Lab 16: Reproductive System

Question 1

reproductive system includes

Answer 1

• gonads (the primary sex organs)

* accessory reproductive structures (ducts, glands and external genitalia)

Question 2

gonads

Answer 2

• produce gametes + sex hormones
Male: testes
Female: ovaries

Question 3

sperm cells (other name)

Answer 3

spermatozoa

Question 4

epididymis

Answer 4

• highly coiled accessory duct

* Function: sperm mature and are stored.

Question 5

ductus deferens (vas deferens)

• what does it form
• each end becomes?

Answer 5

• form spermatic cord

* end of each ductus deferens enlarges to form an ampulla

Question 6

urethra

• from where to where?
• 3 regions

Answer 6

• extends from bladder to penis tip
• reproductive and urinary systems
• three regions: 
-prostatic urethra
-membranous urethra 
- penile (spongy) urethra

Question 7

accessory glands of the male reproductive system

Answer 7

• paired seminal vesicles + prostate gland + paired bulbourethral gland
• secretions of these accessory glands form semen (seminal fluid)

Question 8

internal penis

Answer 8

• 3 columns of erectile tissue (elastic connective tissue, smooth muscle and vascular channels)
•Tunica Albuginea: fibrous tissue that surrounds erectile tissues
Two dorsal columns are called
-corpora cavernosa
-corpus spongiosum: surrounding urethra
• During sexual arousal, the erectile tissue will fill with blood and cause enlargement and erection of the penis.

Question 9

seminiferous tubules

Answer 9

• coiled, makes up testes
• Lined with germinal epithelium in various stages of development
• Function: Location of meiosis and creation of male gametes

Question 10

Spermatogenesis

Answer 10

process of sperm production occurs in the seminiferous tubules

Question 11

Leydig cells (interstitial cell)

Answer 11

secrete testosterone

• necessary for spermatogenesis and for development of the secondary sexual characteristics in the male

Question 12

ovaries

Answer 12

• produce gametes that develop into mature egg cells (ova) after fertilization
• produce the sex hormones - estrogen and progesterone

Question 13

fimbriae

Answer 13

contain cilia that create currents in the peritoneal fluid that propel the ovulated oocyte from the ovary into the uterine tube, where it begins its journey to the uterus.

Question 14

Fertilization of the oocyte

Answer 14

• union of egg and sperm cell nuclei to form a zygote. Takes place in oviduct
• occurs any time (up to 24 hours after ovulation) if sperm are present.
• oocyte carried towards uterus by a combination of muscular peristalsis and beating of cilia lining the tube.

Question 15

uterus

regions / layers

Answer 15

• divided into two regions: body + cervix
• The uterine wall consists of three layers
– perimetrium:
–myometrium: (smooth muscle for labor contractions)
–inner endometrium: two layer
> functional layer (stratum functionalis): site of implantation of fertilized ovum + subsequent shed during menstruation
>basal layer (stratum basalis): stays behind during period to regenerate new layer

Question 16

vagina

Answer 16

• nonkeratinized stratified squamous epithelium

- serves as a passageway for delivery of an infant and for menstrual flow

Question 17

ovary histology

Answer 17

• divided into two regions:

• the cortex: contains follicles + corpora lutea
• medulla: interior part composed of loose connective tissue and blood vessels

Question 18

Oogenesis

Answer 18

• Oogonium = diploid
• Primary Oocyte= diploid meiosis I
• Secondary Oocyte= haploid (these are the ones that get ovulated) Enter meiosis 2 but only complete it if they get fertilized
• Ovum (egg)= haploid

Question 19

atresia

Answer 19

process before birth and during childhood where primary oocyte cells degenerate

Question 20

Name the hormone(s) the corpus luteum secretes.

Answer 20

estrogen and progesterone

Question 21

pathway of a sperm cell from the testes in the male to the site of fertilization of an ovulated oocyte in the female

Answer 21

testis —> epididymis —> ductus (vas) deferens —> ejaculatory duct —> prostate urethra —> membranous urethra —> spongy urethra —> vagina —> cervix —> uterus body —> oviduct

Question 22

Egg/sperm viabily

How to get pregnamt

Answer 22

• An egg must be fertilized within 12 to 24 hours after ovulation
• Sperm can remain viable for about 48 hours after deposition in the vagina
• Pregnancy will most possibly occur if intercourse takes place from a few days before ovulation to 1 day after ovulation.
• About 2000 spermatozoa (out of the 300 million that were ejaculated) reach the vicinity of the ovulated secondary oocyte in the distal oviduct.

