Unit I COPY Flashcards
1
Q
four functional classifications of chemical messangers
A
- paracrine
- autocrine
- neurotransmitters
- hormones
2
Q
what hormones are produced in the anterior pituitary in response to GnRH?
what hormones will GnRH produce?
A
FSH and LH
androgens and estrogens
3
Q
two examples of leaky epithelia
A
- small intestine
- proximal convoluted tubule
4
Q
how can we increase current, flow, or flux
A
increase the driving force or decrease the resistance
5
Q
what happens to Vmax if the number of receptor proteins is doubled
A
the Vmax will also double
6
Q
ovum pickup
A
the process by which a ovulated mature oocyte is released by the ovaries and picked up by the fallopian tubes
7
Q
leptin
A
a peptide secreted by adipocytes that regulates eating behavior, energy, and reproduction
8
Q
how does stimulation frequency effect contraction strength
A
more frequent stimulus can result in summation of contractions
9
Q
at what Vm do funny channels open
A
-50mV
10
Q
at RMP, what is the driving force behind Na flux?
what is that called?
in what direction does it move?
negative or positive
A
the sum of the chemical energy from high Na concentrion outisde the cell and the electrochemical attraction to the anions in the cell
the electrochemical gradient
into the cell
negative
11
Q
T/F graded stimulus can activate individual fibers of a motor unit
A
false, motor units are all or none
12
Q
what can be used in place of conductance? why?
A
the number of leak channels available for a particular ion
because conductance is a measure of membrane permeabilty, and the only place a membrane is passively permeable to an ion is at a leak channel
13
Q
what is the primary function of amino acid messangers
A
neurotransmitters in the CNS
14
Q
what type of receptor is tyrosine kinase?
what does it do?
A
a fast response enzyme
when bound with a protein ligand it allows for the production of PTP, which affects intracellular change
15
Q
what is a normal ICF and ECF for potassium
A
ECF: 4.5 mM
ICF: 150mM
16
Q
two parts of the basolateral membrane
A
- serosal membrane
- peritubular membrane
17
Q
describe the variables and what this equation means (3)
A
- the electrochemical difference is the the driving force behind passive diffusion
- the electrochemical difference is the sum of the chemical energy difference and electrical energy difference
- z = valence of the ion, F = .023kcal/mol *mV, psi1 - psi0 = the membrane potential
18
Q
what hormonal activity signals the start of puberty
A
nocturnal secretion of GnRH
19
Q
Follicle cohort
A
all of the recently activated follicules stimulated by FSH
20
Q
primary endocrine organ
A
an organ whose only job is to secrete or store ligands
21
Q
eicosanoids
A
paracrine ligands derived from arachidonic acid produced by virtually all cels of the body
22
Q
channell
A
a gated pore that can be opened or closed
23
Q
what are three functions of potassium channels
A
- Terminate action potentials
- modulate electrical excitability
- stabilize the resting potential
24
Q
how is the “leading follicle” chosen from the follicle cohort?
how does the criteria change as the mother ages
A
the follicle that tolerates the decline in FSH is considered the leading follicle
younger mothers select the fittest follicle, older mothers select the first follicle that is activated
25
what are the two mechanisms of intercellular communication
direct and indirect
26
equilibrium potential
the membrane potential that will counteract the driving force behind a concentration gradient for a certain ion
27
resting membrane potential for a neuron
-70mV
28
what are the four determinants of gender
1. genetic
2. gonadal
3. ductal
4. genital
29
how does caffiene influence energy production
it inhibits the action of phosphodiesterase, stopping it from breaking down cAMP into AMP to stop protein phosphorylation
30
what happens when a woman has no more eggs
menopause
31
what happens when extrogenous FSH is given during selection of the dominant follicle?
when might this be useful
more follicles survive the selection phase to ovulate
IVF to harvest more eggs
32
what hormone would be absent with a lack of pubic hair
androgens
33
what are 5 types of steroid ligand
1. glucocorticoids
2. mineralocorticoids
3. androgens
4. estrogens
5. progestines
34
GnRh
gonadotropin releasing hormone
35
I = V/R
what is this? what are the variables?
Ohms law
I = Current
V = voltage difference
R = resistance
36
four examples of tight epithelia
1. distal portion of the distal convoluted tubule
2. collecting duct
3. large intestine
4. urinary bladder
37
what is happening in the plateau phase of an isotonic contraction
there is no more tension being produced because the load is moving by shortening muscle fibers
38
direct intercellular communication
when ions and molecules pass directly from the cytoplasm of one cell to another
39
why does menopause cause hot flashes
no estrogen production stimulates increased GnRH production
increased hypothalamic activity causes the hypothalamus to assume core temp is too high
40
how is the process of calcium release into t tubules different for cardiac muscle?
what is the alternative?
there is no mechanical binding
calcium for L type calcium channels binds to the calcium release channels, stimulating ion current
41
if follicles are activated every day, what happens to the activated follicles?
they die unless in the follicular phase (FSH is present)
42
what is happening during the latent phase of an isometric twitch
there has been a stimulus received by the muscle but no calcium release until the end of the latent phase
43
how can low thyroid cause an increase in estradiol
low T3/4 will not give negative feedback to the hypothalamus/pituitary to inhibit TRH and TSH
TSH can cross reaction with FSH and LH receptors to stimulate the production of estradiol
44
how much estradiol needs to be present for ovulation to occur
200 picograms/mL for 24 hrs
45
a patient with precocious puberty needs treatment, what are two options and why would they be effective
1) estrogens, because it will suppress GnRH production but won't decrease estrogen
2) GnRH antagonists to down regulate GnRH receptors in the pituitary, deceasing FSH and LH production
46
secondary endocrine organs (6)
1. heart
2. liver
3. stomach
4. small intestine
5. kidney
6. skin
47
rin
the viscocity of the cytoplasm
48
basolateral membrane
the epitheial cells surfaces that face adjacent cells or toward the underlying connective tissue
49
tight epithelia
cell junctions that maintain large ion concentration and osmotic gradients
50
coulombs law
the attraction between two ions increases or decreases based on charge and decreases the further apart two ions are
51
what happens to ECF and ICF with an infusion of NaCl
ECF experiences an increase in osmolality, causing solute to difuse into the ICF
52
when does osmotic work occur
during active transport with the Na/K pump
53
CRH
corticosteroid releasing hormone
54
what two factors influence conduction velocity and how do they relate to the length constant
1. diameter of the cell (viscosity)
2. presence of myelin (membrane resistance)
55
what would happen if a 30 yr old person were given high doses of testosterone
estrogen would increase through aromatase
increased estrogen and testosterone would decrease FSH and LH
decreased FSH and LH would lead to a lower sperm count
56
what are three possible causes of primary ovarian failure
1. turners syndrome
2. gonadal dysgenesis
3. premature menopause
57
what two potassium channels are in the Kv family?
