Exam 1 Flashcards
What is the cranial region
Hypothalamus and Pituitary Gland
What is the pelvic region
The gonads and the tube system
What is the surge center
part of the brain that releases massive impulses to respond to an abnormal change
What is the tonic center
A part of the brain that releases constant impulses to help maintain homeostasis
What are the functions of the sphenoid bone
It surrounds the hypothalamus and pituitary glands which consists of capillaries that help distribute hormones. It also helps provide protection
The Sella Turcica
Provides structure around the hypothalamus and pituitary. It is the cavity in between the brain and the sphenoid bone
The general functions of the hypothalamus
It is like a thermostat and it senses things then responds.It contains neurosecretory cells and produces neurohormones.
What is the connection between the hypothalamus and the posterior pituitary
It is a direct connection via hormones
General Form of the Posterior Pituitary
It is an extension of the hypothalamus via infundibular stock
Made of neural tissue
Direct extension of axons of the hypothalamus
General Function of the Posterior Pituitary
Site of hormone storage not synthesis
What is the connection between the hypothalamus and anterior pituitary
It is an indirect connection via the primary portal plexus.
Anterior pituitary general form
Located above the roof of the mouth and below hypothalamus
Made of glandular tissue
Anterior pituatary General Function
Site of hormone synthesis
The hypothalamus sends hormone A to the primary portal plexus which then sends it to the anterior pituitary which uses that information to secrete hormone b.
Median Eminence form
contains the infundibular stock and primary portal plexus
What are the immediate effects of severing the pituitary stalk
There is a complete inhibition of the pituitary function
What structure is generally referred to as the body’s thermostat
Hypothalamus
True or False? The anterior pituitary is directly connected to the hypothalamus via hypothalamic neurons
False. The anterior pituitary is connected indirectly via the primary portal plexus.
What happens after GNRH is released from the hypothalamus
It is carried to the anterior pituitary by the primary portal plexus
What structure encapsulates the pituitary gland to aid in protection and diffusion of releasing hormone from the anterior pituitary
sella turcica
True or false? Gonadotropes are individual cells that can be found scattered randomly throughout the anterior pituitary.
False. Gonadtropes are found in clusters not scattered randomly
Where does GNRH enter the blood stream after released from hypothalamic neurons
The median eminence
True or false. Tropes are specialized hormone producing cells found within the posterior pituitary, which stimulate endocrine organs throughout the body.
False they are found in the anterior pituitary
Somatropes
secrete somatotropin
Adrenotropes
secrete adrenocorticotropic hormone
Thyrotropes
secrete thyroid stimulating hormones
What species has an ovulation fossa
Mare
Where are follicles and other functional structures located on the canine ovary
Cortex
What do Sertoli cells in a mature male do
Support gametes and produce steroids
What is a feature of a corpus hemorrhagic
it is similar to a large blood clot
After the ovary, the correct sequence of ducts that ovum pass through on their way toward the cervix is:
Infundibulum, ampulla, isthmus, uterine cornua
In domestic livestock, how much cooler do the testicles have to be in order for sperm production to occur
4-6°C cooler than body temperature
What makes a species with a duplex reproductive tract unique
two cervices and two uterine horns
How does having both circular and longitudinal smooth muscle layers help the tube system
Allows for peristaltic contractions (sequential squeezing)
Main Six Functions of the Female Reproductive Tract
-Hormone Production
-Gamete Production
-Gamete Transport
-Fertilization
-Growth and Development of Offspring
-Parturition
Why is the ovary considered the primary organ
It is the only one that can produce gametes
Ovarian Cytogenic Function
production of gametes (oocytes)
Ovarian Endocrine Function
Secretes Hormones
Tunica Albuginia
Protective white layer that provides structural support and is covered by germinal epithelium.
Cortex
The outer zone and where structures that form the gametes reside
Medulla
The inner zone that contains the blood vessels which help nourish the ovary
Ovulation Fossa
Only present in horses
Where ovulation occurs on the thinning of the medulla
What is different about the configuration of the ovary in horses
The medulla and cortex are reversed. The medulla is on the outside so the horse has the ovulation fossa
Primordial Follicles
One layer of cells that surround the oocyte and is made up of primordial germ cells.
Primary Follicles
One Layer of cuboid epithelial cells.
Increase in size of oocyte and height of follicular cells
Secondary Follicles
Surrounded by several layers of follicular cells
Formation of theca and granulosal cells
Not fluid filled
Tertiary Follicles
Surrounded by several layers of follicular cells in which there is a differentiation. The follicle forms a fluid filled cavity known as antrum.
