A&P CH15 Flashcards
What are sensory receptors?
specialized cells or cell processes that monitor specific conditions in the body or external environment
Where is somatic sensory information distributed to the brain? Where is visceral sensory information
distributed to the brain?
Somatic sensory info- distributed to sensory processing centers in the brain
Visceral sensory info- distributed primarily to reflex centers in the brainstem and diencephalon
Voluntary or involuntary somatic motor commands control which peripheral effector?
skeletal muscles
What is sensation and perception?
sensation- arriving information
perception- the conscious awareness of a sensation
What is the process of transduction?
the conversion of an arriving stimulus into an action potential by a sensory receptor
What is receptor specificity?
a characteristic sensitivity of each receptor
Which type of receptor has the least receptor specificity?
free nerve endings (branching tips of dendrites)
Define receptive field.
the area monitored by a single receptor cell
What is the relationship between receptor field size and the ability to localize a stimulus?
the larger the receptive field - the poorer the ability to localize a stimulus
What is a labeled line?
the link between peripheral receptor and cortical neuron
What are tonic receptors? What are phasic receptors?
tonic receptors- always active
phasic receptors- normally inactive and get activated by a stimulus: provide info about the intensity and rate of change of a stimulus
Define adaptation.
a reduction of receptor sensitivity in the presence of a constant stimulus
Are tonic receptors fast adapting or slow adapting? Are phasic receptors fast adapting or slow
adapting? Note: the way I remember this is that phasic is fast.
tonic receptors: slow-adapting receptors, show little peripheral adaptation
phasic receptors: fast-adapting receptors, peripheral adaptation responds strongly at first but activity gradually decreases
Which of the following situations describe a phasic receptor? Which of the following situations
describe a tonic receptor?
A) jumping into a pool and feeling cold, but then quickly “getting used to” the temperature
B) burning your finger and feeling pain for the entire day
A- phasic receptor
B- tonic receptor
General sense receptors are divided into three types called exteroceptors, proprioceptors, and
interoceptors. What do each monitor?
exteroceptors- provide info about the external environment
proprioceptors- report the position and movements of skeletal muscles and joints
interoceptors- monitor visceral organs and functions
What general stimulus do nociceptors detect? What does the size of their receptive field indicate?
pain receptors. free nerve endings with large receptive fields: difficult to determine the exact source of a painful sensation
Two types of axons, Type A and Type C fibers, carry painful sensations. What is the structural
difference between Type A and Type C fibers? Which one carries fast pain (prickling pain) sensations?
Which one carries slow pain (burning or aching pain) sensations?
Type A axons - myelinated fibers that carry fast or prickling pain
Type C axons - unmyelinated fibers that carry slow or burning and aching pain
Sensory neurons that bring pain sensations into the CNS release which two neurotransmitters?
glutamate and/or substance P
What is phantom limb syndrome?
when pain is still felt in an amputated limb
What is the structure of thermoreceptors? Are they tonic or phasic?
free nerve endings in the dermis, skeletal muscles, liver and hypothalamus: phasic receptors
What are mechanoreceptors sensitive to?
sensitive to physical stimuli that distort their plasma membrane