what do they do
delayed outward and transient outward rectifiers
they allow potassium flux out of the cell to return the cell to RMP
58
what currents are in play during each phase of the cardiac pacemaker action potential
phase 4: If, ICaT, IKv1.1
phase 0: ICaL
phase 3: IKv1.1
59
pores
intergra membrane proteins that for conduits that are always open
60
leaky epithelia
cell junctions cannot maintain large gradients and are used for bulk transport of solute and water
61
unfused tetanus
when summation produces an average constant tension between contractions
62
what two hormones are secreted by sertoli cells
1. androgen binding hormone
2. mullerian inhibiting hormone
63
what direction does a negative delta G move
into the cell
64
what does a nicotinic receptor do on skeletal muscle
opens ion channels, allowing Na and K into the cell, which depolarizes the cell membrane
65
relative refractory period
the interval when a second AP can occur but requires a stronger than normal stimulus
66
synergistic hormone effects (example)
two hormones with the same action but the combination of their effect is greater than there individual sums
(GH and insulin)
67
net diffusion potential
the membrane potential created by movement of ions through leak channels
68
what are two types of cells that always have aquaporins (AQP1)
1. RBCs
2. Renal proximal convoluted tubule
69
at a subsaturation point for different ligands, which will bind more readily to the receptor
the ligand with the highest affinity
70
tertiary ovarian failure
hypothalamic failure to produce GnRH
71
describe the entire process of cross bridge cycling
1. myosin is at rest at right angles to actin, bound to ADP and P
2. myosin binds to actin at binding sites, releasing ADP and P
3. unbound myosin heads change confirmation and shift to a 45 in relation to actin
4. ATP binds with myosin to uncouple it from actin
5. ATP is hydrolyzed into ADP and P to return the head to a 90 deg rest position
72
what are three types of potassium channels
1. delayed outward rectifiers
2. transient outward rectifiers (A type)
3. inward rectifiers
73
what tyoe of ligand are thyroid hormones
amines
74
maximal stimulus
the lowest stimulus that will produce maximal force production
75
six steps for how adenylate cyclase produces a cellular response
1. catecholamines bind to adrenergic receptor
2. receptor releases GDP
3. GTP binds to adenylate cyclase
4. GTP + ATP + adenylate cyclase produces cAMP
5. cAMP activates protein kinase A
6. protein is phosphorylated
76
slow response receptors
receptors that are not bound to their effector and need an intermediary G protein to for a response
77
how can you have two different ligands with the same Vmax but differet KM
KM is based on affinity between the receptor ligand, Vmax is a measure of saturation point.
78
how are voltage gated sodium channels responsible for rapid depolarization
they open and close quickly, allowing the amount of Na moving into the cell to change very fast
79
ACTH
adrendocorticotropic hormone
80
what is happening during phase 0 in a pacemaker cell? what is the cause
upstroke
ICaL brining calcium into the cell through L type channels raises the Vm
81
series elastic component
the non-contractile parts of a cell and the tendons which produce force against stretch
82
what happens hormonally during ovulation
there is a surge in LH
83
name and describe the axis that produces thyroid hormone
thyroid axis
1. TRH is secreted by the hypothalamus into the blood
2. TRH stimulates the anterior pituitary to produce TSH
3. TSH released into the blood acts on the thyroid to produce TH
84
relate elasticity and compliance to a real world object
a rubber band is compliant because it will stretch, and elastic because it will produce force to counteract stretching force and return it to its original shape
85
around what percent of maximum is power the highest
35%
86
T type calcium channels
transient type channels, create a more rapid response
87
what ligands are transported in blood
hormones
88
what is the primary estrogen
estradiol
89
what is the ductal determinant between males and females
females will have muellarian ducts, men will have vestigial muellarian ducts and prominent wolffian ducts
90
what is the action of IP3 produced by phospholipase C in the cell? what process is started
IP3 binds to ion channels on the smooth ER which release Ca, which binds to calmodulin, allowing for the production of protein kinase
91
what three events happen during the luteal phase
1. progesterone production
2. corpus luteum apoptosis
3. Luteal rescue by HCG
92
three parts of the apical membrane
1. brush border
2. mucosal membrane
3. luminal membrane
93
TRH
thyroid releasing hormone
94
what is the function of Ca in excitation-contraction coupling
it links excitation with coupling by binding to troponin to move tropomyosin off myosin binding sites, allowing for activation
95
what is happening during the relaxation phase of an isometric twitch
calcium is being pumped out of the cytoplasm to slow down cross bridge cycling
96
from an energy standpoint, what is a concentration gradient
store potential energy
97
what is the key andogren for skin and prostate
DHT
98
IKir
inwardly rectifying potassium current
99
dopamine
100
what is an example of carrier mediated transport
facilitated diffusion
101
what are three functions of the fallopian mucosa
1. produce suppportive secretions for the egg and sperm
2. help the egg and sperm move
102
what degrades hormones? are intracellular or extracellular hormones more quickly broken down
enzymes
lipophobic (extracellular) are broken down more quickly
103
what causes menopause
primary ovarian failure
104
what is the "triad" of cell structures that participate in propogation of action potentials between muscle cells
the sarcoplasmic reticulum of two cells sandwiching a T tuble
105
gibbs donnan forces
the attraction between extracellular cations to intracellular bound anions
106
what causes skeletal muscle excitation
neuromuscular somatic synaptic transmission
107
what is the length and standard deviation of a normal menstrual period?
28 +/- 3 days
108
amenorrhea
absence of menstration
109
what is electrochemical gradient for sodium at rest
-3.29 kcal/mol
110
antagonistic hormone interaction (example)
two hormones that have opposite effects (insulin and glucagon)
111
what is the difference in excitation-contraction coupling between skeletal and cardiac muscle cells
muscle cells use mechanical coupling between calcium release channels an on the SR and L type calcium channels on the T tubule
in cardiac cells L type calcium channels on the T tubule secrete calcium, which activates calcium release channels
112
what happens to the wolffian and mullerian ducts if there is no SRY gene present
the wolffian ducts will regress, the mullerian ducts will develop, the external genitalia will be female
113
what are the benefits of estrogen replacement therapy
1. reduce intensity and frequency of hot flashes
2. prevent osteoporosis
3. maintain bladder and uterus function
4. reduce the risk of colon cancer
114
knowing the effect of GnRH what are twoclinical applications
1. GnRH infusing pumps to stimulate the ovaries
2. Downregulation of GnRH receptors
115
what type of tissue makes up most of the uterus
smooth muscle
116
what are the three phases of the ovarian cycle
1. follicular
2. ovulation
3. luteal
117
what is the second messanger in the adenylate cyclase reaction? phospholipase C?
cAMP
IP3 and DAG
118
what is happening in the latent phase of an isotonic contraction
muscle is developing tension without moving
119
five step process for G linked receptor interactions
1. a receptor is inactive with a GDP bound to it
2. ligand binding releases GDP
3. GTP is phosphylated to GTP
4. GTP alpha and beta parts disassociated
5. one of the parts binds with the effector
120
what is one long term side effects of hypothalamic amenorrhea
1. osteoporosis caused by low estrogen
121
what are the 3 parts of a G protein
1. alpha
2. beta
3. y
122
aquaporins
specialized water channels in the cell membrane
123
adenohypophysis
the anterior lobe of the pituitary
124
paracrine
a ligand secreted into the ECF which travels by diffusion and binds to a neighboring cell
125
what happens if the anterior pituitary is stimulated by the hypothalamus?
