Reproductive System Flashcards
Sexual reproduction in humans involves:
Meiosis
Fertilization
Prenatal Development
_____-Cell division producing four genetically unique haploid cells (called gametes= sperm in male or ova in female) from stem cells within the gonads that are diploid 2(n) = 46 (Containing two sets of chromosomes).
Gametes are haploid (n) = 23 having only one set of chromosomes
Meiosis
Meiosis
What are gametes?
sperm in male or ova in female
Meiosis
What do the diploid 2 (n) contain?
46 (Containing two sets of chromosomes).
Gametes are _____when having only one set of chromosomes?
Haploid (n) = 23 chromosomes
What is a zygote (2n)?
Fusion of sperm and egg
_____-Fusion of sperm and egg
Creates a zygote (2n), or fertilized egg that will develop into a new organism
Fertilization
_____-zygote grows as cells divide by mitosis:
Mitotic cell division produces two genetically identical cells.
Prenatal Development
Chromosomes:
Humans have _____pairs of chromosomes
23
Chromosomes:
Each somatic cell has two sets of chromosomes (one maternal, one paternal) and is said to be _____ so the chromosome number is 2n.
diploid
Chromosomes:
_____-matching pairs of chromosomes that carry equivalent genes.
Homologous chromosomes
Chromosomes:
There are alternative forms of each gene which are called _____
alleles
Chromosomes:
Gametes only have 23 chromosomes and are said to be_____
haploid (n)
Chromosomes;
One pair of chromosomes, called the _______, determines the sex of the individual (XX in females, XY in males).
sex chromosomes
_____-is a type of cell division that produces gametes (sperm and ova) from stem cells in the reproductive tissue
Meiosis
Meiosis:
______-in preparation for fusing with another gamete
Reduces the original number of chromosomes in half
Meiosis:
____-(scrambling) of parents’ genomes to create a unique set of chromosomes in each gamete
Recombination
Stage of meiosis?
overview Intrephase Meiosis I -Prophase I -Metaphase I -Anaphase I -Telophase I and cytokinesis
Meiosis II Prophase II Metaphase II Anaphase II Telophase II and cytokinesis
What stages of meiosis is this?
_____-In meiosis there is two rounds of division which results in 4 haploid cells:
1st round separates duplicated homologous chromosomes
2nd round separates sister chromatids
Overview
What stages of meiosis is this? \_\_\_\_\_\_\_\_- Occurs prior to Prophase I of meiosis G1 phase S-phase homologous chromosomes replicate into sisters G2 phase – checkpoint
Interphase
What stages of meiosis is this?
____-first division
Meiosis I
What occurs in Meiosis I?
______-
Duplicated homologous chromosomes pair up (tetrads)
Crossing over occurs: homologous chromosome exchange equivalent segments
Prophase I
What occurs in Meiosis I?
____-
Homologous chromosomes line up in pairs along the central plane in tetrads
Independent assortment: which side each chromosome lines up on is independently of the other pairs
Metaphase I
What occurs in Meiosis I?
_____-
Homologous chromosomes are separated and move to opposite poles
Anaphase I
What occurs in Meiosis I?
_____- Results in two haploid cells with 23 duplicated chromosomes
Telophase I and Cytokinesis
_____- second division
Meiosis II
What is the first step of Meiosis II?
Prophase
What occurs in meiosis II?
____- Sister chromatids (duplicated chromosomes) line up along midline
Metaphase II
What occurs in meiosis II?
____- Sister chromatids separate and are pulled towards opposite poles
Anaphase II
What occurs in meiosis II?
_____- Results in 4 haploid gametes from each diploid cell that enters meiosis.
Telophase II and Cytokinesis
____-production of gametes
Gametogenesis
Where does the production of gametes begin?
in utero and resumes during puberty
Mitotic divisions in embryonic gonads increases number of ______.
spermatogonia or oogonia
DNA replication (S-phase) to the primary gametes with 46 duplicated ______
chromosome
Meiosis I to ______ with 23 duplicated chromosomes
secondary gametes
Meiosis II to ______ with 23 chromosomes
egg (ova) or spermatid
______-responsible for the production of sperm and male sex hormone testosterone.
Testes
_____-sac of skin that contains the testes outside the abdominopelvic cavity.
Scrotum
______-smooth muscle in the dermis of the scrotum
Dartos muscle
What are the two protective tunics (tissue layers)
Tunica Vaginalis
and
Tunica albuginea
What type of protective tunics (tissue layers) is this?
_____-serous membrane lining the scrotal cavity, derived from the parietal peritoneum
Tunica vaginalis
What type of protective tunics (tissue layers) is this?
_____-fibrous capsule surrounding the testes
Tunica albuginea
____-tightly coiled tubes found in the testis. Responsible for sperm production.
Seminiferous tubules
_____-is the process by which haploid sperm are produced
Spermatogenesis
_____- stem cells found in the outermost layer of the seminiferous tubule
Spermatogonia
_____-pushed towards the lumen as they undergo meiosis
Spermatocytes
____-immature haploid cells that mature into spermatozoa
Spermatids
____-mature sperm cells.
Spermatozoa
____-support cells surrounding the spermatocytes within the seminiferous tubule.
Sertoli cells
____-endocrine cells that produce testosterone, found in the interstitial space between seminiferous tubules.
Leydig (Interstitial) cells
_____-travels through the inguinal canal to the scrotum
*• Connective tissue and muscle bundles the ductus deferens, nerves, lymph vessels, and testicular artery and vein supplying the testes
Spermatic cord
_____-band of skeletal muscle arising from the internal obliques contracts to elevate testes and pulls them closer to the body to conserve heat
Cremaster
• Regulation of Spermatogenesis
______-
Testosterone also stimulates sex characteristics
Testosterone triggers negative feedback loop to decrease GnRH and LH and secretion
o GnRH to LH to Leydig cells to testosterone to spermatogenesis
• Regulation of Spermatogenesis
_____- Inhibin triggers negative feedback loop for FSH secretion
o GnRH to FSH to Sertoli cells to spermatocyte maturation
_____-spermatozoa flow through the twisted seminiferous tubules of the testes into a series of ducts which transport and store the sperm
Ducts