Exam 1 Flashcards
Oviparous
Female lay eggs which hatch outside the body Ex. birds
Ovoviviparous
Give birth to live young which hatch from eggs inside the body Ex. snakes
Viviparous
Give birth to live young which are nourished by contact between placenta and uterus Ex. mammals
Induced ovulation
Must be induced by mating Ex. cats
Spontaneous ovulation
Happens every time naturally Ex. humans
Delayed Fertilization
When a fertilized egg develops into a blastocyte which remains unattached to the uterus
Delayed development (embryonic diapause)
Suspension of embryonic development
Obligate
Delayed implantation happens every time Ex. Badger
Faculative
Delayed implantation happens based on lactation Ex. mouse
In facultative diapause species what is the stimulus for entry into diapause
lactation and metabolic stress
In facultative diapause species what is the exogenous stimulus out of diapuase
weaning
In facultative diapause species what is the endogenous stimulus out of diapause
ovarian estrogen in rodents and prolactin withdrawal in marsupials
In obligate diapause species what is the stimulus for entry into diapause
Developmental stage in all gestations
In obligate diapause what is the exogenous stimulus out of diapause
photoperiod
In obligate diapause what is the endogenous stimulus out of diapause
prolactin secretion unknown ovarian factors
Spontaneous abortion
A female terminates her current pregnancy when exposed to an unfamiliar male due to a surge in progesterone
Monozygotic Polyembryony
One egg is fertilized then divides forming identical embryos
Intrafollicular fertilization
Fertilization occurs into the follicle prior to ovulation
What is the concept of environmental control of gestation length
Females in a herd give birth shortly before the herd is suppose to migrate
what are the 4 ways hormones can communicate in the body
endocrine, paracrine, autocrine, and intracrine
Steps of endocrine communication
chemical messenger, secreted by endocrine glands, transported by blood, then hits the target tissue (phyiologic response)
How does paracrine communication affect the body
Hormone stimulates adjacent cells w/o entering the blood never entering the blood
How does the autocrine communication affect the body
Hormone stimulates the same cell that secretes the hormone
How does the intracrine communication affect the body
Hormone stimulates the cell w/o being secreted never leaving the cytoplasm
Characteristics of protein hormones
Particularly large molecules, polar (dissolved in water), and must have receptor
Charactistics of steroid molecules
Smaller molecule, non polar (can not mix w/ blood), and there are proteins steroids can blind to
Characteristic of fatty acid hormones
Contains OH and COOH
What are the 3 types of protein hormones
Peptides, proteins, glycoproteins
What are peptide hormones
Short chain of two or more amino acids
What are protein hormones
Long chains of amino acids
What are glycoprotein hormones
protein + carbohydrates and has two subunits alpha and beta
What are steroid hormones
synthesized from cholesterol and has 4 rings
Characteristics of lipid hormones (prostaglandins)
Derived from arachidonic acid and are produced by most tissues in autocrine, paracrine, and endocrine actions
What are the functions of lipid hormones
triangulate smooth muscle contractions, lipid metabolism, mediate inflammation, vasodilation/constriction, maintenance/regresses CL, ovulation, and parturition
4 things that affect the control of the hormone
amount of homrone secreted, number of receptors present, rate of metabolism, affinity of hormone binding to the receptor
Characteristics of protein hormone metabolism
hormone binds to receptor and is internalized, metabolism in circulation and the liver, glycoproteins can be excreted in the urine, liver metabolizes hormones then transports them to the kidneys for excretion
Characteristics of prostaglandin metabolism
metabolized by enzymes in the lungs degraded hormones quickly and horses cannot process prostaglandin in their lungs
Steps of steroid hormone metabolism
Liver removing the double bonds and adding glucuronic acid or suphate group making it water soluble kidneys then remove the steroid metabolite from circulation
Characteristics of hormones
Do not supply energy, regulates rates of specific processes, act in small quantities, short half life, bind to receptors, immediate or delayed action, and help maintain homeostasis
What is negative feedback
The effect of the hormone slow down or stop the hormone from being released ex. when testosterone hits the testis negatively effects the production of the hypothalamus
What is positive feedback regulation
The effect of the hormone enhance or amplifies the hormone being released ex. LH causes more estrogen to be released from the ovary then increases GnRH hormones in the bloodstream
Relationship between the release of GnRH, FSH, and LH
GnRH is released first then shortly after is a surge of FSH, and then finally almost immediately after a surge of LH
Where are the receptors for protein hormones located
on the outer layer of the cell membrane
What are the two different receptors used for steroid hormones
cell membrane receptors triggers fast response and nuclear receptors triggers slow response
What is the process of the 2nd messenger system of protein hormones
G protein triggers adenylate cyclase which turns ATP into cAMP
What do hormone receptors trigger
the promoter inducing transcription
What does the surge center have to produce in order for a female to ovulate
LH
what is the hypothalamus