what happens if there is no communication between the hypothalamus and anterior pituitary
the anterior pituitary will secrete the appropriate hormones for its stimulation
prolactin will be produced because there will be no inhibiting factors from the hypothalamus
126
germ cells
cells that produce gametes
127
what are three specific responses to the LH surge during ovulation
1. resumption of meosis with the expulsion of the 1st polar body
2. release of collagenase and prostaglandins to weaken follicle wall
3. follicular rupture
128
what are three ways blood hormone levels are controlled
1. secretion rate
2. carrier protein binding
3. clearance rate
129
what are three descriptors of normal cervical mucosa
1. scant
2. thick
3. cloudy
130
what amino acid are catecholamines derived from
tyrosine
131
a patient presents with early onset menses, elevated TSH, and an enlarged uterus
what would be the prescribed treatment
Thyroxine (T4) that will provide negative feed back to inhibit TSH production and stop FSH and LH cross-reactivity
132
what are the three phases of an isometric twitch
latent, contraction, relaxation
133
T/F passive transport does not involve energy
false, passive transport releases energy
134
what is the equilbrium potential of potassium under normal conditions
-90mV
135
what are three methods of active solute transpoirt
1. active transport requiring ATP
2. active transport using energy from redox reactions
3. secondary active transport
136
epinephrine
137
what two types of ligands can pass the cell membrane without a carrier
1. steroid hormones
2. T3 and T4
138
current
the flow of charged particles
139
neurotransmitters
ligands secreted from neurons, into a synapse, and bind to a post synaptic receptor
140
what is ion channels are responsible for repolarization of smooth muscle
Kv1.1
141
If
Funny current, a current found in phase 4 of pacemaker cells due to Na inward flux through non fast channels
142
what are two sources of energy for primary active transport
1. ATP hydrolysis
2. directly from a primary metabolic reaction
143
Vmax
the maximum rate at which a ligand will bind to its receptor
144
isotonic contraction
a muscle contraction where there is myosin actin cross bridging and sacromere shortening that results in shortening of the muscle fibers
145
primary active transport
solute movement against electrochemical gradiant that requires energy
146
what is the state of the embryo 7 days after fertilization
it should be implanted on the uterus
147
what are the four states of a follicle
1. primordial
2. preantral
3. antral
4. preovulatory
148
three examples of passive non carrier cell transport
1. simple diffusion across the cell membrane
2. simple diffusion through pores
3. simple diffusion through gated channels
149
KIR
inwardly rectifying voltage gated potassium channels found on cardiac myocyte that keep the cell at RMP by balancing outward flux of potassium
150
what are G protein linked receptors
a receptor that needs to use an intermediary G protein to couple with intracellular effectors and produce a response
151
what is signal amplification in reference to cyclic AMP
the concept that a single ligand can produce several reactions inside the cell
152
neurohypophysis
posterior lobe of the pituitary
153
two epithelial transport membrane
1. transcellular
2. paracellular
154
what is the hormonal cause of spotting during early pregnancy
as the corpus luteum dies the placent takes over producing progestrone, and sometimes there is too much of a decrease
155
androgen insensitvity syndrome
non functional androgen receptors that lead to formation of the wolffian ducts but no DHT to masculinize the external genitalia
156
T/F most receptor/ligand binding is permanent
false, it is temporary and reversible
157
what happens 6 days after ovulation
"hatching" when the blastocyst breaks out of the zona pellucida
158
how do sperm cells develop as they move toward the lumen of seminiferrous tubules
spermatogonium --\> primary spermatocyte --\> secondary spermatocyte --\> spermatids --\> spermatozoa
159
what three factors influence force generated by individual muscle fibers
1. frequency of stimulation
2. fiber diameter
3. changes in fiber length
160
what happens to charge when a membrane depolarizes
charge flows through the cytoplasm to other parts of the cell membrane
161
semen
the 1.5-5mL of fluid emitted at ejaculation
162
T/F G protein effectors are always enzymes
false, they can be ion channels too
163
what is the action of DAG in the cell
activation of protein kinase C and phosphorlyation of protein
164
secondary ovarian failure
pituitary gland malfunction leading to decreased LH and FSH
165
is andropause natural
yes and no, there will be a decrease in testosterone and sperm production around 50 but men will continue tot produce until death
166
what type of regulation cycle is used by most primates
menstrual cycles
167
what are the three factors that influence RMP
1. the attraction of extracellular cations to intracellular anions (Gibbs Donnnan)
2. the membrane potential created by ion flux through leakage channels (net diffusion potential)
3. the membrane potential created by ion pumps that create unequal distribution of ions (electrogenic pump potential)
168
what regulates the maximum amount of force a sarcomere can generate
the amount of contact between actin and myosin
169
transcellular epithelial transport
substances crosses the cell by going through the apical and then basolateral membranes
170
what determines if somone is genetically male of female
a male will have a Y chromosome with a functional SRY gene
171
why is the resting membrane potential of a cell relevant to diffusion
because it is negative, so positive ions are pulled into the cell, and the concentration pushes sodium into the cell
172
why would low BMI cause hypothalamic amenorrhea
the hypothalamus would react to low body fat by inhibiting production of GnRH
173
flux
diffusion
174
what is happening during Phase 4 of a cardiac myocyte contraction
maintenance of RMP caused by inward potassium rectifiers counteracting the flux of potassium out of the cell
175
symport
coupled transport where the linked substances move in the same direction
176
what is the driving force behind simple diffusion
the concentration gradient on either side of the cell membrane
177
how does cell diameter influence viscosity
a smaller cell is more viscous, a larger cell is less viscous
178
how does the hypothalamus regulate ovarian function (2examples)
provides fine tuning in response to environment by increasing or decreasing amplitude and frequency of GnRH pulses (sick or starving)
179
what will the wolffian ducts form into
vas deferens, seminal vesicles, prostate
180
serotonin
an amine neurotransmitter derived from tryptophan
181
how does fiber diameter effect force generation?
a larger fiber has a larger length constant and will conduct an AP further, allowing for the recruitment of other parallel fibers
182
when do women make primary oocytes and primordial follicles?
prior to birth
183
what is the function of the Na/K pumps
the keep a large inward Na gradient to drive secondary active transport
184
what stops the anterior pituitary from secreting large amounts of prolactin
inhibition from dopamine produced in the hypothalamus
185
what is the default phenotype of the external genitalia
female
186
TSH
thyroid stimulating hormone
187
what are two causes of hypothalamic amennorhea
low bf
stress
188
what type of ligand has the largest number of chemical messangers
protein
189
threshold
the lowest stimulus that will produce a contraction
190
what amino acid are T1 an T2 derived from
tyrosine
191
what will a mature oocyte look like on microscopy
a single large cell surrounded by cumulus cells
192
KM
the concentration of a ligand that will elict a reaction rate 1/2 of Vmax
193
estrous cycles
variable reproductive cycles such as going into heat or a rut
194
what hormone causes proliferation of the endometrium
estradiol
195
what happens to actin and myosin during activation
myosin binds to actin
196
where are steroid ligands derived from
cholesterol
197
T/F sperm counts have increasesed 1-2% a year since 1985
3 possible causes
false
1. increased scrotal temperature
2. environmental estrogens
3. high stress
198
what is happening in phase 2? what is the cause?