Question 23

head of a sperm covered by

Answer 23

Acrosome: helmet-like structure
• Acrosomal enzymes and strong flagellar movements help the sperm penetrate the cells of the corona radiata and contact the zona pellucida

Question 24

blastocyst differential forms 2 things

Answer 24

inner cell mass forms embryo,

outer mass [trophoblast] forms placenta

Question 25

amniotic fluid function

Answer 25

cushions and protects the embryo from trauma and extreme temperatures, and keeps the fetal tissues moist

Question 26

what's Amniocentesis?

Answer 26

Amniocentesis - drawing amniotic fluid to examine fetal cells

Question 27

What is Water broke during pregnancy

Answer 27

amnion may rupture, releasing the fluid when “one’s water breaks”

Question 28

Yolk Sac

Answer 28

* Fomed by cells migrating from edge of the hypoblast to cover inner blastocyst cavity * Function: provides nourishment to the embryo while the placenta is being established

Question 29

chorion

Answer 29

* chorion (encases embryo) = extraembryonic mesoderm + trophoblast * chorion develops chorionic villi * Blood vessels form in the chorionic villi for diffusion of gas/nutirents in embryo

Question 30

Gastrulation, what becomes what

Answer 30

* Epiblast --> ectoderm * Hypoblast -->endoderm * cells proliferating in between --> mesoderm

Question 31

Allantois

Answer 31

develops from the endoderm and mesoderm, forms part of the urinary bladder/umbilical chord

Question 32

Germ Layers give rise to:

Answer 32

- Ectoderm: epidermis, glands and nervous tissue. - Endoderm: epithelial lining and glands of the digestive and respiratory systems. - Mesoderm: muscle, blood, bones, the heart and kidneys

Question 33

What is an ectopic pregnancy?

Answer 33

When embryo implants somewhere other than a uterus such as a oviduct

Question 34

What is placenta previa?

Answer 34

Condition where placenta partially/completely blocks neck of uterus interfering with normal delivery of baby

Question 35

Explain the difference between dizygotic (fraternal) twins and monozygotic (identical) twins?

Answer 35

* Identical (monozygotic) twins: develop when 1 egg is fertilized by 1 sperm to produce a single zygote. Developing embryo splits into 2 identical parts. * Fraternal (dizygotic) twins: when 2 eggs are released/fertilized by 2 different sperm

Question 36

Stages of Birth | -3 Stages

Answer 36

Stage 1: Cervix Dilation - dilation of the cervix, lasts 6-12 hours - Regular contractions occur, amniotic sac ruptures releasing the amniotic fluid (water broke) Stage 2: Expulsion/ Delivery - cervix dilated completely (about 10 cm) - fetus passes through cervix and vagina within 2 hours. - Strong contractions occur every 2-3 minutes, mother utilizes abdominal muscles to “bear down”. - Once baby is out and is breathing on its own, the umbilical cord is cut and tied. Stage 3: Afterbirth / Placental Delivery -uterus contracts until the placenta (afterbirth) is expelled (~30 minutes post birth)

Question 37

labour hormone

Answer 37

Oxytocin - positive feedback system to increase the frequency/force of contractions

Question 38

What is a breech presentation?

Answer 38

Baby exists pelvis butt/feet first instead of normal head first orientation

Question 39

Women can experience “false” labour pains. How do these differ from true labour pains?

Answer 39

* “Braxton Hicks” the bodies way of preparing for the real thing * They don’t happen at regular intervals, not painful, don’t feel stronger with time or increase with walking, they don’t feel loser together or last longer as you go

Question 40

Semen Function - which carries the sperm during ejaculation, activates and produces certain nutrients for the sperm, and contains substances that neutralize the somewhat acidic environment in the vagina.

Answer 40

- carries sperm during ejaculation - Activates/produces nutrients for sperm - contains substances that neutralize acidic vagina

Question 41

Spermatogenesis

Answer 41

• spermatogonia (diploid) - mitosis to make more develop from primordial germ cells * primary spermatocytes (diploid) - miosis I (prim to second) gives rise to four sperm cells. * secondary spermatocytes (haploid) - miosis I (second to sperma) * spermatids (haploid) * Spermatozoa (sperm) (haploid) - Transformed by growing a flagellum and shedding most of its cytoplasm