Postlab quiz 6 Flashcards
What is stargardt’s disease also known as
fundus flavimaculatus
Stargardt’s disease is the most common from of this
juvenile macular degeneration
Stargardt’s disease is the loss of this
central vision between the ages of 6 and 20
Stargardt’s disease starts as this
presence of small, yellow spots in eye
With stargardt’s disease vision loss begins this way then quickly does this
slowly
escalates
Causes of stargardt’s disease
Very strong genetic component
Mutation of the gene ABCA4 (one of 21 genes coding for the retina)
Stargardt’s disease: 90% of the cases are this
autosomal recessive
Stargardt’s disease: Specific cause
a dysfunctional protein is made which does not allow normal transport of energy from the photoreceptors centered in the macula lutea
Stargardt’s disease: Lipofuscin build up can result in this
an imbalance between formation and disposal mechanisms in the eye, and is related to the muation in the ABCA4 gene
Stargardt’s disease: The gene is also associated with this
vitamin A processing
Stargardt’s disease: signs and symptoms
blurry/distorted vision loss of fine focusing difficulty recognizing familar faces can lead to blindness deterioration of light sensitive cells color vision affected in late stages
Stargardt’s disease: children with the disease will have difficulty doing this
reading
Stargardt’s disease: treatment
no cure
little can slow progression
wearing sunglasses may slow progression
avoiding excessive vitamin A and Beta-carotene
Stargardt’s disease: excessive vitamin A and Beta-carotene do this
promote accumulation of lipofuscin
Stargardt’s disease: prognosis
No cure
eventually leads to blidness in most cases
Stargardt’s disease: affects this many Americans, and has a frequency of this in children
25000 Americans
1 in 10000 children
Primary sex organs: male, females
testes
ovaries
Sperm and ovum are these types of cells and are denoted in this manor
gamates, haploid
n
Fertilization results in this
zygot
Sex chromosomes: male, female
XY
XX
The zygot grows through
mitosis
These develop in early male embryo
seminiferous tubules
intersitial cells
Indifferent gonads are found at this stage
early embryonic
This determines if indifferent gonads will form testes or ovaries, and results from this
TDF, testes determining factory.
SRY gene on Y chromosome
When do the ovaries develop in the embryo
follicles do not develop until third trimester
Testes produce these two things
testosterone
Mullerian inhibition factor (MIF)
MIF degenerates this
Paramesonephric (mullerian) duct
The paramesonephric (mullerian) duct becomes this in men, and this in woman
Degenerates in men
froms uterus and uterine tubes in females
Epididymides, ductus deferentia, ejaculatory ducts are formed from this in the presence of this
mesonephric (wolffian) duct
testosterone
This happens to the mesonephric (wolffian) duct in females
degenerates because there is no testosterone
other embryonic structures in the presence of testosterone become these
prostate
penis
scrotum
other embryonic structures without the presence of testosterone become these
vagina
labia
clitoris
At this time an ultrasound can be used to determine the sex of an embryo/child
12-13 week
Two structures that regulate gonadal function
hypothalamus
anterior pituitary
THis is released by the hypothalamust and affects this organ
gonadaltropic releasing hormone (GnRH)
anterior pituitary
THis is released by the anterior pituitary in response to GnRH
Gonadotropins (FSH and LH)
FSH stands for
folical stimulating hormone
LH stands for
Leutinizing hormone
T/F: FSH and LH are found in only females
F, found in both males and females
Gonadotropins act on this
gonads
What are the sex steroids
testosterone
estrogen
In the presence of gonadotropins the gonads release/produce this
sex steroids
inhibin
gamets
Sex steroids have this type of affect on the hypothalamus and anterior pituitary
negative
primary sex organ in the male
testis
testes produce this
sperm
Sperm moves from the testes to exit the penis through these structures (in order)
epididymis ductus (vas) deferens ampulla ejaculatory duct urethra
maturation of the sperm takes place in this structure
epididymis
the ampulla, seminal vesicle and prostate form this
ejaculatory duct
Important glands in the male reproductive tract
seminal vesicle
prostate
bulbourethral gland
The external urethral orifice is associated with this part of the penis
glans penis
Hormonally the imporant part of the male reproductive tract is his
testes
Testes contain this important structures
seminferous tubules
intersitital (leydig) cells
sperm is produced in this structure
seminiferous tubles
injected testosterone does this
negatively effects the hypothalamus and anterior pituitary causing FSH and LH to stop being released
