Reproductive System Flashcards
Gonads
ovaries and testes
Gonads produce?
gametes (sex cells)
Sexual maturation, formation of sex cells and pregnancy are controlled by?
hormones secreted by the pituitary gland and gonads
Primary Functions of Male Reproductive System:
- Production of male sex hormones
- formation of sperm (male gamete)
- placement of sperm in the female reproductive tract where one sperm can unite with a secondary oocyte (female gamete)
Organs of male reproductive System:
- paired testes
- accessory ducts
- external genitalia
Testes
Male gonads or sex glands
What divides testes into lobules?
septa and each lobule contains several seminiferous tubules
What lines the seminiferous tubules?
spermatogenetic epithelium and supporting cells
Function of spermatogenic cells
divide to produce sperm
Supporting teste cells:
support and nourish spermatogenic cells
regulate sperm production
Interstitial cells
fills spaces between seminiferous tubules
produce testosterone male sex hormone
Spermatogenesis
process that produces sperm by the division of spermatogenic cells
True or false: Spermatogenesis begins at puberty and continues for a lifetime
true
Spermatogenesis is controlled by:
- follicle stimulating hormone (FSH)
- luteinizing hormone (LH)
- testosterone
Spermatogonium (STEP 1)
Large cell near basement membrane of spermatogenic epithelium.
Contain 46 chromosomes (2 chromatids per chromosome)
Divides by mitosis to form 2 daughter cells with 46 chromosomes each.
Formed in the walls of the seminiferous tubules
Type A spermatogonium
remains a spermatogonium; will divide repeatedly by mitosis.
Formed in the walls of the seminiferous tubules
Type B spermatogonium
is pushed inward and becomes a primary spermatocyte.
46 chromosomes (2 chromatids per chromosome)
Formed in the walls of the seminiferous tubules
Primary Spermatocyte (STEP II)
contains 46 chromosomes (2 chromatids per chromosomes)
undergo meiosis (2 cell divisions) that reduce number of chromosomes in the daughter cell in half
Formed in the walls of the seminiferous tubules
Steps of Spermatogenesis (CHROMOSOME EVENTS)
Prior to meiosis I, chromosomes replicate
Each is composed of two chromatids joined at a centromere.
What happens during metaphase of meiosis I?
chromosomes align as homologous pairs.
What happens during cytokinesis of meiosis I?
members of each pair separate into deferent secondary spermatocytes
Each secondary spermatocyte receives only 23 replicated chromosomes.
Spermatid
Contains 23 chromosomes
4 are formed
loses their cytoplasm and forms a flagellum
forms sperm containing 23 chromosomes.
What happens in meiosis II?
chromatids separate into different daughter cells.
Genetic diversity of sperm
- Random alignment of paire homologous chromosomes, during meiosis I (daughter cells contain different combination of maternal and paternal chromosomes
- Crossover during Meiosis 1:Exchange of DNA between paired homologous chromosomes during meiosis I.
true or false: some chromosomes contain genes from both parents.
true
Head of Sperm
contain 23 chromosomes
Acrosome
covers the nucleus, contains enzymes that help the sperm penetrate a secondary oocyte
Neck of sperm
connects the head to the flagellum
flagellum of sperm
enables movement
middle piece, principal piece and end piece
True or false: Middle piece of flagellum contains the mitochondria?
true
Accessory Ducts (male reproductive tract)
- epididymis
- ductus deferens (vas deferens)
3.ejaculatory duct - urethra
Epidimys
Comma shaped, along the top and back of the testis.
Receives sperm from seminiferous tubules.
Site of sperm maturation and storage.
Mature as they slowly move 10 -14 days. Stored here until they are ejaculated.
True or false: Sperm mature in around 10 to 14 days
true
true or false: sperm stored for mor than 2 months are destroyed and absorbed
true
Ductus deferens
Extends from epididymis upward, merges with duct from the seminal vesicle.
uses peristalsis to move sperm