Reproduction Flashcards
Induced Ovulation in Rabbis (8)
- Copulation stimulates Sensory neurons in the cervix
- Neural Impulses stimulate the brainstem which secretes norepinephrine
- Norepinephrine stimulates GnRH-secreting neurons
- GnRH is secreted into the blood in the hypothalamo-hypophysial portal vasculature
- blood carries GnRH to the pituitary
- Pituitary secretes LH
- LH travels through the body
- LH stimulates ovulation when it reaches the ovaries
Some processes needed for eggs and sperm to meet (6)
- Environmental Queues (is it warm / safe enough)
- Location (is my breeding ground available)
- Development of reproductive organs
- Resources (nests needing to be built)
- Attraction of mate
- Sex
Some processes needed for successful offspring (4)
- Development of Zygotes
- Food for offspring
- Division of parental time
- Evasion of predators
Aspects of reproduction studies by physiologists (6)
- Annual reproductive cycle (Elk growing horns to attract mates every year)
- Mate Association (Male and Female blue crabs travel together before mating)
- Functions of Organs and cells (After nutting the sperm needs to be able to swim to the egg)
- Reproductive Control (The Ovarian Follicle secretes estrogen to prepare the female for pregnancy)
- Provisioning of Offspring (parents expending their own energy for their kids)
- Distinct Physiology of young (bb sea urchins are smaller, have a completely different shape and swim)
Latitude trends in reproduction of white footed mice
White footed mice in the Far north reporduce only 1-2 months of the year. Mice in the far south reproduce all year and the mice in the middle over a period of many months. So as you go more south their reproductive time gets longer and longer
Semelparous species
Species that only reproduce one time in their life then die, such as salmon. Salmon do not feed once they start their journey upstream, they also develop hooked jaws to fight other males with, get a humpback and turn bright red
Dogfish yolks
One yolks are formed in dogfish they remain in the reproductive tract of the mother until the offspring are fully formed. During this time, the yolk is attached to the young’s circulatory system, and their blood flow supplies nutrients from the yolk until it is used up
Embryonic Dispause
a temporary and reservable pause to embryonic development. In silkworm moths, they have many lifecycles over the spring / summer / fall, but the final generation of eggs over the winter delay their development until spring when they hatch . In arctic fur seals, they delay their development until the optimal birthing time is 250 days away, as that’s how long it takes for their young to develop.
Estrus
“Heat” as in “going into heat”. It is timed to lead to mating that syncs up with ovulation
Neuroendocrine system in female mammals involved in ovarian cycles (6)
Hypothalamic GnHR cells: secrete GnHR stimulates secretion of FSH and LH in anterior pituitary
Anterior pituitary: Stimulates theca cells to secrete androgens in the follicular phase (first phase of menstruation), Surge of LH triggers maturation of Oocyte and ovulation .
Theca Cells: Diffuse androgens to granulosa cells for conversion to estrogen
Granulosa cells: At low estrogen concentrations, regulates secretion of FSH and LH in pituitary, at high concentrations promotes secretion of FSH and LH in pituitary
Inhibin: Inhibits FSH secretion
Corpus leteum cells: Causes the endometrium to become excretory
The penis (3)
-Contains 3 compartments that fill with blood to cause an erection
-the prostate gland and paired seminal vesicles secrete most of the fluid for cummin. The Cum is a fix of these fluids and sperm cells
-The paired blubourethral glands secrete a clear mucus ahead of ejaculation
The balls (3)
-Each testis is divided into 200-300 compartments, each containing tubules that connect to the vas deference
-Each tubule is lined with a single layer of Sertoli cells which are sperm producing cells
-Leydig cells are found in the connective tissue between the tubules, and secrete testosterone
Sperm development (5)
spermatogonia develop into primary spermatocytes, then secondary spermatocytes, then spermatids, then finally sperm
Sperm structure (4)
-haploid set of chromosomes
-Tail for mobility
-mitochondria for energy production
-Acrosome which contains enzymes to cut through the egg envelope
Sex determination
In human embryos, at 4 months old male and female genitalia are identical. At 5 months, secretion of testosterone causes the males genitalia to develop into males. If there is no testosterone secretion then the genitalia will continue to develop into female
Testi size
In mammals there are two types of males, single male species (one male mates with each female) and multi-male (multiple males mate with each female). In all mammals, multimale species have much bigger testis
Chorionic Gonadotropin
CG is secreted into the blood by the embryonic Chorion, which sustains the corpus leteum during pregnancy. When the child is born and the placenta is expelled, blood concentrations of estrogen and progesterone plummet.