shrinks testes
Process of producing sperm is known as
spermatogenesis
Steps of sperm production in the testes
some spermatogonia undergo mitosis
other spermatogonia undergo meiosis and form primary spermatocytes
Primary spermatocyes undergo meiosis and from secondary spermatocytes
secondary spermatocytes undergo meiosis and form spermatids
Spermatids mature into spermatezoa
The maturation from spermatids to spermatezoa is know as
spermiogenesis
Primary female sex organ
ovary
Important female reproductive structures
vagina
uterus
overy
uterine tubes
Eggs are release from the overies into this structure
uterine tube towards the uterus
Fertilization takes place here
uterine tube
The zygote develops here
uterus
How long is the egg viable after ovulation
24 hours
Sperm can live this long
36-48 hours within the female reproductive tract
Layers of the uterus
perimetrium
myometrium
endometrium
perimetrium tissue type and function
connective tissue
site of attachement to peritoneal cavity
myometrium tissue type and function
smooth muscle
contractions during labor to assist in delivery of fetus
endometrium tissue type and function
stratified squamous nonkeratinized epithelium; two layers stratum basale and stratum functionale
stratum functionale grows and sheds cyclically. site for implantation of zygote
Female has a limited number of these, that run out at about this time
oogonium
50 years old
Process of oogonium becoming a oocyte
oogonium becomes a primary oocyte
primary oocyte undergoes meiosis to from a polar body (degenerates) and a secondary oocyte
The secondary oocyte only becomes an ovum if this occurs
fertilization
Organ responsible for the formation of the ovum is know as
the follicle
This happens during each menstrual cycle to the follicle
8-10 grow in each overy
This many follicles will ovulate each menstral cycle
1
This hormone stimulates follicles to grow
FSH
When does ovulation occur in the menstrual cycle (days after the onset of bleeding)
day foeteen
Changes in the overy are mimicked by this
changes in the uterus (thickening in the stratum functionale)
This day is when implantation in the uterus will general take place
day 20
Endometriosis is
when the epithelial tissue is not shed from the vagina, but passes back into the uterine tube and back into the abdominal pelvic cavity then some endometral tissue may attach
Birth control: pill
some contain two hormones: estrogen and progestin called comination pills
some are progestin only pill.
most common type of pill
combination
Birth control: patch
Same hormones as in the pill
estrogen
progestin
Birth control: depo provera
long acting progestin from of birth control that is injected into the muscle every 11 weeks
Birth control: nuva ring
Over the course of 3 weeks NuvaRing releases a continuous low dose of estrogen and brogestin.
Hormone release is activated when contact with the vagina occurs
6 muscles of the eye
Superior/inferior rectus
lateral/medial rectus
superior/inferior oblique
Layers of the eye outside to in
Sclera
choroid
retina
The choroid is coated in this
melanin to prevent after images
Rods are responsible for this
dark vs light
cones are responsible for this
detail and color vision
This part of the eye is an extension of the brain
retina
this part of the eye contains all of the rods and cones
retina
What is the back portion of the eye by the optic nerve called
optic disk
There is no vision or blind spot here
optic disk
Layers of the eye through which light passes (out to in)
corneapupillensretina
colored portion of the eye
iris
this is in the middle of the iris
pupil
What helps us focus, and what is it made of
lensprotein
These attach the lens to the ciliary body
zonular fibers
What are the two chambers of the eye, relative to this structure
anterior chamber (infront) posterior chamber (behind)iris
This is in the anterior cavity and maintains the shape of the cornea
aqueous humor
This is the name of the fluid behind the lens, and has this physical property
vitreous humor
gel like to maintain shape behind the lens
T/F: the cornea is not a type of lens
F, its shape defracts lights towards the midline
If the object is close the lens tends to be
thicker
if the object is far the lens tends to be
flatter
accomadation is this process
the process by which we regulate the thickness of the lens
This ciliary muscle is this type of muscle
sphincter
The ciliary muscle is reponsablie for this
adjusting the conformation of the lens
Relaxation of the ciliary muscle does this to the lens
flattens
constrictuion of the ciliary muscle does this
makes the lens fatter
T/F:Looking at close objects far away fatigues the eye
F, close objects fatigue the eye
This is typically concidered far away for vision
