Test 2 Flashcards
Fast acting
Reproductive system and nervous system
Neural control
Regulated by interplay between nervous system and endocrine system
Reproductive system
Transduce external stimuli into neural signals which bring about a change in the reproductive organs and tissues
Nervous system
Neural control exerted by
Simple neural reflexes
Neuroendocrine reflexes
Nerves release messages directly onto target tissues
Direct innervation of the target tissue by neuron
Simple neural reflexes
A substance released by a neuron enter the blood and act on a target tissue
No direct innervation
Neuroendocrine reflexes
Simple neural reflexes and Neuroendocrine reflexes cause _____changes in target tissues
Rapid
Neural reflex
Sensory nerves —> inter neurons in spinal cord —> efferent nerves —> target tissue
Substance of small molecular weight which is released from nerve terminals that caused other nerves to “fire” or causes contraction of smooth muscle that stimulates reproductive tract
Neurotransmitter
Neuroendocrine reflex
Sensory nerves —> inter neurons in spinal cord —> efferent nerves —> hypothalamus —> target tissue
Release excitatory neurotransmitters
Increase possibility of nerve “firing”
Excitatory neurons
Release inhibitory neurotransmitters
Decrease possibility of nerve “firing”
Inhibitory neurons
Postsynaptic action potential
“Firing” of nerve
Neural control center for reproductive hormones
Complex portion of brain consisting of clusters of nerve cell bodies
Hypothalamus
2 groups important in reproduction
Surge center
Tonic center
System filled with cerebrospinal fluid that continually circulates through ventricles of subarachnoid spaces of the central nervous system
Ventricle system
Ventricle system ventricles
Lateral ventricles
3rd ventricle
4th ventricle
Central canal
Rapid response
Little dilution
Short 1/2 life
Hypothalamic-pituitary-gonadal axis
Slow acting
Endocrine control
5 cell types in anterior pituitary gland
- Gonadotropes
- Somatotropes
- Lactotropes
- Corticotropes
- Thyrotropes
A substance produced by a gland that acts on a remote tissue to bring about a change in that tissue
Hormone
Time required for one-half of a quantity of a hormone to disappear from the blood or from the body
Half-life
A cell produces a hormone that acts on the SAME cell
Autocrine
A cell produces a hormone that acts on a REMOTE cell
Endocrine
A cell produces a hormone that acts on a NEARBY cell
Paracrine
Characteristics of reproductive hormones
Act in minute quantities
Short half-lives
Bind to specific receptors
Regulate intracellular biochemical reactions
For hormone to act, must interact with a
Receptor
Reproductive hormones originate from
Hypothalamus
Anterior and posterior pituitary
Gonads
Uterus
Placenta
Produced by neurons in the hypothalamus
Cause the release of other hormones by the anterior pituitary gland
Generally less than 20 amino acids
Hypothalamic hormones
Released into blood from anterior and posterior pituitary glands
Pituitary hormones
Hypothalamic hormone example
GnRH
Pituitary hormone examples
FSH
LH
Prolactin
Oxytocin
Originate from the gonads
Affect function of hypothalamus, anterior pituitary and tissues of the reproductive tract
Include secondary sex characteristics
Gonadal hormones
Estrogens, progestogens, inhibin, some testosterone, oxytocin and relaxin
Ovary gonadal hormones
Testosterone and other androgens, inhibin and some estrogens
Tested gonadal hormones
Prostaglandin F2alpha
Uterus gonadal hormones
Progesterone, estrogen, eCG, hCG
Placenta gonadal hormones
Synthesized by neurons and released directly into blood
Cause a response in target tissues elsewhere in the body
Neurohormones
Neurohormone example
Oxytocin
Synthesized by neurons and cause release of other hormones from the anterior pituitary
Releasing hormones
Releasing hormone example
GnRH
Released by gonadotrope cells of the anterior pituitary gland “tropin”
Gonadotropins
Gonadotropin examples
FSH
LH
Causes follicular growth in ovary
Stimulates Sertoli cells in testis
FSH
Causes ovulation and stimulation of CL in the ovary
Causes testosterone production in testis
LH
