General embryology and fertilization (Part 1)

Oral Histology

Oral Histology

Branch of science that deals with the study of microscopic structures of oral/dental tissues. That deals with detailed histologic structures of the teeth and associated structures with emphasis on its development and clinical considerations.

Embryology

study of origin, growth and development and function of an organism from fertilization to birth

Acrosome, Head, Midpiece, Tail

Label each part

upper vagina

Spermatozoa are deposited in the _____ at insemination.

Insemination

Injection of semen into the vagina

Fertilization (4 weeks)

1st phase of prenatal life

Embryonic phase (5-8 weeks)

2nd phase of prenatal life

Fetal Phase (8 weeks to birth)

3rd phase of prenatal life

Embryonic Phase

What is the most vulnerable phase in prenatal life and the process of macrophogenesis?

Fertilization

What phase in prenatal life is the process of cellular proliferation and migration?

uterus, egg, cervix

Label each part

true

True or False

sperm travels through cervix into uterus searching for egg to fertilize

False, a minute fraction

True or False. If false write the correct answer

There is only 2 minute fraction of spermatozoa deposited in the female reproductive tract to reach the vicinity of the ovulated egg.

chemical hazard and mechanical obstacles

The route of sperm transportation in the female reproductive may be difficult due to?

True

True or False

Chemical hazard is a strong acid secretion

bacteriostatic medium

The natural acidity of the upper vagina act as __________.

bacteriostatic

a state of suspended growth of bacterio

4.3 to 7.2

Vaginal pH can rise up to?

seminal fluid

What acts as an effective buffer (barrier/cushion) against acidity within 8 seconds of insemination?

200 to 300 milion

Number of spermatozoa contained in an ejaculation of semen of a human?

30 minutes

How many minutes can the spermatozoa take to reach the uterine tube?

true

True or False

from the upper vagina, some spermatozoa are transported extremely rapidly up the female reproductive tract

swimming movement

Spermatozoa moves with what kind of movement?

seminal fluid

some component/s of ______ stimulates CONTRACTIONS of upper vagina which may help propel spermatozoa into the cervical canal

false

True or False

hormonally induced does not change the time of ovulation which reduce the viscosity of the mucus and allow better penetration of spermatozoa

oral cavity

what does oral stomodium/stomatodium mean?

development of the tooth

what does odontogenesis mean?

hard tissues and soft tissues

Tissues in the mouth

hard tissue

enamel, dentin, cementum is an example of what kind of tissue?

soft tissue

pulp is an example of what kind of tissue?

upper uterine tube

where does fertilization occur?

zygote

the union of male and female gametes forms a _______?

mechanical obstacles

This is an example of chemical hazards or mechanical obstacles of spermatozoa?

1. Crooked and compressed cervical canal

2. Narrowed uterine tube

3. Occluded by disease

utero-tubal junction

acts as a valve that prevents the passage of spermatozoa into the uterine tube

true

True or False?

SLOW PHASE OF SPERM TRANSPORT is where the spermatozoa enter the cervix, and they lodge in numerous irregular crypts (pit) that line the cervical canal

True

True or False?

ONCE IN THE CERVICAL CRYPTS – spermatozoa is slowly released into the uterine cavity

True

True or False?

ONCE IN THE UTERINE TUBES - spermatozoas continues their upward path by combination of “muscular contractions and ciliary currents to the tube”and swimming of spermatozoa

upper end of the uterine tube

It is when the swimming activity of the spermatozoa is very prominent

positive rheotactic response

the gentle current where spermatozoa orient themselves to move against

true

True or False

ONCE THROUGH THE FEMALE REPRODUCTIVE TRACT – spermatozoas penetrate the membrane surrounding the egg also known as CAPACITATION

thick mucus

what fills the cervical canal

spasmodic contractions

orgasm of females causes ______ of the smooth muscles of the uterus

human follicular fluid

It is said to possess sperm attracting property

capacitation of spermatozoa

process in which the spermatozoon, after it reaches the ampulla of the fallopian tube, undergoes a series of changes which leads to its ability to fertilize ovum

