chapter 16 part 1

What is a stimulus?

A stimulus is any change in the environment that can provoke a response in a sensory receptor.

How does receptive field size impact sensory information specificity?

The size of the receptive field affects how accurately a sensory receptor can pinpoint the location of a stimulus; smaller receptive fields provide greater specificity.

How is a stimulus different from a sensation?

A stimulus is the detected change in the environment, while a sensation is the conscious perception of that stimulus.

How do sensory receptors encode extra data?

Sensory receptors encode modality, stimulus location, and intensity into a sensory message through patterns of action potentials.

What occurs during sensory adaptation?

Sensory adaptation is the process by which sensory receptors become less responsive to constant stimuli over time.

How do tonic receptors differ from phasic receptors?

Tonic receptors maintain consistent activity in response to a stimulus, while phasic receptors respond quickly to changes but adapt quickly.

What are the general senses and special senses?

General senses include touch, temperature, pain, and proprioception; special senses are vision, hearing, taste, smell, and balance.

What is the difference between somatic sensations and visceral sensations?

Somatic sensations arise from skin, muscles, and joints (external environment), while visceral sensations originate from internal organs (internal environment).

What sensations are detected by exteroceptors, interoceptors, and proprioceptors?

Exteroceptors detect external stimuli (like touch and light); interoceptors detect internal stimuli (like pain and pressure); proprioceptors provide information about body position.

How are chemoreceptors activated?

Chemoreceptors are activated by the presence of specific chemicals in the environment.

How are thermoreceptors activated?

Thermoreceptors are activated by changes in temperature.

How are photoreceptors activated?

Photoreceptors respond to light, specifically photons.

How are mechanoreceptors activated?

Mechanoreceptors are activated by mechanical pressure or distortion.

How are baroreceptors activated?

Baroreceptors are sensitive to changes in pressure, particularly in blood vessels.

How are nociceptors activated?

Nociceptors are activated by potentially damaging stimuli, such as extreme heat, cold, or injury.

Where are free nerve endings located and what is their function?

Free nerve endings are found throughout the body and detect pain, temperature, and some light touch sensations.

Where are root hair plexuses located and what is their function?

Root hair plexuses are associated with hair follicles and detect light touch.

Where are tactile discs located and what is their function?

Tactile discs are located in the epidermis and detect light touch and texture.

Where are lamellated corpuscles located and what is their function?

Lamellated corpuscles are located in deep skin layers, joints, and internal organs, and detect deep pressure and vibration.

Where are bulbous corpuscles located and what is their function?

Bulbous corpuscles are found in the dermis and detect skin stretch.

Where are tactile corpuscles located and what is their function?

Tactile corpuscles are located in the papillary layer of the dermis and detect light touch.

What causes referred pain?

Referred pain occurs when pain is perceived in an area of the body that is different from the actual site of a stimulus or injury.

Where is referred pain felt from the heart?

Referred pain from the heart is often felt in the left arm, neck, or jaw.

Where is referred pain felt from the liver?

Referred pain from the liver can be felt in the right shoulder and abdominal area.

Where is referred pain felt from the kidneys?

Referred pain from the kidneys may be felt in the lower back or flanks.

Where is referred pain felt from the appendix?

Referred pain from the appendix is typically felt in the lower right abdomen.

What does it mean for olfaction and gustation to be chemical senses?

Olfaction and gustation are considered chemical senses because they detect the presence of chemicals in the environment.

What are the three cell types in the olfactory epithelium?

The three cell types are olfactory sensory neurons, supporting cells, and basal cells.

Trace the process of olfaction from olfactory hairs to the temporal lobe of the brain.

Olfactory hairs detect odorants, send signals to olfactory bulbs, which then transmit information via olfactory tracts to the temporal lobe.

What are the types of tongue papillae?

The types of tongue papillae include filiform, fungiform, circumvallate, and foliate papillae.

What are the functions of the three cell types inside taste buds?

The three cell types are gustatory receptor cells (taste), supporting cells (protection), and basal cells (regeneration).

Trace the process of gustation from gustatory microvilli to the insula of the brain.

Gustatory microvilli detect tastants, send signals to cranial nerves, which transmit to the gustatory cortex located in the insula.

What chemicals are detected as sweet, salty, sour, bitter, and umami?

Sweet: sugars; Salty: sodium ions; Sour: hydrogen ions; Bitter: alkaloids; Umami: amino acids.