Z332 final Flashcards
1
Q
Primary sex organs
A
production of gametes and sex hormones
gonads = testes and ovaries
2
Q
secondary (accessory) sex organs
A
transporting and sustaining gametes
3
Q
hormones
A
chemical signals produced by endocrine (ductless) glands
long distance in blood and/or lymph
prolonged effects
4
Q
erectile tissue
A
corpus spongiosum and corpus cavernosa
5
Q
scrotal temp
A
normal body temp 37 C, scrotal temp ~3 lower
necessary for normal spermatogenesis, higher temps –> decreased fertility
6
Q
dartos and cremaster muscles
A
control surface area and distance from body
control scrotal temp
7
Q
pampiniform plexus
A
countercurrent heat exchange
network of veins and arteries, cool venous blood absorbs heat from arterial blood
8
Q
ways to control scrotal temp
A
dartos and cremaster muscles
pampiniform plexus
sweat glands
lack of fat layer
9
Q
cryptorchidism
A
undescended testes
typically descend from abdominal cabity 1-2 months before birth
unilateral or bilateral
reduced fertility and increased risk of testicular cancer
10
Q
seminal vesicle
A
60-70% vol of semen
bicarbonate (increase pH), prostaglandins, fructose, citrate, coagulating proteins, ions
11
Q
prostate
A
25% vol of semen
citrate (increase pH), enzymes break down clot, seminalplasmnin (antibiotic), ions
12
Q
bulbourethral gland
A
~1% vol semen
mucous/lubrication, increase pH to neutralize urethra
13
Q
benign prostatic hyperplasia (BPH)
A
enlargement of prostate, elderly men, hormone level change with age, risk of bladder infections, kidney damage
14
Q
prostate cancer
A
second most common cancer death, androgen dependent, cancerous tissue leaks more PSA (prostate specific antigen) into circulation
15
Q
spermatogenesis
A
400 million/day
in seminiferous tubules
diploid spermatogonia stem cells –> haploid sperm
spermatids to mature sperm: elongation, get rid of excess cytoplasm, form tail
16
Q
mitosis end product
A
2 daughter cells identical to each other and parent
diploid
produce cells for growth and repair
17
Q
meiosis end product
A
4 daughter cells genetically different from each other and parent
haploid
produce cells for reproduction = gametes (sperm and eggs)
18
Q
spermatogonia
A
diploid stem cell, divides by mitosis
19
Q
at puberty…
A
2 types of daughter cells (A and B) from spermatogonia mitosis
20
Q
type A daughter cells from spermatogonia
A
stays at basal lamina
21
Q
type B daughter cells from spermatogonia
A
moves toward lumen
becomes primary spermatocyte
22
Q
primary spermatocyte
A
goes through meiosis
23
Q
after meiosis I
A
2 haploid secondary spermatocytes
24
Q
after meiosis II
A
four total haploid spermatids
25
sperm head
mostly nucleus/DNA
| genetic
26
acrosome
contains hydrolytic enzymes for penetrating egg
27
midpiece of sperm
lots of mitochondria for energy
| metabolic
28
sperm tail
flagellum
| locomotor
29
leydig cells
secrete testosterone
30
sertoli cells
```
sustentocytes
supportive roles, nutrients
move cells to lumen
secrete testicular fluid
phagocytosis
chemicals to regulate spermatogenesis
blood-testis barrier
secrete ABP and inhibin (high sperm count = high inhibin)
```
31
blood-testes barrier
tight junctions between sertoli cells
maintains environment
excludes toxins
prevents sperm antigens from entering blood
spermtogonia are outside barrier
type B daughter cells pass through junctions
32
epididymis
where sperm are collected and mature
33
sperm stored in
ductus deferens
34
path of sperm
seminiferous tubules, epididymis, ductus deferens, urethra
35
hypothalamic - pituitary - gonadal axis
hypothalamus --> anterior pituitary --> gonads --> sex hormones
36
releasing hormones in hypothalamic - pituitary - gonadal axis
secreted by hypothalamic neurons, stimulate pituitary
37
tropic hormone in hypothalamic - pituitary - gonadal axis
regulated activity of other endocrine organs
38
GnRH
gonadotropin-releasing hormone
39
FSH
follicle-stimulating hormone
| stimulates sertoli cells to secrete ABP (keep T concentration high around spermatogenic cells)
40
LH
luteinizing hormone
stimulates leydig cells to secrete T and little estrogen
elevated T triggers spermatogenesis
41
endocrine control
hypothalamus --> anterior pituitary --> testes --> testosterone secretion and other effects
42
testosterone
development of male reproductive structures depends on prenatal secretion of male hormones
