4 Sensory Systems Free Online FlashCards

What is a receptor potential?

A receptor potential is a change in a receptor’s membrane voltage caused by stimulus energy; if large enough, it increases sensory-neuron signaling.

What information travels through the dorsal column–medial lemniscus pathway?

The dorsal column–medial lemniscus pathway carries fine touch, vibration, and conscious proprioception. It ascends on the same side of the spinal cord, crosses in the medulla, then relays through the thalamus to primary somatosensory cortex.

How do rods and cones differ in their visual roles?

Rods are especially sensitive in dim light. Cones support color vision and fine detail, particularly in the central retina.

What does the cochlea’s tonotopic map represent?

Different places along the cochlea respond best to different frequencies, forming a tonotopic map that is maintained in parts of the auditory pathway and cortex.

What is distinctive about olfaction’s initial route to primary cortex?

Olfactory neurons send signals to the olfactory bulb and onward to olfactory cortical areas. Unlike other major senses, olfaction’s initial route to primary cortex does not first relay through the thalamus.

How do the thalamus and context influence sensory processing?

The thalamus relays and helps regulate much sensory information before it reaches the cortex; olfaction is a notable exception to the usual first thalamic relay. Attention, expectations, and context can also shape interpretation.

Which stimulus types do major receptor classes detect?

Mechanoreceptors respond to physical deformation, photoreceptors to light, and chemoreceptors to chemicals. Thermoreceptors and nociceptors respond to temperature and potentially damaging stimuli.

What is a receptive field, and how does its size affect spatial discrimination?

A receptive field is the region of sensory space that can change a neuron’s activity. Smaller, more densely sampled fields support finer spatial discrimination.

What is sensory adaptation?

Adaptation is a reduced response to a sustained, unchanging stimulus; it makes changes in that stimulus more noticeable.

What does the anterolateral pathway carry, and where do its fibers generally cross?

The anterolateral (spinothalamic) pathway carries pain, temperature, and aspects of crude touch. Its fibers generally cross within the spinal cord and ascend on the opposite side.

Why is pain not a direct measure of tissue damage?

Pain is not a simple readout of tissue damage: spinal and brain circuits can amplify or inhibit nociceptive signals, and attention and context can shape the experience.

How does the optic chiasm route information from visual space?

At the optic chiasm, some retinal fibers cross: information about the left visual space goes to the right cerebral hemisphere, and information about the right visual space goes to the left.