plateau
potassium current outward through KV1.1 is balanced out by calcium current through L type caclium channels, resulting in a prolonged contraction
199
syngamy
the fusion of two cells, in our case to produce a zygote
200
what happens to muscle cell when calcium is removed from the cytoplasm
with no calcium to bind troponin, tropomyosin will cover the cross bridge sides and block myosin attachments
201
what three events happen in the follicular phase
1. menses
2. follicle recruitment
3. selection of the dominant follicle
202
describe the gonadal axis
1. GnRH is produced in the hypothalamus
2. GnRH stimulates the production of LH and FSH in the anterior pituitary
3. LH and FSH stimulate the production of androgens and estrogens from the gonads
203
what are the two key componenets of a menstrual cycle
1. release of generally one egg
2. growth and maturation of the uterine lining
204
flux
the number of moles of a solute that cross a unit area of a membrane per unit of time (moles/cm2 \* s)
205
what are the three phases of cardiac pacemaker depolarizaion
Phase 4: slow diastolic depolarization
Phase 0: Upstsroke
Phase 3: repolarization
206
what is a normal ICF and ECF for sodium?
ECF 145mM
ICF 9.5mM
207
where is depolarization the strongest? what happens as you move away from this point
at the point of membrane stimulation and it goes down the further away you go
208
what is the contribution of the following three factors or RMP
indirect Na/K
Gibbs donnan
electrogenic effect of Na/K
- 56mV
- 10mV
- 4mV
209
two types of secondary active transport
1. symport
2. antiport
210
osmosis
the diffusion of water across a cell membrane
211
in terms of energy, what direction does diffusion move
from high energy to low energy
212
what hormonal process must happen to masculinize the the external genitalia
testosterone must be converted into DHT with 5 alpha reductase
213
Lupron
a GnRH agonist that will bind to receptors and stop the release of sex hormones
214
compliance
the abilty for an object to change shape
215
what is the relationship between KM and affinity
the ligand with the highest affinity has a lower KM
216
tonicity
the comparision of effective osmolalities between two solutions seperated by a membrane
217
what determines the status of a voltage gated ion channel
the membrane potential
218
two examples of slow response receptors
1. muscarinic receptor
2. adrenergic receptor
219
isometric contraction
a contraction with myosin-actin cross bridge cycling, sarcomere shortening, but no movement
220
what is the driving force of simple diffusion
the chemical energy difference on each side of the concentration gradient
221
T/F most target cells have receptors for only one ligand
false, most have receptors for many different ligands
222
how long after syngamy will the first mitotic division take place
24 hours
223
when do menopausal women have the highest instances of hot flashes
the first 3 year post menopause
224
LH
lutenizing hormone
225
permissive hormone effects 9example)
when one hormone needs another to do its function (estradiol produces receptors for progeterone)
226
what is happening during the contraction phase of an isometric twtich
calcium that has been release by the SR binds to troponin, moving tropomyosin and allowing for cross bridge cycling
227
in Ix = gx (Vm - Ex), if Ix is negative, what does that mean? positive?
if current is negative that means that the equilbrium potential Ex is greater than the membrane potential Vm and postive ions will move into the cell
If current is positive then positive ions will move out of the cell
228
gonad
generic term refering to the reproductive organs of both genders
229
what is the effect of progesterone on prolferative endometrium
switches cells from hypertrophy to secretion to stop growth and supply nutrients for a fertilized egg
230
Gibbs-Donnan effect
the effect of a charged membrane on charged particles, leading to unequal distribution of ions across the membrane
231
what are the hormones released by the anterior pituitary
1. prolactin
2. TSH
3. ACTH
4. GH
5. LH
6. FSH
232
what hormones are produced by theca cells in response to LH?
what how are these hormones altered by granulosa cells stimulated by FSH
androsteinedione and testosterone
aromatized into esterone and estradiol
233
L type calcium channels
slower operating channels that create a sustained response
234
what are two types of calcium channels
L type and T type
235
what other ion is responsible for determining the voltage needed to open voltage gated ion channels? why
Calcium, because a significant amount of intracellular Ca will increase the membrane potential and decrease the electrochemical driving force of Na
236
what determines the activation of a follicle
it is a spontaneous daily event that happens with no known contributatory factors
237
why is 28 days a normal cycle?
because it takes 14 days for a oocyte to mature, and 14 more days before the corpus luteum dies so the cycle can restart
238
what happens to most of the K brought into the cell from the Na/K pump
it is recycled through the basolateral membrane via K channels
239
what is happening durin phase 3 in a cardiac pacemaker cell? what is the cause?
repolarization
IKv1.1 moving potassium out of the cell via delayed outward rectifiers
240
hormones
ligands secreted into blood by endocrine cells, transported by the blood to a target cell receptor
241
what is the threshold potential for skeletal muscle
-70mV
242
what is the process by which phospholipase C produces IP3 and DAG
1. epinephrine binds to adrenergic receptors
2. receptor release GDP
3. GDP --\> GTP
4. GTP binds with phospholipase C
5. IP3 and DAG are produced
243
under microscopy a zygote appears to have three protonuclei
what does that mean
polyspermia
244
what is the main glucocorticoid
cortisol
245
what is happening in the relaxation phase of an isotonic contraction
tension declines to zero
246
what is the function of the sertoli cells
secrete androgen binding protein to keep levels of testosterone between the cells high where it can act on developing spermatocytes
247
what types of solutes are capable of simple diffusion? examples (3)
solutes must be uncharged and hydrophobic
1. gasses
2. steroid hormones
3. anesthetics
248
norepinephrine
249
what is ficks first law of diffusion
flux will move from areas of high concentration to areas of low concentration
250
epinephrine
a catecholamine secreted by the adrenal medulla
251
how is it possible that a sperm can enter the fallopian tubes within one hour of sexual intercourse
there are cillia that beat and help it move
252
where do lipid soluble (lipoholic) ligands have their receptors
inside the cell
253
what is a calcium channel?
a fast ion channel found on the cell membrane
254
where does ovum pick up occur
in the "pouch" formed by the peritoneum between the bladder and the anterior wall of the uterus
255
what is the net diffusion potential if the membrane is permable to more than one ion?
