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387 Cards in this Set

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What is the major factor that regulates insulin secretion?
Blood glucose
What does increased blood glucose do to insulin secretion?
Increases it
What cells of the pancreas produce insulin?
Beta cells
What does glucose bind to on beta cells?
Glut 2 receptors
What happens after glucose binds to glut 2 receptors?
Glucose gets oxidized to ATP
What does the oxidation of glucose to ATP do ?
Closes K+ channels causing depolarization
What channels does depolarization of the beta cell open?
Ca2+ channels
What does increased Ca2+ in the beta cell do?
Stimulates insulin secretion
If the ATP inside the beta cell is low, are the K+ channels open or closed?
They are closed; hyperpolarized
If the ATP inside the beta cell is high, are the K= channels open or closed?
They are open; depolarized
What is similar to the action of ATP that can also stimulate the secretion of insulin?
Sulfonylurea drugs
If the K+ channels are open in the beta cell, is insulin going to get secreted?
No
If the K+ channels are open in the beta cells, is insulin going to get secreted?
Yes
How does insulin act to decrease blood glucose?
Increased uptake of glucose into
cells
Promotes formation of glycogen
Decreased gluconeo
Decreased fatty acid conc
Decreased AA conc
Decreased K+ conc
Is insulin anabolic or catabolic?
Anabolic
What are the main functions of insulin?
Increase uptake of nutrients
Increase storage of nutrients
Decrease breakdown of stored nutrients
What does low insulin do to growth hormone?
Decreases growth hormone
What does insulin do to carbohydrate metabolism?
Increases carbohydrate metabolism
What does insulin do to fat metabolism?
Decreases fat metabolism
What do Glut 4 receptors do to blood glucose?
Glut 4's move to the plasma membrane and take up glucose within seconds
Is insulin secreted in response to depolarization or hyperpolarization of pancreatic beta cells?
Depolarization due to the rise in ATP
With high blood glucose, are Glut 4 receptors increased or decreased?
Increased
In high blood glucose, is glycogen synthesis increased or decresased?
Increased
In high blood glucose, is glycogenolysis increased or decreased?
Decreased
In high blood glucose, is triglyceride synthesis increased or decreased?
Increased
In high blood glucose, is lipolysis increased or decreased?
Decreased
What stimulates the secretion of insulin after a meal?
Glucose
Amino Acids
FFA
Ketoacids
K+
What do epi and norepi do to insulin secretion?
Turn it off; decrease it
What does excessive growth hormone and cortisol do to insulin secretion?
Increases it
What does Ach do to insulin secretion?
Increases it
What does somatostatin do to insulin secretion?
Decreases it
Which rises first, insulin or blood glucose?
Insulin--rises at the thought of food
What does the liver store glucose as?
Glycogen
When is glycogen converted to glucose?
When plasma glucose is low
How does insulin enter beta pancreatic cells?
Through Glut 2 receptors
What does insulin do to the conversion of glycogen into glucose?
Inhibits the conversion
Does insulin activate or inhibit glycogen synthase?
Activates glycogen synthase
What inhibits glucose production by the liver?
Insulin
Hyperglycemia
Parasympathetics
What stimulates glucose production by the liver?
FFA
Cortisol
Glucagon
Epi
Growth hormone
Sympathetics
Does the brain require glucose?
Yes
Does the brain require insulin?
No
Does the intestine require insulin?
No--but does depend on SGLT
Does the muscle require insulin?
Yes
How does muscle cause a rapid increase in glucose uptake?
Glut 4 receptors to the plamsa membrane
Does insulin reduce or increase the release of glycerol?
Reduces the release of glycerol
Does insulin increase or reduce the uptake of glucose?
Increases the uptake of glucose
Do high FFA levels stimulate or inhibit insulin secretion?
Stimulate insulin secretion
Do high AA levels stimulate or inhibit insulin secretion?
Stimulate insulin secretion
Does increased blood glucose stimulate or inhibit insulin secteion?
Stimulates insulin secretion
Does increased keto acids stimulate or inhibit insulin secretion?
Stimulate insulin secretion
Does a high level of growth hormone and cortisol stimulate or inhibit insulin secretion?
Stimulates insulin secretion
Does a high level of Ach stimulate or inhibit insulin secretion?
Stimulates insulin secretion
Does somatostatin stimulate or inhibit insulin secretion?
Inhibits insulin secretion
Does epi and norepi stimulate or inhibit insulin secretion?
