repro 2

Question 1

what is vasocongestion?

Answer 1

erection in both states; artieral blood flow to erectile tissues exceed veinous outflow

Question 2

what are erogenous zones?

Answer 2

regions of the body with receptors fO creor tactile stimuli

Question 3

how is NO created to generate an erection?

Answer 3

ACh released from parasympathe)c nerves binds muscarinic ACh receptors on endothelial cells

• results in produc)on of nitric oxide (NO) in endothelial cells
• NO then enters smooth muscle cell and causes relaxa)on of vascular smooth muscle
• engorgement compresses veins

Question 4

emission vs ejaculation

Answer 4

Emission (sympathe)c) is the movement of sperm out of the vas deferens and into the urethra, where it is joined by secre)ons from the accessory glands to make semen.
Ejacula)on (soma)c) is the expulsion of semen (~3ml) by a series of rapid muscular contrac)ons accompanied by sensa)ons of pleasure. -erec)on and ejacula)on can occur in absence of mechanical s)mula)on, non-sexual erec)on occurs in REM sleep

Question 5

describe the events of fertilization

Answer 5

1. sperm binds sperm-binding receptors and sperm and egg plasma membranes fuse
2. cortical granules in egg release enzymes by exocytosis into intracellular zone–>causes hardening–>only one sperm can fertilize egg
3. sperm nucleus moves into cytoplasm of egg
4. oocyte nucleus completes meoisis division (another polar body formed)
5. the two nuclei now fuse

Question 6

Progesterone slows down smooth muscle contrac)on in fallopian tubes–ensures fertilization is distal fall tub

Answer 6

ya

Question 7

describe the blastocyst

Answer 7

• -approximately composed of 100 cells:
  
  • -outer cell layer (trophoblast) that’s sticky and surrounds an inner cell mass
  • • -implants approximately 7 days aYer ovula)on
• upon contact with endometrium trophoblasts proliferate and secrete proteoly)c enzymes allowing blastocyst to penetrate wall

Question 8

what is the chorion?

Answer 8

formed from th outer layer of blastocyst–encloses embryo and forms placenta—inner cell mass forms embryo and other extraembryonic membranes:
–amnion: secretes amniotic fluid
–allantois: becomes part of umbillical crd (grows from inner cell mass)
yolk sac– functions as the embryo’s CV system until the placenta can form; helps fetus absorb nutrients and gases

Question 9

what are chorionic villi?

Answer 9

formed from chorionic cells–penetrate the vascularized endometrium–Secrete enzymes that break down walls of maternal blood vessels; Nutrients gases and wastes exchange across membranes of villi mainly by diffusion

Question 10

describe hCG and its role

Answer 10

corpus luteum has 12-days it must “survive” before degeneration; human chorionic gonadotrpoin is secreted from chorionic villi; similar to LH and binds LH receptors of corpus luteum–>continues progesterone secretion–keeps endometrium in tact
-hCG s)mulates testosterone produc)on in
developing testes in male fetuses
-hCG is hormone detected by pregnancy tests
-chorionic villi of developing placenta secrete human chorionic gonadotropin (hCG)
-similar to LH, binds LH receptors of corpus luteum, con)nues progesterone secre)on, keeping endometrium intact
-aYer 7 weeks placenta takes over progesterone produc)on

Question 11

what are the hormones and their roles that the placenta secretes?

Answer 11

1. prog and est–negative feedback to hypothal–>prevent follicle formation
   - -estrogen: develops milk-secreting ducts in the breast
   - -progesterone: maintains endometrium, suppresses contractions
   - -corpus luteum now denegerates
2. human placental lactogen
   - -similar to growth hormone; may be needed for breast development and milk production during pregnancy
   - -alters mothers glucose//FA metabolism o support growing fetus–causes insulin sensitivity–blood glucose remains elevated
   - -In ~4% of women insulin insensi)vity leads to gesta)onal diabetes

Question 12

describe parturition

Answer 12

• normally occurs between the 38th-40th week of gesta)on
• begins with labor, the rhythmic contrac)ons of the uterus
• -contractions may be due to oxytocin, or corticotropin-releasing hormone released from the placenta
• Days prior to onset of labor the cervix soYens and ligaments holding pelvic bones together loosens under enzyma)c control (estrogen or relaxin)

Question 13

During puberty estrogen s)mulates the growth and branching of milk ducts and deposi)on of fat.

• glands further develop at pregnancy due to estrogen, growth hormone and cor$sol
• final development: progesterone converts duct epithelium into a secretory structure.

Answer 13

ya