Lecture 5 - Sensory Systems Flashcards
What is a sense?
Information received from sensory systems from external and internal environments through specialized cells at the periphery that is used to regulate movements
What are specialized cells at the periphery responsible for?
Transmission of information to the CNS (afferent)
What are the five senses?
Sight, hearing, taste, touch, smell
What are other senses outside of the commonly known five senses?
Balance (vestibular), pain, pressure, itch, temperature, proprioception
What three things do sensory receptors share in common?
They respond to a physical stimulus, convert stimulus to nerve impulses (APs), and give information for the CNS to use
What happens when contact with a particular stimuli occurs?
Changes in the membrane of the sensory neuron that causes the generation of APs which transmits info the the CNS
How are sensory neurons activated?
By specific stimuli, each is sensitive to a particular form of physical energy
What type of physical energy is vision stimulated by?
Light
What type of physical energy is hearing stimulated by?
Air pressure (waves)
What type of physical energy is balance stimulated by?
Head motion
What type of physical energy is touch stimulated by?
Mechanical, thermal, etc.
What types of information does the sensory system transmit to the CNS?
Modality of the stimuli (what), location of the stimuli (where), intensity of the stimuli (strength), and duration of the stimuli (time)
What are the four types of motor related sensory systems?
Vision, vestibular (balance), cutaneous, and proprioception (muscle, tendon, and joint)
What are the sensory neurons of the visual system?
Rods and cones
How many sensory neurons are in the each eye?
125 million
What do rods do?
Dim light
What do cones do?
Focus on bright light and colors
What do visual receptors do?
Turn light into electrical signals that pass along the optic nerve to the vision centers in the brain
What does the vestibular system do?
Provide a sense of balance and head orientation
What is the vestibular apparatus?
Semicircular canals
How does the vestibular system function?
Hair cells detect movement of fluid
What type of information do cutaneous receptors receive?
Temperature (thermoreceptors), pain (nocioreceptors), and pressure (merkel’s)
How is sensitivity determined?
Based on the number of receptors in a particular area.
Is sensitivity equal on all parts of the body?
No