Inhibits insulin secretion
What stimulates glucagon secretion?
Decreased blood glucose levels
What does glucagon do to the blood glucose concentration?
Increases it
Do decreased fatty acids stimulate or inhibit glucagon secretion?
Stimulate glucagon secretion
What cells of the pancreas secrete glucagon?
Alpha cells
Do increased amino acids stimulate or inhibit glucagon secretion?
Stimulate glucagon secretion
What tissue does glucagon work on?
Liver and adipose tissue
Does insulin increase or reduce the uptake of glucose?
Increases the uptake of glucose
Do high FFA levels stimulate or inhibit insulin secretion?
Stimulate insulin secretion
Do high AA levels stimulate or inhibit insulin secretion?
Stimulate insulin secretion
Does increased blood glucose stimulate or inhibit insulin secteion?
Stimulates insulin secretion
Does increased keto acids stimulate or inhibit insulin secretion?
Stimulate insulin secretion
Does a high level of growth hormone and cortisol stimulate or inhibit insulin secretion?
Stimulates insulin secretion
Does a high level of Ach stimulate or inhibit insulin secretion?
Stimulates insulin secretion
Does somatostatin stimulate or inhibit insulin secretion?
Inhibits insulin secretion
Does epi and norepi stimulate or inhibit insulin secretion?
Inhibits insulin secretion
What stimulates glucagon secretion?
Decreased blood glucose levels
What does glucagon do to the blood glucose concentration?
Increases it
Do decreased fatty acids stimulate or inhibit glucagon secretion?
Stimulate glucagon secretion
What cells of the pancreas secrete glucagon?
Alpha cells
Do increased amino acids stimulate or inhibit glucagon secretion?
Stimulate glucagon secretion
What tissue does glucagon work on?
Liver and adipose tissue
Does glucagon increase or decrease glycogenolysis?
Increases it---prevents the recycling of glucose into glycogen
Does glucagon increase or decrease gluconeogenesis?
Increases gluconeogenesis
What does glucagon do to lipolysis?
Increases lipolysis
What does low blood glucose stimulate?
Release of glucagon
What does the release of glucagon do?
Activates adenylate cyclase
What does activated adenylate cyclase do?
Increased cAMP
What does increased levels of cAMP cause?
Activation of glycogen phosphorylase and inhibition of glycogen synthase
Activation of glycogen phosphorylase does what?
Breaks down glycogen to glucose and release glucose into blood
In a fasting state, will you have a low or high insulin/glucagon ratio?
Low ratio
In a well fed state, will you have a low or high insulin/glucagon ratio?
High ratio
Is glucagon catabolic or anabolic?
Catabolic
What is the major hormone for the regulation of Ca2+?
Parathyroid
What stimulates the secretion of parathyroid hormone?
Decreased serum Ca2+ levels
What does decreases in serum Mg2+ concentration do to PTH secretion?
Increases PTH secretion
What does PTH do to bone resorption?
Increases bone resorption by activating osteoclasts--brings Ca2+ from the bone to the ECF
What does PTH do to Vitamin D?
Activates Vitamin D which increased Ca2+ absorption from the diet
What does PTH do the calcium resorption in the kidney?
Increases it
What does PTH do to the resorption of phosphate in the kidney?
Decreases the resorption of phosphate by the kidney
What does high Ca2+ do to the secretion of PTH?
Inhibits the secretion
What does high active Vitamin D do to the secretion of PTH?
Inhibits the secretion
What are the main functions of PTH?
Increases resorption of bone
Increases absorption of Ca2+ from the diet
Increases resorption of Ca2+ from the kidneys
Decreases resorption of phosphate from the kidneys
When Ca2+ levels are high, what happens?
Calcium gets secreted from the plasma into the bone and absorption decreases from the gut
When Ca2+ levels are low, what happens?
Calcium gets released from the bone into the blood and absorption from the gut is increased
What happens to the calcium in aging?
Calcium intake decreased--therefore osteoporosis
If bone loss is occurring, are you hypocalcemic or hypercalcemic?
Hypercalcemic--less Ca2+ in bone and more in blood
What is sacrificed to maintain the plasma Ca2+ concentration?
Bone
What does a high pH (alkaline) do to Ca2+?
Attracts Ca2+
What does a low pH (acidic) do to Ca2+?
Repels Ca2+
In alkalosis, is free Ca2+ low or high?