Produced by gonads to stimulate reproductive tract, to regulate function of the hypothalamus and anterior pituitary, and to regulate reproductive behavior
Cause development of secondary sex characteristics
Sexual promoters
High concentrations during pregnancy
eCG, hCG, placental lactogen
Pregnancy maintenance hormones
Mammary gland development
Placental lactogen
Cause destruction of the CL
Prostaglandin F2alpha
Luteolytic hormones
Promote metabolic well being
Exert indirect effect on reproduction
General metabolic hormones
3 types of biochemical classifications
Protein hormones
Steroids
Prostaglandins
Protein hormones
<20 amino acids
Peptides
Polypeptide hormones which contain carbohydrate moieties 70 KD
Can be composed of two side by side polypeptide chains with carbohydrates attached to each chain
Increased amount of carbohydrate = increased half life
Glycoproteins
Hormones all contain the same alpha subunit but s unique beta subunit (FSH, LH)
Anterior pituitary
Glycoproteins Half - life =
Minutes to hours
> 20 amino acids
Only peptide bonds to break down
Protein hormones
Core of all steroid hormones
Cyclopentanoperhydrophenanthrene nucleus
Synthesized from cholesterol
Composed of 4 acetate rings
Cholesterol, progesterone, testosterone, estradiol
Steroids
Number of carbons cholesterol
27 carbons
Number of carbons progesterone
21 carbons
Number of carbons testosterone
19 carbons
Number of carbons estradiol
18 carbons
Steroids half life
Hours to days
Synthesized from arachidonic acid
Rapidly degraded in blood
One of the most ubiquitous, physiological active substances in the body
20-carbon unsaturated hydroxy fatty acids
Prostaglandins
Prostaglandin half-life
Seconds
Receptors are part of plasma membrane
Protein hormones
Receptor in nucleus
Steroid hormones
Receptor in plasma membrane
Prostaglandin
Binds to receptor and elicits same biological effect as native hormone
Agonist
Binds to receptor but does not elicit same biological effect as native hormone
Antagonist
Receptor domain regions
Extracellular domain, transmembrane domain, intracellular domain
Site which binds specific hormone
Extracellular domain
Changed its configuration and activates other protein hormones in response to hormone binding at the Extracellular domain
Transmembrane domain
Function unclear
Intracellular domain
Types of hormone release
Episodic, basal, sustained
Associated with hormones under nervous control
Nerves of the hypothalamus fire and neurohormones are released in a sudden burst or pulse
Episodic hormone release
Hormone stays low but fluctuates with low amplitude pulses
Basal hormone release
Hormone remains elevated, but a relatively steady fashion for a long period of time
Sustained hormone release
Fitting two adjacent pieces of a puzzle
Hormone-receptor binding
Hormone receptor complex activates a membrane-bound enzyme — adenylate Cyclades
Mediated by a membrane- bound protein (G-protein)
Activation of adenylate Cyclase
Adenylate cyclase activation
cAMP triggers activation of control enzymes called protein kinases
Convert substrates into products
Regulatory and catalytic subunits
cAMP binds regulatory subunit and causes activation of catalytic subunit
Protein kinase activation
Products made by cell are generally secreted by the cell
Synthesis of new products
Physiological activity of a hormone depends on
Pattern and duration of secretion
Half-life
Receptor density
Receptor-hormone affinity
Hormonal potency is influenced by
Receptor density
Hormone receptor density
Promote synthesis of receptor
Up regulation
Inhibit synthesis of receptors
Down-regulation
Steroid hormones Metabolized in the liver - 2 methods
Double bonds within the steroid become saturated
Attachment of sulfate or glucuronide residue
Leads to double bond reduction and inactivity of hormone
Double bonds within the steroid become saturated
Allows hormone to be secreted in urine or feces
Attachment of sulfate or glucuronide residue
Protein hormones are ____________ mostly
Glycoproteins
Removal of glycosylation sites
Allows molecule to bind to cells
Internalized and degraded in cytoplasm
Liver
Glycoprotein hormones <55,000 daltons are filtered through glomerulus
Secreted into urine and eliminated
Kidneys
Radioactive hormones compete with
Native hormone
