Lab 5 Flashcards
Homeostasis
The ability of the body to maintain relatively constant state
Sensor
detects changes
a Receptor can also be?
Cells that serve as sensors
Special senses
Vision taste touch smell hearing equilibrium
keeps us aware of the world around us and it’s effects on us
Adequate stimulus
Each receptor type detects specific stimulus
What does Chemoreceptors detect
Detect:
CO2, H+, pH, O2, molecules in food or air, blood glucose
What do Mechanoreceptors detect
Detect:
pressure stretch or compression of cell acceleration sound
What do Photoreceptor detect
Detects lights photons of varying wavelength
Density of receptors
Determine sensitivity to the stimulus
Perception
A conscience understanding of the stimulus been detected.
End result of the processing takes place in the brain
Properties of stimulus vary based on
Mortality -what is been detected by receptor
Location- Source of stimulus
Intensity- The strength of the stimulus (stronger more action potential)
Duration- How long the stimulus is present
Tonic receptors
Slow adapting
active as long as a signal is present
Phasic receptors
Fast adapting.
Only generate action potential’s when there is a change in stimulus
Hearing FB loop
Stimulus- Sound waves cause fluid movement
Transduction- Hair cells stereocilia compress or stretch cell membrane ion channels open change in membrane potential release of neurotransmitters activate primary sensory neuron
Integrating center- auditory cortex
Hearing located in cochlear
Stereocilia used in hearing and equilibrium
Equilibrium FB loop
Stimulus
Fluid movement causing movement of endolymph in vestibular apparatus
Transduction-
The stretch of the hair cell membrane
Mechanical gated Ion channels open
Change in membrane potential (charge cell) hyperpolarization/ depolarization
Release of neurotransmitters to activate primary sensory neurons
Integrating center:
cerebral cortex cerebellum
Vision FB Loop
Stimulus photons, light Changes shape Transduction- Light absorbed by pigment Chemical cascade that leads to opening or closing of ion channels When activated the photo receptor cells Release of neurotransmitters To the Bipolar cells. Bipolar cells synapse with the ganglion cells that make up the optic nerve
Integrating center:
Visual cortex
Photo receptors two kinds that detect photons
Rods and cones
Rods detect low light night vision. The pigment rhodopsin is altered when light enters.
The pigment in the cone cells are altered by different wavelengths of light
the blue cones detect wave links at low end of the spectrum
green in the middle range and red in the high range.Cones detect bright light in color vision
Olfaction FB Loop
Stimulus-
odorant molecules That enter the air and then enters In the nasal cavity binding to dendrites.
Transduction-
Depolarization of receptor, G protein coupled receptor with the cAMP cascade On the dendrites that have binding sites for odorant molecules.
When activated olfactory sensory neurons synapse with secondary sensory neurons in the olfactory bulb
the signal pathway continues along the olfactory track and finally to the limbic system or olfactory cortex-
Integrating center:
Olfactory cortex
Limbic system of the brain
Does not pass through the hypothalamus
Taste FB Loop
Stimulus
molecules or ions in food
Transduction-
Depolarization of taste cells
When activated Taste cells release signal molecules including serotonin or ATP
To the primary sensory neuron.
Combination of receptors activated along with other chemicals and foods that serve as modulators.
Integration center
Gustatory cortex
Webers hearing test
Tuning fork middle of the forehead
normal: sound equals on both sides
abnormal: louder on one side
Rinnes hearing test
Tuning fork placed on mastoid process,(jaw bone) once hearing is stopped then place near ear.
Rinnes positive- normal air conduction louder than bone conduction
Rinnes negative- abnormal bone conduction it’s louder than air conduction
Ishihara color test
Test to see if colorblind and to what colors you are blind to
Red green color blindness
Most common and
most common especially in males because they carry the X trait gene
Cones
Responsible for light in color vision
three types
red blue and green
What is a Blindspot test?
Located on the surface of the retina called the optic disc
Where all the axons exit the eye and converge to form the optic nerve
location of the Blindspot is located in the lateral visual field of each eye.
When only one Eye Is being used, the brain fills in the missing Visual information Based on the surrounding area.
