Lecture 4

Question 1

What is sensory processing?

Answer 1

• Sensory processing is the neurological process that organizes sensation from one’s own body and the environment, thus making it possible to use the body effectively within the environment.
• Specifically, it deals with how the brain processes multiple sensory modality inputs, such as proprioception, vision, auditory system, touch, olfactory, hearing, and the gustatory system into usable functional outputs.

Question 2

Sensation

Answer 2

The detection of environmental stimuli.

Question 3

Perception

Answer 3

Awareness of what we sense.

Question 4

What are the five sensory systems?

Answer 4

1. The auditory system.
2. The olfactory system.
3. The gustatory system.
4. The somatosensory system.
5. The visual system.

Question 5

Information in each sensory system flows along “functional pathways” in a precise way. What pathway is that?

Answer 5

Sensory receptor cells → Thalamus → Primary Cerebral Cortex.

Question 6

Sensory Receptor Cells

Answer 6

• A sensory nerve ending that responds to a stimulus in the internal or external environment of an organism.
• In response to stimuli, the sensory receptor initiates sensory transduction by creating action potentials in the same cell or in an adjacent one.

Question 7

Sensory Transduction

Answer 7

The process by which a cell converts an extracellular signal, such as light, taste, sound, touch or smell, into electric signals.

Question 8

Somatosensation

Answer 8

• “Body Sense.”

- A collective term for the sensations of touch, temperature, body position, and pain.

Question 9

What are the three sensory receptor cells of the somatosensory system?

Answer 9

1. Mechanoreceptors.
2. Thermoreceptors.
3. Nociceptors.

Question 10

Mechanoreceptors

Answer 10

• The sensation of touch is detected by touch receptors called mechanoreceptors.
• Express ion channels sensitive to kinetic energy.

Question 11

Thermoreceptors

Answer 11

• The sensation of temperature is detected by pain receptors called thermoreceptors.
• Express ion channels sensitive to thermal energy.

Question 12

Nociceptors

Answer 12

• The sensation of pain is detected by pain receptors called nociceptors.
• Express ion channels sensitive to intense thermal energy, kinetic energy, and noxious chemicals.

Question 13

What is sound?

Answer 13

Sounds are pressure waves in the air

Question 14

The Auditory System

Answer 14

• Allows us to detect sounds in our environment.

- These stimuli are transduced by sensory receptor cells called hair cells.

Question 15

What are the five true tastes processed by the gustatory system?

Answer 15

1. Salty
2. Sour
3. Sweet
4. Bitter
5. Umami

Question 16

Salty

Answer 16

The detection of sodium ions for salty things.

Question 17

Sour

Answer 17

The detection of hydrogen ions from sour things.

Question 18

Sweet

Answer 18

The detection of chemical structures associated with sweet things.

Question 19

Bitter

Answer 19

The detection of chemical structures associated with bitter things.

Question 20

Umami

Answer 20

The detection of glutamate.

Question 21

Taste is transduced by what?

Answer 21

Chemoreceptors called taste cells.

Question 22

Why do we smell?

Answer 22

• Detection of odors can contribute to “flavor.”

- Detection of odors can be a signal of something harmful.

Question 23

The ____________ allows us to smell many things.

Answer 23

Olfactory System.

Question 24

Smell is transduced by what?

Answer 24

Chemoreceptors called olfactory receptor neurons.

Question 25

How does the brain process pain?

Answer 25

• When we get hurt, special tissue damage-sensing nerve cells, called nociceptors, fire and send signals to the spinal cord and then up to the brain.
• There, processing work gets done by cells called neurons and glia, which is our grey matter.
• Our sensing pathway carries the pain information from the spinal cord to the brain that ends in the cortex.
• The cortex decides what to do with the pain signal.

Question 26

Smell and the brain.

Answer 26

• Smell begins at the back of nose, where millions of sensory neurons lie in a strip of tissue called the olfactory epithelium.
• The tips of these cells contain proteins called receptors that bind odor molecules.
• This neural code begins with the nose’s sensory neurons. Once an odor molecule binds to a receptor, it initiates an electrical signal that travels from the sensory neurons to the olfactory bulb, a structure at the base of the forebrain that relays the signal to other brain areas for additional processing.
• One of these areas is the piriform cortex, a collection of neurons located just behind the olfactory bulb that works to identify the smell.
• Smell information also goes to the thalamus, a structure that serves as a relay station for all of the sensory information coming into the brain.
• The thalamus transmits some of this smell information to the orbitofrontal cortex, where it can then be integrated with taste information. What we often attribute to the sense of taste is actually the result of this sensory integration.