the average between the conductance of the ions
256
how can a genetically male person produce enough estrogen to have normal female sex characteristics
aromatase produced in adipose tissue will convert testosterone into estradiol
257
what is the primary androgen
testosterone
258
norepinephrine
a catecholamine that acts as a CNS and PNS neurotransmitter and as a hormone secreted from the adrenal medulla
259
how long does the LH surge during ovulation lasat
48-50 hours
260
what are Kv1.1 and KV1.4
what is the difference between the two
outward rectifiers of the Kv family
Kv1.1 is slow to open and close, KV1.4 is fast
261
three treatments of hypothalamuc amenorrhea
1. estrogen replacement
2. GnRH to stimulate FSH and LH production
3. direct FSH and LH
262
what hormone produced in the hypothalamus inhibits production of GH in the anterior pituitary
somatostatin
263
T/F together the hypothalamus and pituitary regulate almost every body system
true
264
# define resting membrane potential
what is the RMP in a normal cell
the membrane potential created by a distribution of ions inside and outside the cell at rest
-70mV
265
what are the general time periods for the follicular phase, ovulation, and the luteal phase of the menstrual cycle
1. follicular phase: day 1-14
2. ovulation: day 14
3. luteal phase: day 14-28
266
absolute refractory period
the interval during an AP at which time a second AP cannot occur in any circumstance
267
T/F smooth muscle doesn't have Ca channels
false, they don;t have Na channels
268
indirect intercellular communication
ligands released from one cell bind to a receptor on another
269
what are three methods of solute transport across cell membranes
1. passive/non-carrier mediated
2. passive/carrier mediated
3. active
270
what is the primary progestin
progesterone
271
what is membrane potential?
the voltage created by differently charged ions on either side of a cell membrane?
272
what happpens one a sperm penetrates an egg?
why is this relevant
cortical granules inside the egg release their contents to harden the egg
it is unlikely that one sperm would fertilize one ovum, so it prevents polyspermia
273
potential risks of estrogen supplementation
1. increase risk of MI
2. increased risk of breast cancer
3. increase risk of DVT
274
what is the equation for net diffusion potient? what does it mean
Ediff = (gK/(gk + gNa)EK + (gNa/(gk + gNa)ENa
the net diffusion potential for a cell is equal to the conductance K divided by the conductance of K and Na multiplied by the equilibrium potential for K, added to the conductance of Na over conductance of both ions times the membrane potential of Na
275
what are the three periods of an isotonic twitch
latent, plateau, and relaxiation
276
what hormone allows for follicular growth
FSH
277
what was Knobils experiment
he removed the arctuate nucleus from monkeys and gave them endogenous GnRH to see how the they would respond to differently levels
278
what is the mean for the onset of menopause? the range
51
35-65
279
what are 3 specific effects of androgens
1. hair thickening and darkening on the face, pubic, and axilla
2. muscle growth and maintenance
3. vocal cord changes
280
can estrogen be converted back into testosterone
no, they are converted by one way enzymes
281
describe the hormonal process during menstruation (6)
1. FSH stimulates the production of follicles
2. follicles produce estrodiol and inhibit to decrease FSH
3. high estradiol produces an LH surge which triggers ovulation within 38 hours
4. follicle remains form the corpus luteum which produces progesterone
5. fertilized egg produces HCG which saves the corpus luteum
6. without fertilization estrogen and progesterone decrease and lead to menstruation
282
how fast do calcium channels open and close in comparison to Na channels?
why is this relevant
more slowly
calcium channels create a more sustained depolarization which is useful in cardiac and smooth muscle
283
what is the electrochemical gradient for potassium at rest
0.27 kcal/mol
284
where are the Na/K pumps located
the basolateral membrane
285
what influences Vmax
the number of ligands up to Vmax, then only increasing the proteins will change anything
286
what is the cause of the absolute refractory period
inactivation of Na channels until the cell is hyperpolarized
287
what is the charge inside the cell? why
negative, because the positive sodium is pumped out
288
how does the myosin head uncouple from actin? how does it return to its resting state
ATP binds with myosin to release the actin filament, then ATP is hydrolyzed to return myosin to resting state
289
if a membrane is only permeable to one ion, what will the net diffusion potential be?
the same as the equilibrium potential
290
# define menarche
what is the average age?
the range?
the onset of menstration
12.8
9-15.5
291
what happens in secondary active transport
two simultaneous movement of two link substances across a cell membrane
292
what stops more follicles from growing during the follicular phase
estradiol and inhibin B decease the amount of FSH, which slows follicular growth
293
where are the receptors for non-lipid soluble (lipophobic) ligands found
on the cell memrbane
294
what happens to the ECF and ICF with an infusion of isotonic saline
ECF increases with no increase in ICF because there is no change in osmolality
295
four functions of the hypothalamus
1. temperature control
2. hunger
3. thirst
4. pituitary stimulation
296
describe the variables
* E si the equilibrium potential for the ion
* R is the ideal gas constant
* T is the temperature in kelvin
* Xi is the ICF solute concentration
* Xo is the ECF solute concentration
* zx is the valence of electron x
* F is Farraday constant
297
osmolality
the total number of osmotically active solutes in a solution
298
hormonally what happens during menopause
the ovaries no longer secrete estrogen so the hypothalamus and anterior pituitary produce FSH and LH to try and increase estrogen
299
what current is responsible for depolarization of skeletal muscle? repolarizartion
INa
IKV1.1
300
how does changing fiber length effect contraction strength
increasing the fiber lengh will stretch the sarcomeres, which can allow for more or less contract between the sarcomeres depending on the start position
301
what is the effect of rm on cable properties? rin?
increasing rm will increase cable properties
increasing rin will decrease cable properties
302
what must happen during the relative refractory period to cause another AP
there must be a excitatory potential strong enough to open enough sodium channels to over come the slowly closing K channels
303
what is the enzyme that converts testosterone into DHT
5 alpha reductase
304
what are four groups of amine ligands
1. catecholamines
2. thyroid hormones
3. serotonin
4. histamine
305
at RMP what is the driving force behind K flux?
what direction does it move?
negative or positive
the sum of the chemical energy difference move K out of the cell minus the electrostatic attraction of K to intracellular anions
out of the cell
positive
306
at what point does an embryo lose totipotency
when it enters the uterus 5 days after ovulation
307
what are the five phases of a cardiac myocyte
Phase 4: rest
Phase 0: Upstroke
Phase 1: early repolarization
Phase 2: Plateau
Phase 3: final repolarization
308
what are six steps in passive membrane transport through integral membrane proteins
1. the carrier protein is open
2. x enters the protein and bind to the binding site
3. outer gate closes and x becomes trapped in the protein
4. inner gate opens with x still bound
5. X exits the inside of the cell
6. the outer gate closes, occluding the empty binding site
309
what is used to determine the electrochemical gradient
310
what are the two extrinsic regulatory systems of the body
nervous and endocrine system
311
what are 4 thinsg that happens when calcium channels open
1. the PM depolarizes
2. muscles contract
3. secreton
4. calcium binds to calmodulin
312
when is sodium conductance the highest in a neuronal cell? potassium?
during depolarization
during repolarization
313
if estradiol levels are found to be normal in an amenorrheic patient what can we conclude
that her ovaries, pituitary, and hypothalamus are all working properly
314
why did the monkeys in Knobils experiment stop producing LH despite increasing levels of GnRH
the target cells downregulated their receptor production because there was too much GnRH
315
what is the relationship between solute concentration and water concentration
as solute concentration goes up water concentration goes down
316
what is the equation for conductance? what are the variables?