Free Ca2+ is low
In acidosis, is free Ca2+ low or high?
Free Ca2+ is high
Who has a positive calcium balance?
Children
Who has a negative calcium balance?
Pregnant women
What do osteoblasts do?
Build bone
What does bone formation require?
Normal levels of Ca2+, phosphate, alkaline phosphatase, and osteocalcin
What do osteoclasts?
Break down bone
Where do osteoblasts get their Ca2+ from?
The plasma
What activates osteoblasts?
Calcitonin
What hormone stimulates osetoclasts?
Parathyroid--indirectly
Do osteoclasts have PTH receptors?
No
What does PTH act on directly?
Osteoblasts
What does PTH act on indirectly?
Osteoclasts
What does Vitamin D do?
Provides Calcium and phosphate to the ECF to make bone
What does Vitamin D deficiency cause?
Rickets in children and osteomalcia in adults
How does Vitamin D maintain a normal calcium level?
By increasing absorption from the gut
Besides food, what is another way the body manufactures Vitamin D?
Sunlight
What is the active form of Vitamin D?
1,25-dihydroxycholecalciferol
What are the actions of active vitamin D in the bone?
Increase gut absorption of Ca2+ and phosphate
Therefore making Ca2+ available for bone making
What does the active from of Vitamin D do in the skeletal muscle?
Increases Ca2+ uptake by skeletal muscle cells
Increases Ca2+ uptake by the SR
A deficiency of Ca2+ in the muscle would cause?
Weakness in muscles
Abnormal contractions
If PTH is high, Ca2+ levels are?
Low
If PTH is low, Ca2+ levels are?
High
When Ca2+ plasma levels are high, is the less or more Vitamin D in the active form?
Less Vit D in the active form
When serum Ca2+ is low, do you want to excrete more or less Ca2+? What does this do to PTH?
Excrete less Ca2+--More parathyroid
What does elevated PTH make you do to Ca2+?
Retain Ca2+
What makes PTH?
Chief cells of the parathyroid
What does high phosphate mean?
Low calcium and high parathyroid
If the PTH is high, what is happening to the phosphate?
It is being excreted
Is PTH synthesized continuously or intermittenly?
Continuously
When Ca2+ in the serum is high, what happens to the continuously synthesized PTH?
The chief cells destroy the synthesized PTH
Are PTH and free serum calcium antagonistic or synergistic?
Antagonistic
Is Ca2+ absorption from the gut passive or active?
Both--a small amt enters through tight junctions--the other enters through Ca2+ channels
Is PTH secretion pulsatile?
Yes--mainly at night
What does PTH do to phosphate?
Causes excretion of phosphate
What is calcitonin secreted by?
C cells in the thyroid
What does calcitonin do to serum Ca2+ levels?
Decreases it
Does calcitonin inhibit osteoclasts or osteoblasts?
Osteoclasts
What does calcitonin stimulate?
Osteoblasts
In hypocalcemia, is PTH high or low?
High
In hypocalcemia, is Calcitonin high or low?
Low
In hypercalcemia, is PTH high or low?
Low
In hypercalcemia, is calcitonin high or low?
High
In hyperparathyroidism, is the plasma Ca2+ high or low?
High
In hyperparathyroidism, is the phosphate high or low?
Low
Is the renal excretion of phosphate high or low in hyperparathyroidism?
High
In hyperparathyroidism, is the urine calcium high or low?
Low
What two hormones are secreted by the posterior pituitary?
ADH and oxytocin
Where specifically are ADH and oxytocin produced?
Hypothalamic Neuron Cell Bodies in vesicles
What is another name for ADH?
Vasopressin
What are the actions of oxytocin?
Contractions of myoepithelial cells in the breast
Contraction of the uterus
What are the actions of ADH?
Increases H2O permeability
Constriction of vascular smooth muscle
Regulates volume
How is growth hormone released?
Pulsatile fashion
When is growth hormone typically secreted?
At night
What increases growth hormone secretion?
Sleep
Stress
Puberty
Starvation
Exercise
Hypoglycemia
What decreases growth hormone secretion?
Somatostatin
Obesity
Hyperglycemia
Pregnancy
Does growth hormone prefer fat metabolism or carbohydrate metabolism?
Fat metabolism
What are the functions of growth hormone?
Increase protein synthesis
Increase linear bone growth
Increase plasma glucose
Increase fat metabolism
Increases AA uptake
What stimulates growth hormone?
