Reproduction & development Flashcards
The cells that produce testosterone in the testes are called:
interstitial cells (Leydig)
Which hormone causes ovulation to occur?
Luteinising hormone (LH)
Interstitial (Leydig) cells in the testes produce:
testosterone
The inner cell mass of the blastocyst will:
form the embryo
During the secretory phase of the menstrual cycle:
progesterone levels are at their highest
The cells of developing ovarian follicles secrete:
oestrogen.
Foetal growth is supported by nutrients from the mother by:
close proximity of maternal and foetal blood in the placental structures
Pressure on the cervix late in pregnancy causes an increase in the blood levels of:
oxytocin
The placenta is a vitally important metabolic organ which is made up of contributions from the mother and the foetus. Which portion is from the foetus?
Chorion
The surge in luteinising hormone that occurs during the middle of the ovarian cycle:
triggers ovulation; is triggered by extremely high levels of oestrogen; & causes the formation of the corpus luteum
A study of the effects of prolonged periods of driving on sperm count in men found that driving for several hours per day was associated with a higher incidence of low sperm count and infertility. Which of the following factors would be most likely to be involved in this effect?
The temperature of the scrotum might be increased during driving, inhibiting sperm production.
During her pregnancy, Miranda’s blood glucose levels have been higher then normal. Miranda is worried that this means she has developed diabetes which will need treatment for now on. Which of the following explanations is most likely?
The increased blood glucose level is normal during pregnancy, and occurs as a result of an increased cortisol level.
Describe the ovarian cycle
Follicular phase,
ovulation,
luteal phase
Follicular phase (development of follicles in the ovary), ovulation (release of egg), luteal phase (formation of corpus luteum)
Describe the Uterine cycle
Menstrual phase,
proliferative phase,
secretory phase
Menstrual phase (shedding of uterine lining), proliferative phase (rebuilding of uterine lining), secretory phase (preparation of uterus for embryo implantation)
What are the breasts made up of?
The breast consists of glandular tissue, ducts, and fatty tissue
Briefly describe the process of sperm production in the testes
Occurs in the seminiferous tubules. Immature sperm cells undergo mitotic division (spermatogonia), followed by meiotic division (spermatocytes), and differentiation into sperm cells (spermatids). Sperm cells are then released into the epididymis for maturation.
Where is sperm produced?
The semiiferous tubles
Where are sperm released into for maturation?
The epididymis
What secretions are passed to the semen along the route to ejaculation?
Seminal vesicles, prostate gland, and bulbourethral glands contribute fluids to semen.
These fluids provide nourishment, buffer acidic environments, and enhance sperm motility
What are the main developmental processes that occur during the three trimesters of pregnancy
Fertilization, Implantation, and Embryo and foetal development
Further development of organs and systems
Organs become functional, growth and deposition of adipose tissue
Main events in the first trimester
Cleavage - Cell division following fertilization
Implantation - Attachment of the blasocyst to endometrium
Placentation - Formation of placenta
Embryogenesis - Formation of embryo
How much does the mothers cardiac output change during pregnancy?
30 -50%
How much does the mothers plasma volume increase by during pregnancy?
50%
Erythropoesis by 25%
What feedback loop is used in labour?
Positive feedback
What hormones are released to initiate labour (parturition)
Oestrogen and oxytocin
What are the 3 stages of labour?
Dilation, Expulsion and Placental
What hormones are released for control of lacatation?
Prolactin and Oxytocin
What are some of the main causes of female infertility?
ovulation disorders, fallopian tube blockage, or problems with the uterus or cervix
What are some of the main causes of male infertility?
low sperm count, abnormal sperm function, or blockages in the reproductive tract
What is IVF?
in vitro fertilization
involves fertilizing eggs outside the body and transferring embryos to the uterus
What is ICSI?
intracytoplasmic sperm injection
involves injecting a single sperm into an egg
What is ovulation and what hormones are involved?
Ovulation is the release of a mature egg from the ovary after a surge of LH from the pituitary gland.
This is triggered by high levels of oestrogen.
How long does the corpus leutum survive?
14 days
What stops the corpus leutum from degenerating?
Progesterone which is supplied by the corpus leutum due to the release of hCG by the embryo
What forms the placenta?
Both maternal and foetal tissues
How long does it take the placenta to develp?
12 weeks
What are teratogens and why are they a problem
Teratogens are substances or factors that can cause abnormalities or malformations in the developing foetus and can increase the risk of birth defects or pregnancy complications.
Examples of teratogens are: certain medications, alcohol, drugs, infections, or radiation
What does progesterone do?
Maintains the lining of the uterus
Inhibits FSH/LH/GnRH
Provides secretions from the the lining
What stimulates the growth of the corpus luteum
LH
What signals the production of LH?
GnRH as well as a surge of oestrogen mid cycle
What signals the release of GnRh
Low progesterone levels
What hormones are released by the placenta?
hCG
Progesterone
Oestrogen
Relaxin
What hormones are released by the corpus luteum?
Progesterone
Oestrogen
Relaxin
What hormones are released by the Posterior Piuitary?
Oxytocin
What hormones are released by the Hypothalamus?
GnRH
What hormones are released by the Anterior Pituitary?
Prolactin
GH - FSH and LH