5 IMPORTANT COMPONENTS OF FERTILIZATION

1 Initial membrane contact between egg and sperm 2 Entry of sperm cell into the egg

2 Entry of sperm cell into the egg
3 Prevention of polyspermy by the egg
4 Completion of meiosis by the egg

5 Formation and fusion of male and female pronuclei leading to the first cleavage division

removed from the female reproductive tract

what happens to spermatozoa that are not directly involved in fertilization?

swept through the cervix and into the vagina

what happens to sperm in the uterine cavity after sperm transport?

ingested by phagocytosis

what happens to sperm in the uterine tube after sperm transport?

corona radiata

• layer that is very important in egg transport

• without this later ovum makes little progess

true

True or False

the freshly ovulated egg surrounded by corona radiata, lies free in the peritoneal cavity

nucleus containing chromosomes, autosome containing enzymes, corona radiata

label each part (number 1-3)

zona pellucida, ovum, sperm cell nucleus inside ovum

label each part (number 4-6)

3 days

it takes _ days for an unfertilized egg to pass through the uterine tube

true

True or False

pregnancy can still occur in the absence of female orgasm

fertilization

phenomenon in the field of biology

process

fertilization is _____ not a single event

false, depression of metabolic activity

True or False, if false write the correct answer

When free from the ovary, the ovum undergoes changes such as:

• aging or deterioration

• cytoplasm becomes coarsely granular

• elevation of metabolic activity

limited viability

ovum and spermatozoa have ______ once they are in the female reproductive tract

24 hours

Ovulates eggs must be fertilized within __ hours

overripe and non-viable

If not being fertilized within 24 hrs what happens to the egg?

1 or 2 days

How many days does the fertilizing power of sperm last?

epididymis, ductus deferens

when it comes to the viability of ova and spermatozoa:

in _______ and ______ spermatozoa remains non motile

gametes

mature male and female germ cells that are capable of functioning in fertilization

corona radiata, zona pellucida

PENETRATION OF CORONA RADIATA

spermatozoa penetrates the cells of _______ and the _______ before they can contact the plasma membrane of the egg

hyaluronidase

sperm derived enzyme that facilitates penetration of CR by dissolving extracellular matrix around the cells

sperm receptors

PASSAGE THROUGH ZONA PELLUCIDA:

where specific molecules on the sperm head bind to (when it reaches zona pellucida)

acrosome, capacitation

PASSAGE THROUGH ZONA PELLUCIDA:

________ reaction results from further contact with the sperm head

• ________ is its pre requisite

• Lytic enzymes stored within the acrosome are released

• Causes change in plasma membrane of the sperm that allows it to fuse egg cell membrane

pervitalline space

ONCE THROUGH THE ZONA PELLUCIDA:

spermatozoon enters the fluid filled _____

• between the zona and plplasma membrane

Fertilization cone

WHEN SPERM MAKES CONTACT WITH THE EGG:

Cytoplasm of the egg bulges out in elevated process. What comes up?

retracts, ovum, penetration

plasma membrane of the egg and sperm fuse together, then the fertilization cone _______

-  Carrying the sperm head into the ____

-  Completes the phase of ______

muscular contractions
ciliary currents

What propels spermatozoa on its upward path inside the UTERINE TUBE?

minute fraction

Only a ______ of spermatozoa will ever reach the ovulated egg

motility of spermatozoa

When it comes to the viability of ova and spermatozoa

__________ only aroused when, at the moment of ejaculation, are mixed with secretions of seminal vesicles, prostate, and bulbourethral glands

ovary
ovulation
oocyte

label

fertilization
day 0
fertilized egg (zygote)

label and insert the day

day 1
first cleavage

label and insert the day

day 2
2 cell stage

label and insert the day

day 3-4
4 cell stage

label and insert the day

uterus
8 cell uncompacted morula

label

day 4
8 cell compacted morula

label and insert the day

day 5, trophectoderm, blastocoel, inner cell mass, early blastocyst

label and insert the day

days 6-7
zona pellucida
late stage blastocyst (hatching)

label and insert the day

day 8-9, epiblast, hypoblast, implantation of the blastocyst

label and insert the day