neuro endocrine cells synthesis of releasing factors and oxytocin
How does close association of the anterior pituitary and the hypothalamus affect hormone disturbation
allows for minute quantities of the hormone to be carried out no dilution in circulation required
Is there a physical connection between HYPO and AP
no
Are HYPO and PP physically connected
yes
How do HYPO neurons and hormones travel to PP capillary plexus
nerve axons
What are the secreting neurons
two groups of nerve cells which release peptide hormones that produce hormones for the posterior and anterior (GnRH) pituitary
What is the function of the hypophyseal portal vessels
carry releasing hormones to anterior pituitary
Where does the posterior pituitary originate
neural ectoderm
Where does the anterior pituirary originate
oral ectoderm
What does kisspeptin stimulate
GnRH
What is the relationship between testosterone and kisspeptin
Testosterone blocks kisspeptin when testosterone decreases kisspeptin signals the release of GnRH
Where does the hormonal surge of LH come from in the female brain
AVPV
What is the function of GnRH
Stimulating the release of FSH and LH from anterior pituitary driving reproduction
What hormones does Parlodel-Bromocriptine Ergotalkaloid gland produce
Dopamine, Corticotropic Releasing Hormone (CRH), Growth Releaseing Hormone (GRH), and Oxytocin
What is the function of CRH
Stimulates ACTH release and can trigger parturition
What hormones does the anterior pituitary produce
FSH, LH, prolactin, Growth hormone, and Adrenalcorticotropic hormone (ACTH)
What is the function of FSH
Stimulates follicle growth, estrogen, and spermatogenesis in males
What is the function of LH
Stimulates ovulation, supports CL formation and progesterone secretion, testosterone, and synthesis by leydig cells of testis
What is the function of Adrenalcorticotropic Hormone (ACTH)
Release of corticosteroids and glucocorticoids from adrenal cortex and initiates parturition
What is the function of estrogen
Controls mating behavior, secondary sex characteristics, maintenance of female duct system, and mammary growth
What hormone does Corpus Luteum produce
progesterone
What is the function of progesterone
Maintenance of pregnancy, mammary growth and secretion, and final follicular growth
What hormone does the uterus produce
Prostaglandin F2 alpha
What are the functions of prostaglandin
Regression of the CL, stimulate myometrial contractions, ovulation, and sperm transport
What hormone does the pineal gland produce
Melatonin
What are the functions of melatonin
Control of seasonal reproduction in mares and ewes and regulates hair growth
What is the gene that triggers the development of testes by binding to regulatory elements to DNA to alter gene expression
SRY
What is the function of SOX9 gene
It blocks the activation of female genes such as Wnt4, Rspo1, and FoxL2
What does the Y chromosome in Klinefelter’s syndrome (XXY) trigger
The development of male attributes such as testicular hypoplasia (sterile)
How are people w/ Turner’s syndrome sterile (XO)
Ovaries are inactive
What two genes trigger the formation of the genital ridge
WT1 (Wilms Tumor Gene) and SF1 (Steroidogenic Factor 1)
What is the genital ridge
It begins the ventral surface of the mesonephros as paired thickenings of the coelomic epithelial layer
In the embryo where are the primordial germ cells located
The yolk that then travel to the midgut to be inserted into circulation
What is the genitial tubercle
The penis or clitoris
What is the genitial fold
The prepuce or inner vulva
What is the genitial swelling
Scrotum or outer vulva
What does PGC mean
Primordid germ cells
What do PGCs form into in the testes
spermatogonia
What do PGCs form into in the ovaries
oogonium/oocytes and granulosa cell formation
What is the tubular reproductive tract of females
Oviduct, uterus, cervix, and anterior vagina
What is the tubular reproductive tract of males
Epididymis, vas deferens, and vesicular glands
What two hormones trigger the formation of the male tubular tract and stops the formation of the female tubular tract
Testosterone and Anti mullerian hormone
What produces testosterone
The leydig cells in the testes
What is Gubernaculum
An elastic ligament that attaches to the testicle
What has to happen for testicles to descend from the abdomen and into the scrotum
Shortening of the inguinal ligament and increase in the intra abdominal pressure
What is the inguinal canal
Where the testicle has to descend through to reach the scrotum
Whatis the role of 5 alpha reductase
Turning testosterone into DHT
What is the role of DHT
It triggers the development of external genitalia
What hormone can naturally cross the blood brain barrier
Testosterone
What enzyme does estrogen bind to that keeps it from crossing the blood brain barrier
Alpha fetoprotein produced in the liver
What happens to testosterone in the brain
Aromatase converts it into estrogen inducing the male brain
What is the role of the blood brain barrier
Filters things in the blood so that everything does not reach the brain
What is the genotype, gonads, repro hormones, tubular tract, external genitalia, and brain of testicular feminization
XY, testes, testosterone & AMH but no testosterone receptors, no male or female tract, female, male
What is the genotype, gonads, repro hormones, tubular tract, external genitalia, and brain of androgenital syndrome
XX, ovaries, testosterone (fetal adrenal), male and female tract, male, male
What is the genotype, gonads, repro hormones, tubular tract, external genitalia, and brain of persistent mullerian duct
