24 - Male Reproduction Flashcards
Spermatogenesis is a meiotic process that culminates in the formation of (DIPLOID/HAPLOID) spermatids.
Haploid
Primordial germ cells migrate into future testes and become _________.
Spermatogonia
Spermatogonia begin mitotic division at puberty and become ________ _________.
Primary spermatocytes
Primary spermatocytes complete the first half of meiosis and become ________ ________.
Secondary spermatocytes
Secondary spermatocytes complete the second half of meiosis and become _________.
Spermatids
Spermatids undergo differentiation to become _______ _______.
Mature sperm
These cells are located within the seminiferous tubules.
Sertoli cells
_______ cells act as nurse cells (sustentacular cells) that surround primary spermatocytes and “nurse” them through the process of spermatogenesis and spermatogenesis (differentiation of spermatids into mature sperm).
Sertoli
Sertoli cells form _______ from testosterone, which is thought to be important for spermiogenesis.
Estrogens
During spermatogenesis, which step first gives haploid cells?
End of meiosis I – Secondary spermatocytes
Proacrosomal vesicles coalesce to form the acrosome, which contains _________ and proteolytic enzymes.
Hyaluronidase
What moves to the base of forming flagellum and wrap around it?
Mitochondria
The excess cytoplasm that is sloughed off from the forming sperm is called the…
Residual body
Sperm cells are stored in the _______ until ejaculated. They must remain here for a minimum of 18 to 24 hours in order to gain motility.
Epididymis
Passage through the epididymis requires several (HOURS/DAYS).
Days
These are found in interstitial spaces in testes and they secrete testosterone.
Cells of Leydig
Cells of Leydig are stimulated by ________ ________ secreted by the anterior pituitary.
Luteinizing hormone
______ is also necessary for spermatogenesis.
FSH
Male accessory glands include the…
Seminal vesicles
Prostate gland
These are paired structures behind the prostate and each one is a loculated tube lined with secretory epithelium.
Seminal vesicles
Seminal vesicles secrete a mucoid material that contains…
Fructose Citric acid Additional nutrients Prostaglandins Fibrinogen
During emission and ejaculation, the contents of the seminal vesicles are emptied into ejaculatory ducts containing sperm. This is ______ percent of the total volume of semen.
60
_______ provides energy for sperm, and ________ make cervical mucous more receptive to sperm movement and may cause retro-peristaltic contractions of uterus and fallopian tubes.
Fructose
Prostaglandins
During emission and ejaculation, the prostate gland has _____ percent of the total volume of semen.
30
The prostate gland has a milky fluid containing calcium, citrate ions, phosphate ions, clotting enzyme, and profibrinolysin. This fluid is slightly _______, which may help to neutralize acidity of other seminal fluids and vaginal secretions of the female.
Alkaline
These are any steroid hormone that have masculinizing effects.
Androgens
Androgens include…
Testosterone
Dihydrotestosterone
Androstenedione
Androgens can be synthesized in the testes and adrenal glands from…
Cholesterol
Acetyl-CoA
Cells of Leydig are numerous in newborn males and adult males after puberty but are almost nonexistent in testes during childhood. These cells produce…
Testosterone
After secretion, 97 percent of testosterone is loosely bound with ________ or tightly bound with _______ _______.
Albumin
Beta globulin
T/F. Testosterone circulates in blood for 30 minutes to several hours, then its transferred to tissues or degraded to inactive products that are subsequently secreted.
True
Testosterone that enters tissues is mostly converted to _________, especially in prostate and in fetal external genitalia.
Dihydrotestosterone
Testosterone that is not fixed in tissues is converted in the liver to _________ and _________. These are conjugated as either glucuronides or sulfates and excreted into the gut via bile or urine via kidneys.
Androsterone
Dehydroepiandrosterone
This hormone is a 10-amino acid peptide produced by neurons located in the arcuate nuclei of the hypothalamus. It is transported to the anterior pituitary via the hypothalamic-hypophyseal system. It stimulates the anterior pituitary to produce LH (mostly) and FSH (gonadotropic hormones).
Gonadotropin-Releasing hormone (GnRH)
This hormone is a glycoprotein that activates cAMP second messenger system in target tissues and causes sertoli cells to secrete testosterone. Testosterone has a negative feedback effect on the hypothalamus.
Luteinizing Hormone (LH)
This is secreted by sertoli cells and inhibits secretion of FSH by the anterior pituitary. It also inhibits secretion of GnRH to a lesser extent.
Inhibin