Amount of radioactive hormone that binds is
Inversely proportional to the concentration of unlabeled hormone in the animal’s blood
Advantage of no radioactivity
Series of well-controlled steps to determine presence or absence of hormone
Can also determine quantity of hormone present
Relatively inexpensive
ELISA
1/2 life shortest to longest female
- PGF2a
- GnRH
- prolactin
- LH
- FSH
- hCG
- eCG
- Estradiol - 17B
- Estradiol cypionate
Inherently female
Hypothalamus
Testosterone _______ the brain and eliminates ______ _______ _______ in males
- Defeminizes
- GnRH surge center
Male or female: surge and tonic center
Female
Male or female: tonic center only
Male
Produced by fetal liver
Binds estradiol-17B and not testosterone
a-fetoprotein
Female alpha-fetoprotein
Binds estradiol-17B so it can’t cross the blood-brain barrier
Male alpha-fetoprotein
Doesn’t bind testosterone so it can cross the blood-brain barrier
Conversion of testosterone to estrogen-17B by aromatase
Occurs in brain
Aromatization
Triggers changes in neurons of brain
Surge center does not develop
Aromatization estrogen
Ability to accomplish reproduction successfully
Puberty
Requires development of specific hypothalamic neurons so that there is a release of adequate quantities of GnRH at appropriate frequencies
Pubertal onset
Puberty is influenced by
Acquisition of threshold body size
Exposure to certain environmental and social cues
Genetics of animal
Definition of puberty onset in female
Age at first estrus
Age at first ovulation
Age at which a female can support pregnancy
Definition of puberty onset in male
Age when behavioral traits are expressed
Age at first ejaculation
Age when spermatozoa fist appear in ejaculate
Age when spermatozoa first appear in urine
Age when ejaculate contains threshold number of spermatozoa
Onset of puberty requires high frequency _____ _______
GnRH pulses
Before puberty GnRH
Lower pulse frequency
Lower pulse amplitude
After puberty GnRH
Higher pulse frequency
Higher pulse amplitude
Age at puberty is influenced by
Breed
Threshold body size
External or social factors
External or social factors species:
season of birth
Photoperiod at time of pubertal onset
Sheep
External or social factors species:
Density of housing groups (same sex)
Swine
External or social factors species:
Presence of opposite sex during peripubertal period
Swine and cattle
Controlled by ability of hypothalamus to secrete GnRH in sufficient quantities
NOT due to anterior pituitary’s ability to produce LH and FSH
NOT due to gonads ability to respond to LH and FSH
Onset of puberty
Rheostatically controlled light switch
Development of hypothalamus
Hypothalamic GnRH centers
Tonic
Surge (preovulatory)
GnRH neurons must “fire” frequently and release large quantities of GnRH to induce the LH surge
Preovulatory GnRH surge
Tonic center must also mature in function to regulate
Tonic frequency of LH pulses
Controlled by a “pulse generator” to read
Internal and external signals to induce GnRH release and onset of puberty
Prepubertal female has lack of _____ _______ to stimulate ______ ________
- Gonadal estradiol
- Surge center
Surge center is quite sensitive to _______ __________
Estradiol feedback
Main endocrine profile difference between postpubertal males and females
LH surges in female but there are no LH surges in male
Nutrients utilized for maintenance
Degree of fatness: newborn
Energy consumption increases
Body mass increases
Relative surface area of body decreases
Degree of fatness: growing neonate
Both ____ and ________ are important to onset of puberty
Age
Fatness
Hormonal peptide produced by fat cells
Leptin
The amount of leptin in blood is directly related to the amount of ___ ____ ____ ______
Fat in the body
Leptin receptors are in
Liver
Kidney
Heart
Skeletal muscles
Pancreas
Anterior pituitary
Hypothalamus
What is not known in males
Mechanism of fatness for puberty
Environmental and social conditions
Season of birth and photoperiod
Social cues
Pheromones in urine
Olfactory recognition
At puberty, female enters state of __________ ______
Reproductive cyclicity
Provide female with repeated opportunities to become pregnant
