Shared Flashcard Set

Details

Chapter 7
Objectives
43
Physiology
Undergraduate 2
02/21/2011

Additional Physiology Flashcards

 


 

Cards

Term
How does the nervous system code for the modality of a stimulus?
Definition
Modality is a stimulus type. The receptor is sensitive to a specific modality. The neuron will only carry out one modality to consciousness.
Term
How does the nervous system code for the intensity of a stimulus?
Definition
Intensity is the frequency of neuronal firing. It is coded by the Weber-Fechner law: the more intense of a stimulus, the greater the generator potential and the neuron will fire more frequently.
Term
How does the nervous system code for the location of a stimulus?
Definition
Locality is the area the stimulus arrives at. The size of the receptive field determines the ability to precisely pinpoint the sensation.
Term
Adequate Stimulus
Definition
The modality of a stimulus to which a particular sensory receptor is most sensitive.
Term
Sensory unit
Definition
Afferent neurons plus the receptors it innervates.
Term
Receptor field
Definition
Area of the body that, if stimulated, results in activity of that neuron.
Term
Receptor adaption
Definition
Decreases the receptor sensitivity which results in a decrease in action potential frequency.
Term
Propioception
Definition
The sense of posture and position. It is sensory info dealing with the position of the body in space and its parts relative to one another.
Term
Describe the ascending pathways for somatic sensations.
Definition
Most convey info about a single type of sensory information. They may converge or diverge to interneurons.
Term
Functions of specific ascending pathways.
Definition
Carry single types of stimuli that pass to the brainstem & thalamus then to specific sensory areas of cortex-somatosensory cortex then to the complex integration areas. (Cross to other side of brain)
Term
Functions of the nonspecific (polymodal) ascending pathways.
Definition
Activated by sensory units of several different types to indicate something is happening. End in reticular formation and regions of thalamus/brainstem and are not highly discriminative.
Term
Receptor/Graded potential
Definition
A graded potential produced at the peripheral endings on afferent neurons in response to a stimulus.
Term
Graded potentials characteristics
Definition
Can be summed, has no threshold, has no refractory period, decrementally, duration varies, initiated by stimulus.
Term
Action potential characteristics
Definition
Depend on voltage gated channels, can not be summed, has threshold, has a refractory period, constant for all cell types, initiated by graded potential.
Term
Where is the somatosensory cortex located?
Definition
Parietal lobe of brain
Term
What kinds of sensations are perceived in the somatosensory cortex?
Definition
Information from somatic receptors (receptors in framework or outer walls)
Term
Where is the auditory cortex located?
Definition
Temporal lobe of brain.
Term
Where is the visual cortex located?
Definition
Occipital lobe of brain.
Term
Function of primary sensory cortex
Definition
Produces sensation and crude feelings but no interpretation or analysis
Term
Function of sensory association cortex
Definition
Gives meaning to sensation, interpretation, and perception.
Term
Tonic receptors
Definition
Slow adapting and will continue to fire.
Term
Phasic receptors
Definition
Rapidly adapting and will fire quickly but then stop firing after further stimulation.
Term
How is the sensation of pain created?
Definition
Pain receptors (nociceptors) are stimulated by chemicals released by damaged tissue then substance P is released to fire neuron and reticular formation/thalamus
Term
What role is played by the enkephalins and endorphins in the perception and appreciation of pain?
Definition
An enkephalin is a peptide neurotransmitter at some synapses that is activated by opiate drugs and can inhibit pain pathway (Mu receptors)
Term
Referred pain
Definition
When visceral pain is referred or is sensed arising from a different somatic location. Why? Pain may be referred due to convergence on the same neuron due to neurons being at the same site or nearby.
Term
How do you focus your eye for near vision?
Definition
Using rounded lens
Term
What muscle is involved in focusing your eye for near vision?
Definition
Contracted ciliary muscles-slackened zonular fibers
Term
What nervous system is used for focusing your eye for near vision?
Definition
Firing of parasympathetic nerves (miosis) muscarinic
Term
What is the neurotransmitter used for focusing your eye for near vision?
Definition
Acetylcholine
Term
What is the receptor for focusing your eye for near vision?
Definition
Circular muscle of iris
Term
How do you focus your eye for far vision?
Definition
Flattened lens
Term
What muscle is involved in focusing your eye for far vision?
Definition
Relaxation of ciliary muscle and zonular fibers. Oval shaped radial muscle of iris.
Term
What is the neurotransmitter for focusing your eye for far vision?
Definition
Norepinpehrine/epinephrine
Term
What is the receptor used for focusing your eye for far vision?
Definition
Sympathetic beta 2 receptor
Term
How does sound stimulate the hair cells of the organ of Corti?
Definition
Hair cells have sound receptors so the vibrations open and close potassium channels which send impulses (mechanoreceptors with hairlike sterocilia)
Term
How are these receptors in the Organ of Corti arranged with respect to pitch?
Definition
Lower pitch- vibrations are further down the cochlea. High pitch- vibrations are closer to the oval window.
Term
What do the semicircular canals monitor?
Definition
Angular acceleration (rotation)
Term
How does the stimulation of the semicircular canals cause activation of these receptors?
Definition
Movement of fluid bends the stereocilia and acceleration in release of chemical transmitters from hair cells. Also, this movement causes depolarization (according to direct hyperpolarization or polarization)
Term
What do the utricle and saccule monitor?
Definition
Linear Acceleration (gravity)
Term
How does this stimulus of the utricle and saccule cause activation of these receptors?
Definition
Displacement of projecting hairs (covered with otoliths) to move and pull against hair cells so that stereocilia ben and stimulate receptor cells. Stimulated by changes in head position.
Term
Location of somatosensory
Definition
Parietal lobe of brain
Term
Location of visual cortex
Definition
Occipital lobe of brain
Term
Location of auditory cortex
Definition
Temporal lobe of brain.
Supporting users have an ad free experience!