Week 5 - Exam prep Flashcards
Which of the following statements regarding growth factor secretion is correct?
A) Growth factors are released only during periods of homeostasis.
B) Growth factor release is independent of disturbances in homeostasis.
C) Growth factor release increases in response to disturbances in homeostasis, such as breakdown of the blood-retinal barrier (BRB).
D) Growth factor release decreases if the blood-retinal barrier (BRB) breaks down.
C) Growth factor release increases in response to disturbances in homeostasis, such as breakdown of the blood-retinal barrier (BRB)
What distinguishes reversible from irreversible cell injury?
The permeabilization of cell, nuclear or mitochondrial membrane signifies irreversible cell injury
What are two characteristics of irreversible cell injury?
- mitochondrial function cannot be restored
- membrane integrity cannot be restored
Which of the following cellular responses is characterized by a reversible change in cellular appearance, especially a change in nuclear size?
A) Hypertrophic
B) Hyperplastic
C) Atrophic
D) Dysplastic
E) Metaplastic
F) Neoplastic
D) Dysplastic
Hypertrophic –> larger cell size
Hyperplastic –> greater number of cells
Atrophic –> reduction in cell size
Metaplastic –> reversible change in cell type
Neoplastic –> uncontrolled cellular replication
What’s characteristic of Congenital Hypertrophy of the RPE?
larger cells ——> appear darker/ more pigmented
non-progressive
Does not affect Vision
Which of the following statements accurately describes apoptosis?
A) Apoptosis leads to the adaptation of cells to changes in the environment.
B) Apoptosis causes surrounding cells to become unhealthy.
C) Apoptosis results in inflammation.
D) Apoptosis allows a cell to die without affecting neighboring cells, without causing inflammation, and without causing widespread dysfunction.
D) Apoptosis allows a cell to die without affecting neighboring cells, without causing inflammation and without causing widespread dysfunction
Does necrosis affect neighboring cells?
Yes
(Domino effect)
Which occur more frequently, apoptosis or necrosis?
Apoptosis occur more frequently and typically involves individual cells.
Necrosis occurs less frequently and involves many cells and may not be localized
Describe autophagy
Autophagy produces relatively low levels of inflammation compared to necrosis and often occurs in response to nutrient depletion
Field of view in indirect ophthalmoscopy depends on?
- lens diameter
- lens power
Magnification of indirect ophthalmosopy
Mag = - (power of pt eye)/ power of lens
e.g.
20D lens mag = 60/20 = -3x (assuming a distance of 25cm)
what if you change the distance to 40cm
25/40 x (-3) = -1.9x
Why may an examiner choose to stay at 40cm rather than 25cm for 20D BIO?
- Larger field of view with 40cm
- Image magnified at 25cm and harder to examine peripheral retina
- When the examiner is closer to the condensing lens, the depth of focus decreases, making it difficult to maintain a sharp focus
Which statement is inaccurate for fundus examination with the direct
ophthalmoscope?
a. The optic disc will appear larger in a myopic eye than a normal or hyperopic eye.
b. The optic disc will appear smaller in a myopic eye than a normal or hyperopic eye.
c. The optic disc will appear smaller in a hyperopic eye than a normal or myopic eye.
d. Smaller details can be observed than with the indirect ophthalmoscope.
B) The optic disc will appear smaller in a myopic eye than a normal or hyperopic eye
remember mag = power/4
emmetrope = 60/4 = 15
myope = 64/4 = 15
hyperope = 58/4 = 14.5
Also remember, in myopic eyes the Optic disc is usually larger due to elongation of the globe
The indirect ophthalmoscope employs one of the brightest light sources used in
clinical ophthalmology. Why is such a bright light necessary?
- Illumination of the fundus
- Visualization of pathologies
- Pupil dilation
- Depth of focus
- Penetrate through cataracts
What is the effect of common refractive errors on the apparent size of the optic
disc as seen with a direct ophthalmoscope?
a. The optic disc will appear smaller in a myopic eye than an emmetropic eye.
b. The optic disc will appear larger in a hyperopic eye than an emmetropic eye.
c. The optic disc will appear smaller in a myopic eye than a hyperopic eye.
d. The optic disc will appear smaller in an aphakic eye than an emmetropic eye.
C) The optic disc will appear smaller in a myopic eye than a hyperopic eye