maintains sex organs (low T = low fertility)
secondary sex characteristics
some converted to estrogen or DHT
43
clitoris homologous structure
glans penis and corpus cavernosa
44
labia majora homologous structure
scrotum
45
labia minora homologous structure
spongy urethra
46
paraurethral gladn homologous structure
prostate gland
47
bulb of vestibule homologous structure
corpus spongiosum
48
grater vestibular gland homologous structure
bulbourethral glands
49
SRY region
on Y chromosome, master switch
| initiates testes development
50
XO
turners syndrome
| female w/o ovaries
51
XXY
klinefelter's syndrome
| male, usually sterile
52
YO
males die during development
53
wolffian duct
future male duct
54
mullerian duct
future female duct
55
differences in external genitalia are largely driven by
production of DHT in the dermal layers of urethral folds and labioscrotal swellings
56
females produce eggs (follicular maturation) and males produce sperm in response to
FSH
57
endometrium
stratum basalis and stratum functionalis
| sf sloughed off during menstruation
58
menstrual cycle
changes in endometrium in response to varying ovarian hormones
constriction of blood vessels = oxygen deprevation and cells die
sloughing of stratum functionalis
59
ovulation at day
14
60
phases of menstrual cycle
menstrual flow : 1-5
proliferative phase: 5-14
ovulation: 14
secretory phase: 14-28
61
oogenesis
years to complete
lifetime supply of primary oocytes at birth
only ~500 released over life
62
steps in oogenesis
```
diploid oogonia (stem cell) divides by mitosis
oogonia gradually turn into primary oocytes which start meiosis but arrest early
each month 1 primary oocyte continues through meiosis
```
63
meiosis of primary oocyte results in
2 unequally sized haploid cells: secondary oocyte and first polar body
64
secondary oocyte
arrests in metaphase II of meiosis
this is ovulated cell
if no sperm penetration - deteriorates
sperm penetration - completes meiosis resulting in large ovum and small secondary polar body
65
end result of secondary oocyte meiosis
three small polar bodies and 1 large ovum
66
primordial follicle surrounds
primary oocyte
67
proliferation of cells -->
secondary follicle
| granulosa cells interact w/ oocyte
68
late secondary follicle
extr cells, connective tissue layer
69
vesicular (graafian) follicle
fluid filled cavity (antrum) forms
70
2 phases of ovarian cycle
follicular and luteal
| whole ovarian cycle ~28 days
71
luteal phase
ruptured follicle collapses after ovulation
| remaining granulosa cells enlarge to form corups luteum (endocrine structure)
72
corpus luteum
no pregnancy: degenerates, stops producing hormones, forms corpus albicans
pregnancy: persists (until placenta is producing hormones) due to hCG secretion from embryo's chorion
73
endocrine control (female)
hypothalamus --> anterior pituitary --> ovaries --> estrogen secretion and other effects
74
LH
triggers ovulation, production of E2
75
follicles release
E2 and inhibin
76
corpus luteum releases
E2, P4, inhibin, and relaxin
77
both LH and FSH stimulate
follicles to secrete estrogen
78
E2
estrogen
79
P4
progesterone
| from corpus luteum
80
3 phases in female reproductive cycle
menstrual, preovulatory, postovulatory
81
menstrual phase
~5 days, stratum functionalis sheds (50-150ml blood, tissue fluid, mucus, cells)
E2 and P4 low: inhibition of GnRH, FSH, and LH
82
preovulatory phase
variable in length, dominant follicle secreting E2 --> stimulates regeneration of stratum functionalis (endometrium )
cervical mucus thins
ovulation at end of this phase
83
ovarian cycle=
menstrual phase and preovulatroy phase
84
ovulation
follicle is almost mature it releases more and more estrogen under influence of LH
high levels of E2 exert positive feedback on Hypo/Ant. Pti. --> LH surge --> ovulation
85
postovulatory phase
ruptured follicle collapses = corpus luteum (influenced by LH, produces E2, P4, etc)
86
lack of P4-->
menstruation
87
E2 and P4 inhibits
FSH
88
corpus luteum releases P4 -->
slight increase in temp
89
hCG
human chorionic gonadotropin
| home pregnancy kits detect this
90
4 stages of sexual response cycle
desire
arousal
orgasm (emission, ejaculation) - shortest, intense
resolution
91
flaccid
at rest vessels constricted
92
during erotic stimulus....