Growth hormone releasing hormone
What inhibits growth hormone?
Somatostatin
What stimulates the production of IGF?
GH
PTH
Sex steroids
What does trauma do to GH?
Decreases it--therefore, decreases IGF and IGF receptors
What two hormones are secreted by the posterior pituitary?
ADH and oxytocin
Where specifically are ADH and oxytocin produced?
Hypothalamic Neuron Cell Bodies in vesicles
What is another name for ADH?
Vasopressin
What are the actions of oxytocin?
Contractions of myoepithelial cells in the breast
Contraction of the uterus
What are the actions of ADH?
Increases H2O permeability
Constriction of vascular smooth muscle
Regulates volume
How is growth hormone released?
Pulsatile fashion
When is growth hormone typically secreted?
At night
What increases growth hormone secretion?
Sleep
Stress
Puberty
Starvation
Exercise
Hypoglycemia
What decreases growth hormone secretion?
Somatostatin
Obesity
Hyperglycemia
Pregnancy
Does growth hormone prefer fat metabolism or carbohydrate metabolism?
Fat metabolism
What are the functions of growth hormone?
Increase protein synthesis
Increase linear bone growth
Increase plasma glucose
Increase fat metabolism
Increases AA uptake
What stimulates growth hormone?
Growth hormone releasing hormone
What inhibits growth hormone?
Somatostatin
What stimulates the production of IGF?
GH
PTH
Sex steroids
What does trauma do to GH?
Decreases it--therefore, decreases IGF and IGF receptors
If GH is high before puberty, what happens?
Gigantism--increase bone growth
If GH is high after puberty, what happens?
Acromegaly--structures still growing are nose, hands, feet, eyebrows, chin
What do patients with excess GH have?
High fasting glucse
High insulin secretion
BUT are resistant to insulin actions
What does GH do to glucose levels?
Raises glucose levels
What does absence of growth hormone result in?
Short stature
What is Laron's syndrome?
Patients are unresponsive to growth hormone--high levels of growth hormone but low IGF-1
What happens to IGF-1 when GH is low?
IGF-1 is low
What are the actions of IGF-1?
Increase linear growth
Increase lean body mass
Increase organ size
What do the direct actions of GH lead to?
Increase in plasma glucose
What do the indirect actions of GH lead to?
Mostly through IGFs--anabolic
What are the gonadotropins?
LH and FSH
What do FSH and LH do?
Sexual maturation in males and females
What does an increase in FSH do in the female?
Increases follicle growth and estrogen secretion
What does an increase in FSH do in the male?
Stimulates the Sertoli cells for speramtogenesis
What does an increase in LH do in the female?
Stimulates ovulation
Formation of the corpus leteum
Synthesis of estrogen and progesterone
What do an increase in LH do in the male?
Stimulates the leydig cells to secrete testosterone
How are gonadotropes secreted?
Pulsatile
What are the classic endocrine glands that secrete steroid hormones?
Adrenal Cortex
Testes
Ovaries
Placenta
What are all steroid hormones derived from?
Enzymatic modification of cholesterol
What facilitates the movement of cholesterol from the outer mitochondrial membrane to the inner mitochondrial membrane?
STAR
Once inside the mitochondria, what is cholesterol converted to?
Pregnenolone
What action converts cholesterol into pregnenolone?
Cleavage of the side chain
What is the precursor for all adrenal, gonadal, and placental steroids?
Pregnenolone
What determines the rate of steroid release?
The rate of hormone synthesis
How does release of steroid hormones occur?
Diffusion through the plasma membrane
The portion of cholesterol that is not used in steroid hormone synthesis is stored as what?
Cholesterol esters
How are steroid hormones transported in plasma?
Bound to proteins
What are the three main specific steroid hormone binding proteins?
Sex hormone-binding globulin
Corticosteroid-binding globulin
Vitamin D-binding globulin
Besides bound to proteins, what other ways can steroids be transported?
Bound to albumin
Free fraction
How is cAMP involved in steroid hormone synthesis?
Increased cAMP activates PKA
PKA activates STAR synthesis
STAR moves cholesterol into inner mictochondrial membrane
Cholesterol is broken down into pregnenolone
Instead of getting degraded, steroid hormones are converted to what?
Inactive metabolites
Where is the principal site of steroid inactivation?
The liver
What are inactive metabolites conjugated with in the liver?
Glucuronic acid or sulfate
What does conjugation of inactive metabolites allow?