I = gV
I = current
g = conductance
V = voltage
317
what are the five structural classifications of chemical messangers
1. amino acids
2. amines
3. steroids
4. proteins
5. eicosanoids
318
what will the mullerian ducts form into
fallopian tubes, uterus, upper vagina
319
how does male endocrine control differ from female
FSH acts on the testes to stimulate sperm production
LH stimulates secretion of androgens
320
menstrual cycle
the periodic release of an egg from the ovary to a prepared uterus, and the shedding of the uterine lining if the egg is not fertilized
321
describe the process for the posterior pituitary to secrete hormones
1. ADH and oxytocin are made in the hypothalamus
2. hormones are packed and sent to the neural endings in the pituitary
3. when stimulated the hypothalamic neurons release hormones into the blood
322
what is the sequence of female pubertal development
1. breasts
2. pubic hair
3. growth
4. menarche
323
dopamine
a catecholamine CNS neurotransmitter
324
SRY
sex determining region of the Y chromosome which determines if ovaries or testes will form
325
what is the RMP of skeletal muscle
-90mV
326
what position is the myosin cross bridge in relation to actin at rest
at a 90 degree angle and not touching
327
what might be suspected besides menstration when a pediatric patient presents with vagina bleeding
1. foreign body
2. sexual abuse
3. trauma
328
what type of receptor is a nicotinic receptor
what does it do?
a fast ion channel
when bound with acetylcholine nicotinic receptors open and allow flux of ions
329
what is the physiologic definition of conductance
the rate at which an ion corsses a 1cm area of a membrane driven by a 1 M concentration gradient
330
why is epithelial transport important to homeostasis
it controls the composition of interstitual fluid through membrane transport between the body and environment
331
rm
the resistance of the cell membrane to positive outward current
332
describe the process of calcium release through mechanical coupling in skeletal muscle
1. skeletal muscle is stimulated by AcH release from a neuron
2. skeletal muscle depolarizes, opening L type calcium gated channels on the T tubule
3. L type channels physically bind to calcium release channels on the SR
4. calcium release channels release calcium into the T tubule to bind with troponin allow myosin cross bridges to form
333
what are inward potassium rectifiers
what do they do
potassium channels with a Mg "gate" that only allows one way diffusion of potassium
return the cell membrane back to RMP after hyperpolarization
334
what type of receptor is a muscarinic receptor?
what does it do?
slow response receptor bond it an ion channel
* acetylcholine from a neuron binds to muscarinic receptors on smooth muscle or another neuron
* GDP is released and phosphorylated into GTP
* GTP binds to a Na(neuron) or Ca(smooth muscle) channel to allow flux
335
if motor unit 1 requires a 5 V stimulus, unit 2 a 10, and unit 3 a 15 V stimulus, how much will it take to stimulate all the motor units
15V
336
what cells in the testes secrete testosterone
leydig cells
337
what is the largest energy expenditure in basal metabolism
the Na/K pump
338
what is HCG?
what produces it?
human chorionic gonadotropin
a fertilized embyro implanted into the uterus
339
GHRH/GHIH
growth hormone releasing/inhibiting hormone
340
what will a fetal ovary produce that will determine gender
estradiol and oocytes
341
what is the equation used to determine RMP? explain
Em = Ediff + EP
the RMP is equal to the net diffusion potential plus the electrogenic pump potential
342
what do the wollfian ducts and mullerian ducts determine
internal genital development
343
flow
movement of matter
344
what current is responsible for Phase 0? what creates it
INA
flux of sodium through gated channels
345
T/F the size of the follicular cohort varies with age
true
346
what causes smooth muscle excitation
either electric coupling or autonomic stimulation
347
what are the four main hypothalamic-pituitary axes
1. tthyroid
2. adrenal
3. liver
4. gonads
348
what is the primary mineralocorticoid
aldosterone
349
receptor antagonist
an exogenous compound that binds to a receptor and produces no response
350
why is it impractical to measure the concentration of water
because there is too mich water to be accurate
351
what happens to current when the membrane potential (Vm) is equal to the equilibrium potential (Ex)? why?
there is no flow of current
because there is no driving force
352
what are the three steps in the life cycle of a follicle
1. resting phase
2. active phase
3. ovulation or death
353
at what age would menopuase be considered premature
younger than 35
354
how can a chromosomal XY fetus end up without male genitalia
if the androgen receptors in development are not sensitive the testes will not descend and male genitalia will not form
355
what four actions signal follicle activation
1. flattened granulosa cells becoming cuboidal
2. proliferation of granulosa
3. formation of the zona pelucida
4. growth of the oocyte
356
what are the two refractory periods of an action potential
absolute and relative
357
what four hormones are capable of cross reacting with other receptors at high doses
1. FSH
2. LH
3. HCG
4. TSH
358
what two factors determine the amount of flux (diffusion)
1. permeability of the membrane to X
2. magnitude of the gradient fo X across the membrane
359
receptor agonist
an exogenous compound that binds to a receptor and causes a normal biologic response
360
what are the three major events of the luteal phase
1. progesterone production
2. corpus luteum death without a fertilized egg
3. CL saved by HCG produced by a fertilized egg
361
what are four common specific amino acid messangers
1. glutamate
2. aspartate
3. glycine
4. GABA
362
summation
when successive depolarization events converge on a muscle cell, causing the release of more calcium and a stronger contraction
363
A type rectifying channels
KV 1.4
364
what is testosterone converted into
dihydrotestosterone
365
why does the menopause cause peripheral dilation, perspiration, compensatory tachycardia
hypothalamic disregulation causes the hypothalamus to think body temp is too high and tries to cool down
366
what are three indicators of androgen sensitivity syndrome
1. 46 XY genome
2. absent uterus and upper vagina
3. no androgen receptors mean no pubic or axillary hair
367
why does a cell do osmotic work
to counter act donnan forces that move ions into the cell
368
what would you expect to see in tertiary ammenorrhea
low BMI, high stress level, or delayed puberty
369
what are two methods of regulating a hormonal response once it has started
changing the production of the stimulating ligand
changing the rate of clearance
370
why must animal cells perform osmotic work
because animal cells swell rather than increase osmotic pressure as water enters and must pump water out of the cell
371
describe the interaction between the hypothalamus and anterior pituitary to secrete hormones
1. neurosecretory cells in the hypothalamus produce releasing hormones
2. releasing hormones are secreted in to the hypothalamic-pituitary portal system
3. the portal system carries releasing hormones to the anterior pituitary and stimulates the secretion of trophic hormones
372
what is the gentital determinant of gender
whether there are ovaries or testes indicated by high levels of androgens
373
elasticity
the force a subtance produces that resists change in shape
374
what are the primary endocrine organs (9)
1. hypothalamus
2. pituitary
3. pineal
4. thyroid
5. parathyroid
6. thymus
7. adrenal
8. pancreas
9. gonads
375
four symptoms of menopause
1. amenorrhea
2. vasomotor flushes
3. decreased vaginal lubrication
4. accelerated calcium loss
376
what is totipotency?
why is a relevant?
