brain and spinal cord
CNS contains the
sensory (afferent) division
does something about it
motor (efferent) division
walking/ skeletal muscles
somatic nervous system
autonomic nervous system
stimulatory, speeds up
inhibitory, slows down
thermostat of body
body temp set to
responds to mechanical force such as touch, pressure (such as blood pressure), vibration and stretch
sensitive to temperature changes
respond to light, in the retina of the eye
respond to chemicals such as the nose and mouth (taste buds)
responds to damaging stimulus that causes pain
opening/closing of the eye
awareness of changes in the internal and external environments
conscious interpretation of stimuli
part of the sensory system serving the body wall and limbs
report body movements
receptor level: sensory receptors
three main levels of neural integration: one
circuit level: ascending pathways
three main levels of neural integration: two
perceptual level: neuronal circuits in the cerebral cortex
three main levels of neural integration: three
change in pH, receptor
tells diaphragm and external intercostals to breathe more, effector
the type of stimulus that activates them, their body location and their structural complexity
classification of receptors is based on
specificity, the greater its specificity
the stimulus must match the ________ of the receptor. the more complex the sensory receptor,
the stimulus must be applied within a sensory receptors ________, the particular area monitored by the receptor.
the smaller the receptive site
________________, the greater the ability of the brain to accurately localize the stimulus site.
receptor potential, transduction
the stimulus energy must be converted into the energy of a graded potential, called a ________. this process is called ________.
membrane depolarizations that summate and directly lead to generation of action potentials in an afferent fiber are called ________.
a generator potential in the associated sensory neuron must reach ________ so the voltage- gated sodium channels on the axon are opened and nerve impulses are generated and propagated to the CNS.
information about the stimulus (strength, duration, and pattern) is encoded in the ________ of nerve impulses.
the stronger the stimulus
the greater the frequency,
a change in sensitivity in the presence of a constant stimulus.
fast adapting, often giving bursts of impulses at the beginning and at the end of the stimulus.
Pacinian and Meissner's corpuscles
examples of phasic receptors (skin receptors for deep pressure and light touch)
provide a sustained response with little or no adaptation.
nociceptors and proprioceptors
examples of tonic receptors
phenomenon describing the exact point in the cortex that is activated always refers to the same "where," regardless of how it is activated.
ability to detect that a stimulus has occurred. simplest level of perception.
the ability to detect how intense the stimulus is.
allows us to identify the site or pattern of stimulation.
two point discrimination test
test determining how close together two points on the skin can be and still be perceived as two points rather than as one.
histamine, k+, atp, acids and bradykinin
examples of pain producing chemicals
long- lasting or very intense pain inputs, such as limb amputation can lead to
phantom limb pain
pain perceived in a tissue that is no longer present
sensory receptors are specialized to respond to changes in their environment, which are called ________.
simple receptors are modified dendritic endings of sensory neurons, examples are the ________.
sense organs, special senses
complex receptors are actually ________, localized collections of cells associated with ________ (vision, hearing, equilibrium, smell and taste).
unencapsulated dendritic endings
free, naked nerve endings are called
naked nerve endings
present nearly everywhere in the body and are particularly abundant in epithelia and connective tissue and respond chiefly to temp and painful stimuli. L:intero, extero, proprio
heat or cold outside of the range of thermorecetors activates ________ and is perceived as painful.
another sensation mediated by free nerve endings (histamine)
tactile (Merkel) discs
modified free nerve endings associated with enlarged, disc shaped epidermal cells which lie in the deeper layers of the epidermis and function as light touch receptors. L: extero
hair follicle receptors
free nerve ending receptors that wrap basketlike around hair follicles, are light touch receptors that detect binding of hairs (mosquito landing on arm). L: extero
virtually all encapsulated dendritic endings are
meissners (tactile) corpuscles
found just beneath the epidermis and the dermal papillea and are expecially numerous in sensitive and hairless skin areas (nipples, finger tips, soles of feet) L: extero
pacinian (lamellated) corpuscles
scattered deep in the dermis and in subcutaneous tissue underlying the skin. stimulated by deep pressure. L: extero, intero, some proprio
largest corpuscular receptors