Facilitates the clearance of hormones by increasing their solubility in water and by decreasing their affinity for binding proteins
How are conjugated metabolites excreted?
By the kidneys
What does the zona glomerulosa of the adrenal gland secrete?
Aldosterone
What does the zona fasiculata of the adrenal gland secrete?
Cortisol
What does the zona reticularis of the adrenal gland secrete?
Androgens
What is the primary regulator of aldosterone?
The renin-angiotensin system
What causes renin release?
Low BP
Decrease in fluid volume
Sympathetic stimulation
How is aldosterone synthesis stimulated?
Angiotensin 2 activates the IP3 pathway and stimulates the release of calcium; the rise in calcium increases the STAR protein synthesis
What is the action of aldosterone?
Increase Na reabsorption
Increase K excretion
Where is the prinicpal site of aldosterone action?
The kidney
What are the three types of estrogen?
Estradiol (E2)
Estrone (E1)
Estriol (E3)
What is the most potent form of estrogen?
Estradiol
Which form of estrogen is most important in menopause?
Estrone
What is the form of estrogen most involved in pregnancy?
Estriol
What are the actions of LH and FSH regulated by?
cAMP
What do the theca cells respond to?
LH
What do the granulosa cells respond to?
FSH
Do the theca cells have a blood supply?
Yes
Do the granulosa cells have a blood supply?
No
What does LH produce in the female?
Androgens
What does FSH produce in the female?
Estradiol
What is the common hormone between the theca and granulosa cells?
Androstenedione
What cells of the two cell model actually make the estrogen?
The granulosa cells
What are the steroids that promote gestation?
Progestins
What is the principal source of progesterone?
The corpus luteum
At what age are the gonadotropin levels lowest in a woman?
During childhood
What is the predominant hormone during the reproductive years?
LH
What is the predominant hormone during menopause?
FSH
Which hormone is predominant throughout a woman's life?
FSH--except during the reproductive years
What is an early indicator of puberty?
Nocturnal LH release
When does the follicular phase begin?
At the onset of menses
How long is the follicular phase?
Variable in length
What does the follicular phase of the reproductive cycle correspond to in the endometrial cycle?
The proliferative phase
How long does the luteal phase last?
It is constant--around 13-14 days
What does the follicular phase of the reproductive cycle correspond to in the endometrail cycle?
The secretory phase
When does the luteal phase end?
At the onset of menses
What phase of the cell cycle do primordial follicles stop?
Prophase 1
Do primordial follicles contain a granulosa cell layer?
Yes--but it is an immature cell layer
How does a primary follicle differ from a secondary follice?
The secondary follicle contain a thecal layer
What is another name for a secondary follicle?
Preantral follicle
At what age are the gonadotropin levels lowest in a woman?
During childhood
What is the predominant hormone during the reproductive years?
LH
What is the predominant hormone during menopause?
FSH
Which hormone is predominant throughout a woman's life?
FSH--except during the reproductive years
What is an early indicator of puberty?
Nocturnal LH release
When does the follicular phase begin?
At the onset of menses
How long is the follicular phase?
Variable in length
What does the follicular phase of the reproductive cycle correspond to in the endometrial cycle?
The proliferative phase
How long does the luteal phase last?
It is constant--around 13-14 days
What does the follicular phase of the reproductive cycle correspond to in the endometrail cycle?
The secretory phase
When does the luteal phase end?
At the onset of menses
What phase of the cell cycle do primordial follicles stop?
Prophase 1
Do primordial follicles contain a granulosa cell layer?
Yes--but it is an immature cell layer
How does a primary follicle differ from a secondary follice?
The secondary follicle contain a thecal layer
What is another name for a secondary follicle?
Preantral follicle
At what age are the gonadotropin levels lowest in a woman?
During childhood
What is the predominant hormone during the reproductive years?
LH
What is the predominant hormone during menopause?
FSH
Which hormone is predominant throughout a woman's life?
FSH--except during the reproductive years
What is an early indicator of puberty?
Nocturnal LH release
When does the follicular phase begin?
At the onset of menses
How long is the follicular phase?
Variable in length
What does the follicular phase of the reproductive cycle correspond to in the endometrial cycle?
The proliferative phase
How long does the luteal phase last?
It is constant--around 13-14 days
What does the follicular phase of the reproductive cycle correspond to in the endometrail cycle?
The secretory phase
When does the luteal phase end?