15ft
The areas of greatest visual acuity occur at these 2 locations. These receptors are most present here
fovea centralis
macula lutea
cones
The iris does this
limits the amount of light that enters the eye
The iris is composed of these two types of muscles
radially and circulalry arranged smooth muscle fibers
Contraction of the radial muscles of the iris does this
opens (diolates) iris to allow more light in
circular muscles contracting int he iris do this
shrink the pupil allowing less light inot the eye
This nerve will constrict the radial muscles of the eye
postganglionic sympathetic axon from the superior cervical ganglion
this nerve will constrict the circular muscles of the eye
postganglionic parasympathetic axon from the oculomotor nerve
This happens to the image as it passes through the strucutres of the eye
its is flipped upside down, and left to right
Emmetropia =
normal visionrays focus on retina
Myopia =
nearsightedness
eye is to largerays focus infront of the retina
What corrects myopia
concave lens,
(-) diopter
diverging lens
Hyperopia =
farsightedness
eye is to smallrays focus behind retina
What corrects hyperopia
convex lens,
(+) diopter
converging lens
Astigmatism =
cornea is unevenly curvedrays do not focus
This causes patches of vision in focus and out of focus
astigmatism
What corrects astigmatism
uneven lens
This is used to discribe the direction in which the correction should be made for astigmatism
cylinder
Rods are most dense here
in the edges of the retina
cones are most dense here
fovea centralis
The cylinder discribes distortions in astigmatism at these points
distinct angles from the center of vision
cones use this to transmit detail
temporal summation
temporal summation requires this (eye)
higher light intensity
Rods use this to transmit signals
spatial summation
spatial summation requires this (eye)
lower light intensity
amacrine cells appear here
between bi-polar and ganglion cells
horizontal cells appear here
between photoreceptor and bi-polar cells
Amacrine and horizontal cells do this
modify synapses to enhance contrast associated with vison
Fibers of the optic nerve are formed by this
axons of ganglion cells
On this visible light spectrum red is here
700
on the viable light spectrum violet is here
400
ROYGBIV =
red orange yellow green blue indigo violet
Three types of cones
S (blue) cone
M (green) cone
L (red) cone
missing one of these types of cones is a condtion called
color blind
This test, tests for color blindness
ishihara test
The negative image test shows us this about photoreceptors
they adapt to stimulishows us the chemistry of rods and cones
These are the color compensations for a negative image test (3)
black -> white
Red -> green
blue -> yellow
Tapedum lucidem
refracts light to expose photorecpetors to more light
night vision in animals
accommodation
changes in optical power to maintain clear image or focus
Distance, light, zonular fiber, ciliary body, lens, and fatigue: Dilated pupil
Far distance Dim light tight zonular fibers relaxed ciliary body flat lens no fatigue
Distance, light, zonular fiber, ciliary body, lens, and fatigue: constricted pupil
close up bright light loose zonular fibers contracted cilliary body thicker lens high fatigue
Pathway of light entering the eye
cornea aqueous humor pupil lens vitreous humor retina
PHBAG
photoreceptors horizontal cells bipolar cells amacrine cells ganglion cells fibers of optic nerve
Negatvie afterimage is caused by this
over stimulation of the photoreceptors which lead to bleaching (light adapted)
diopters are this
the measurement of the refractive power of a lens
formula for diopters
1/focal length (m)
near point
closest distance at which one can see an object in sharp focus
Formula for a persons visual acuity
V = d/D d = distance at which the person can read the letters D = distance at which a normal eye can read the letters
Normal vision is rated at this
20/20
a person with less than average vision will have a rating such as
20/25
Snellen test
standard eye chart test
The instrument used to map the field of vision is call this
a perimeter
These are a continuation of the choroid
Suspensory ligaments that are attached marginally to ciliary bodies
This can provide important information about the anatomy of the inner eyeball
opthalmoscope
The view of the retina seen with an opthalmoscope is call this
fundus oculi
photopic vision
bright light - color vision
scotopic vision
dim light - night vision
This color spot is best used with an ophthalmoscope for these reasons
less irritating to the eye and displays the blood vessels more clearly
when using the ophtalmoscope a 0 appears on the windo if this occurs
subject and examiner are both normal (emmetropic) vision
