Reproduction System Flashcards
What are the reproductive systems
Produce new individuals through germ cells and fertilization
Scrotum
- contains the testes
- Sac of loose skin divided into two pouches.
- Contains dartos muscle, causing wrinkling
Testes Temperature
Sperm survives in 3 degrees lower than body core temp.
95 degrees, anything warmer than that can cause infertility
Cremaster muscle
Elevates testes on exposure to cold and during arousal
Warmth reverses the process
Testes
Paired oval glands, about 2 in. by 1 in.
- Endocrine and Exocrine
- Has several butter layers ( tunica vaginalis and tunica albuginea being the prominent )
- Divided in two lobules, Each filled with seminiferous tubules where sperm is formed
Descent of Testes
- Develop in pelvic cavity near the kidney
- Descend into the scrotum by passing through the inguinal cavity during 7 months of development
Tunica Vaginalis
Piece of peritoneum that descends with the testes
It allows for easier movement of testes within the scrotum bc of fluid in air.
Location of Sperm formation
Seminiferous tubule
Leydig cells secrete testosterone
What are the supporting cells of sperm formation
Sertoli cells: Extend from basement membrane to lumen
- form blood
- support, nourish and protect developing sperm
- produce fluid and control the release of sperm into the lumen
What is Spermatogenesis
process by which the seminiferous tubules of the testes produce haploid sperm
Take about 70 days
100 million sperm in 1 ml
ejaculate about 3-5 ml
Less than 20 million sperm in an ml of someone infertile
Starts at Spermatogonia
Spermiogenesis
The maturation of spermatids into sperm cells
Spermiation
The release of sperm cells from a steroli celll
Sperm and its parts
Are adapted to reaching and penetrating a secondary oocyte to achieve fertilization and create a zygote
Head, Neck, Midpiece, Tail
Hormonal controls of spermatogenesis
at Puberty
LH stimulates Leydig cells to secrete testosterone
FSH stimulates spermatogenesis
Inhibin is released if too much sperm as a negative feedback
Testosterone hormonal effects
At puberty, the final development of secondary sexual characteristics
- sexual behavior
- male metabolism ( bone and muscle mass heavier)
- deepening of voice
Pathway of Sperm Flow
Seminiferous tubules Straight tubules Rete Testes Efferent Ducts Ductus Epididymis Vas deferens SPERMATIC CORD Pubic synthesis SEMINAL VESSICLES EJACULATORY DUCTS URETHRA OUT THROUGH SPONGE URETHRA
Epididymis
Comma shaped organ
The tail region continues to duct deferens
Sperm is transported out of the testes through the efferent ducts in the epididymis which empty into a single tube called the ductus epididymis
Histology of epididymis
Lined with pseudostratified columnar epithelium -a layer of smooth muscle Site of sperm maturation Storages sperm for 1-2 months Propels sperm onwards
Ductus (Vas) Deferens Pathway
The 18-inch muscular tube ascends along the epididymis and up through the spermatic cord reaching the posterior surface of the urinary bladder and empties into the prostatic urethra with seminal vesicle
Vas Deferens
Lined with pseudostratified columnar epithelium and covered with a heavy coating of muscle
The dilated portion is called the ampulla
Stores sperm and propels them towards the urethra during ejaculation
Vasectomy
Male sterilization -Vas deferens is cut and tied off -Sperm production continues -Sperm degenerate 100% effective and 40% reversible
Ejaculatory ducts
Formed from the duct of seminal vesicle and ampulla of vas deferens About 1 inch long function is to eject spermatozoa into the prostatic urethra and eject seminal vesicle secretion just before the release of seman from the urethra
Urethra
Pathway for urine and semen Are 3 regions -Prostatic urethra -Membranous urethra -Penile urethra
Accessory sex glands
Seminal Vesicles
Prostate gland
Cowpers gland
Seminal vesicle
Found posterior to the bladder
Secretes sugar, gives sugar to semen, for ATP
Prostate gland
Size of chestnut found inferior to the bladder
-Secretes milky fluid that increases sperm mobility and viability
Cowpers gland
Pea-sized
Secretes alkaline mucus, gives semen stickiness
semen
A mixture of sperm and seminal fluid
Milky appearance and sticky
Ph is 7.2-7.7
Penis
The passageway for semen and urine
Composed of 3 erectile tissues
Composed of bulb, crura, body and glans penis
Erection
- Parasympathetic
- Sexual stimulation dilates the arteries supplying the penis
- Blood enters the penis compressing the veins so that the blood is trapped
- Parasympathetic reflex causes ejaculation
Ejaculation
- Sympathetic
- Muscle contractions close at the base of the bladder and move fluids through the vas deferens, small seminal vesicles, and ejaculatory ducts
- ischiocavernosus and bulbospongiosus complete the job
Glans penis
The enlarged distal end of corpus cavernosum
Covered by loosely fitting foreskin
Circumcision
The removal of the foreskin
3-4 days after birth
Possible lowers UTI’s, cancer and sexually transmitted disease
Female reproduction system
Involves Ovaries: produce secondary oocyte and hormones Uterine tubes: aka fallopian tubes Transport fertilized ova Uterus: Where fetal development occurs Vulva: Vagina and external genitalia Mammary Glands: Produce milk
Ovary
2 Almond shapes
Supported by ligaments
The main function is to produce Oocytes within the folicles
Histology of ovaries
Germinal epithelium: Simple epithelial covering over the ovary
Tunica albuginea: Capsule of dense connective tissue
Cortex: Region just deep to tunica and contains follicles, follicular cells, and granulosa cells
Medulla: Deeper region that is composed of connective tissue, blood vessels, and lymphatics
Histology of Graafin Follicle
Zona Pellucida: Clear area between the secondary oocyte and granulosa cells
Corona Radiata: Granulosa cells attached to zone pellucid, still attached to oocyte at ovulation
Antrum: Follicular fluid formed by granulosa cells
Oogonia
Germ cells from yolk sac that migrate to the ovary during fetal development
Divide into germ cells, some becoming primary oocytes.