Lecture 23: Embryology, Pregnancy and Child Birth

Question 0

Spermatozoa viable for how many hours in female tract?

Answer 0

48 hours

Question 1

Oocytes viable for how long?

Answer 1

12-24 hours

Question 2

Sperm must be undergo what? takes 6-8 hours after ejaculation.

Answer 2

Capacitation

Question 3

Once a single sperm binds to oocyte plasma membrane a reaction occurs to exclude what?

Answer 3

All other sperm

Question 4

Blastocyst implants into endometrium by secreting what, onto the endometrial surface?

Answer 4

digestive enzymes, cytokines and growth factors

Question 5

Trophoblast cells secrete what substance which is measured in urine to test for pregnancy.

Answer 5

human chorionic gonadotrophin

Question 6

hCG prompts corpus luteum to keep secreting what, until

placenta takes over?

Answer 6

progesterone

Question 7

Placenta makes and secrete what two hormones for the remainder of pregnancy until birth?

Answer 7

oestrogen and progesterone

Question 8

Chorionic villi project from fetal tissue into maternal

blood vessels to form what two structures?

Answer 8

umbilical arteries and vein

Question 9

Placenta =

Answer 9

chorionic villi + decidua basalis

Question 10

The umbilical vein during pregnancy does what?

Answer 10

oxygenated blood => mother=>placenta =>Fetus

Question 11

The umbilical artery does what during pregnancy?

Answer 11

deoxygenated blood + waste => fetus =>placenta =>mother

Question 12

What are the four Embryonic membranes:

Answer 12

• AMNION
• YOLK SAC
• ALLANTOIS
• CHORION

Question 13

Name the 3 primary germ layers:

Answer 13

• ECTODERM
• MESODERM
• ENDODERM

Question 14

What do the three germ layers contain?

Answer 14

Ectoderm => epidermis, nervous system

Mesoderm => smooth muscle, connective tissue, blood vessels, blood cells, skeleton, skeletal muscle, reproductive and excretory
organs.

Endoderm => epithelial linings of respiratory passages and digestive tract.

Question 15

Neuroectoderm forms what two structures?

Answer 15

Brain and spinal cord

Question 16

Neural crest cells form what?

Answer 16

dorsal root (sensory) ganglia of spinal and cranial nerves.

Question 17

What do Somites form?

Answer 17

axial skeleton + adjacent muscles + dermis.

Question 18

As the embryo folds it encloses part of the yolk sac

that goes on to develop into what structure?

Answer 18

digestive tube

Question 19

Endodermal tube forms the EPITHELIAL LININGS of what 3 structures?

Answer 19

Digestive system, respiratory systems and associated glands

Question 20

Intermediate mesoderm forms what?

Answer 20

gonads, kidneys, adrenal cortex

Question 21

Lateral somatic mesoderm form what?

Answer 21

dermis, peritoneum, limb buds

Question 22

Lateral splanchnic mesoderm forms what?

Answer 22

cardiovascular system organs, connective tissues, all but

epithelial lining of digestive and respiratory organs.

Question 23

Blood supply to the foregut ( epigastric )?

Answer 23

Coeliac artery (except pharynx, respiratory tract,                              
most of oesophagus)

Question 24

Midgut ( umbilical) derivatives

Answer 24

• Small intestines (inc. most of duodenum)

* Caecum, vermiform appendix, ascending colon, right 1⁄2 - 2/3 of transverse colon.

Question 25

Blood supply to the midgut (umbilcal) derivatives

Answer 25

Superior mesenteric artery

Question 26

Hindgut (hypogastric) derivatives

Answer 26

• Distal part of transverse colon, descending colon, sigmoid colon, rectum, anal canal.
• Epithelium of urinary bladder and most of urethra.

Question 27

Blood supply to the hindgut derivatives?

Answer 27

Inferior mesenteric artery

Question 28

4thweek of development – ventral and dorsal buds from?

Answer 28

Foregut

Question 29

By the end of the 6th week, the rotation of the duodenum has brought ventral and dorsal buds together to?

Answer 29

Fuse

Question 30

Ventral bud forms what?

Answer 30

head and uncinate process.

Question 31

Dorsal bud forms what?

Answer 31

Neck, body and tail

Question 32

Endoderm of primitive gut gives rise to most of the what?? of the digestive tract.

Answer 32

epithelium and glands

Question 33

Epithelium from cranial and caudal extremities is

derived from the ?

Answer 33

ectoderm of the stomodeum

Question 34

Muscular and connective tissue components of

digestive tract are derived from the?

Answer 34

splanchnic mesenchyme surrounding primitive gut.

Question 35

4 weeks gestation:
Signals from heart trigger underlying endoderm to generate primary liver bud as an outgrowth of the ventral wall of the? .

Answer 35

FOREGUT

Question 36

Five Months

A protective coating begins to form on baby’s skin, what is it called?

Answer 36

vernix caseosa

Question 37

By 4th month the uterus fills the?

Answer 37

pelvis

Question 38

By 9th month the fundus of the uterus is at the level of the?

Answer 38

xiphoid process

Question 39

Abdominal organs are pushed superiorly under the?

Answer 39

diaphragm.

Question 40

Coccyx permitted to move more posteriorly to increase?

Answer 40

pelvic outlet

Question 41

Conjugate distance between sacral promontory and

posterosuperior aspect of pubic symphysis is?

Answer 41

Fixed

Question 42

Transverse diameter & amount of pelvic rotation permitted around sacrum is increased due to?

Answer 42

effect of relaxin hormones on pelvic ligaments

Question 43

Back pain in pregnancy

Answer 43

• Increased maternal weight spine.
• Referred pain from visceral compression.
• Direct compression on exiting nerve roots in pelvis.
• Venous congestion in pelvis and lumbar spine from uterus compression inferior vena cava.
• Relaxin hormone causing ligamentous laxity.
• Pelvic instability.

Question 44

What is the let down reflex?

Answer 44

oxytocin binds to myoepithelial cells surrounding alveoli –>
milk ejected form alveoli into ducts from both breasts