Human Phys Chapter 7
Flashcard Set: BIOL 4431 Chapter 7
Basic Definitions
Q: Define sensation and perception. How are they related?
A: Sensation is the detection of stimuli by sensory receptors, while perception is the interpretation of those sensory signals by the brain. Sensation provides the raw data, and perception organizes and interprets it.
Types of Sensory Receptors
Q: What do mechanoreceptors detect?
A: They detect mechanical forces such as touch, pressure, vibration, and stretch.
Q: What do thermoreceptors detect?
A: They detect temperature changes.
Q: What do photoreceptors detect?
A: They detect light and are responsible for vision.
Q: What do chemoreceptors detect?
A: They detect chemical stimuli such as taste and smell.
Q: What do nociceptors detect?
A: They detect pain and potentially harmful stimuli.
Sensory Processes
Q: Define sensory transduction.
A: It is the process of converting a physical stimulus into an electrical signal in a sensory receptor.
Q: Define receptor potential.
A: It is the graded change in membrane potential in response to a stimulus.
Q: How are sensory transduction and receptor potential related?
A: Sensory transduction leads to receptor potential, which may trigger action potentials in neurons.
Types of Senses
Q: Define somatic (general) and special senses.
A: Somatic senses include touch, pain, temperature, and proprioception, while special senses include vision, hearing, taste, smell, and equilibrium.
Q: Classify the following sensations: vision, temperature, pain, touch, pressure, hearing.
A:
Somatic Senses: Temperature, pain, touch, pressure
Special Senses: Vision, hearing
Neural Pathways
Q: What happens when sensory information reaches the cerebral cortex?
A: The information is processed in the receiving (primary sensory) and association areas for interpretation.
Vision
Q: Identify the function of the retina.
A: It contains photoreceptors (rods and cones) that detect light and initiate visual processing.
Q: Identify the function of the cornea.
A: It refracts (bends) light to help focus it on the retina.
Q: Identify the function of the lens.
A: It adjusts its shape to focus light on the retina for clear vision.
Q: Where are photoreceptor cells located, and what are their functions?
A: They are in the retina; rods detect low-light vision, and cones detect color and sharp vision.
Q: How do photopigments contribute to phototransduction?
A: Photopigments in rods and cones absorb light, leading to changes in membrane potential and initiating neural signals.
Q: How does binocular vision result in optic tract crossover?
A: Each eye sends information to both hemispheres, allowing depth perception and coordination between both visual fields.
Q: Outline the visual pathway from the retinal ganglion cells to the cortex.
A: Retinal ganglion cells → Optic nerve → Optic chiasm → Optic tracts → Thalamus → Visual cortex
Hearing (Audition)
Q: Identify the function of the external auditory canal.
A: It channels sound waves to the tympanic membrane.
Q: Identify the function of the tympanic membrane (eardrum).
A: It vibrates in response to sound waves.
Q: Identify the function of auditory ossicles.
A: They amplify and transmit vibrations from the eardrum to the inner ear.
Q: Identify the function of the oval window.
A: It transmits vibrations from the ossicles to the cochlea.
Q: Identify the function of the cochlea.
A: It converts sound vibrations into neural signals via hair cells.
Q: What is the function of hair cells in the cochlea?
A: They detect sound vibrations and convert them into electrical signals.
Q: How are stereocilia activated in the cochlea?
A: Vibrations cause movement of the basilar membrane, bending the stereocilia, which opens ion channels and triggers action potentials.
Q: Outline the auditory pathway to the cortex.
A: Cochlea → Auditory nerve → Brainstem → Thalamus → Auditory cortex