Cumulus
Granulosa cells that take care of the oocyte
Granulosa Cells
Inner most cells that surround oocyte and add the fluid
Thecal Cells
surround granulosa cells and maintain structural support and well as produces testorone
Mural Cells
A type of granulosa cells underneath the thecal cells that add the fluid and produce estrogen
Corpus Hemorrhagicum
A newly ruptured follicle that is essentially a blood clot
Corpus Luteum
After the CH
“Yellow Body”
Produces Progesteronee
Corpus Albicans
“White Body”
Scar Tissue
remains after the CL regresses
Mucosal layor
directly supports lumen and releases fluid to help nourish
Submucosal Layer
Carries the blood vessels and lymphatic system
Muscularis
The muscle layer that contains both circular and longitudinal layers
Serosal Layer
Outer Protective Layer
What is the general structure of the uterus
There is the body, the cornua(horns) and is composed of three layers
What are the three general functions of the uterus
-Development of offspring
-Sperm survival
-Regulation of the cycle
-Parturition
Perimetrium
-outermost protective layer in the uterus
-similar to the serosal layer
Myometrium
-muscle layers in the uterus
-similar to the muscularis layer
Endometrium
-secretory lining of the uterus
-submucosa and mucosal lining
Bicornuate Uteri
Centrilized Uterine Body and Uterine Horns
Duplex uteri
Two cercvixes and to unterine bodies
Simplex Uteri
no uterine horns
Cervical Structure
It is constricted and thickend as well as has secretory and ciliated cells lining cervix
Cervical Functions
It is a physical and chemical barrier between the uterus and the outside. It also helps with sperm function and storage
Cervix Annular Rings
-Cow and Ewe
-Filter mechanism
Cervical Interdigitating Pads
-Sow
-Filter mechanism but also provides stimulation to the boar
Cervical Longitudinal Folds
-mare
-has folds of cervical lining
Vaginal Structure
-squamos epithelial cell layer surrounded by the muscular wall
General Vaginal Function
It is a copulatory organ, has sperm function, chemical barrier (helps maintain pH balance), and responsive to steroids
Major parts of the external genetalia
-vestibule or vagina
-urethral opening
-labia majora and labia minora
-Clitoris
External Genetalia Functions
-protection
-stimulation
-sexual attracta
Functions of the male reproductive tract
-Hormone Production
-Gamete Production
-Gamete Transport
-Urination
-Ejaculation
Testicles Form
-primary male reproductive organ
-paired in mammals
-found outside the body wall
-must descend into scrotum to ensure normal function
Gubernaculum
Muscle that attaches from the base of the scrotal pouch and the base of the testicle in which the swelling allows testicle descent
Inguinal cavity
whole in cavity in male and closes after testicular descent
Cryptocordism
If the testes do not descent
Time of testicular descent for bulls and rams
midterm gestation
Time of testicular descent for boar
last quater of gestation
Scrotal Skin
has an increased number of sweat glands for temperature regulation
Cremaster Muscle
A muscle that temperalily moves the testes to and from the body cavity
Tunica Dartos
Muscle that allows for long term moved closer to and from the body cavity
Pampiniform Plexus
slows the speed of the blood down to help cool the testes
Cytogenic Function of the Testes
-Production of Gametes
-spermatoza
Testes endocrine function
-secretes hormones
-steroid
-protein peptides
Interstitial Cells (Leydig)
outside the tubule
produces testorone to the blood supply or tubule
Basement membrane
Basal lamina
Outermost layer of seminiferous tubule and provides structure
Primordial Germ Cells
Spermatigonium and either self renews or repopulates
Caput
Head of the epididymis
absorption to concentrate sperm
transport
Corpus
body of epidermis
secretions mature sperm
removes cytoplasmic droplet
forward/progressive motility
fertility
Cauda
Tail of the epidydimis
storage for ejaculation
can cause leakage
Vas Deferens-Ducuts Deferens Form
continuation of the caudal epididymis
Enters the pelvic urethra just posterior to bladder
Vas Deferens Function
contractile tube for sperm transport
longitudinal and circular muscular layers
Muscular Ampulla
bull, ram and stallion
temporary holding area of cells during reproduction
thickening of vas deferns
Seminal Vesiccles form
-vesicular glands
-paired
-lobulated except in stallions
Seminal Vessicles function
production of seminal fluid
sperm viability
flushes tract
Seminal Plasma
flushes reproductive tract helps nutrients and buffer to help with cell survival
What do seminal vesicles produce
fructose
citric acid
insitiol
Prostate Form
Body and/or disseminate
small in bull and ram
large in boar
2 lobes in stallion
What does the prostate produce
-prostate specific antigens
-other proteins
Bulbourethral Gland
Cowpers Gland
Paired
Produce large gelatinous function
Vascular Penes
No sigmoid flexure
Penis fills with blood
raises blood pressure
In Humans and Stallions
Fibroelastic Penes
rigid in non erect state
s shape due to sigmoid flexure
raised blood pressure mean straightens
in bulls, rams and boars
Penis Retractor Muscle and Sigmoid Flexus
allows extension and retraction of the penis and sigmoid flexure extends in copulation
Ischiocavernous and. bulbospongiousus muscles
skeletal muscles for the ejaculation process
Blood-Testes Barrier
tight junctions only allow the gametes, no immune cells, because the cells Innside are haploid immune cells would. destroy sperm cells
Wired Communication
communication with neurons
Wireless communication
communication via endocrine glands
Neurocrine
uses neurons
-axonal transport
then via blood
Exocrine
-secreted into ducts or epithelial surface
-saliva, sweat, milk and pancreatic enzymes
-many times related to digestive function, secretion of enzymes ect..