If conception does occur, then female enters a period of anestrus during pregnancy which ends after parturition, uterine involution and lactation
Estrous cycle
Estrus is a
Noun
Estrous is an
Adjective
“Heat”
Period of sexual receptivity
Estrus
Period from 1st estrus to the next
Estrous cycle
Uniform distribution of estrous cycles throughout the entire year
Polyestrus
“Clusters” of estrous that occur during a certain season
Seasonally polyestrus
Short-day breeder
Sheep
Long-day breeder
Horses
Only one estrous cycle per year
Periods of estrus last for several days
Monoestrus
Period from regression of CL to ovulation
Generally short, <20% of cycle
Follicular phase
Follicular phase structure
Follicle
Follicular phase hormone
Estradiol
Period from ovulation to CL regression
Very long, ~80% of cycle
Luteal phase
Luteal phase structure
CL
Luteal phase hormone
Progesterone
Follicles do or don’t continue to grow during luteal phase
Do
Formation of ovulatory follicles
E2 secretion
Proestrus
Sexual receptivity
Peak E2 secretion
Estrus
CL formation
Beginning of P4 secretion
Metestrus
Sustained luteal secretion of P4
Diestrus
Period immediately before estrus
2-5 days in length
Due to FSH and LH
Progesterone dominance to estradiol dominance
Proestrus
Estradiol is dominant and at peak levels
Mating posture
Ovulation for all species but cow
Visible behavioral symptoms
Estrus
Period between ovulation and formation of function CL
P4 levels increase over this period
Ovulation occurs at start of this period in cattle
Metestrus
Period from formation of fully functional CL to lysis of the CL
Longest stage of estrous cycle
10-14 days in length
Females don’t display sexual receptivity m
Diestrus
Dog estrous cycle phases
Proestrus, estrus, Diestrus, anestrus
Cat estrous cycle phases
Proestrus estrus proestrus, Diestrus and anestrus
Cat polyestrous cycles: Felids
Induced ovulated
Compilation induces LH surge
Interestrus period following estrus in Queen that has not been induced to ovulate by copulation
Postestrus
“Without cyclicity”
Ovaries remain inactive
Anestrus
Anestrus can be caused by
Pregnancy
Lactation
Presence of offspring
Season
Stress
Pathology
Events that occur between the onset of two successive menstrual periods
Menstrual cycle
Sloughing of the endometrium to the exterior
Menses
Follicular phase menses length
2 to 5 days
Follicular phase proliferative phase length
9 days
Luteal phase secretory phase length
14 days
Ovulation occurs on day
14
Anestrus in women
Amenorrhea
4 events take place during follicular phase
gonadotropin release from the anterior pituitary
Follicular preparation for ovulation
Sexual receptivity
Ovulation
Place in order the following items associated with the effect of photoperiod on short day breeders
Superior cervical ganglion
GnRH
Short day length
LH
Pinealocyte
Hypothalamus
Retina
Suprachiasmatic nucleas
Anterior pituitary
Melatonin
- Short day length
- Retina
- Superchiasmatic nucleas
- Superior cervical ganglion
- Pinealocyte
- Melatonin
- Hypothalamus
- GnRH
- Anterior pituitary
- LH
Rank the following hormones with regard to half-life from shortest to longest
Prolactin
eCG
PGF2a
Estradiol benzoate
LH
hCG
Oxytocin
Estradiol-17B
FSH
- PGF2a
- Oxytocin
- Prolactin
- LH
- FSH
- hCG
- eCG
- Estradiol-17B
- Estradiol Benzoate
Would you expect return to cyclicity following parturition to be shortened or would you expect return to cyclicity following parturition to be delayed:
Exposing ewes to rams
Shortened
Would you expect return to cyclicity following parturition to be shortened or would you expect return to cyclicity following parturition to be delayed:
Limiting suckling sessions to 4 times per day in the beef cow
Delayed
Would you expect return to cyclicity following parturition to be shortened or would you expect return to cyclicity following parturition to be delayed:
Utilizing beef cows that lose weight following calving
Delayed
Would you expect return to cyclicity following parturition to be shortened or would you expect return to cyclicity following parturition to be delayed:
Bottle feeding a baby following 4 months of breast feeding in humans
Shortened
Would you expect return to cyclicity following parturition to be shortened or would you expect return to cyclicity following parturition to be delayed:
