MISC "LOOK IN THE BOOK" questions Dr. A Flashcards
(23 cards)
Regarding the Dorsal Column-Medial Lemniscal Pathway, this pathway carries 2-point discrimination touch. What other kinds of sensory information does this pathway carry?
Sensory: Fine touch, pressure, vibration
Primary fibers go all the way up and synapse on the 2nd in the Medulla… Fasc. Gracillis vs. Fasc. Cuneatus
Referred Pain:
List the kinds of stimuli that can excite visceral pain nerve endings.
FILL IN
Referred Pain:
Name two visceral areas that are insensitive to pain of any type
- Parechyma of the Liver
2. Alveoli of Lungs
Headaches:
What kinds of injuries and conditions can result in a headache?
- Dr. Shnyra’s lectures, about 45 mins in.. (J/K)
- Tugging of Venous sinuses around the brian
- Damage to tentorium
- Stretching of dura at the base of the brain
* *Middle Meningeal artery**
Brain stem and cerebellar vault headaches will be felt:
in the posterior half of the head, occipital bone and upper crown area.
Cerebral vault headaches are felt:
Temporal lobe areas as well as anterior section of forehead/ frontal lobe area
Nasal sinus and eye headaches
ummmm… yeah.
Headaches caused by meningitis
SEVERE headaches. Inflammation of the meninges. The entire head will be feeling the referred pain.
Low cerebral spinal fluid headache
Especially when the patient is sitting upright, they will experience intra-cranial weight of the brain that distorts the dural surfaces. Elicits pain.
Weight of brain not fully suspended by the water cushion… imagine trying to relax in an empty bathtub… no go.
Migraine:
The book talked about many theories. exhaustion of the smooth muscle, emotional overload, stress, cortical depression, excess local Potassium ion concentration in the cerebral extracellular fluid.
Signatures: Different with each person, usually involves nausea, light sensitivities and changes in the field of vision.
What type of lenses are used to correct emmetropia?
None, those people are freaks of nature, and completely perfect in every way, including the shape of their eyeball :)
What type of lens for Hyperopia
Hyper means OVER or ABOVE. The eye is projecting light rays WAY PAST the retina. Use a converging lens to get those to converge CLOSER on the retinal.
What type of lens for Myopia
That is called nearsighted. So if the light rays are coming together too NEAR the retina, we need to spread them out a little.. use a DIVERGING lens.
How is a tonometer used?
A tonometer measures interocular pressure. . The cornea is anesthetized. The footplate of the tonometer is placed against the cornea and a force is applied. The amount of displacement is measured.
Picture it this way, if you have a fully inflated balloon with a lot of internal resistance, if you apply force to it, it will not budge much, if at all. If the balloon has a little “Give” in the surface tension, when you apply a force, it will not be a strongly opposed.
Glaucoma:
Glaucoma is the biggest cause of blindness. Interoccular pressure becomes unreasonably high. As the pressure increases for an extended time, the axons of the retina start to become detached and neuronal pathways might not work right. Over time, these fibers become starved for nutrients.
Not mentioned in the book, but Dr. Friedlander described the detached retina/ macular degeneration as a curtain that has fallen on the floor.
The canal of schlem is meant to relieve pressure and allow those fluids to move… plug up the hose, you are gonna have problems.
Small Muscles of the Ear:
What effect do the two opposing forces cause the ossicular system?
Opposition creates rigidity of the system, reducing conduction of low frequencies.
What is the function of this system (the attenuation reflex?)
Protects the cochlea from damaging vibrations caused by loud sounds.
Removes background noise
What effect do these two muscles have on a person’s sensitivity to their own speech?
Decreases hearing sensitivity to own voice
Collateral nerve activated at the same time the brain activates the voice mechanism.
Auditory Nervous System Pathway
Where does decussation occur between right and left pathways?
that nerve fibers from the spiral ganglion of
Corti enter the dorsal and ventral cochlear nuclei
located in the upper part of the medulla. At this point,
all the fibers synapse, and second-order neurons pass
mainly to the opposite side of the brain stem to
terminate in the superior olivary nucleus.
A few second-order fibers also pass to the superior olivary nucleus on the same side. From the superior olivary nucleus, the auditory pathway passes upward through the lateral lemniscus. Some of the fibers terminate in the nucleus of the lateral lemniscus,
but many bypass this nucleus and travel on to the inferior colliculus, where all or almost all the auditory fibers synapse. From there, the pathway passes to the
medial geniculate nucleus, where all the fibers do synapse. Finally, the pathway proceeds by way of the
auditory radiation to the auditory cortex,
located mainly in the superior gyrus of the temporal lobe.
Auditory NS Pathways:
What is the relationship between the auditory tracts and the RAS?
.
Where is the auditory cortex located?
Superior gyrus of the temporal lobe.
Distinguish between the primary auditory cortex and the auditory association areas
.
Explain how a person determines the direction from which sound comes.
Horizontal distance: the brain knows the difference between when the sound his one ear vs. the second one. It measures the intensities between these two receptors. Look at page “660 ish” and read about how the ear distinguishes noise in all directions.