NO from parasympathetic nerves dilates arteries = increase blood flow
veins cannot drain --> erection
93
emission and ejaculation from _____reflexes
sympathetic and somatic
94
Viagra
phosphodiesterase inhibitor increases nitric oxide
95
emission stage of male orgasm
sympathetic response of moving sperm and semen through ducts
96
capacitation
sperm becoming motile
undergo capacitation in female reproductive tract after insemination
2-10 hours
acrosome membrane weakens
97
oxytocin
increases muscular contractions during ejaculation
98
resolution phase
```
sympathetic signals constrict artery and reduce blood flow to penis
cardiovascular and respiratory responses back to normal
refractory period (~10 mins to few hours)
```
99
estrogen
development, maintenance of female reproductive structures
secondary sex characteristics
lower blood cholesterol
100
progesterone
prepare/maintain endometrium for implantation
| prepare mammary glands
101
proliferative phase of menstrual/uterine cycle
functional layer of endometrium is rebuilt
102
secretory phase of menstrual/uterine cycle
begins immediately after ovulation, enrichment of blood supply and glandular secretion of nutrients prepare endometrium to receive an embryo
corresponds to luteal phase
103
menstrual phase + proliferative phase =
follicular phase
| before ovulation
104
fertilization in
ampulla of fallopian tube
105
cervix has grooves and mucous that filter
most well developed sperm for entry (millions in vagina, only thousands make it too uterus)
106
flowback
in 94% of copulation
| less than 1% of sperm might be retained in female reproductive tract
107
uterine contractions & orgasm
draw sperm and watery midcyclle mucus from cervix to uterus
108
max sperm retention when
female climax >0-1min post ejaculation
109
testes size comparisons
gorilla, orangutan, human, chimp
110
___ fuels competition
testosterone
111
the presence of an attractive woman....
elevates testosterone and physical risk taking in young men
112
females initiate sex more in ______ phase
ovulatory
113
higher average ___ in women who orgasmed
testosterone (orgasm didn't lead to elevated T)
| high T pre and post intercourse
114
multiple partners associated with _____
higher testosterone
115
once ovulated, oocyte in viable for
12-24 hours
116
"obstacle course" sperm must travel through
flowback
harsh environment (low pH, viscosity, immune)
distance
finding the egg (which tube)
117
fertilization
when sperm and egg combine to form zygote
move toward egg due to chemical cues
not first sperm to reach egg
118
path of sperm cell during fertilization
corona radiate, zona pellucida (acrosomal reaction), plasma membrane of secondary oocyte, cytoplasm of secondary oocyte
119
after sperm penetration
oocyte completes meiosis II
sperm and ovum nuclei swell forming pronuclei
pronuclei approach each other and mitotic spindle forms between them
chromosomes intermix, DNA replicates
120
cleavage
rapid mitotic division
121
implantation
begin 6-7 days after ovulation
| blastocyte implants on endometrium
122
developing zygote secretes hormones to
maintain corpus luteum
123
embryo gets nutrients from ____
endometrium until placenta is formed
124
placenta gets nutrients from
maternal blood by diffusion
| active transport - maternal and fetal blood do not mix
125
maternal effects of pregnancy
increased MR, blood volume, urine production, uterus size, mammary gland production
126
rising fetal _____ stimulates placental E2
adrenocortical hormones (ex: cortisol)
127
____ stimulate uterine muscle contraction
oxytocin and prostaglandins
128
hormone axis
causal chain of events and structures that lead to an outcome
hypothalamus, pituitary, trop hormones, gland, hormone, target cells
129
intercellular communication
direct - gap junction
endocrine - hormones
synaptic - neurotransmitters
paracrine- extracellular fluid
130
lipid-soluble hormones
hydrophobic
steroids, thyroid hormones, gases
can pass through membrane
bind to transport protein to travel in blood
131
water-soluble hormones
hydrophilic
amines, peptides
travel alone in bloodstream
must bind to receptor on cell membrane
132
all major hormones circulate to...
