Lab practical #2 Flashcards
The essentials to a reflex mechanism are
receptor organ and effector organ and some type of communications network
Innate
the appropriate response to the stimulus has been built into the nervous system
Result of pupillary reflex
after shining the flashlight, the pupil constricts or contracts
Consensual reflex
normally a light that is directed into one eye produces pupil constriction in both eyes
What happens to pupil size when the sphincter muscles of the iris contract?
Pupil size decreases (constricts)
What happens to pupil size when the dilator muscles of the iris contract?
Pupil size increases (dilates)
Pupil Accomodation
The pupils constrict when looking at a near object and dilate when looking at a far object
Lens Accomodation
When an individual looks at a near object, the ciliary muscles will contract and when an individual looks at a far object, the ciliary muscles will relax
Convergence in Accommodation
When an individual shifts their focus from a far object to a near object, the eyes will converge to keep the image focused
Jendrassik’s Maneuver
used in a medical setting to elicit a change in response in tendon reflex activity by forcing the individual to focus their attention on their arms (by pulling outward) rather than their leg (where the reflex is occurring)
Achilles reflex results
the contraction of the gastrocnemius muscle should cause plantar flexion of the foot
Biceps and Triceps reflex
you cannot contract the bicep and tricep muscles at the same time, they are antagonistic muscles; bicep muscles relax while tricep muscles contract when pushing down on the table and vice versa when pushing up on the table
Ciliospinal reflex
response mediated over the sympathetic nervous system in response to a painful stimulus; when pinching the left side of the back of the neck, the left pupil dilates and the right pupil remains the same
Babinski reflex
indicative of dorsiflexion (flexed upward)
Nystagmus
if the canals are stimulated under experimental conditions, reflex response results in a movement of the eyes called nystagmus
Rotary nystagmus fast phase vs slow phase
fast phase = same direction of movement, slow phase = opposite
Post-rotary fast phase vs slow phase
Fast phase = opposite direction of movement, slow phase = same direction
What types of movement is the anterior semicircular canal stimulated by?
stimulated during actions that cause the head to tilt upside down, such as a backflip
What types of movement is the posterior semicircular canal stimulated by?
stimulated during actions that cause the head to tilt towards the side such as a cartwheel
What types of movement is the lateral semicircular canal stimulated by?
stimulated by actions that cause side-to-side movement, such as spinning in a circle
Proprioception and spatial orientation
Connected, it is harder to orient your body with your eyes closed
Mechanoreceptors
Various specialized sensory receptors located in specific areas of the skin
Receptive Fields
allow us to identify a stimulus on the body and react to it accordingly
Two-point threshold
the smallest distance at which two points of contact can be felt
Sensory Adaptation
if a stimulus is applied for a prolonged period of time without movement, the rate of acceleration receptor discharge will slow, and conscious awareness of the stimuli will decline or is lost
Weber Test
Conductive Deafness: lateralization in poorer ear
Nerve Deafness: Lateralization to the better ear
* tests for nerve deafness
Rinne Test
Conductive Deafness: Sound perceived as long or longer by bone conduction
Nerve Deafness: sound perceived longer by air conduction
* tests for conduction deafness
Myopia
an individual’s inability to focus light properly on the retina resulting in nearsigntedness
**individuals are prescribed glasses with concave lenses to create sharper distant vision
Presbyopia
A loss of near-focusing ability
**individuals are prescribed glasses with convex lenses to correct for the loss of lens elasticity
Blind spot (optic disc)
an area on the retina where the optic nerve and blood vessels enter and leave the retina and there are no rods and cones for visual reception
Where is the blind spot located
the nasal side on the retina and the temporal side in the visual field
What does 70/50 mean?
you can see something from 70 feet away, but the normal eye can see it from 50 feet away, so your vision is above average
Red wavelength
560nm
Blue wavelength
420nm
Green color wavelength
530 nm
On which chromosome is the color blindness gene found?
X chromosome
Is color blindness more common in males or females?
males