At the onset of menses
What phase of the cell cycle do primordial follicles stop?
Prophase 1
Do primordial follicles contain a granulosa cell layer?
Yes--but it is an immature cell layer
How does a primary follicle differ from a secondary follice?
The secondary follicle contain a thecal layer
What is another name for a secondary follicle?
Preantral follicle
What part of the growing preantal follicle cycle is FSH independent?
The first 60 days
Do the preantral follicles express LH and FSH receptors during the FSH independent stage?
Yes
What part of the growing preantral follicle cycle is FSH dependent?
The last 20 days
During the last 20 days of the growth phase, if FSH is not present, what happens to the preantral follice?
It will stop growing and undergo atresia
During what stage of the reproductive cycle is a follicle selected?
During the early follicular phase
In what stage of follicle development do we see a dramatic increase in the amount of estrogen being produced?
During the dominant stage of the follicle
How does the dominant follicle suppress development of the other recruited follicles?
Production of estrogen by the dominant follicle suppresses FSH secretion--as FSH levels fall, other follicles undergo atresia
During the early follicular phase, do granulosa cells express LH receptors?
No
During the mid follicular phase, do granulosa cells express LH receptors?
A few--to be able to respond to the LH surge
When do granulosa cells express the most LH receptors?
During the late follicular phase
What effects does LH have on the preovulatory follicle?
Induces the expression of progesterone receptors and COX-2
What is the pathway of follicle growth and developement?
Recruitment
Selection
Dominance
Preovulatory
What stage of meiosis is the secondary follicle arrested in?
Metaphase 2
What promotes the resumption of meiosis?
LH
What is associated with the LH surge?
Ovulation
What does Inhibin B inhibit?
FSH
What does inhibin B do?
Breaks down the granulosa layer
What is inhibin A assoiciated with?
LH
When is inhibin B the highest?
During the follicular phase
When is inhibin A the highest?
During the luteal phase
What causes the egg to be released during ovulation?
The positive feedback of estrgoen on the pituitary
What is the primary hormone responsible for the proliferation of the endometrium?
Estrogen
What are te primary hormones responsible for the secretory phase of the endometrium?
Progesterone and estrogen
What causes the start of menses?
The sudden drop in estrogen and progesterone levels
What is PGF2 repsonsible for?
Induces the expulsion of the uterine lining and also causes cramps
Where does fertilization occur?
Where estrogen is dominant--the ampulla of the fallopian tube
What is the primary hormone responsible for transport and fertilization of the egg?
Estrogen
What hormone is responsible for causing the fallopian tube to relax so the egg can move down?
Progesterone
What does sperm bind on the zona pellucida?
ZP3
What dissolves the zona pellucida allowing the egg and sperm to fuse?
Hydrolytic enzymes released from the acrosomal cap
When the sperm cytosol enters the egg, calcium rises. What does the stimulate?
The 2nd meiotic division and the egg releases granules that harden the zona pellucida preventing other sperm from entering
What does the attachment of the blastocyst to the uterine wall require?
Progesterone
Is the placenta secretion regulated by maternal or fetal signs?
No--it is autonomous
What cells form the early placents?
The syncytiotrophoblast
When does implantation occur?
When progesterone is the highest
What hormones are secreted during pregnancy?
hCG
Progesterone
hCS
Estrogens
When is hCG the highest during pregnancy?
At the beginning until about the 12th week
What are the functions of hCG?
Prolong the life of the corpus luteum and to stimulate testosterone production by the fetus
What is responsible for producing the majority of estrogen during pregnancy?
The fetal adrenal glands--secreting DHEA which go on to make estrogen
What is essential for breast development during pregnancy?
Prolactin
Estrogen
Progesterone
What are the actions of prolactin?
Promote breast development during pregnancy
Promote milk synthesis and secretion
How is prolactin inhibited during pregnancy?
Estrogens and Progesterones
What inhibits prolactin in non pregnant individuals?
Dopamine
What is the most potent release of prolactin after delivery?
Suckling
What causes the iniation of lactation?
A drop in estrogen and progesterone
Prolactin
When the sperm cytosol enters the egg, calcium rises. What does the stimulate?
The 2nd meiotic division and the egg releases granules that harden the zona pellucida preventing other sperm from entering
What does the attachment of the blastocyst to the uterine wall require?
Progesterone
Is the placenta secretion regulated by maternal or fetal signs?