Weaning piglets from sows at 21 days of age
Shortened
Would you expect age at puberty to be sooner/younger or would you expect age at puberty to be later/older:
Utilize ewe lambs that were born in the spring
Sooner/younger
Would you expect age at puberty to be sooner/younger or would you expect age at puberty to be later/older:
Decrease the number of gilts per pen
Later/older
Would you expect age at puberty to be sooner/younger or would you expect age at puberty to be later/older:
Increase the average daily gain (growth rate) of dairy heifers
Sooner/younger
Would you expect age at puberty to be sooner/younger or would you expect age at puberty to be later/older:
Provide gilts with daily boar exposure beginning at appropriate time
Sooner/younger
Would you expect age at puberty to be sooner/younger or would you expect age at puberty to be later/older:
Feed beef to heifers to achieve a high growth rate
Sooner/younger
What estrous cycle to pigs exhibit
Polyestrus
What estrous cycle to deer exhibit
Seasonally polyestrus
What estrous cycle to horse exhibit
Seasonally polyestrus
What estrous cycle to wolf exhibit
Monoestrus
Estrous cycle that is 17 days in length is for which species
Cat
Estrous cycle that is diestrus only occurs after mating is for which species
Cat
Estrous cycle that contains a metestrus sub-phase is a _____ estrous cycle
Typical
Estrous cycle that contains an anestrus sub-phase if for which species
Dog
Estrous cycle that contains a post-estrus sub-phase is for which species
Cat
Estrous cycle that the proestrus sub-phase lasts for 9 days is for which species
Dog
Produced by all tissues of the body
Is it a characteristic of a protein, steroid, or prostaglandin hormone?
Prostaglandin hormone
A pair of hormone:receptor complexes bind to the DNA
Is it a characteristic of a protein, steroid, or prostaglandin hormone?
Steroid hormone
Derived from cholesterol
Is it a characteristic of a protein, steroid, or prostaglandin hormone?
Steroid hormone
Requires a binding protein to move through the blood
Is it a characteristic of a protein, steroid, or prostaglandin hormone?
Steroid hormone
Hormone is rendered inactive upon saturation of double bonds in liver
Is it a characteristic of a protein, steroid, or prostaglandin hormone?
Steroid hormone
Is conjugated to sulfated or glucoronides for excretion in urine or feces
Is it a characteristic of a protein, steroid, or prostaglandin hormone?
Steroid hormone
Activates cAMP and protein kinases following binding to its receptor
Is it a characteristic of a protein, steroid, or prostaglandin hormone?
Protein hormone
Receptor is located in the nucleus
Is it a characteristic of a protein, steroid, or prostaglandin hormone?
Steroid hormone
Glycoproteins are removed allowing molecule to bind to liver cells
Is it a characteristic of a protein, steroid, or prostaglandin hormone?
Protein hormone
Derives from arachidonic acid
Is it a characteristic of a protein, steroid, or prostaglandin hormone?
Prostaglandin hormone
Produce growth hormone
Somatotropes
Produce high amplitude GnRH
Surge center
Produce low amplitude GnRH
Tonic center
Produce leptin
Adipocytes
Produce oxytocin
Periventricular nucleus (PVN)
The luteal phase represents 50% of the cycle
Is it a characteristic of the estrous or menstrual cycle?
Menstrual cycle
Ovulation occurs at the start/end of the cycle
Is it a characteristic of the estrous or menstrual cycle?
Estrous cycle
No defined periods of sexual receptivity
Is it a characteristic of the estrous or menstrual cycle?
Menstrual cycle
The follicular phase represents 20% of the cycle
Is it a characteristic of the estrous or menstrual cycle?
Estrous cycle
Ovulation occurs in the middle of the cycle
Is it a characteristic of the estrous or menstrual cycle?
Menstrual cycle
Sloughing of the endometrium to the exterior
Is it a characteristic of the estrous or menstrual cycle?
Menstrual cycle
Estradiol-17B levels increase during the luteal phase of the cycle
Is it a characteristic of the estrous or menstrual cycle?
Menstrual cycle
Which of these are not characteristic of sexual differentiation of the brain?
