A&p Ch. 27 And 28

Front 1

Meiosis

Back 1

Formation of gametes. Maintains chromosome number from generation to generation because it reduces the number to one copy of each chromosome (23 total) in each sperm and each egg so that at fertilization there are 46.

Front 2

Spermatogenesis

Back 2

The process of taking an immature spermatagonia through two mitotic divisions and reducing chromosome number by half. Results in 4 spermatids connected by cytoplasm.

Front 3

Spermiogenesis

Back 3

Final maturation process of spermatids, shedding cytoplasm and forming flagella and acrosome.

Front 4

Acrosome

Back 4

Head piece of sperm containing hydrolytic enzymes needed to penetrate the egg.

Front 5

Capacitation

Back 5

Softening of the head of the sperm (the acrosome), releasing hydrolytic enzymes allowing the sperm to penetrate the egg.

Front 6

Hormones involved in sperm development

Back 6

Hypothalamus releases gonadotropin releasing hormone (GnRH) which stimulates anterior pituitary to release LH and FSH. Leutinizing hormone (LH) released by anterior pituitary stimulates interstitial cells in testes to secrete testosterone. Follicle stimulating hormone (FSH) causes maturation of spermatagonia. Testosterone is important in sperm production and secondary sex characteristics.

Front 7

Where is sperm stored?

Back 7

Epididymis

Front 8

Pathway from testicles to urethra

Back 8

Testes --> efferent ductules --> epididymis --> vas deferens --> ejaculatory duct --> urethra

Front 9

Oogenesis

Back 9

While spermatogenesis results in 4 sperm cells, oogenesis results in only one egg. Process of egg development. Meiosis II only occurs if fertilization occurs.

Front 10

Hormones involved with ovum development

Back 10

Same as for sperm development, but LH stimulates development of estrogen and progesterone, and FSH stimulates development of oocyte.

Front 11

HcG

Back 11

Produced by embryo. Maintains corpus luteum beyond the normal ten days (for up to 3 months) until the placenta is formed.

Front 12

Mechanisms for maintaining the lower temperature in scrotum

Back 12

1. Dartos muscle

2. Cremaster muscle

3. Pampiniform plexus

Front 13

Ovarian ligament

Back 13

Connects the ovary to the uterus.

Front 14

Endometrium

Back 14

Stratum functionalis is shed during menstruation.

Stratum basalis builds up stratum functionalis.

Front 15

Glands producing secretions for semen

Back 15

60% from seminal vesicles, 30% prostate gland (sperm activator), 10% bulbourethral glands

Front 16

Ovulation

Back 16

On Day 14 of monthly cycle, an LH surge from the anterior pituitary causes the egg to be released (ovulation). Mittelschmerz is a twinge of pain sometimes felt at ovulation. 1 to 2% of ovulation result in an egg being released from both ovaries (which can lead to fraternal twins).

Front 17

Menstrual cycle

Back 17

Monthly cycle associated with the maturation of an egg.

Follicular phase: (Days 1-14)

Luteal phase: (Days 14-28)

Ovulation on day 14.

Front 18

Role of corpus luteum

Back 18

Secrete progesterone and estrogen to maintain stratum functionalis. If conception occurs, HcG released by the fetus helps maintain the corpus lutein until a placenta is formed. If it does not, the corpus luteum breaks down after about 10 days, leaving only a scar known as the corpus albicans.

Front 19

Location of fertilization

Back 19

Distal end of fallopian tube

Front 20

Function of GnRH

Back 20

Released from hypothalamus, stimulates anterior pituitary to release FSH and LH.

Front 21

Stages of labor

Back 21

Dilation stage

Expulsion stage (delivery of baby)

Placental phase (delivery of placenta)

Front 22

Major cause of testicular cancer

Back 22

Cryptorchidism (undescended testicles)

Front 23

Prolactin

Back 23

Stimulates milk production

Front 24

Progesterone's job is to ______________ if pregnancy occurs.

Back 24

Maintain the uterine lining

Front 25

Prostate cancer

Back 25

Second most common cancer in men. Easily treated if it's encapsulated, so early detection is key.

Front 26

Apgar score

Back 26

Scale rating how healthy the baby is on birth. 0 to 2 points each for heart rate, respiration, color, muscle tone, reflexes.

Front 27

Blocks to polyspermy

Back 27

1. Membrane depolarization

2. Zonal inhibiting proteins (ZIPs)

Polyspermy results in a non-viable zygote.

Front 28

Embryonic development stages

Back 28

Zygote (fertilized egg) --> Cleavage (rapid division of cells) --> morula (3 day old embryo - 16 or more cells --> Blastocyst --> implantation

Front 29

Primary germ layers

Back 29

Ectoderm (forms nervous system and skin), endoderm (forms epithelial linings of digestive, respiratory, and urigenital systems), mesoderm (forms all other tissues)

Front 30

Gastrulation

Back 30

Formation of germ layers. Sets the stage for organogenesis. By the 8th week of pregnancy all organ systems are recognizable.

Front 31

Amnion (upper part)

Back 31

Epiblast cells transform into a transparent membranous sac. This sac will eventually fill with amniotic fluid and will completely encase the embryo.

Front 32

Ectopic pregnancy

Back 32

Development of embryo outside uterine cavity.

Front 33

Yolk sac (lower part)

Back 33

Hypoblast cells that form a sac on the central surface of the embryo.

Front 34

At what point do the cells become an embryo?

Back 34

At completion of embryogenesis (about 16 days) when germ layers are formed.

Front 35

Purpose of uterus

Back 35

Receive, retain and nourish a developing embryo.

Front 36

Purpose of inner cell mass?

Back 36

That is the embryo

Front 37

Embryonic membranes

Back 37

1. Amnion - from epiblast cells, accumulates amniotic fluid (about 1 L by the time the baby is born).

2. Yolk sac - bottom part, forms part of digestive tube along with the endoderm.

3. Allantois - spot that goes into umbilicus

4. Chorion - trophoblasts. The baby's contribution to the placenta.

Front 38

What has happened by end of first trimester?

Back 38

Bones are ossified, limbs are formed, heart is beating.

Front 39

Teratogens

Back 39

Anything that can cause birth defects

Front 40

Problems affecting premature infants

Back 40

Lack of surfactant on lungs, liver not being fully functional

Front 41

Aneuploidy

Back 41

Presence of an abnormal number of chromosomes in a cell

Front 42

When does implantation occur?

Back 42

Between 6 and 14 days after ovulation.