XY, testes, testosterone but no AMH or AMH activity, male and female, male, male
What is the genotype, gonads, repro hormones, tubular tract, external genitalia, and brain of penis at twelve
XY, testes, testosteron & AMH but no alpha reductase enzyme activity, male, female at birth then male at puberty, male
Where do sperm form in the penis
Seminiferous tubule
What is the route of sperm
Seminiferous tubule, rete tubules, efferent ducts, head of epididymis, body of epididmyis, tail of epididymis, ductus deferens
What are the four things involved in regulating the testicular temp
Scrotum, dartos muscle, cremaster muscle, pampiniform plexus
How does the scrotum assist in thermo regulation
The temp of the scrotum triggers the body to raise the testis into the body to maintain the temp thru receptor that communicate directly w/ the brain
How does the tunica dartos muscle assist in thermo regulation
Contracts during cold weather and relaxes during warm weather
How does the cremaster muscle assist in thermo regulation
It pulls the testicle to the body during cold weather relaxes during warm weather pulling it away
How does the pampiniform plexus assist in thermo regulation
The veins surround the artery cooling the temp of the blood coming from the body
What is the function of the rete testis
Network of collecting tubules
What is the function of the efferent ducts
Fluid absorption
What is the function of the epididymis
Transport, concentration, maturation, and storage of sperm
What is the function of the vas deferens
Transport of sperm
What is teh cytoplasmic droplet
A droplet of cytoplasm that starts at the base of the head of the sperm and gradually works it way to the tail keeping it sterile untill it is removed at the tail of the epididymis
What are the four things that affect sperm production
Size of testes, size cauda epididymis, cryptorchidism, effect of ejactulation
What is the function of the ductus deferens
Takes the sperm from the epididymis
What are the three glands that produces seminal plasma
Vesticular gland, prostate gland, and cowper’s gland
What are the four muscles that are involved in ejactulation
Bulbospongiosus, ischiocavernosus, retractor penis, urethralis muscle
What is the funcion of the seminal plasma
To protect the sperm from any pH change
What is the colliculus seminal
Opening where sperm and seminal fluid are released together
What is the function of the bulbospongiosus muscle
When it contracts it pushes semen through the penis to the outside world during ejaculation
What is the function ischiocavernosus muscle
When it contracts it closes the crura stopping blood flow to the penis and the lack of blood return increases the BP of the penis
What is the function of the retractor penis muscle
When it contracts it pulls the penis pulling the penis inside creating the S shape but when relaxed it allows the penis to become straight
What is the helicine arteries
Two arteries in the penis that is stimulated by nitric oxide which causes vasodilation when GTP is converted to cGMP by guanylate cyclase and stops occuring when phosphodiesterase cleaves cGMP to GMP
Where does blood come from
The cavernosal artery aka erection canal
What are the steps of ejaculation
Intromission, sensory stimulation of glans penis, sudden powerful contraction of the urethralis, ischiocavernous, and bulbospongiosus, finally expulsion of semen
What is intromission
Process where penis is inside the vagina
What is inside the vagina that stimulates teh glans penis
An increase in temp and pressure
What happes if you cut the sigma flexure on a ram
They will become sterile
What does it mean for a penis to be fibroelastic
It will never increase in length or diameter
What are the steps of erection in ruminants
Vasodilation of the helicine arteries increasing the blood flow into the cavernous spaces, the ischiocovernosus muscle contracts forcing blood into erection canals, an increase in blood pressure, and retractor penis muscle relaxes straightening the sigmoid flexure
What is emission
Contractions of tail epididymis and vas deferens moves sperm into pelvic urethra in front of the colliculus seminalis
What is the function of the urethralis muscle
It moves semen to the root of the penis
What is the function of the hypothalamo-hypophyseal portal vessels
Close association allows for minute quantities of hormone to carry out their action and their is no dilution in circulation
What nerves produce oxytocin
PVN
What is the path of hormones produced in the HYPO neurons
They travel via nerve axons to the PP capillary plexus moving to the rest of the body via the carotid artery
What is the gland that produces, chemical class, and function of GnRH
The hypothalamus, decapeptide, and stimuluates release of FSH and LH
What is the gland that produces, chemical class, and function of corticotropic releasing hormone (CRH)
Parlodel-bromocriptine ergotalkaloid, peptide, and stimulates ACTH release
What is the gland that produces, chemical class, and function of adrenalcorticotropic hormone (ACTH)
Anterior pituitary, protein, and release of corticosteroids and glucocorticoids from adrenal cortex and initiates parturition
What is the gland that produces, chemical class, and function of prostaglandin F2 alpha
Uterus, lipid, and regression of CL
What is the gland that produces, chemical class, and function of melatonin
Pineal gland, biogenic amine, and control of seasonal repro in mare and ewe and regulates hair growth
What duct system from the kidney is used to form the oviduct and epididymis
The mesonephric duct