Endocrine signaling
endo=in, internal
-substance produced in one site travels via blood supply to affect processes in another organ (tissue)
-classical effects of hormones
-example: gonadotropins
Paracrine Signaling
A type of endocrine signaling
-alter activities (+/-) neighboring cells of different types
Autocrine Signaling
-Alters activities neighboring cells of the same type or the secreting cell itself
Autocrine
-a type of endocrine signaling
-alters activities neighboring cells of the same type or the secreting cell itself
Juxtacrine signaling
- a type of endocrine signaling
-alters actvities of cells immediatley adjacent cells transmitted directly through components of a cell membrane
Hormone definition
substance secreted by a cell that acts on some target cell (receptors)
they travel through blood, lymph, diffusion, cerebrospinal fluid and interstitial fluid
Ablation
remove and study change in activity
Replacement
after ablation, add substance back
Betholds Experiment
-castrated 6 roosters
-re-implanted a testis in 2 roosters (normal)
-transplanted a testis from another bird in 2 roosters (normal)
-left 2 castrated roosters to testis-less (lacking masculine charecteristics)
Sterioid Hormones (General Information)
-Cholesterol Backbone
-Adrenocorticoids
-Sex Hormones
-active metabolites of vitamin D
Chemical Properties of Steroid Hormone
-small
-hydrophobic/lipophilic
-travel in blood w/ carrier
-lipid soluable and diffuse through cell membranes
-cytoplasmic or nuclear receptors(also lipid membranes)
What is the precursor for testosterone and estrogen
progesterone
What is the precursor for estrogen
testerone
Progesterone Production in a luteal cell
promote energy of cholesterol into mitochondria
regulated by STAR
CYP11A
Goes from cholesterol to pregenolone by reducing the number of carbons
HSD3B1
goes from pregnolone to progesterone by changing the structure
Aromatase
causes testorone to go to estrogen by losing one carbon
Non-steroid hormones
proteins/peptides
eicosanoids
biogenic amines and catecholamines
Chemical Properties of non-steroid hormones
-large
-hydrophilic
-not lipid soluble so can’t fit through membrane
most hormones
received by receptors external to the cell membrane
requires second messenger mechanism of action
Where are receprtors for non-steroid hormone located
on the cell membrane
Where are the receptors for steroid hormone located
found in the cells cytoplasm or in its nucleus
What constitutes the effectiveness of a hormone
-number of specific hormone receptors available
-the affinity of hormone binding to receptor
Agonist hormone
can bind to the hormone receptor and superstimulate the response
Antagonist hormone
stops the signaling and shuts down the response
Positive feedback mechanism
increases the amount of hormone
Negative feedback mechanism
regulates and can recognize to much hormones and can shut that hormone production down
What is oxytocin
a non steroid neuropeptide
produced in hypothalamus
-stored in posterier pituatary and nerve signals cause release
Functions of oxytocin
-promptes smooth muscle contraction
-milk letdown and is the love/trust hormone
What is gonadotrppin releasing hormones
-produced and stored in the hypothalamus
-non steroid neuropeptide
What does gonadotropin releasing hormone do
-target gonadropes in anterior pituitary
-responds to steroid hormones produced by the gonads
-released into the primary portal plexus
Growth hormone releasing hormone
-44 amino acids
-stimulates growth hormone production and release
Thyrotropin releasing hormone
stimulates thyrotropin stimulating hormone and prolactin production and release
Corticotropin Releasing Hormone
Stimulates adrenocrticotropic hormone production and release
What is follicle stiumulating hormone
-glycoprotein
-produced and stored in anterior pituitary
-responds to gnrh pulses
FSH Ovary function
stimulates follicle growth and development as well as stimulates estrogen production
FSH Testes Function
supports Sertoli cell function and estradiol production
What is luteinizing hormone
-glycoprotein
produced and stored in anterior pituitary
responds to gnrh pulses
LH Ovary Functions
stimulates ovulation and luteinization of the follicle and progesterone secretion
LH Testes Function
targets leading cells to stimulate testosterone T production
FSH and LH subunits
alpha is the same and beta is what provides specificity
Somatropin Hormone
stimulate cell growth, reproduction and regeneration
