Chapter 27: Male Reproductive System Flashcards
gametes
sex cells
zygote
fertilized egg
male and female gametes combine their genes to form
zygote
parent producing sperm is considered
male
parent with Y chromosome is
male
sperm aka
spermatozoon
embryo
egg (ovum)
parent producing eggs considered
female
primary sex organs (gonads)
- produce gametes
- testes, ovaries
secondary sex organs
- organs other than gonads that are necessary for reproduction
- male: ducts, glands, penis delivers sperm cells
- female: uterine tubes, uterus, vagina receiving sperm
secondary sex characteristics
- features that distinguish the sexes and influence mate attraction
- Develop at puberty
secondary sex characteristics in both sexes
- Pubic and axillary hair
- scent sweat glands (APOCRINE)
- pitch of the voice
male secondary sex characteristics
- Facial hair
- coarse and visible hair on the torso and limbs
- muscular physique
female secondary sex characteristics
- Distribution of body fat
- breast enlargement
- finer, less body hair
somatic cells
- 23 pairs of chromosomes (diploid)
- 22 pairs of autosomes and 1 pair of sex chromosomes
sex cells (gametes)
- 22 Chromosomes + 1 sex chromosome (haploid)
- Males produce some Y-carrying sperm and some X-carrying sperm
- All eggs carry the X chromosome
Sex of child determined by
male and type of sperm
X-carrying sperm fertilizes the egg
fetus will be female
Y-carrying sperm fertilizes the egg
fetus will me male
Genital tubercle
becomes the head (glans) of the penis or glans clitoris
Pair of urogenital folds
encloses male urethra helping to form the penis or forms the labia minora
Pair of labioscrotal folds
becomes either scrotum or labia major
what happens by week 12 of pregnancy?
either male or female genitalia are distinctly formed
Male and female organs that develop from the same embryonic structure are
homologous
The descent of the testes begins as early as
6 weeks
cryptorchidism
- undescended testes
- about 3% of boys
Internal median septum
divides scrotum into right and left compartments
Each compartment in the scrotum has
one testis and spermatic cord
Superficial inguinal ring
inferior entrance to inguinal canal
Deep inguinal ring
superior exit to pelvic cavity
Within scrotum, spermatic cord passes through strips of internal oblique muscle called the
cremaster
human testes reside in the
scrotum and are adapted to its cooler temp
sperm production temp must be held at
about 35 degrees celsius
cremaster role in regulating temp (heating)
- when its cold, cremaster contracts to hold testes closer to body
- when warm, cremaster relaxes and testes further from body
dartos fascia role in regulating temp (heating)
smooth muscle contracts when cold
The pampiniform plexus (Cooling)
surrounds testicular artery; countercurrent blood flow removes heat from descending arterial blood, to be carried away by ascending venous blood
endocrine glands in testes secrete
testosterone and other androgens
exocrine glands in testes secrete
sperm
testis structure
- oval and slightly flattened
- covered by tunica albuginea and tunica vaginalis
tunica albuginea
white fibrous capsule
seminiferous tubules
- where sperm is produced
- lined with a thick germinal epithelium
- consists of nurse cells, interstitial cells, BTB
interstitial endocrine cells
- produce testosterone
- between seminiferous tubules
nurse cells (supporting cells, Sertoli)
- protect germ cells, promote development
- secrete androgen binding protein and inhibin which regulate sperm production
blood-testis barrier (BTB)
prevents antibodies and immune cells from attacking germ cells
rete testis
- collects sperm from the tubules
- Sperm flow with fluid secreted by nurse cells
- Sperm do not swim while in the male reproductive tract (duct system)