Growth And Development

Front 1

Where are germs cells found for spermatogenesis?

Back 1

Basement membrane

Go through 3 types of division: mitosis, meiosis 1, meiosis 2

In the end, one cell gets left behind you and get 4 functional sperm cells

Spermatogenesis occurs from birth to death

Front 2

When does meiosis 1 start in oogenesis?

Back 2

Meiosis one occurs before birth

Nothing happens in childhood other than degradation of eggs

At puberty, a few eggs start dividing to form 2 cells.

One cell becomes a polar body

The other goes to an ovum

Meiosis 2 occurs with fertilization

Front 3

Where does fertilization occur?

Back 3

Occurs in outer 1/3 of uterine tube (Oviduct, fallopian tube)

Front 4

Across me enzymes digest what part of the egg?

Back 4

Zone pellucida, and corona radiata (aka cumulus cells)

Front 5

What happens when one sperm enters ovum?

Back 5

Block to polyspermy

And the sperm releases its DNA into ovum

Front 6

Cleavage

Back 6

When zygote immediately begins to divide upon fertilization (mitosis)

Front 7

When does implantation occur?

Back 7

<10 days

The store of nutrients in the ovum keeps it viable until implantation

Front 8

Morola

Back 8

A solid clump/mass of cells which takes about 3 days to form.

Occurs after the zygote

Front 9

Blastocyst

Back 9

hollow ball of cells that has formed by the time it reaches the uterus. Is after the morola. Contains the:

Tropoblast- outer cell layer, forms fetal part of placenta. Contains chorionic villi (finger like projections in placenta)

Inner cell mass- forms the embryo, yolk sac (non nutritive) , and amniotic cavity (fluid filled shock absorbing sac) .

Blastocele

Front 10

Placenta

Back 10

Has important endocrine functions:

Secretes large amounts of HCG which stimulates the corpus luteum to continue its secretion of estrogen and progesterone

HCG is the basis of a pregnancy test.

Front 11

Stem cell types

Back 11

Totipotency- from fertilized egg. Differentiates into ANY kind of stem cell in zygote

Pluripotency- what ^ divides into. Found in embryonic germ cells. Produce a broad range of cell types

Multipotency - adult stem cell found in some tissues, can produce a few cell types. Has three layers: ectoderm, endoderm , mesoderm

Unipotency - somatic cells. Keep generating just that type of cell

Front 12

Formation if primary germ layers (histogenesis)

Back 12

Each germ layer arise in 1st trimester and give rise to specific organs and tissues

Ectoderm- outside layer (skin, brain, nerves)

Mesoderm- middle layer (cardiac, skeletal, blood)

Endoderm- inside layer (GI tract, lungs, pancreas)

Front 13

Organogenesis- of the reproductive tract

Back 13

Organogenesis- The way tissues arrange themselves into organs.

Male and female reproductive tracts are similar.

In embryonic development:

Males - gonads attach to the mesonephric (wolffian) ducts

Females - gonads don't attach, but the paramesonephric (mullerian) ducts develop into female reproductive tract

Front 14

Organogenesis of the external genitals

Back 14

In males the genital tubercle becomes the glans penis. Fold become penis shaft and scrotum.

In female the genital tubercle becomes the clitoris and folds become labia.

We are all born female until testosterone develops wolffian ducts in males.

Front 15

Another name for birth

Back 15

Parturition

Front 16

Hormone cycle of birthing

Back 16

Cortisol triggers labour, reduces HCG + progesterone, removes the brake on oxytocin, which causes uterine muscles to contract (positive feedback)

Prostaglandins enhance oxytocins effect.

Front 17

Neonatal period

Back 17

First 4 weeks after birth

Dramatic changes at a rapid rate (resp and cardio)

Front 18

Effects of aging

Back 18

Decline in every organ system

Degeneration of mitochondria

Limit on cell reproduction

Environmental factors

Muscle mass decreases to 50% by 80