Reproductive Systems Flashcards
Why is sexual reproduction important?
It produces variation with a species
It provides a basis for natural selection within a species
What are the testes?
The male gonads, primary reproductive organ
Produce sperm and testosterone
What is the scrotum?
The sac that contains the testes
Cooler temperature to keep the sperm cells alive
What is the vas deferens?
Tube that conducts sperm towards the urethra
What is the urethra?
Conducts semen towards the penis
What is the ejaculatory duct?
A tubule formed at the union of the vas deferens, seminal ducts, and the opening of the urethra
What is seminal fluid?
A secretion of the male reproductive organs composed of sperm and fluids
The fluid part of semen is secreted by three glands; seminal vesicle, prostate gland, and Cowper’s gland
What is the seminal vesicle?
Contributes to seminal fluid
Secretion contains fructose (source of energy for the sperm cell) and prostaglandins
What is the prostate gland?
Contributes to seminal fluid
Secretion contains buffers that protect the sperm from the acidic environment of the vagina
What is the Cowper’s gland?
Structure that contributes a music rich fluid to seminal fluid
Mucus is thought to protect the sperm from acids in urethra associated with urination, and may also assist in sperm movement
What is the acrosome of a sperm cell?
The cap found on sperm cells that contains enzymes that permit the Soren to move through the outer layers of the ovum (egg)
What is spermatogenesis?
The process by which spermatogonia divide and differentiate into mature sperm cells
Site of spermatogenesis is the seminiferous tubules (coiled ducts within the testes)
Newly produced sperm cells will mature in the epididymis
What are Sertoli Cells?
Specialized cells within the seminiferous tubules
Provide metabolic and mechanical support for developing sperm
What are Interstitial (Leydig) Cells?
Cells found in testes surrounding seminiferous tubules
Secrete testosterone
What is the location and location and function of the hormone testosterone in the male reproductive system?
Found in interstitial cells
Stimulated spermatogenesis, promotes and regulated the development of secondary sex characteristics, associated with sex drive
What is the location and location and function of the hormone FSH in the male reproductive system?
Found in pituitary gland
Stimulates the production of the sperm cells in the seminiferous tubules
What is the location and location and function of the hormone LH in the male reproductive system?
Found in the pituitary gland
Promotes production of testosterone by interstitial cells of Leydig
What is the location and location and function of the hormone GnRH in the male and female reproductive system?
Found in hypothalamus
Stimulated secretion of FSH and LH
What are the ovaries?
Produce hormones (estrogen and progesterone)
Site of ovum development and ovulation
What are the Fallopian tubes (oviducts)?
Carry ovum from ovary to uterus
Site of fertilization
What is the fimbriae?
Sweep the ovum into the Fallopian tube after ovulation
What is the uterus?
Organ in which embryos and fetus develops
Involved in menstruation
What is the endometrium?
lining of the uterus
What is the cervix?
Spectated the vagina from the uterus
Holds fetus in place during pregnancy
Dilated to allow fetus to leave the uterus
What is the vagina?
Extends from cervix to external environment
Provides pathway for sperm and menstrual flow
Functions as the birth canal
What is oogenesis?
Is the formation of an ovum
Occurs in specialized cells in the ovaries called follicles
Within the follicle an oocyte undergoes meiosis and becomes an ovum
What are the two types of cells contains in the follicle?
A primary oocyte
Cells of granulosa
What are the cells of granulosa in the follicle?
The layer of cells that forms the follicle wall
These cells provide nutrients for the developing oocytes
What is the location and location and function of the hormone LH in the female reproductive system?
Found in the anterior pituitary
Ovulation and formation of the corpus luteum
What is the location and location and function of the hormone FSH in the female reproductive system?
Found in the anterior pituitary
Development of follicle in ovary
What is the location and location and function of the hormone Estrogen in the female reproductive system?
Found in the follicle cell and corpus luteum
Secondary sex characteristics and thickening of endometrium
What is the location and location and function of the hormone Progesterone in the female reproductive system?
Found in the corpus luteum
Stimulated the endometrium, inhibits ovulation
What is the location and location and function of the hormone Inhibin in the female reproductive system?
Found in the corpus luteum
Inhibits GnRH
What is the flow phase of the menstrual cycle?
Menstruation
Days 1-5
What is the follicular phase of the menstrual cycle?
Follicle develops and the endometrium is restored
Estrogen from follicle cells is produced
Days 6-13
What is the ovulation phase of the menstrual cycle?
Oocyte bursts from ovary
Day 14
What is the luteal phase of the menstrual cycle?
Corpus luteum forms, endometrium thickens
Estrogen and progesterone from corpus luteum
Days 15-28
What hormones should a women be given before egg harvesting?
Estrogen because it causes ovulation
What hormones should a women be given pre-implantation?
Progesterone because it strengthens endometrium
What is an oviduct?