the ability for any cell from a blastocyst to produce a fetus
blastomeres can be removed for genetic testing
377
what are the negative feedback mechanisms that control male endocrine function
inhibin from sertoli cells reduces FSH
increased circulating testosterone decreases LH
estrogen aromatized from testosterone deceases FSH
378
what is a fast response receptor? give two examples
when the plasma membrane receptor and effector are the same protein
nicotinic receptor and tyrosine kinase receptor
379
what effect can clinical down regulation of GnRH receptors have
reversible menopause or andropause
380
based on chemical energy and concentration, where will potassium be driven in the cell
it will depend on if the chemical energy is overcome by potential energy of the concentration gradient
381
what is a simple way the body can regulate function
by regulation of current flux and flow
382
what does it mean to say the equilibrium potential of potassium is -90mV
at any membrane potential greater than -90mV, K will flux into the cell due to the electrochemical driving force
383
four types of hormone interaction
1. antagonistic
2. addittive
3. synergistic
4. permissive
384
How many different receptors can a ligand bind to
usually more than one, but different receptors have a different affinity for a single messanger
385
motor unit
a neuron and all the muscle fiber it innervates
386
what does it mean to say Na has and equilibrium potential of +60mV
it will require a membrane potental greater than 60mV to stop Na flux due to diffusion
387
what two factors allow a follicle to become the "dominant follicle"
1. increased number of FSH receptors
2. increased vascularity
388
what were two important early discoveries from Knobils experiment
1. when the arctuate nucleus was removed prolactin stayed high
2. increasly high doses of GnRH only increased LH levels to a certain amount before they dropped off
389
what is the normal concentraion of calcium in the cytoplasm?
where is the majority of calcium stored
0
in the sacroplasmic reticulum
390
Ito
current created by potassium flux through transient outward gated potassium channels during phase 1 of a cardiac myocyte action potential
391
describe an example of signal amplification
1. catecholamine bind to adrenergic receptor
2. receptor produces several G proteins
3. each G protein activates one adenylate cylase
4. each adenylate cyclase produces several cAMP
5. each cAMP activates several protein kinases
6. each protein kinase phosphorylates several proteins
392
what two factors effect the cable properties of a cell
1. rm
2. rin
393
what lab values would you expect in secondary ovarian failure
defininatly decreased FSH and LH
possibly increased prolactin or decreased TSH leading to hypothyroid
394
gonadal dysgenesis
failure of the germ cells to migrate to the gonads during development
395
what is used to determine the concentration gradient
the ideal gas law
396
arcuate nucleus
a collection of neurons that produce GnRH in the hypothalamus
397
tyrosine kinase receptor
a fast PM enzyme that phosphorylates tyrosine with ATP to make PTP and cause a cellular response
398
T/F cardiac muscle doesn't require an outside stimulus
true, pacemaker cells will depolarize on their own, gap junctions allow for the AP to travel, and the ANS modulates the response
399
FSH
follicle stimulating hormone
400
what is cervical mucosa like around ovulation
copius, clear, and supportive
401
ohms law
the amount of number of ions that move from one area to another is equal to the voltage difference between the ions divide by the resistance
402
how does physiologic regulation take place
through communication between structures using chemical signals
403
what three ligands are transported by diffusion
autocrines, paracrines, neurotransmitters
404
what are two plasma membrane receptors that a ligand will bind with
1. ion channels
2. enzymes
405
what is the equilbrium potential of sodium? potassium?
Na: 72.9 mV
K: -91.68 mV
406
what happens in cardiac pacemaker cells during phase 3? what is the cause?
final repolarization
L type calcium channels close, Kv1.1 channels are open, resulting in a strong outward IKv1.1
407
contractile component of muscle
cellular components that generate force (sarcomeres)
408
what is the difference between a neurotransmitter and hormone
where they are found
409
describe the load-velocity curve
higher loads produce more force but less velocity, therefore less power
loads that are too low produce high speed but don't generate much force, there for less power
410
where do most hypothalamic hormones bind
to receptors on the pituitary
411
length constant
the distance that a graded potential will travel through cytoplasm until it has diminished to 37% of its original strength
412
antiport
coupled transport where the two substances move in opposite directions
413
when is FSH the highest during the follicular phase? when does it decrease?
FSH is the highest during menses, decreasing during follicle recruiment
414
if a male were to present with extremely high levels of FSH and LH what would you expect
primary testicular failure caused by infection or pituitary tumor
415
what are three catecholamines
1. epinephrine
2. norepinephrine
3. dopamine
416
what is the most common cause of secondary ammenorrhea
pregnancyq
417
FSH is needed to progess between what two follicular states?
preantral and antral
418
what will stimulate the onset of puberty
increased body size, specifically body fat, that stimulates leptin production
419
what two hormones are secreted from the posterior pituitary
1. oxytocin
2. ADH
420
what happens if a membrane potential is positive
cations are less likely to diffuse into the cell because the inside is positive
421
what is the electrical definition of conductance
1 seimen of conductance will produce a 1 amp current when the potential is 1 volt
422
why would high BMI delay menopause
because aromtase conversion of androgens to estrogens will continue to stimulate the uterus
423
what is happening during phase 4 in a cardiac pacemaker cell? what causes it?
slow diastolic depolarization
If and ICaT currents bringing Na and Ca into the cell, IKv1.1 moving K out of the cell in opposition resulting in a slow progression to threshold
424
what is an example of a cell that places aquaporins based on hormonal control
cells in the renal collecting duct in response to ADH
425
what is a denuded oocyte? how can one be made?
a oocyte with all the cumulus cells stripped away by pipetting or enzymes, leaving only the zona pellucida
426
T/F receptors show specificity for a messanger
true
427
name and describe the axis that produces cortisol
adrenal axis
1. CRH is produced in the hypothalamus and released into the blood
2. CRH stimulates anterior pituitary produce of ACTH
3. ACTH acts on the adrenal cortex to produce cortisol
428
what is the relationship between membrane potential and current
for Na and K, increasing the membrane potential will increase the current
429
what were three final conclusions from Knobils experiments
1. the ovary and production of steroids are most important to menstruation
2. GnRH is secreted in pulses
3. constant GnRH will cause down regulation of receptors
430
how is secretion rate regulated
negative feedback through end product inhibition
431
nicotinic receptor
a fast ion channel receptor found on the PM of in muscle and nervous tissue
432
what happens to an older mother who is fertilized with older eggs
she has a success rate higher than she would using her own eggs
433
what formula is used to determine single species ion flow
Ix = gx (Vm - Ex)
I = current
g = conductance
(Vm - Ex) = the electrochemical driving force across a membrane
434
what two hormones are secreted by growing follicles?
what is their effect on menstruation
estradiol and inhibin B
decrease production of FSH by through negative feedback at the hypothalamus and anterior pituitary
435
what hormone is elevated in a pediatric patient with an enlarged uterus and early onset period
estradiol
436
what happens to active force as length increases? passive force?
active force decreases, passive force increases
437
name and describe the axis that produces GH
growth hormone axis
1. GHRH is produced in the hypothalamus
2. GHRH stimulates production of GH in the anterior pituitary
3. GH acts on somatic cells to produce growth
4. GH also acts on the liver to produce IGF
438
define all variables
R = ideal gas constant (.002kcal/mol)
T = temp in Kelvin (310 in humans)
Xi = intracellular fluid concentration of X
X0 - extracellular fluid concentrationof X
439
statistically speaking older mothers are less likely to carry to term and more likely to produce a fetus with birth defects
why?