nearly all the body's tissues
133
_____determines whether a hormone acts on a cell
presence or absence of specific receptors (a protein)
| receptors can promote or inhibit transcription of different genes
134
target cell
cell that has a particular hormones receptors
| ex: cell with testosterone receptors is a target cell of T
135
____ often affect gene expression within the cell
lipid soluble hormones
| receptors can promote or inhibit transcription of different genes
136
direct gene activation
steroid hormone diffuses in and binds an intracellular receptor
receptor-hormone complex enters nucleus
receptor-hormone complex binds specific DNA region
binding initiates transcription of the gene to mRNA
the mRNA directs protein synthesis
137
second-messenger signaling systems
only method water soluble hormones can act; but both lipid and water soluble can use
can have large effects - signal amplification
138
responsiveness of cell depends on
hormone concentration
abundance of receptors for hormone
strength of binding
influences of other hormones: permissiveness, synergistic, antagonistic
139
duration of hormone action
usually released in short bursts
increased stimulus = more frequent bursts = increase in concentration
concentration controlled via negative feedback (usually)
140
most hormones subjected to ____ in target tissues and liver
enzymatic degradation
| --> inactivated, exreted
141
pituitary gland
hypophysis
| most important/master endocrine gland b/c it secretes tropic hormones
142
hypophyseal portal system
tropic hormones of anterior and posterior pituitary enter blood through hypophyseal portal system
artery --> capillary bed
vein --> capillary bed
eventually to heart and whole body
143
humoral stimulus
hormone release caused by altered levels of certain critical ions or nutrients
144
neural stimulus
hormone release caused by neural input
145
hormonal stimulus
hormone release caused by another hormone (a tropic hormone)
146
protein bound hormones cannot diffuse easily out of capillaries so they must...
dissociate to become biologically active
147
steroid hormones are synthesized from
cholesterol
148
in bloodstream, most testosterone is bound to
transport proteins
149
hypothalamic pituitary adrenal axis (HPA axis)
```
hypothalamus
CRH
pituitary
ACTH
adrenal cortex
cortisol (glucocorticoid)
target cells
```
150
prednisone
synthetic glucocorticoid
151
cushing's syndrome
excess glucocorticoids
insomnia, severe fatigue, weak muscles, high bp and blood glucose, thirst, anxiety, depression, fatty hump between shoulders
similar symptoms to chronic stress and/or side effects of synthetic glucocorticoids
152
hypothalamic pituitary thyroid axis (HPT axis)
```
hypothalamusactive
TRH
pituitary
TSH
thyroid
thyroxine (T4) and triiodothyroine (T3)
target cells
```
153
metabolism
sum total of body's chemical reactions
154
production of thyroid hormones
in thyroid follicular cells
iodide oxidized and added to thyroglobulin
results in T1 and T2, combine to form T3 and T4
T4 greater quantity, converted to T3
T3 is most biologically
155
thyroid hormones bind to
intracellular receptors
156
only gland that stores large amounts of its hormones
thyroid
157
thyroid hormones increase
basal metabolic rate and o2 consumption
158
thyroid hormones regulate
tissue growth and development and reproduction
| blood pressure, body temp
159
grave's disease
hyperthyroidism
| anxiety, breast enlargement in men, difficulty concentrating, double vision, etc.
