REPRODUCTIVE SYSTEM (Male Reproductive System) Flashcards
Functions
1.Production and transport of male sperm cells
2.Production of male hormones like testosterone
Gonads
* Male – testis
* Female – ovary
REPRODUCTIVE SYSTEM
- wrinkled sac containing testis, epididymis, and vas deferens
- dartos muscle
- regulates testicular temperature
- cold temperature – testis gets closer to the body
- warm temperature- testis hangs loosely
- spermatogenesis requires 2-3 °C lower than body temperature
Scrotum
- Body
* made up 3 erectile tissues
a. Corpora Cavernosa
o 2, dorsolateral, vascular spaces
b. Corpus Spongiosum
o contains spongy urethra
o located ventrally - Root
* proximal
a. Bulb
o expanded proximal portion of corpus
spongiosum.
o Covered by bulb spongiosum.
b. Crura
o proximal tapered parts of corpora
cavernosa.
o Covered by ischiocavernosum. - Glans penis
* expanded distal end of corpus spongiosum
* distal terminal urethra is expanded called
fossa navicularis
* prepuce and frenulum
Penis
- intra-abdominal during fetal life
- descends and covered by tunica vaginalis from peritoneum
- deep covering tunica albuginea
- divides the testis into lobules
- each lobule contains seminiferous tubule
Cells in the Testis
1.Spermatogenic cells
2.Sertoli cells/ Sustentacular cells
3.Interstitial cells of Leydig
Testis
o grow and mature to form mature sperm cells
Spermatogenic cells
o support and protect sperm cells
Sertoli cells/ Sustentacular cells
o secrete testosterone
o located in between seminiferous tubules
Interstitial cells of Leydig
- comma shaped, 4cm long
- located posterior to the testis, with ff parts, head, body and tail
- tail is continuous with vas deferens
Functions
1.Site of sperm maturation – mobility and capability to fertilize an ovum (10-14 days)
2.Storage of sperm cells
3.Propel sperm cells to vas deferens
Epididymis
- Continuation of epididymis
- 45cm long
- Passes through the inguinal canal and enter the pelvic cavity
- Joins the duct of seminal vesicle to form ejaculatory duct – which will drain to the prostatic urethra
- Will go to the back of urinary bladder and will dilate to form your ampulla
Functions
1.Storage of sperm cells
2.Conveys sperm cell from epididymis to ejaculatory duct and urethra
3.Reabsorbed not ejaculated sperm cells
Vas/ Ductus Deferens
- Located within the urogenital diaphragm on either side of membranous urethra
- Opens into penile urethra
Secretions
1.Alkaline fluid
2.Mucus – lubricates penis and lining of urethra
Cowper’s (Bulbourethral) Gland
- passage way of urine and semen
Male Urethra (20 cm)
- Traverse prostate gland
- widest, most dilatable
Prostatic (2-3 cm)
- traverses’ urogenital diaphragm
- shortest and least dilatable
Membranous (1 cm)
- longest, travers’s corpus spongiosum
Penile (15-20 cm)
- Located postero-inferior to urinary bladder
- 5cm long
- Convoluted pouch
- 60% of semen volume
- Secretes fructose
Secretions
1.Alkaline viscous fluid
2.Prostaglandin
3.Clotting protein
Seminal vesicle
- located beneath urinary bladder with 5 lobes
- surround prostatic urethra
- secretes milky, slightly acidic pH 6.5 seminal fluid
Secretions
1.Citric acid – for ATP energy of sperm cells
2.Acid phosphatase
3.Proteolytic enzyme – breaks down clotting protein
4.Prostate specific antigen (PSA)
Prostate gland
o neutralizes acidic environment of vagina and male urethra
o contains fructose for energy source of sperm cells
Alkaline viscous fluid
o mobility and sperm viability
o stimulate smooth muscle contraction of female
Prostaglandin
o coagulate sperm after ejaculation
Clotting protein
- volume- 2.5- 5ml with 50-150million sperm cells/ml appro 300-500millions sperm
- Slightly alkaline 7.2-7.7
- Contains seminal plasmin destroys certain bacteria
- Once ejaculated sperm coagulates in 5min due to clotting protein from seminal vesicle
- About 10-20 min liquefies due to prostate specific antigen (PSA) and other proteolytic enzymes from prostate
Components of ___________
1.Seminal fluid
2.Sperm
Semen
- secretion from glands
- prostate gives milky white, seminal vesicle and bulbourethral gland sticky appearance
Seminal fluid
a. Head
o Acrosomes with lysosomal enzymes for
penetration of zona pellucida of 2°
oocyte
o Nucleus – with 23 chromosomes haploid
number
b. Mid Piece – with mitochondria
c. Tail – flagella for motility
Sperm
- Enlargement and stiffening of the penis
- Due to tactile, visual, auditory, olfactory and imagination reaches erection center in hypothalamus — sends parasympathetic nerve impulses into the penis — vasodilatation of helicine arteries into the penis – erection
Erection
- Powerful expulsion of semen from the urethra to the exterior — due to sympathetic reflex— closure of smooth muscle sphincter at the base of urinary bladder peristaltic contraction of the male reproductive tract
Ejaculation