Location where the egg becomes fertilized
What is the process of cleavage?
The zygote is dividing without any increase in size
Cells are becoming smaller
What is a blastocyst?
By the time it reaches the uterus, the zygote has developed into a fluid filled structure called a blastocyst
It possesses an inner cell mass which forms the embryo
The outer layer consists of cells collectively called trophoblast, which go on to form the placenta
What is the process of fertilization?
150 to 300 million spermatogenesis travel through the cervix upon ejaculation, a few 100 will reach the Fallopian tubes
Only a single sperm fuses with the ovum to form a zygote
Fertilization normally occurs in the Fallopian tube
What is the implantation of the blastocyst?
The blastocyst attaches to the endometrium wall
Occurs approximately one week after fertilization
Implantation takes approximately 5 days
What is an ectopic pregnancy?
On rare occasions, a fertilized embryo embeds itself in the Fallopian tube (or other structures) instead of the uterine lining
How does the maintenance of the endometrium work during the start of pregnancy?
The outer layer of cells in the blastocyst produces hCG
hCG maintains the corpus luteum during the first 3 months of pregnancy, which prevents the shedding of the endometrium
Pregnancy tests work by identifying hCG in urine
Once the placenta is formed, hCG is no longer produced
What is the process of gastrulation?
The formation of the three primary germ layers of the blastocyst
Each layer will undergo a series of changes to be distinct structures that later develop into organs
What structures does the germ layer ectoderm (outer) form?
Skin, hair, fingernails, sweat glands
Nervous system, brain, peripheral nerves
Lens, retina, cornea
Inner ear, cochlea, semicircular canals
Teeth, inside lining of the mouth
What structures does the germ layer mesoderm (middle) form?
Muscles (skeletal, cardiac, smooth)
Blood vessels and blood
Kidney, reproductive structure
Connective tissue, cartilage, bone
What structures does the germ layer endoderm (inner) form?
Liver, pancreas, thyroid, parathyroid
Urinary bladder
Lining of digestive system
Lining of respiratory tract
What is the process of neurulation?
Between weeks 3 and 8 organs form
The germ layers separate and form organs
During the 3rd week a band of mesoderm cells forms along the back of the embryonic disk
These cells form a rod-like notochord, which will make up the skeleton
The nervous system develops from the ectoderm located above the notochord
What is the process of organ formation?
After neurulation the heart begins to form
This is followed by blood vessels, lungs, kidneys, arms and legs, and the structures of the head
The brain continues its development and the gonads begin to develop external genitalia (about the 6th week)
What is the placenta?
Forms from cells from the endometrium and the fetus and has numerous blood vessels
What is the chorion?
Becomes the placenta
The outermost membrane surrounding an embryo
What is the yolk sac?
Does not provide nutrients
Goes on to form the digestive system
What is the umbilical cord?
Connect embryo to placenta
What is the allantois?
Forms blood vessels of placenta, exchange gas, handle waste, future umbilical cord
What is the amnion?
Membrane that closely covers the embryo
Fills with amniotic fluid which forms amniotic sac which provides a protective environment for embryo of fetus
What happens in the first trimester of pregnancy?
By week 2 germ layers form
By the end of this trimester the heart, brain, limb buds, have all developed
Arms and legs move and there’s a sucking reflex
At the end external reproductive organs are present
What happens in the second trimester of pregnancy?
Fetus moves enough to be noticed
All organs have formed
Eyelids and eyelashes form
Cartilage is replaced with bone cells
Soft hair covers body
What happens in the third trimester of pregnancy?
Rapid growth of baby particularly layers of fat
Organ systems are already established but continue to develop
What happens in the latent phase of labour?
Labour begins 38 to 40 weeks after conception
Initially the cervix begins to thin and the mucus plug that sealed the cervix falls out
What happens in the active phase of labour?
Oxytocin, from the pituitary gland, causes contractions
Cervix begins to dilate, contractions become regular and intense
Prostaglandins appear in mother’s blood
In the end the cervix has dilated to 10 cm diameters
What happens in the birth phase of labour?
Contractions move fetus to birth canal
Relaxin (placenta) loosens ligaments in pelvis
Uterine contractions and active pushing by the mother to push the baby out of the birth canal
What happens in the afterbirth phase of labour?
Once the baby is born the umbilical cord is slipped and cut
A number of contractions expel the placenta and most of the umbilical cord
What is a beech birth?
The baby enters the birth canal feet or buttocks first
A breech baby who is delivered buttocks first can be delivered normally but an episiotomy may be required
If the baby arrives feet first a Caesarian section birth may be performed
What is the process of lactation?
During pregnancy, high levels of estrogen and progesterone prepare the breast for milk production
Each breast has 20 glands that produce milk
Prolactin levels rise dramatically after birth, which stimulated milk production in eco fund glands