160
goiter
enlargement of thyroid gland, due to hyper or hypothyroidism
161
cretinism
severe hypothyroidism in infants, mental retardation and physical abnormalities
162
growth hormone axis
```
hypothalamus
GHRH
pituitary
hGH
liver
IGF
target cells
```
163
inhibits release of tropic hormone
inhibiting hormone , GHIH
164
growth hormone effects
increases rate of protein synthesis
mobilization of fatty acids
decreases glucose utilization
acts synergistically with insulin
165
acromegaly
excess GH during childhood, growth of cartilage and membranous bone
166
lack of IGFs in African pygmies results in
smaller stature, but still sexually mature
167
ADH
antidiuretic hormone, vasopressin
168
stored and released from posterior pituitary
ADH and oxytocin
169
ADH produced by
hypothalamus
170
role of oxytocin
female: childbirth, uterine contractions
male: ejaculation
171
oxytocin is both...
hormone and neurotransmitter
| the love drug- monogamous and promiscuous voles..
172
as a hormone, oxytocin promote
general trust and cooperation
173
melatonin
antioxidant
maintains circadian rhythmicity, reflects day length
seasonal changes
pineal gland receives indirect input from SCN
hypothalamus --> reduce GnRH (inhibits reproductive function, many influence time of sexual maturation)
174
SCN
suprachiasmatic nucleus
biological clock
photoreceptive optic gangial project to SCN from retina, then to pineal gland
175
seasonal affective disorder
SAD
symptoms appear in fall-winter
depression, anxiety, social withdrawal, weigh gain
176
alpha cells
from pancreas
glucagon
stimulates glycogen breakdown
177
beta cells
from pancreas
insulin
stimulates glycogen formation
178
diabetes mellitus
blood glucose concentration increase
cell use of glucose decreases
increase use of fat and protein
179
type 1 diabetes
insulin dependent diabetes mellitus
caused by lack of insulin
auto immune disorders, viral infection, hereditary tendency for beta cells to degenerate
180
type 2 diabetes
non insulin dependent diabetes mellitus
| caused by lack of sensitivity of target cells to metabolic effects of insulin = insulin resistance
181
adrenal gland
steroids: mineralcorticoids (zona glomerulosa), glucocorticoids (zona fasciculate), androgens (zona reticularis)
amine derivatives: epinephrine and norepinephrine
182
medulla
epinephrine and norepinephrine from chromaffin cells
stimulus: innervation by sympathetic NS
target: everything, enhances sympathetic response
183
stress response
combined action of ANS and endocrine system
increase heart rate and force
constriction of blood vessels of viscera and skin
dilation of blood vessels in heart, lungs, brain, skeletal muscle
contraction of spleen
glycogen to glucose in liver
sweating
dilation of airways
decrease digestion
water retention
184
sustained stress can lead to
disease: IBS, ulcers (facilitated not caused), hypertension, anxiety/depression, migraines, suppressed immune function, 2/3 of people overeat
185
myocardial ischemia
once coronary arteries damaged, they vasoconstrict in response to stress (usually dilate)
186
chronic stress
distress
| disrupts homeostasis
187
eustress
maintains homeostasis
188
calcitonin
released from thyroid gland
stimulus: increased Ca
effect: inhibits osteoclasts to decrease Ca levels
189
parathyroid hormone (PTH)
stimulus: low Ca
effects: stimulates osteoclasts to increase Ca, acts on kidneys to slow low of Ca and Mg in urine, promotes formation of calcitrol (vit D3) to increase absorption of Ca, Mg and Po4 in GI tract
190
thymus
hormones function in development and maintenance of immune system
thymosins
191
thymosins
promotes development and maturation of T-lymphocytes (WBC)
192
menopause
no more primordial follicles left to develop
193
sex determination
sperm: X or Y
eggs: X or X
Y chromosome contain SRY gene, codes for protein that stimulates AMH (anti-mullerian hormone)
female by default, no Y then feminized
194
androgen insensitivity syndrome
XY, CAIS (complete, androgen, insensitivity)
| external genitalia are female
195
simplest eye has
photoreceptor, dark pigment, connection to motor structures
196
cup eye,
detects intensity and direction of light, planaria
197
compound eye
detailed images, fly
198
camera eye
detailed images, human
199
a patch of light sensitive cells could evolve to....