because older eggs are less capable
440
what two things regulate the secrete of anterior pituitary hormones
1. negative feed back from the trophic hormones
2. negative feed back from organ stimulated by pituitary hormones
441
what lab values would you expect in primary ovarian failure
increased LH and FSH as the pituitary tries to stimulate estrogen production
442
what is KM a measure of
affinity of a ligand for its receptor
443
what causes the change in cervical mucosa throughout the menstrual cycle
estradiol
444
paracellular epithelial transport
substances bypass the cell and cross epithelium through cell junctions
445
what happens when myosin binds to actin
ADP and P are released, allowing the myosin head to move from a 90 to 45 deg angle to actin
446
what is the process of a neuronal depolarization, propogation, and repolarization (10)
1. Excitatory impulses release acetylcholine on to nicotinic receptors
2. nicotinic receptors open ligand gated sodium channels
3. summation of EPSPs opens enough ligand gated sodium channels to bring the neuron to threshold (-55mV)
4. the axon hillock depolarizes, opening a cascade of Na channels
5. the charge is propogated down the axon by sequentially opening Na channels
6. As the membrane potential increases, voltage gated KV 1.4 channels open
7. at Vm 30mV sodium channels are closed, KV 1.1 channels are open
8. as Vm decreases, Kv 1.1 channels close slowly
9. hyperpolarization occurs as Vm drops below RMP
10. inward rectifiers allow potassium flux back into the cell to return it to RMP
447
what drives the rhythm of the menstrual cycle
maturation of the follicle and oocyte
448
apical membrane
the cell surfaces that face inward toward a lumen
449
histamine
a paracrine amine ligand derived from histadine
450
what three things are needed for sperm production (what do they do)
1. FSH (sertoli cell function)
2. LH (stimulates leydig cells to make androgens)
3. high levels of intratesticular testosterone
451
what are three causes of precocious puberty
1. central lesion in the CNS
2. peripheral increase in estrogen
3. obesity
452
list the androgens from least to most potent
dihydroepiandrosterone, androstenedione, testosterone
453
PRH/PIH
prolaction releasing/inhibiting hormone
454
why would obesity cause precocious puberty
adipose tissue contains aromatase which will convert androgens into estrogens and stimulate menses and breast development
455
secondary ammenorrhea
the absence of a period for three months in a women who prevously had them
456
what are the hormones released by the hypothalamus
1. PRH
2. PIH
3. TRH
4. CRH
5. GRHR
6. GHIH
7. GnRH
457
what will fetal testes produce that determine gender
testosterone to maintain the wolffian ducts and anti-muellarian hormone to regress the muellarian ducts
458
primary amenorrhea
never had a period before
459
what happens when calcium binds to calmodulin
protein kinase is formed, which phosphorylates protein to cause a response in the cell
460
what is a T tubule? what is the function?
extensions of the cell membrane from one muscle cell to another
they allow for rapid activation of L type calcium channels and propogate depolarization to surrounding cells
461
what three factors determine the magnitude of cell response to a ligand
1. messanger concentration
2. number of receptors on target cell
3. affinity between receptor and ligand
462
what are two methods for cells, tissues, and organs regulation
extrinsic and intrinsic
463
what is the nerst equation and what is it used for
used to determine the equilibrium concentration of an ion
464
cable properties
the ability of the cytoplasm to conduct electricity
465
how are hormones transported in blood
some can dissolvle in blood, some need a protein carrier
466
what direction does a positive delta G move
out of the cell
467
what ion channels cause depolarization in smooth muscle? why is this relevant
Calcium channels
because calcium channels open much slower than Na channels and produce a slower depolarization
468
what percent of the total sperm content semen are motile and morphologically normal
about 1/2
469
how do carrier proteins regulate blood hormone levels
lipoholic hormones can only have a concentration equal to the concentration of carrier proteins
470
recruitment
the stimulation of multiple muscle fibers through a stronger stimulus
471
how do ligands with intracellular receptors create a response in the cell
* hormones bind to receptor
* hormone/receptor complex binds to DNA at a promotor
* allow for gene expression and protein synthesis
* new protein produces a response
472
primary ovarian failure
dysfunction of the ovaries that doesnt allow for menstruation
473
T/F preovulatory follicles can be seen under a microscope
true
474
what is happening in cardiac muscle during Phase 1? what is the cause
early repolarization
transient outward rectifiying K channels open as Na gated channels are closing
475
fused tetanus
when summation by repeated stimuli causes a max tension curve with no individual contractions
476
autocrine
a ligand secreted by a cell into the ECF that binds on its own receptors
477
two places where epithelial transport takes place
1. apical membrane
2. basolateral membrane
478
two ways to produce a functiona vagina
progressive vaginal dilation or surgery
479
what happens to ECF and ICF with an infustion of solute free water
the ECF experiences an intial decrease in osmolality, causing solutes to diffuse out of the ICF to restore equalibrium
480
additive hormone effects (example)
two hormones have the same effect through different mechanisms, so the effect is the sum of the individual effects (cortisol and GH on lipolysis)
481
what would happen if there were no plateau in an isometric contraction
there would be no shortening of sarcomeres greater than the elasticity of the tendons, so no movement would take place (isometric)
482
two types of epithelial cell junctions
1. tight
2. leaky
483
leuprolide
GnRH antagonist used to decrease estrogen or androgen production by downregulating GnRH receptors
484
described the amount of force produced by these situations
1. actin myosin overlapping
2. actin myosin in contact with no H band
3. actin myosin in contact with an H band
4. actin myosin with some heads exposed
5. no contact of the myosin heads
1. less force because some of the cross bridge sites are covered by the adjecent actin filament
2. maximum number of cross bridges = max force
3. max force because there are no exposed myosin heads
4. less force because of fewer binding sites are accessible
5. no force because there are no binding sites accessible
485
why are Kv1.1 channels called delayed outward rectifiers
they are slow to completely open and slow to completely close
486
what current is at work during each phase of a cardiac myocyte contraction and what direction is it moving
phase 4: IKir, into the cell
phase 0: INa, into the cell
phase 1: Ito
phase 2: ICaL, IKv1.4, IKv1.1
phase 3: IKv1.1
487
what is the equilbrium potential for sodium
around 70mV
488
how is calcium removed from the cytoplasm?
Na-Ca pump and Ca pump remove calcium from the cell
Ca sequestering pump pumps Ca into the SR where it bound to calreticulin and calsequestrin
489
explain how high TSH can cause early onset period
TSH in high doses can cross react with GnRH receptors in the ovary and produce estradiol
490
what are three types of ligands that can't cross the cell membrane
1. proteins
2. amino acids
3. amines (except thyroid hormone)
491
what two ions are not included in the chord conductance equation? why?
Cl and Ca
because Cl regulates passively and plays no role in forming potentials, and animal cell membranes are virtually impermeable to Ca
