Embryology

Question 1

What is a zygote?

Answer 1

ovum + sperm

diploid cell (23 + 23 chromosome)

Question 2

Prenatal defintion

Answer 2

before birth

Question 3

postnatal defintion

Answer 3

after birth

Question 4

Where does embryo arise from

Answer 4

• arises from inner cell mass

- term is used from 2nd week to end of the 8th week

Question 5

Definition of fetus

Answer 5

after 8 week of fertilization, a developing human

Question 6

Definition of embryonic induction

Answer 6

one tissue (inducer, organizer) determine the fate of another tissue

Must be close enough to other tissue

Question 7

What are example of embryonic induction

Answer 7

notochord –> neural tube

optic vesicle –> development of eye

Question 8

What covers ovum?

Answer 8

Zona pellucida - transparent membrane

Corona radiata -
layer of follicular cells

Question 9

What are produced after the 2 meiosis of egg?

Answer 9

3 polar bodies ( not viable for fertilization)

1 viable gamete

Question 10

What does ejaculated sperm undergo?

Answer 10

capacitation

Question 11

What is capacitation?

Answer 11

removal of glycoprotein and seminal protein coat

By female secretion

Question 12

Where does capacitation occur?

Answer 12

uterus, uterine tube

Question 13

What is acrosomal reaction?

Answer 13

development of perforation in acrosome

release of enzyme of the perforation–> dissociation of corona radiata zona pellucida

Question 14

What is effect of acrosomal reaction?

Answer 14

• changes in the CR and ZP prevent other sperm from entering

- completion of 2nd meiotic division

Question 15

What is the result of fusion of pronuclei?

Answer 15

nuclei of egg and sperm meet each other and the fuse

–> restoration of diploid cell

Question 16

Site for fertilization?

Answer 16

ampulla of uterine tube

Question 17

What is cleavage?

Answer 17

mitosis of the diploid zygote

Question 18

what does the mitosis produce

Answer 18

a morula - a ball of cells (blastomere)

Question 19

Does the size of the zygote change after mitosis?

Answer 19

no, it stays the same but many small blastomere

Question 20

When and where does morula occur?

Answer 20

3-4 days after fertilization, at the intramural of uterine tube

Question 21

What does morula develop into?

Answer 21

a blastocyte, and then divide into 2 masses as fluid increases

1. Trophoblast (outer cell layer)
2. Inner cell mass (embryoblast)

Question 22

what is the function of placenta?

Answer 22

• anchor the developing offspring
• channel for exchange of nutrient and waste
• secretes estrogen and progesterone

Question 23

What does inner cell mass develop into

Answer 23

• epiblast –> amniotic fluid (fluid filled)

- hypoblast –> yolk sac (blood cell production)

Question 24

What is the embryonic disc composed of?

Answer 24

1. epiblast-floor of the amniotic cavity

2. hypoblast- roof of the yolk sac

Question 25

When does bilaminar embryo occur?

Answer 25

week 2 of fertilization

Question 26

When does trilaminar embyro occur?

Answer 26

week 3 of fertilization

Question 27

What is gastrulation?

Answer 27

the transition from bilaminar to trilaminar embyro

Question 28

What is trilaminar embyro consist off?

Answer 28

aka primary germ layers 1. ectoderm 2. mesoderm 3. endoderm

Question 29

What tissue does ectoderm develop into

Answer 29

- CNS/PNS - posterior pituitary - epidermis: skin, eyes , nails

Question 30

What tissue does mesoderm develop into

Answer 30

- connective tissue (cartilage, bone , tendons, ligaments muscle) - epithelium of the vascular system - heart, circulation system - internal sex organ

Question 31

What tissue does endoderm develop into

Answer 31

- epithelium: | thyroid, thymus , larynx, trachea, lungs, Gi tract, bladder, vagina, uretha

Question 32

What are the 4 basic tissue of the human body?

Answer 32

1) Epithelium - covering/lining/glandular 2) connective - connecting, supporting 3) muscle - movement 4) nervous - transmission of impulses

Question 33

Characteristics of epithelium ?

Answer 33

- cells organized into sheet to cover area of body - cell appearance is associated with their function - rest on basement membrane

Question 34

How is epithelium classified?

Answer 34

- arrangement - shape - surface specialization

Question 35

How are the types of cell arrangement?

Answer 35

- Simple - 1 layer - stratified - more than 1 layer - pseudostratified - 1 layer but seems more than 1 layer because of the height

Question 36

What are the shapes of cell?

Answer 36

squamous : flat, plate-like cuboidal: w and l are the same columnar : height > width , tall and thin

Question 37

What are the specialization of cell

Answer 37

* Cilia: they beat to facilitate movement (dirt, mucous in resp. tract) * microvilli: increase the surface area for nutrient absorption (GI tract)

Question 38

What form glands?

Answer 38

epithelial cell

Question 39

What are 2 types of glands

Answer 39

exocrine- discharges hormone via duct | endocrine - discharges secretion directly into bloodstream