Urinary, Reproductive, and Development Systems

Urinary SystemFunction: help keep the body in homeostasis by controlling the composition and volume of blood by removing and restoring selected amounts of water and solutes

urinary bladder - the storage organ for urine

urethra - a single tube that drains urine from the urinary bladder out the body

kidneys - the paired organs that remove waste products and stabilize both the volume and composition of the plasma within the blood

ureters - paired muscular tubes that transports urine from the kidneys to the bladder

Nephron – Functional unit of the kidneyafferent arteriole

renal corpuscle ( containing glomerulus)

efferent arteriole OR proximal convoluted tubule

loop of henle

distal convoluted tubule

collecting duct

Reproductive System Function of Reproductive System: to perpetuate the species

Gonads - reproductive organs, male - testes and female - ovaries

Male reproductive system - responsible for the production of hormones and the formation, nutrition, storage, transport, and delivery of the male gamete - sperm

TestesEpididymisDuctus (vas) deferensSpermatic cordSeminal vesiclesProstrate glandBulbourethral glandsUrethraPenis

Female reproductive system - responsible for the production of hormones and the formation, support, transport, and delivery of the female gamete - ovum. Additionally, the female reproductive system protects and supports the developing embryo and nourishes the growing fetus

ovariesuterine tubes: fallopian tubes or oviducts, fimbriae, infundibulum, ampulla,isthmusUterus: body,cervixVagina

Development terms

spermatazoa (sperm)– deliver paternal chromosome to ovum

ovum (egg) – provides nourishment and maintenance of embryo as well as contributing maternal chromosomes

fertilization – fusion of two haploid (half normal # of chromosomes)

gametes producing a diploid (normal # of chromosomes) zygote.

• Fertilization normally occurs in ampulla of uterine tube.

• Spermatozoa travel from vagina to ampulla.

•Only 1 spermatozoa penetrates to fertilize ovum.

•Nucleus of ovum and sperm in fertilized egg are male and female pronucleus which fuse to produce one nucleus (zygote).

•Zygote starts dividing (cleavage) in uterine tube, implants in endometrium (glandular inner lining) of uterus, continues dividing to produce embryo (fertilization to 3 months) then fetus (3 months to delivery).

placenta –structure that permits diffusion between fetal and maternal circulatory systems

umbilical cord – connecting stalk between fetus and placenta NOTE – uterus and fetus push many abdominal organs out of normal position during development

Fetal Circulation

Blood travels from the mother to the placenta then to the fetus through the umbilical vein to the ductus venosus (a shunt to bypass the liver and directly enter the IVC), then to the IVC and into the RA. From the RA blood travels either to:

1) the foramen ovale (opening b/t atria) to the LA to the LV then through the aorta

2) the RV to the pulmonary trunk to either:

a) the lungs and then back to the LA to the LV and then to the aorta

b) through the ductus arteriosus (a blood vessel that connects the pulmonary trunk to the aortic arch

in the fetus) and then to the aorta

Once blood enters the aorta it either travels through:

1) systemic circulation

2) the internal iliac arteries to the umbilical arteries back to the placenta

Birth Stages

full term pregnancy – fetus in uterus, cervix closed

dilation stage – fetus in uterus, cervix open, amnion ruptures (water breaks)

expulsion stage – fetus in uterus, start of head passage

expulsion stage – fetus in uterus, end of head passage

placental stage – ejection of placenta from uterus, note umbilical cord containing umbilical artery (blue) and vein (red)