What system carries fine touch and vibration to the cortex?

The dorsal column-medial lemniscus system carries fine touch and vibration to the cortex.

What is the function of the ventral commissure in the spinal cord?

The ventral commissure allows for the crossing of pain and temperature fibers.

What types of receptors are involved in detecting pressure and vibration?

Pacinian corpuscles and Meissner's corpuscles are involved in detecting pressure and vibration.

What are the differences between rapidly adapting and slowly adapting receptors?

Rapidly adapting receptors respond quickly to stimuli but cease firing when the stimulus is maintained, while slowly adapting receptors continue to respond throughout the duration of the stimulus.

Which cranial nerve carries somatosensory information from the face?

The trigeminal nerve (Cranial Nerve V) carries this information.

What is the main purpose of the free nerve endings?

Free nerve endings are primarily responsible for detecting pain and temperature.

What happens when touch is sustained over time?

Sustained touch can lead to sensory adaptation, where the sensation becomes less noticeable.

What areas does the somatosensory cortex correspond to in the body?

The somatosensory cortex has a homunculus representation where different areas correspond to different body parts.