No--it is autonomous
What cells form the early placents?
The syncytiotrophoblast
When does implantation occur?
When progesterone is the highest
What hormones are secreted during pregnancy?
hCG
Progesterone
hCS
Estrogens
When is hCG the highest during pregnancy?
At the beginning until about the 12th week
What are the functions of hCG?
Prolong the life of the corpus luteum and to stimulate testosterone production by the fetus
What is responsible for producing the majority of estrogen during pregnancy?
The fetal adrenal glands--secreting DHEA which go on to make estrogen
What is essential for breast development during pregnancy?
Prolactin
Estrogen
Progesterone
What are the actions of prolactin?
Promote breast development during pregnancy
Promote milk synthesis and secretion
How is prolactin inhibited during pregnancy?
Estrogens and Progesterones
What inhibits prolactin in non pregnant individuals?
Dopamine
What is the most potent release of prolactin after delivery?
Suckling
What causes the iniation of lactation?
A drop in estrogen and progesterone
Prolactin
When the sperm cytosol enters the egg, calcium rises. What does the stimulate?
The 2nd meiotic division and the egg releases granules that harden the zona pellucida preventing other sperm from entering
What does the attachment of the blastocyst to the uterine wall require?
Progesterone
Is the placenta secretion regulated by maternal or fetal signs?
No--it is autonomous
What cells form the early placents?
The syncytiotrophoblast
When does implantation occur?
When progesterone is the highest
What hormones are secreted during pregnancy?
hCG
Progesterone
hCS
Estrogens
When is hCG the highest during pregnancy?
At the beginning until about the 12th week
What are the functions of hCG?
Prolong the life of the corpus luteum and to stimulate testosterone production by the fetus
What is responsible for producing the majority of estrogen during pregnancy?
The fetal adrenal glands--secreting DHEA which go on to make estrogen
What is essential for breast development during pregnancy?
Prolactin
Estrogen
Progesterone
What are the actions of prolactin?
Promote breast development during pregnancy
Promote milk synthesis and secretion
How is prolactin inhibited during pregnancy?
Estrogens and Progesterones
What inhibits prolactin in non pregnant individuals?
Dopamine
What is the most potent release of prolactin after delivery?
Suckling
What causes the iniation of lactation?
A drop in estrogen and progesterone
Prolactin
What hormone is responsible for milk secretion?
Prolactin
What hormone is responsible for milk ejection?
Oxytocin
What are the three reflexes mediated by suckling?
Milk secretion--PL
Milk ejection--Oxytocin
Suppression of GnRH release-PL
What cells produce testosterone?
Leydig cells
What cells are involved in spermatogenesis?
Sertoli cells
What cells does LH stimulate?
Leydig cells
What cells does FSH stimulate?
Sertoli cells
What is the more potent form of testosterone called?
DHT
What breaks down testosterone into DHT?
5-alpha-reductase
What binding protein is required for spermatogenesis in the sertoli cells?
ABP--androgen binding protein
Via what does FSH elicit a variety of responses in the sertoli cells?
cAMP
What is used clinically as markers of Sertoli cell function?
ABP
What do Sertoli cells secrete that are important for development of the Wolffian pathway?
Anti-mullerian hormone
What does inhibin do in males?
Increases testosterone secretion
What does activin do in males?
Decreases testosterone secretion
What kind of feedback does inhibin have on GnRH stimulated FSG secretion by the anterior pituitary?
Negative feedback
What does spermatogenesis require in adults?
Functional Sertoli cells and an intact hypotalamic-pituitary-gonadal axis
How is GnRH realeased?
In pulsatile fashion--absolute requirement for a functioning reproductive system
Is LH required for spermatogeneis?
Yes, indirectly
What is the regulator of spermatogenesis?
Testosterone
How is GnRH activity mediated?
Through the IP3 pathway
What does continuous exposure to GnRH do?
Suppresses gonadotrop secretory activity
What does inhibin in males inhibit?
FSH
Is the erectile response sympathetic or parasympathetic?
Parasympathetic
Is the emission and ejaculatory response sympathetic or parasympathetic?
Sympathetic
What is primary hypogonadism?
Primary testicular failure
What is an example of primary hypogonadism?
Klinefelter's Syndrome
What is secondary hypogonadism?
Impaired gonadotropin secretion
What is Kallman's syndrome?
Gondatropin deficiency caused by deficient production of GnRH--GnRH fail to migrate to the hypothalamus