complex eye in ~360,000 generations (few hundred thousand years)
complex eye has evolved more than once
200
lateral rectus
abducens
201
superior oblique
trochlear
202
lacrimal gland
CN VII (facial)
203
eye blink nerve
facial VII
204
fibrous tunic
cornea and sclera
| avascular connective tissue
205
conjunctiva
covering sclera, vessels
206
vascular tunic
choroid, ciliary body, iris
| action during accommodation
207
neural tunic
retina
208
cornea easily transplanted w/o rejection because
avascular
209
sclera is continuous with
dura mater on posterior side
210
glaucoma
eye disorder in which optic nerve suffers damage, permanently damaging vision in affected eye, progressing to complete blindness. associated with increased pressure of fluid in eyes
211
aqueous humor produced
via filtration at ciliary processes, flows through eye, reabsorbed via scleral venous sinus (canal of schlemm)
212
DNA identification
vitreous humor can be helpful
213
zonular fibers of lens
suspensory ligaments
214
pupil constriction
parasympathetic
| sphincter pupillae muscle contracts
215
pupil dilation
sympathetic
| dilator pupil muscle contracts (radial muscle?)
216
tapetum lucidum
reflective layer within choroid
helps with night vision
not in humans
217
red eye
due to reflectance of light from camera flash on blood vessels at back of eye
218
crystallins
in lens, proteins
219
cataracts
lens becomes cloudy due to clumping of crystallins
220
accommodation
change in lens shape to focus on near object
increases refractory power
sympathetic activation
CN III oculomotor
(when ciliary muscle relaxes, the suspensory ligaments stretch on lens which flattens it)
when ciliary muscle contracts, less pressure to stretch lens so gets fat - convex = focus closer
221
refraction
bending of light as it encounters a medium of different density
refracted most when entering cornea
refracted again when entering lens, gets directed to focal point on retina
222
astigmatism
curvature of cornea or lens varies from one axis to another, images appear distorted
223
nearsighted
eye ball too long
224
farsighted
eye ball to short
225
concave lens
diverges light , focus on farther image
226
convex lens
converges light, focus on closer image
227
nearsighted needs ___ lens
concave
228
farsighted needs
convex lens
229
lasik surgery
reshaped cornea, affecting focal point of light
230
2 layers of retina
pigmented layer: prevents light scatter, sores vit A
| neural layer: contains photoreceptors, bipolar cells, ganglion cells
231
detached retina
separation of pigmented and neural layers
vitreous humor seeps in
blindness if not treated - lack of nutrients for photoreceptors
232
photoreceptors get nutrients from
pigmented layer of retina and from choroid
233
rod photopigment
rhodopsin (retinal + opsin )
234
cones photopigment
photopsin (retinal + an opsin)
3 different opsins - one for each color
one type of opsin per cone
235
cones color
red, green, blue
236
fibers going to hypothalamus (suprachiasmatic nucleus) help regulate
circadian rhythm
237
olfactory cilia
mostly nonmotile, increase surface area
238
olfactory receptors
olfactory sensory neurons, bipolar, lifespan 30-60 days
239
nasal epithelium innervated by
CN VII facial
240
odorants...
must be volatile (airborne) and dissolve in fluid coating olfactory epithelium
bind to receptors, G protein pathway activated and cAMP gated channels opens
most active more than one receptor, most receptor can respond to more than one odorant
241
olfactory transmission...
