Anatomy - Embryology

Question 1

When does menarche occur in females?

Answer 1

Age 12-15

Question 2

When does puberty occur in males?

Answer 2

13-16

Question 3

Where does fertilization occur?

Answer 3

Uterine (Fallopian) tube

Question 4

What is the inferior part of the birth canal?

Answer 4

Vagina

Question 5

What are the two parts of the uterus?

Answer 5

Upper 2/3 = body

Lower 1/3 = cervix

Question 6

What is the constricted region between the uterine body & cervix called?

Answer 6

Isthmus

Question 7

The 2 constricted openings at the superior and inferior uterus are called:

Answer 7

Internal os (body of uterus); external os (opening to vagina)

Question 8

What are the 3 layers of the uterus? (Superficial to deep)

Answer 8

Perimetrium (thin external)
Myometrium (thick smooth muscle)
Endometrium (thin internal)

Question 9

What is sloughed off during menstruation?

Answer 9

Functional layer (endometrium)

Question 10

What structure protects & nourishes the fetus during pregnancy?

Answer 10

Uterus

Question 11

Who produces estrogen & progesterone?

Answer 11

Ovaries

Question 12

During spermatogenesis/oogenesis, the first meiotic division …

Answer 12

Chromosome number diploid –> haploid

Question 13

What are homologous chromosomes?

Answer 13

One from each parent

Question 14

When do homologous chromosomes pair and cross-over?

Answer 14

Prophase I

Question 15

What are sister chromatids?

Answer 15

Identical copies of each chromosome

Question 16

What are homologous chromosomes?

Answer 16

One from mother, corresponding one from father

Question 17

T/F In meiosis, homologous chromosomes stick together in pairs

Answer 17

True; when paired, non-sister chromatids can trade places (cross-over)

Question 18

What happens during meiosis II?

Answer 18

Sister chromatids separate

Question 19

What is it called when homologous chromosomes fail to separate?

Answer 19

Nondisjunction

Question 20

What is trisomy 21?

Answer 20

Down syndrome (gamete with 24 chromosomes unites with a normal one)
* Trisomy 21 = three chromosome 21's

Question 21

What is Mittelschmerz?

Answer 21

A sign of ovulation; may be used as a sign of ovulation, but more accurate measurements i.e. basal temperature

Question 22

What are the 4 major hormones that govern ovulation?

Answer 22

Estrogen, progesterone, FSH & LH

Question 23

What is the acellular hlycoprotein coat that surrounds the secondary oocyte?

Answer 23

Zona pellucia

Question 24

Degeneration of the corpus luteum is governed by which hormone?

Answer 24

hCG

Question 25

Contraceptives prevent...

Answer 25

Ovulation

Question 26

How many sperm per mL semen?

Answer 26

100 million

Question 27

How much sperm per ejaculation?

Answer 27

3 mL semen / 300 million sperm

Question 28

What is vasectomy?

Answer 28

Bi-lateral excision of vas deferens

Question 29

Where is typical site of fertilization?

Answer 29

Ampulla of the uterine tube (proximal to the infundibulum)

Question 30

What is the corona radiata?

Answer 30

The cellular layer outside the zona pellucida

Question 31

Differentiate between the trophoblast and the embryoblast?

Answer 31

Embryoblast: discrete group of blastomeres Trophoblast: thin outer cells that give rise to the embryological placenta

Question 32

What are the 2 layers of the trophoblast and what special factor do they secrete?

Answer 32

1. Cytotrophoblast [cellular layer] 2. Syncyntiotrophoblast [pierces endometrium] * Secrete early pregnancy factor at 24-48 hours post-fertilization

Question 33

What is the difference between the epiblast and the hypoblast?

Answer 33

Epiblast: will eventually form the embryo Hypoblast: thin cell lining of the blastocyst cavity [lines primitive yolk sac]

Question 34

What cells line the primitive yolk sac?

Answer 34

Hypoblast cells

Question 35

Which chromosome is the male chromosome?

Answer 35

Y

Question 36

What percentage of pregnancies result in early spontaneous abortion?

Answer 36

45%

Question 37

What is the commonest reason of spontaneous abortions?

