reproductive system II

Question 1

what is the purpose of the scrotum?

Answer 1

it is the skin and fascia around the testes
-3 degrees cooler than body temp
-contracts and pulls when cold; relazed when warm as temp. is critical to sperm survival

Question 2

what are the function of the testes?

Answer 2

-produce testosterone
-leydig cells
-triggered by LH
-produce sperm

Question 3

what does each teste contain?

Answer 3

-~800 feet of seminiferous tubules
-broken down into 250-300 lobules

Question 4

what is spermatogenesis?

Answer 4

-64-74 days to mature sperm
~200 million per day ; 20% is rejects
-require proper temp and pH for proper motility and number production

Question 5

what 2 types of cells are the seminiferous tubules made from?

Answer 5

a) germ cells; sperm forming cells
b) sertoli/sustentacular cells; support cells

Question 6

what is the function of sertoli cells?

Answer 6

-blood-testis barrier
-assist sperm production; differentiation and phagocytizes defective sperm
-secrete seminiferous fluid
-leydig cells to secrete testosterone
-secretes inhibin (inhibits FSH)

Question 7

what is the epididymis and ductus/vas deferens?

Answer 7

-epididymis = ~6m long, 20 day journey of sperm maturation
-vas deferens/ductus= sperm can be stored here up to 2 months then reabsorbed; stores and transport sperm

Question 8

what are the 3 accessory glands and their secretions?

Answer 8

a) seminal vesicle (~60% of semen)fructose, alkali, prostaglandins, clotting factors
b) prostate alkali, prostaglandins, enzymes (clot/liquify semen)
c) cowpers/bulbourethal gland produce mucus to neutralize acid of urine in male ureter and lubricates urethra

Question 9

how does ejaculation occur?

Answer 9

-vasodilaton to penis; increased blood flow and erection occurs (parasympathetic)
-ejaculation is sympathetic control
-4-7 mL ~400 million sperm per ejaculate

Question 10

what are the early development stages?

Answer 10

cleavage (blastula) –> implantation –> gastrulation –> placentation –> organogenesis

Question 11

what are the 3 layers in gastrulation?

Answer 11

-ectoderm = outer layer; nervous/epithelial
-mesoderm = muscle/kidney
-endoderm = lines digestive tract; gut/liver

Question 12

when does implantation occur?

Answer 12

implantation of blastocyst occurs at roughly 7-10 days

Question 13

what occurs at 4 weeks gestation?

Answer 13

-somites are forming; spinal cord
-eyes and ear start to form

Question 14

what occurs at 5 weeks gestation?

Answer 14

*3 weeks since implantation and missed period *
-heart is beating
-placenta is fully operational
-mouth/liver/kidney/digestive systems
-limb buds form

Question 15

what are the 3 stages of parturition?

Answer 15

a) cervical dilation
b) delivery of baby
c) delivery of placenta

Question 16

what stage of labour is the longest?

Answer 16

cervical dilation (rising levels of oxytocin) can range from 2-24 hours as the cervix must reach a dilation of 10 cm

Question 17

how long does delivery of baby last? delivery of placenta?

Answer 17

-delivery of baby lasts 30-90 mins; cervical dilation and effacement is complete
-placenta is delivered 15-30 mins after baby is born