Na and Ca enter cell
impulse transmission due to Na entry
Ca has role in olfactory adaptation
242
olfaction pathway
only sensations that go directly to cerebral cortex w/o first synapsing in thalamus
some axons go to limbic system and hypothalamus (emotional memory)
orbitofrontal area: odor identification and discrimination
243
4 types of papillae
vallate, fungiform, follate, filiform
244
papillae that have tastebuds
vallate, fungiform, follate
245
tastes
```
sweet - sugar and alcohols
sour - acids, H+
salty - metal ions, NaCl
bitter - alkaloids, caffeine
umami- glutamate and aspartate
```
246
gustatory epithelial cell
```
receptors/ taste cells
gustatory hairs (microvilli) extend through pore, contact saliva
```
247
tastants
chemicas, must dissolve in saliva to inteact with hair and cause transduction
248
transduction mechanism different for different tastes...
salty: influx of Na depolarized cells
sour: H+ acts intracellular to open cation channels
bitter, sweet, umami: receptor coupled with G protein (gustducin), Ca released, cation channels open
249
higher amplitude of sound =
louder
250
each 10dB increase is
10x increase in intensity
251
threshold of human hearing
0-120 (painful )
252
short wave
higher frequency, higher pitch
253
human hearing pitch range
20-20,000
| most sensitive between 1500-4000
254
cerumen
earwax, helps remove debris
255
auditory tube
pharyngotympanic tube = Eustachian tube
| swallowing or yawning opens tube to equalize pressure in middle ear w/ external pressure = ear popping
256
evolutionary history of ear bones
stapes from 2nd gill arch
| malleus, incus, tympanic annulus from 1st gill arch
257
stapedius muscles and tensor tympani muscles
contract reflexively in response to loud sounds, limits vibration of ossicles and helps prevent damage
258
bony labyrinth
```
cavity with 3 regions (vestibule, semicircular canals, cochlea)
contains perilymph (continuous with CSF)
```
259
membranous labyrinth
```
sacs and ducts lining body labyrinth, suspended in perilymph
contains endolymph (high K concentration)
```
260
vestibule
contains utricle and saccule, oval window
261
semicircular canals
one in each plane, semicircular ducts
262
cochlea 3 compartments
scala vestibule: continuous with vestibule, abuts oval window
scala meida: cochlear duct
scala tympani: ends at round window
263
scala tympani and scala vestibule join at
helicotroma (apex of spiral)
264
high frequency sound displace basilar membrane
near base
265
medium frequency sounds displace basilar membrane
near the middle
266
low frequency sounds displace basilar membrane n
near apex
267
each hair cells has
numerous stereocilia linked together and a single kinocilium
268
movement of basilar membrane bends stereocilia...
toward kinocilium = opens cation channel, K and Ca flow in, = graded depolarization
away from kinocilium - channels close, repolarization
269
perception of loudness
more movement of membrane = more frequent APs
270
conduction deafness
problems with sound conduction through inner ear fluids
| blockage, ruptured eardrum, middle ear infection, otosclerosis
271
sensorineural deafness
damage due to neural structures (hair cells to auditory cortex)
loss of hair cells throughout life or due to prolonged exposure to loud noises or single explosive loudness
degeneration of cochlear nerves, strokes, tumors, etc.
272
static equilibrium
senses position of body relative to force of gravity (linear acceleration)
directed by maculae in utricle (horizontal movement) and saccule (vertivle)
stereocilia and kinocilium project into otolith membrane
otoliths add weight and inertia
273
dynamic equilibrium
maintenance of body position in response to rotational acceleration
orientation of semicircular canals,
crista ampullaris
274
equilibrium organs
vestibular apparatus (vestibule and semicircular canals)
saccule (macula) - vestibule
utricle (macula) - vestibule
ampulla of semicircular ducts/canals (cupula)
275
vestibular apparatus
sends warning signals, does not automatically correct/compensate for forces of equilibrium
