Reproductive & Development

Male & Female reproductive structures

Male reproductive structures

Female reproductive structures

Reproductive structures

Testes

Reproductive structures

Produce Sperm & Testosterone

Scrotum

Controls temperature of testes

Seminiferous Tubules

Where sperm is made

Interstitial cells

Testosterone production

Vas deferens

Carries Sperm through ejaculatory duct

Ejaculatory duct

Takes sperm through prostate

Penis

Delivers sperm to vigana

Urethra

Carries semen & urine to outside the body

Prostate gland

Raises semen PH

Seminal Vesicle

Provides fructose for nourishment

Cowper's Gland

Adds lubrication

Copora cavernosa & Corpus spongiosum

Fills with blood to cause erection

Epididymis

Coiled tubule that stores sperm

Ovary

Production + Maturation of an Oocyte, Hormone production

Uterine Tube

Carries zygote to uterus, site of fertilization

Uterus

Site of implantation, protects and nourishes a developing human

Vigana

Receives Sperm + is the birth canal

Clitoris

Sexual Stimulation

Graafian Follicles

Mature Follicles

Meiosis, Spermatogenesis, oogenesis, and Menstrual cycle

Meiosis

Meiosis 1

Meiosis 2

Prophase 1- Homologous pairs of chromosome are separated after synapsis and crossing over occurs

Metaphase 1- Homologous replicated chromosomes line up obove and below the equator of the cell , forming a double line of chromosomes

Anaphase 1 - Maternal and paternal pairs of replicated chromosomes are separated and pulled in opposite ends of the cell, a process called reduction division. siter chromatids remain attached

Telophase and cytokinesis 1- the opposite of prophase 1 and two cells are produced each containing 23 replicated chromosomes only, still composed of sister chromatids

Prophase 2 - Nuclear envelope breaks down and replicated chromosomes cluster together. there is no crossing over

Metaphase 2 - Spindle fibers extend from the centrioles to each chromatid in each chromosome and align the replicated chromosomes along the equator of the cell

Anaphase 2 - Sister chromatids of each replicated chromosome are pulled apart at the centromere . sister chromatids now called single chromosomes

Telophase and cytokinesis 2 - Nuclear division finishes the nuclear envelope re form. Four new daughter cells are produced each containing 23 single chromosomes only

Oogenesis

Before birth

Childhood

Monthly , from puberty to menopause

Oogenia are diploid cells containing 23 pairs of chromosomes that are the orgin of the oocytes. Mitotic divisions of oogonia produce primary oocytes , which are diploid cells.

Primary oocytes start the process of meiosis but are arrested in prophase 1

Follicle development - primordial follicle

Ovary is inactive . it houses primordial follicles . some atresia of primordial follicle occurs

Meiosis 1 arrested

Up to approximately 20 primordial follicles mature into primary follicles every month . some primary follicles mature into secondary follicles . primary follicles that do not mature undergo atresia

Typically only one secondary follicle matures into a mature follicle , where the primary oocyte completes the first meiotic division to produce a polar body and secondary oocyte , The secondary oocyte is a haploid cell that is arrested in the second meiotic metaphase

If the secondary oocyte is fertilized it completes the second meiotic division and becomes an ovum , if the secondary oocyte is not fertilized , it degenerates .

Spermatogenesis

Germ cells that are the orgin of the sperm are diploid cell containing 46 chromosomes , or 23 pairs called spermatogonia . Mitotic divisions of these cells produce a new germ cell and a committed cell, The committed cell is a primary Spermatocyte

Meiosis 1 begins in the diploid primary spermatocytes . the haploid cells containing 23 chromosomes only produced during meiosis 1 are called secondary spermatocytes

Meiosis 2 originates with the secondary spermatocytes and produces spermatids.

The process of spermiogenesis begins with spermatids and results in morphologic changes needed to form sperm that will be motile

Hormones

Female

Male

GnRH

Hypothalamus

stimulates anterior pituitary to produce and secrete FSH AND LH

FSH

Anterior pituitary

Stimulates development and maturation of ovarian follicle

LH

Anterior pituitary

Stimulates ovulation when there is a peak in LH

Estrogen

Ovarian follicles before ovulation , corpus luteum after ovulation , or placenta during pregnancy

Initiates and maintains growth of the functional layer of the endometrium

Progesterone

corpus luteum or placenta during pregnancy

Primary hormone for functional layer growth after ovulation; causes increase in blood vessel distribution , uterine gland size, and nutrient production

Inhibin

Ovarian follicles

Inhibits FSH secretion so as to prevent excessive follicular development

GnRH

secreted by the hypothalamus stimulates the anterior pituitary to secrete FSH AND LH

LH

stimulates interstitial cells to secrete testosterone

FSH

stimulates sustenticular cells to secrete ABP, which helps keep testosterone levels high on the testes

Testosterone

stimulates spermatogenesis but inhibits GnRH secretion and reduces the anterior pituitary's sensitivity to GnRH

Rising sperm count levels cause sustentacular cells to secrete inhibin , which which further inhibits FSH secretion

Menstrual cycle

Menstrual Phase

Occurs during 1-5 days in the cycle. This phase is marked by sloughing of the functional layer of the endpmetrium and lasts through the period of menstrual bleeding

proliferative phase

follows , spanning approximately 6-14 days . this is the initial development of the new functional layer of the endometrium overlaps the time of follicle growth and estrogen secretion by the ovary

Secretory phase

occurs 15- 28 days. During secretory increased vascularization and development of the uterine glands occcurs primarly in response to progesterone secretion from the corpus luteum

Embryonic and Fetal Development

Embryonic

Fetal Development

week 3 is considered an embryo

Primitive streak appears, gastrulation occurs three primitive layers form.

Notochord developes and Neurulation begins with neural fold and neural groove

week 4

heart is formed and its the first organ to function

somites are semi developed but still are cartilage

Liver also starts to develop

Week 5

same as week 4 but the embryo develops an optic vesicle and Arm and leg buds

Week 6 to end of 8 or beginning of 9

All internal organs complete , some functioning

Extremities develop from limb buds

Cartilage skeleton and muscles complete

placenta and umbilical cord function, Facial features and ears nearly complete , and embryo assumes a human appearance

Layers

endoderm

mesoderm

Ectoderm

It develops into the nervous system , sense organs , skin and skin derivatives

develops into the digestive and its derivatives

This will form the circulatory system, excretory system , most reproductive and skeletal and muscles

9- 12 weeks

Primary ossification centers appear in most bones, reproductive organs begin to develop

Coordination between nerves and muscles for movement of limbs occurs

Brain enlarges , body enlarges , epidermis of the skin become more fully developed , permanent kidneys develop , plate roof of mouth developes

weeks 13- 16

Body grows rapidly , ossification in the skeleton continues

Limbs become more proportionate in length to the body , and brain and skull continue to enlarge

week 17-20

Muscle movements become stronger and more frequent , lunugo covers skin

limbs near final proportions , brain and skull continue to enlarge

weeks 21-38-

body gains major amount of weight , subcutaneouse fat is deposited , eyebrows and eyelashes appear

eyelids open , testis decent into scronum month 9, and blood cells form in marrow only