Prolactin
similar structure to GH
promotes lactation, nest building and motherly instinct
Thyroid Stimulating Hormone
stimulates release of T3 and T4 from thyroid
Adrenocorticotrpic Hormone
stimulates release of cortisol from adrenal gland
What is testorone
Steroid Hormone
- Responds to LH pulses from AP
- Negative feedback to hypothalamus
What secretes testotorone
leydig cells in testes and theca cells in follicles
Testosterone general actions
-behavorial changes for sexual receptivit
-stimulates anabolic growth
Testorone actions in males
promotes spermatogenesis
promotes secretion of accessory sex glands
Testoronbe actions in females
substrates for estrogen production
masculinization
What is estrogen
steroid hormone
responds to FSH pulses from AP
Positive and Negative feedback to hypothalamus
What secretes estrogen
secreted by
-Sertoli cells in testes
granuloma cells in follicles and placenta
Estrogen action
In males
feminization
In females
initiates durge of GnRH from pituitary
increases secretory activity of the tube system
increases uterine tone by heightening myometrium
What is Progesterone P4
Steroid Hormone
-responds to LH pulses from AP
-Negative feedback to hypothalamus
What secretes progesterone
Secreted by:
Luteal cells in the corpus leteum
placenta
Progesterone Actions
-required to maintain pregnancy
-inhibits GnRH pulses and LH surge
-Decreases secretory activity of tube system
-Decrease uterine tone
What is prostaglandin f2 alpha
-eicosanoids
responds to OXT induced muscle contrations
What secretes prostaglandin f2 alpha
secreted by the uterine gland and vesicular gland
Prostaglandin F2 alpha actions
-Promotes smooth muscle contractios
-vasoconstricter
-kills the corpous luteum (lteolysis)
-Involved in ovulation
What is Prostaglandin E2
-eicosanoids
short half life
What secretes prostaglandin E2
secreted by
-uterine endometrium
-granulosa and theca cells
-embryonic membranes
Prostaglandin E2 actions
-promotes P4 production by CL
-Promotes vascularization of tissues
vasodialater
-involved in ovulation
What is Human Chorionic Gonadotropin
-Glycoprotein
-found in other primates
-produced by trophoblastic cells of the blastocyst
HCG actions
acts like LH to stimulate P4 production by CL
indirectly blocks luteolysis
causes ovulation in non-primate females
-embryo-increases fetal growth
Equine Chorionic Gonadotropin
-aka pregnant mare’s serum gonadotropin
-glycoprotein
-produced by endometrial cups of the placenta
Equine Chorionic Gonadotropin actions
-causes formation of accessory CL=P4 production
-indirectly block luteolysis
-acts like FSH in other species
Interferon Tau (IFNT)
Glycoprotein only found in ruminants
produced by trophoblastic cells of the blastocyst
IFNT Actions
-Inhibits OXT receptors
-Prevents PGF2a synthesis
-promotes protein production to nourish conceptus
Mitosis
produces two identical daughter cells
What cells does meiosis happen in
only in germ cells within ovary or testes
Genital Ridge
-formation of primary sex cords
-pcg undergos mitosis
-sealed by tunica albungica
Mesonephros
Male wolfian duct
AMH and Androgen
Forms:
Rete Testes
Efferent Ducts
Epididymis
Vas Deferens
TDF-testis determining factor
synthesized by developing sex cords
causes differention of sertoli cells
Anti-Mullerian Hormone Produced
AMH or MIH
sertoli cell product
Female Development
No Y chromosome
No AMH or androgens
Forms
ovidycts
uterus
anterior vagina
How can you tell the difference between a mature sperm and an immature sperm
the cytoplasmic droplet is not present in a mature sperm
What section of the male reproductive tract do sperm become fertile
corpus epididymis
Destruction of this ligament will result in unilateral or bilateral cryptorchidism and an increased risk for developing inguinal hernias.
Gubernaculum
True of False. Inguinal Hernias occur in females
false
True or False? During an erection, blood flow and pressure are only important in species with a vascular penis type.
False
True or False? A cryptorchid male produces sperm but not any hormones.
False
In general, the hypothalamus,
produce A) hormones, whereas the anterior pituitary produces B) hormones.
A) releasing and B) stimulating
Complete the following statement:
Failure to maintain the testes 4-6 degrees cooler than normal body temperature results in…
Suppression of primordial germ cells resulting in a reduced sperm count, without impacting testosterone synthesis by the interstitial cells.