A. Testosterone is converted to estradiol-17B by aromatase within the brain
B. The surge center is defeminized by testosterone
C. Estradiol-17B binds to alpha-fetoprotein, removing its lipid-like properties so that it is unable to cross the blood-brain barrier
D. Both A and C
E. Both B and C
B
Which of the following is involved in luteolysis or regression of the corpus luteum?
A. Counter-current exchange between the uterine artery and ovarian vein
B. Counter-current exchange between the uterine vein and ovarian artery
C. PGF2a passes through the lungs prior to reaching the ovary
D. A and C
E. B and C
B
Which of the following species can have a fertile first estrus following parturition?
A. Sow
B. Queen
C. Mare
D. B and C
E. All of the above
D
Why is the hormone, GnRH, so difficult to measure?
A. There are no RIA or ELISA tests available
B. It is rapidly broken down in circulation (short 1/2 life)
C. It must be sampled from the hypothalamo-hypophyseal portal blood
D. Both B and C
E. All of the above
D
Which of the following would be characteristic of a radioimmunoassay (RIA)?
A. Radioactive hormone competes with native hormone
B. Amount of radioactive hormone that brings to inversely proportional to the amount of unlabeled hormone in the blood
C. Relatively inexpensive compared to an ELISA
D. A and B
E. All of the above
D
Which of the following are important to promote attainment of puberty?
A. Increased frequency of GnRH pulses
B. Increased amplitude of GnRH pulses
C. Enough glucose in the blood to stimulate glucose sensing neurons in the brain
D. Both A and B
E. All of the above
E
Which of the following is the primary difference between the mechanisms associated with seasonal anestrus in the mare and ewe?
A. The way the retina senses chances in the light:dark cycle
B. How the pinealocytes produce melatonin
C. The method by which the pinealocytes respond to excitatory neurons
D. Response of the hypothalamus to melatonin
E. A and D
D
Which of the following is characteristic of the process of progesterone priming?
A. The first estrous cycle exhibited following anestrus is silent
B. The first estrous cycle exhibited following anestrus may be shorter than normal
C. Ovulation does not occur during the first estrous cycle exhibited following anestrus
D. A and B
E. All of the above
D
T/F: a neuroendocrine response involves the release of a neuron or one into the blood which then acts on a remote target tissue
True
T/F: A pregnancy test in women would be an example of a radioimmunoassay (RIA)
False
T/F: an antagonist is a substance which binds to a receptor and activated a similar cellular response to the native hormone
False
T/F: to perform an ELISA for measurement of hormone levels, both an antibody linked to a solid substrate and an antibody liked to an enzyme are required
True
T/F: the average length of the estrous cycle in the ewe is 21 days
False
T/F: the process of “progesterone priming” requires that the behavioral center of the brain to be exposed to estrogen so that a corpus luteum can be formed during the next estrous cycle
False
T/F: the hormone, progesterone, is released in an episodic manner
False
T/F: the specialized region (nuclei) of the hypothalamus associated with the posterior pituitary gland is called periventricular nucleus (PVN)
True
T/F: the average duration of estrus in the female cat (Queen) is 8 days
False
T/F: a good landmark for the hypothalamic nerve centers within the brain that are associated with reproduction is the third ventricle
True
French soldiers eating frog legs in North Africa caused two outbreaks of
Priapism
What material is extracted from a beetle
Cantharidin
Painful and prolonged penile erection
Priapism
The word pituitary is derived from the Latin word…
Pituita - means mucus
The existence of the pituitary gland was recognized as early as
200 AD
The pituitary gland was thought to be a
Mucus secreting organ for lubrication of the throat
The dramatic effects of male castration have been recognized for over
2,000 years
The testis was known to control
Virility and sterility
Warriors thought that eating ______ of their enemy increased courage
Hearts
Eating _______ of sheep was thought to improve the intelligence of the mentally challenged
Thyroids
Eating liver from ______ cured liver ailments
Wolves
Eating ______ from rabbits cured nervousness
Brains
Eating _____ from foxes cured respiratory disorders
Lungs
Eating ____ _______ was believed to increase sexual prowess
Sex glands
Brown-séquard injected himself with
Testicular extracts
The leading cause of death in the early 1900s in young women was
Childbirth - bleeding to death
What is administered to women to prevent bleeding during childbirth as well as to enhance uterine contractions for expulsion of the fetus?