Answer 37

Chromsomal abnormalities

Question 38

Why might it be important to determine the sex of the cleaving zygote in vitro?

Answer 38

Families with sex-linked diseases

Question 39

Which part of the blatocyst penetrates the endometrium?

Answer 39

Synciotrophoblast

Question 40

What does the synciotrophoblast secrete?

Answer 40

hCG (early pregnancy tests)

Question 41

What is the bilaminar disk?

Answer 41

Epiblast + Hypoblast

Question 42

What is the chorionic cavity?

Answer 42

The space surrounding the primary yolk sac and amniotic sac, except where the connecting stalk attaches to the cytotrophoblast of the blastocyst

Question 43

What suspends the embryo, amniontic sac & umbilical vesicle to the chorionic cavity?

Answer 43

The connecting stalk

Question 44

Where is the commonest site of an ectopic pregnancy?

Answer 44

Uterine tube

Question 45

Does the morning after-pill (large doses of estrogen) prevent fertilization or implantation?

Answer 45

Implantation -- a large amount of estrogen disturbs the normal balance between estrogen and progesterone that is necessary to prepare the endometrium for implantation

Question 46

Where does fertilization take place?

Answer 46

Uterine tube

Question 47

Where does implantation take place?

Answer 47

Posterior uterine wall

Question 48

This type of device can be inserted into the uterus through the vagina & cervix which prevents implantation

Answer 48

IUD (intra-uterine device)

Question 49

What are "mesenchymal cells"?

Answer 49

Mesoderm -- have the potential to differentiate into fibroblasts, chondroblasts and osteoblasts

Question 50

The notochord is the precursor to: (2)

Answer 50

1. Axial skeleton 2. Future site of vertebral bodies * * Nucleus pulposis**

Question 51

The early embryo has 2 membranes (one caudal, one cranial). What are they?

Answer 51

1. Oropharyngeal membrane | 2. Cloacal membrane

Question 52

What structure extends from the caudal wall of the umbilical vesicle into the connecting stalk?

Answer 52

The allantois

Question 53

The blood vessels of this structure become the umbilical arteries and veins

Answer 53

Allantois

Question 54

This process forms the neural plate, neural folds and their closure

Answer 54

Neurulation

Question 55

What are the most common tumors in newborns?

Answer 55

Sacrococcygeal teratoma (remnant of the primitive streak -- pluripotent cells -- can include tissues derived of all 3 germ layers)

Question 56

Failure of the neural folds to fuse and form the neural tube can result in: (2 -- 1 caudal, 1 cranial)

Answer 56

Caudal: spina bifida cystica Cranial: anencephaly (meroencephaly)

Question 57

Differentiate between the products of the 4th left/right pharyngeal arches.

Answer 57

L: aortic arch R: r. subclavian

Question 58

Differentiate between the products of the 6th left/right pharyngeal arches.

Answer 58

L: PA, ductus arteriosis R: PA

Question 59

Neural crest cells give rise to:

Answer 59

MOTEL PASS - Melanocytes - Odontoblasts - Tracheal cartilage - Enterochromaffin cells - Laryngeal cartilage - Pseudounipolor - All ganglia/adrenal medulla - Schwann cells

Question 60

Differentiate between the derivatives of the ectoderm/mesoderm/endoderm.

Answer 60

Ectoderm: epithelium & communication Mesoderm: movement (muscles, ligs, cart) Endoderm: excretory (GI, resp., urinary)

Question 61

What is the primary imaging modality for the evaluation of the fetus?

Answer 61

Ultrasound

Question 62

Differentiate between chorionic villus sampling and amniocentesis.

Answer 62

CVS: earlier (sample chorionic tissue) Amnio: fluid from amniotic cavity

Question 63

Alpha fetoprotein levels would indicate:

Answer 63

1. Open neural tube defects | 2. Ventral wall defects (gastroschesis/omphalocele)

Question 64

How might we measure the age of the fetus?

Answer 64

Chorionic sac size (ultrasound)

Question 65

What is the general name of functional endometrium of a gravid woman?

Answer 65

Decidua