Embryology, Exam 1, Ch 2

Front 1

What is a Zygote?

Back 1

* The developmental period from the two cell stage to late morula

2 cell stage --> 4 cell stage --> morula

Front 2

What is Gametogenesis?

Back 2

1) Reduction of the number of chromosomes in each gamete (sex cell) to 1/2 that of a normal somatic cell (46 to 23)

2) It alters the shape of each gamete in preparation of fertilization

Front 3

What is Meiosis?

Back 3

1) A special type of cell division that occurs only in the germ cells (sex cells)

2) Diploid germ cell is reduced to haploid germ cells

3) During meiosis there is an interchange of chromatid segments (crossover)

Front 4

Spermatogenesis

Back 4

The process of going from:

46 diploid --> 23 haploid --> 4 sperm from 1 cell, each has 23 chromosomes

Front 5

Oogenesis

Back 5

1 immature cell (46 diploid) --> mature --> lose polar body, extra chromosomes (23 haploid) --> sperm (fertilized) --> lose other polar body --> 46 chromosomes in ONE oocyte

Front 6

What is involved in the hormonal cycle?

Back 6

1) Hypothalamus

2) Pituitary Gland

3) Ovaries, uterine tube, and uterus

Front 7

What is the mechanism of the hormonal cycle?

Back 7

1) Hormone releasing factors (HRF) are released through the pituitary or hypophyseal system

2) HRF taken to the anterior lobe of the pituitary gland

3) Where they are manufactured into Gonadotropic Hormones:
FSH - Follicle Stimulating Hormone
LH - Lutenizing Hormone

Front 8

What are the 3 phases of the ovarian cycle?

Back 8

1. Follicular Phase
2. Ovulatory Phase
3. Luteal Phase

Front 9

Follicular Phase

Back 9

Development and maturation of the follicles around the oocyte (Pituitary releases FSH, the FSH stimulates the production of estrogen)

Front 10

Ovulatory Phase

Back 10

Ovulation and release of the oocyte (FSH and LH), even if fertilization doesn't occur

Front 11

Luteal Phase

Back 11

Development of the corpus luteum (LH stimulates production of progesterone)

Front 12

Uterine Cycle Menstrual

Back 12

Functional layer sloughed off

Front 13

HORMONE LEVELS
(progesterone, estrogen, FSH, LH, temperature)
1) Follicular Phase
2) Luteal Phase

Back 13

1) progesterone -, estrogen +, FSH +, LH -, temperature (no change)

2) progesterone +, estrogen -, FSH -, LH +, temperature +

Front 15

Male Cycle

Back 15

Pituitary release mFSH and mMLH -->

mFSH --> seminiferous --> inhibin

mLH --> leydig cells (testes) --> testosterone

Front 16

What is Mittelschmerz?

Back 16

A variable amount of abdominal pain accompanies ovulation in some women

Front 17

Stigma

Back 17

* A bulge on the surface of the ovary

* occurs close to ovulation

* it is the result of a maturated and enlarge follicle

Front 18

Cumulus Oophorus

Back 18

Oocyte is pushed to one side of the follicle where it is surrounded by granaulosa cells

Front 19

Where is the site of fertilization?

Back 19

Ampulli/Ampulla

Front 20

Capacitation

Back 20

1) The acrosome (cap) comes off of the sperm

2) It starts in the unterus/uterine tubes and lasts 6 - 7 hours

Front 21

Acrosomal Reaction

Back 21

A reaction during fertilization that involves the release of enzymes for penetration of the layers surrounding the oocyte

Front 22

Zona Pellucida

Back 22

A glycoprotein shell surrounding the oocyte that the sperm tries to penetrate

Front 23

What are the results of fertilization?

Back 23

1. Restoration of diploid chromosomal number (46 d)

2. Species variation

3. Determination of sex

4. Initiation of zygote division

Front 24

How do our bodies prevent polyspermy?

Back 24

Polyspermy causes extra chromosomes. The sperms initial contact with zona pellucida causes a change in the resting membrane potential of the fertilized oocyte. In other words, the doors lock and no sperm can get in

Front 25

What are the phases of the ovarian and uterine cycles?
1-5
5-14
14-27
27-28

Back 25

Days:
1-5: menstral phase
5-14: Proliforative phase
14-17: Luteal Phase
27-28: Ischemic Phase (if not fertilized)
start over

Front 26

What happens simultaneously in the ovary and uterus cyles during days 5 - 14?

Back 26

Proliforative Phase:
Hypothalamus --> GRH --> Pituitary releases FSH --> stimulates follicle growth --> estrogen increases --> uterus lining begins to develop

Front 27

What happens simultaneously in the ovary and uterus cyles during days 14 - 27?

Back 27

Luteal Phase:
Hypothalamus --> GRH --> Pituitary releases LH --> ovulation --> estrogen- and progesterone + --> developing corpus luteum

* Lining of the uterus continues to thicken

Front 28

What happens simultaneously in the ovary and uterus cyles during days 27 - 28?

Back 28

Ischemic Phase:
If the oocyte has not been fertilized the corpus luteum degenerates and the menstrual phase begins. If fertilization has occured the corpus luteum keeps growing.