Oxytocin
The jest account of reproductive physiology was recorded in about _______ in ___________
- 3200 BC
- Mesopotamia
Whether or not the sprouts germinated determined the
Pregnancy status
Women wishing to know their pregnancy stays would insert an _______ into the vagina
Onion
Species that males and females must be paired before they reach puberty
Clouded leopards
It is said that puberty begins during the ______ in children
Night
It seems as if these increases in GnRH secretion are associated with ____ stages of sleep
REM (rapid eye movement)
______ choirs were composed of adult male singers castrated in boyhood so as to retain soprano or alto voices
Castrato
The age of puberty in girls is ______
Decreasing
Puberty occurred at about ___ years of age in the mid ____ in _______
- 17
- 1800s
- Norway
Today reproductive endpoint occurs at ___ years of age in _____ and ____
- 12
- Europe
- U.S.
Naked mole rats dominant female called
The Queen
The queen uses ____ ______ to suppress puberty
Tactile stimulation
Rare individuals are diagnosed as males having a deficiency in receptors for
Androgens
Victorian women inserted wooden blocks inside their vaginas to obstruct the passage of _____
Sperm
The word menstrual is derived from the Latin word meaning
Month
In historical Latin folklore the moon was believed to regulate not only the tides of the sea, but also the monthly
Emotional tides of women
To offset females preying on males of their species, the males ______ after the female to
1.Hibernate
2. Breed sleeping females
One type of cystic ovarian disease results in
Nymphomania
Women were not employed in the opium industry during the ___ century because it was believed that menstruating women would make the opium _____
- 19th
- Bitter
The mouthbrooder fish is so called because fertilization actually takes place in the female’s
Mouth
Unlike humans, other animals apparently do not have
Menopause
The female African elephant remains reproductively competent until she is in her
Nineties
During the Middle Ages women throughout Europe hollowed out ____ _____ and used them to cover their _____ in the same way women use the diaphragm today
- Lemon halves
- Cervix
Initiated after luteolysis
Follicular phase
The follicular phase consists of
Proestrus and estrus
High progesterone during
Luteal phase
At luteolysis the ____ _____ of progesterone on the hypothalamus is removed
Negative feedback
4 events take place during follicular phase
Gonadotropin release from the anterior pituitary
Follicular preparation for ovulation
Sexual receptivity
Ovulation
Follicular phase is governed by
Hypothalamus
Anterior pituitary
Ovary
Plays an obligatory role
Releases GnRH which is at the top of the chain
Hypothalamus
Clustered of nerve cell bodies
Hypothalamic nuclei
2 types of hypothalamic nuclei
Surge
Tonic
Tonic and surge centers of hypothalamus control
GnRH release
Surge center responds dramatically to high
Estradiol
Basal secretion of GnRH
Neurons here - episodic profile
Tonic center
Release small pulses of GnRH over a long period of time
Occurs spontaneously in rhythmical fashion
Episodic profile
Preovulatory center
Preovulatory release of GnRH that stimulates a LH surge causing ovulation
Releases basal levels of GnRH until it receives the appropriate signal
Surge Center
The follicular phase only represents ___% of the estrous cycle
20
_____ ____ and ______ occur continuously throughout the estrous cycle
Follicle growth and degeneration
The majority of the follicles life is spent in the
Preantral stages
Small antral follicles: pig
Less than 3mm
Small antral follicles: mare
Less than 10mm
Medium antral follicles: pig
4-6mm
Medium antral follicles: mare
10-20mm
Large antral follicles: pig
Greater than 6mm
Large antral follicles: mare
Greater than 20mm
A cohort of small antral follicles and produce estradiol
Some undergo atresia
Recruitment
A group of growing follicles which haven’t undergone atresia are selected
Selection
Involves emergence of dominant follicle(s) from cohort or already recruited antral follicles - may become the dominant follicles or may undergo atresia
dominance
Not perforated
Occurs at all 3 levels
Atresia
___% of all follicles undergo atresia
90
