Reproductive physiology II (male) Flashcards
Scrotum
- what is
- temperature
- Skin and fascia around testes
- 3 ̊ cooler than body temperature
Smooth muscle
* Contracts and pulls testes close when cold
* Relaxes when warm
- Temperature is critical to sperm survival
testes
- what do they do
- how long tubules
Produce Testosterone
-Leydig cells
- Triggered by LH
Sperm production
Contains ~800 feet of seminiferous tubules each testis into 250– 300 lobules
* Lobules contain 1–4 seminiferous tubules
Spermatogenesis
- how long/much
- what does require
64-74 days to maturation
~200 million / day
- 20% rejects
Require proper temp and pH
* Motility and number
Anatomy of a spermatozoan
- parts of it
- acrosome /mitochondria
Tail for motility, DNA head
Acrosome
-Digestive enzymes
-Break down egg wall
Mitochondria
-energy
Seminiferous tubules
- germ cell
sustentacular (sertoli) cells
- what do
- assist in
- help with
Germ cells- sperm-forming cells
- support cells
- blood- testis barrier
Assist sperm production
* Differentiation
* Phagocytizes defective sperm
- Secrete seminiferous fluid
- Aids Leydig cells to secrete
testosterone - Secretes inhibin
- Inhibits FSH
Epididymis
Ductus or Vas deferens
-6m long (when uncoiled)
-20-day journey
- Site of Sperm maturation
- Stores and transports sperm
-Stored for up to 2 months
Then resorbed
Accessory glands
- secretion vital to sperm survival
Seminal vesicles
Seminal Vesicles
Prostate Gland
Bulbourethral Gland
* Cowper’s gland
~60% of semen volume
Fructose to nourish sperm
Alkali
* Neutralize vaginal acid
Substances for sperm motility
Prostaglandins
* Vaginal contractions
Clotting factors
* inertial
prostate gland
- encircles urethra
- 25-30% of seminal fluid
Encircles urethra
- 20—30 compound glands
~25—30% of seminal fluid
Alkali
* Neutralize vaginal acid
Prostaglandins
* Enhance sperm motility
Enzymes that clot and then liquefy semen
Bulbourethal Glands
- size/location
- production
Pea-sized, inferior to prostate
Produce mucus
- mucus enters spongy urethra
* Neutralizes traces of acidic urine
* Lubricates urethra
Ejaculation
- what is
- how much
Vasodilation to penis
- Increased blood flow
Erection
* parasympathetic control
Ejaculation
* sympathetic control
Ejaculate - 4-7 mL
Semen ~400 million sperm
Male fertility problems
- Blocked tubules
-Decreased sperm count or quality (usually hormonal)
* Less than 60 million/ejaculation is considered infertile
- Decreased sperm motility (hormonal)
- Decreased Accessory gland secretion
needed for sperm viability and survival)
Male vs female sperm
Male (Y)
-Lighter, faster, more fragile
- Die in ~24 hours
- Conceived if “deposit” close to ovulation (day 14)
Female Sperm (X)
- Heavier, slower swimmers, hardier
-Live 2-3 days
- Conceived if “deposit” is early in cycle (day 11-13)
Fertilization
- where goes to
- followed by
100% of sperm delivered to vagina
3% survive to cervix
.1% survive to uterus
.001% survive to oviducts
Oviducts site of fertilization
Fertilization is followed by cell cleavage
- many smaller cells called blastomeres
Early development
Cleavage (Blastula)
Implantation
Gastrulation
Placentation
Organogenesis
5 Weeks Gestation
(3 weeks since implant and
missed period)
- most likely one to test on
- heart is beating
- placenta is fully operational
-mouth/liver/kidney/digestive systems
-Arm and leg buds
Parturition
- stages of labour
Cervical dilation (higher oxytocin)
* Longest stage
* 2- 24 hours
Delivery of baby
* cervical dilation and effacement is complete
* lasts ~ 30 to 90 minutes
Delivery of placenta
* uterine contractions separates placenta from uterine wall
* usually within 15 to 30 minutes after baby is born
After delivery, uterus shrinks to pregestational size (involution)
